Consequences of ADHD

Completely revised 09/2026

Author: Ulrich Brennecke
Review (April 2024): Waldemar Zdero, M.A. in Psychology

ADHD is not limited to inattention, restlessness, and impulsivity. If ADHD remains untreated or is not treated adequately, it has lifelong consequences. (Review, E 1a)¹

The Consequences of Untreated ADHD (1.)

ADHD is associated with a life expectancy that is, on average, about 7 to 13 years shorter. This is primarily due not to ADHD itself, but to its consequences. These include accidents, injuries, suicide, and substance use disorders. Quality of life is also significantly impaired. In this regard, ADHD ranks among the ten most severe mental disorders. (Review, E 1a)²

In addition, the following occur more frequently

• Accidents, broken bones, and concussions
• Depression, anxiety disorders, eating disorders, and sleep problems
• physical illnesses, ranging from tooth decay and periodontitis to respiratory diseases
• Addiction and Smoking
• Experiences of violence and bullying, both as a victim and as a perpetrator
• Criminal behavior, although this is usually caused by additional Disorders and not ADHD alone
• dropping out of school, lack of a diploma, unemployment, and lower income
• Breakups, moves, and homelessness

How ADHD Treatment Makes a Difference (2.)

A large portion of these risks can be reduced through treatment. In large registry studies, ADHD medications were associated with decreases in mortality, the number of accidents and injuries, suicide attempts, substance abuse, and criminal behavior. Academic performance and work capacity improved. These studies are observational studies. They show correlations but do not prove causation. Furthermore, some studies found no effect on quality of life, and robust evidence spanning several years is still lacking. Both of these points are discussed in Chapter 2.

The Cost of ADHD to Society (Parts 3 and 4)

ADHD results in higher costs for health care, education, and social services. Added to this are losses due to absenteeism, unemployment, and disability. These costs affect not only people with ADHD themselves, but also their families and society as a whole. Several studies have concluded that treatment is also economically worthwhile.

All figures cited are averages based on large groups. They do not predict how an individual’s life will unfold. Many people with ADHD lead lives without the difficulties described here. Furthermore, the figures primarily reflect untreated ADHD. They should therefore be viewed primarily as a reason why early detection and appropriate treatment are important, and not as a foregone conclusion.

1. Consequential Risks of ADHD¶

People with ADHD have to cope with significant limitations on their quality of life.
(E 1a): Untreated or inadequately treated ADHD has a massive impact throughout a person’s entire life. (Review, E 1a)³ (Review, E 1a)⁴
Without treatment, people with ADHD had worse long-term outcomes than people without ADHD in all 9 outcome categories examined (systematic review, k = 351 studies with 636 individual outcomes, E 1a):⁵

• 74% of the results (from 244 studies) were worse
• 26% of the results (from 89 studies) were comparable
• Less than 1% of the individual results (6 out of 636) were better than those in the control group (with a small Effect size). These were included in the comparable results

In a New Zealand birth cohort that was followed through age 40, adolescents aged 14 to 16 who were in the top quartile for ADHD symptoms had an increased risk in early adulthood of substance use disorders, depression, suicidal ideation, delinquency, and unemployment, as well as lower income, less home ownership, more unstable relationships, and a lower standard of living. After adjusting for pre-existing individual and family risk factors, as well as for concurrent social behavior disorders and oppositional defiant disorder, the associations weakened. For substance use and delinquency, they persisted with ORs ranging from 1.4 to 1.6. (Birth cohort, N = 1,265 at birth, follow-up over 40 years, E 2b)⁶

1.1. Life expectancy reduced (by about 7 to 13 years)¶

1.1.1. Increased overall mortality (+7% to +364%)¶

• Reduced life expectancy (cohort study, E 2b)⁷
  • reduced by 8 to 13 years (estimated, not observed life expectancy)
  • (E 3): 11.1 years (overall life expectancy) (expert report, E 4)⁸ (Guest article in a medical journal, E 4)⁹ or 12.7 years (healthy life expectancy) (case-control study, E 3)¹⁰ for ADHD that persisted into adulthood
  • (E 3): 8.4 years (overall life expectancy) and 9.6 years (healthy life expectancy) for ADHD-C in childhood overall (case-control study, E 3)¹⁰ (Expert report, E 4)⁸ (Guest article in a medical journal, E 4)⁹
  • (E 2b): by 6.78 years to 8.64 years among adults diagnosed with ADHD in the United Kingdom (n = 30,039, cohort study, E 2b)¹¹ (brief report, E 4)¹²
    • 6.78 years for men
    • 8.64 years for women
  • 6.5 years (overall life expectancy) or 7.4 years (healthy life expectancy) for childhood ADHD-C that did not persist into adulthood (case-control study, E 3)¹⁰
  • 9.6% of children with ADHD died by age 46, compared with 3.9% of children without childhood attention problems (aHR 2.15; before age 30, aHR 6.20; perinatal risk cohort, n = 839, E 2b)⁷
• possibly due in part to genetic factors (Mendelian randomization, E 2b)¹³
• Low income is associated with a life expectancy that is 6 to 8 years shorter (book chapter, E 4)¹⁴, while ADHD is associated with low income (see below).
• also (but not only) due to a decline in conscientiousness (Expert Report, E 4)⁸
  • The lowest quartile (25%) of conscientiousness was associated with a 7- to 8-year reduction in life expectancy (even among highly gifted individuals and regardless of ADHD) (case-control study, E 3)¹⁰
  • On average, people with ADHD were among the 5 to 7 percent with the weakest behavioral inhibition, which Barkley considers a core component of conscientiousness
• For comparison: life expectancy is reduced by 6.1 to 6.5 years for individuals diagnosed with autism without intellectual disability, and by 7.3 to 14.6 years for those with intellectual disability (United Kingdom) (cohort study, E 2b)¹⁵

1.1.2. Increased risk of suicide (+61% to +383%)¶

(E 1a): Increased risk of suicide (meta-analysis, E 1a)²⁶ (Evidence Report, E 4)²⁷ (systematic reviews, k = 28 and k = 40, respectively, E 1a)²⁸, more pronounced in hyperactivity than in inattention (n = 71, emergency room sample, cohort study, E 2b)²⁹, but also in cases of subclinical ADHD traits in the general population (cohort study, E 2b)³⁰. In preadolescent children, ADHD was the mental disorder most strongly associated with suicidal ideation after depression (depression: d = 0.90; ADHD: d = 0.54; meta-analysis, k = 58, n = 626,486,590, E 1a)³¹

• 4.83-fold increased risk of death by suicide (SMR 4.83; 95% CI 1.14 to 20.46; birth cohort, n = 5,718, E 2b)¹⁹
• 4.7-fold increased risk of suicidal behavior (suicide attempt or suicide); 4.1-fold for ADHD without psychiatric comorbidity, 10.4-fold for ADHD with psychiatric comorbidity (n = 2.9 million, cohort study, E 2b)³²
• 3.33-fold increased risk of suicide (meta-analysis, k = 9 longitudinal studies, children and adolescents, E 2b)³³
  • 3.95 times the risk of suicidal thoughts
  • 3.34 times the risk of suicide attempts
  • 3.89 times the risk of fatal suicide
• People with ADHD (ages 5 to 24) have a 2.9-fold higher risk of completed suicide compared to rates in the general U.S. population (Review, 2004, E 1a)³⁴
• A 2.54-fold increased risk of suicide attempts by age 23 among women who exhibited persistently high levels of inattention and hyperactivity-impulsivity between the ages of 6 and 12 (cohort study, E 2b)³⁵
• A 2.4-fold increased risk of suicide among those diagnosed with ADHD in the previous year (AOR 2.37). After adjusting for other mental disorders, the association was no longer significant (case-control study, 2,674 suicides compared with 267,400 controls, E 3)³⁶
  • Women: 3.14 times (1.80–5.50)
  • Men: 1.92 times (1.38–2.67)
  • After additional adjustment for anxiety, bipolar, depressive, and schizophrenia-spectrum disorders, the AOR was 0.88 (0.66–1.18, not significant); among men, it was 0.67 (0.48–0.95).
  • ADHD accounted for 1% of suicide mortality—the smallest proportion among all disorders studied (population-attributable fraction)—while depression accounted for 27%—the largest proportion.
• A 2.3-fold increase in current suicide risk (MINI Interview) among individuals with ADHD at age 22. (Birth cohort, N = 3,781, E 2b)³⁷
  • antisocial personality disorder 3.2
  • Generalized Anxiety Disorder 3.7
  • social anxiety disorder 4.0
  • Bipolar I 4.2
  • PTSD 5.0
  • Major Depression 5.6
  • 10.7 for three or more Disorders
• A 2.23-fold increased risk of suicide attempts among men with hyperactivity/impulsivity and inattention that decreased over time (cohort study, E 2b)³⁵ - Comorbid severe depression increased the risk 10- to 18-fold
  • Comorbid bipolar disorder type 2 increased the risk by a factor of 7 to 13
• Girls with ADHD are 2.22 times more likely to have suicidal thoughts (15.6% vs. 7%)³⁸
• A 1.81-fold increased risk of suicide attempts among women with high inattention and low hyperactivity-impulsivity. Symptoms were assessed between the ages of 6 and 12, and suicide attempts were tracked up to age 23. (Cohort study, E 2b)³⁵
• Boys with ADHD are 1.61 times more likely to have suicidal thoughts (7.6% vs. 4.7%)³⁸
  • comorbid major depression
    • OR 10.4 for passive suicidal thoughts
    • 19.4 for suicide attempts
  • comorbid bipolar II disorder
    • OR 6.8 for suicide attempts
    • 12.8 for passive suicidal thoughts
• 9.9% of 211 adult ADHD patients reported a suicide attempt. This was associated with comorbid personality disorders (OR 6.6), but not with ADHD symptoms (cross-sectional study, E 3)³⁹
• Even higher in cases of untreated ADHD (unpublished presentation, E 4)⁴⁰⁴¹
• Adults with ADHD (n = 74) had a lifetime prevalence of: (cross-sectional study, E 3)⁴²
  • Suicidal thoughts: 59.5%
    • were correlated with the severity of inattention symptoms in adulthood, low self-esteem, and impairments in social functioning
  • Severe suicidal thoughts: 16.2%
    • Physical activity had a protective effect
  • suicidal behavior: 9.5%
  • self-harming behavior not related to suicide: 10.8%
• 33.2% of 431 children and adolescents with ADHD (ages 5 to 15, clinical sample in Japan) reported suicidal thoughts. These did not correlate with the severity of ADHD symptoms. (Cohort study, E 2b)⁴³
• (E 1a): Suicidal thoughts (meta-analysis, E 1a)⁴⁴ (cross-sectional study, E 3)⁴⁵ and increased suicide attempts (cross-sectional study, E 3)⁴⁶
  • though not among veterans with ADHD after adjusting for comorbid psychopathology (n = 342, retrospective study)

1.2. More Frequent Accidents and Injuries¶

ADHD is associated with an increased risk of accidents and injuries. ^{47 48 49 50}

1.2.1. Increased risk of injury (+40% to +150%)¶

• (E 1a): Increased risk of injury (cohort study based on health insurance data, E 2b)⁵¹ (meta-analysis, E 1a)⁵²

  • by 149% (aHR 2.49) among children and adolescents in Taiwan (n = 9,010, cohort study, E 2b)⁵³
  • a 137% increase in severe injuries among adults (12.4% versus 5.2%) (cohort study, E 2b)⁵⁴
  • a 65% reduction in overall injuries among adults (39.5% vs. 24.0%) (cohort study, E 2b)⁵⁴
  • by 41% among 15- to 17-year-old students (RR 1.41) (cross-sectional study, E 3)⁵⁵

• Increased risk of bone fractures (Mendelian randomization, E 2b)⁵⁶

  • particularly in cases of ADHD-HI and ADHD-C. (Cross-sectional study, E 3)⁵⁷
    • Among 754 children and adolescents with ADHD, 15% suffered a fracture of a limb, 69% of which were in the upper extremities
    • ADHD-I was associated with a lower risk of fracture compared with the other presentation types (OR 0.40)

• by 106% in adults (HR 2.06) (cohort study, E 2b)⁵⁴

• for girls: +62% (HR 1.62) (cohort study, E 2b)⁵⁸

• in boys: +38% (HR 1.38) (cohort study, E 2b)⁵⁸

• Total fractures: +17% (OR 1.17) (meta-analysis, k = 10, E 1a)⁵⁹

  • In cases of untreated ADHD, traumatic fractures increase by 79% (OR 1.79) and stress fractures by 12% (OR 1.12)
  • not elevated during treatment with stimulants

• Concussions

  • (E 3): Twice as common in children with ADHD (+100%; 23.9% versus 11.4%, OR 2.45 (cross-sectional study, E 3)⁶⁰; 10.6% versus 5.6% (cross-sectional study, E 3)⁶¹)
  • More common among college athletes, with a correspondingly longer recovery time. Recovery time returned to normal when stimulants were used (cohort study, E 2b)⁶²

1.2.2. Increased risk of accidents (+36% to +89%)¶

In cases of ADHD, an increased risk of accidents or injuries was found to be

• 60 to 89% (OR 1.60, 95% CI 1.34 to 1.91, KiGGS survey, n = 13,437; OR 1.89, 95% CI 1.84 to 1.95, health insurance data, n = 383,292, E 3)⁷⁶
• 65% among n = 18,416 children aged 6 to 17 (RR 1.65) (cohort study, E 2b)⁷⁷
• 57% among n = 3,202 schoolchildren aged 15 (RR 1.57) (cohort study, E 2b)⁷⁷
• 47% in the parent report, 36% in the teacher report, and 53% in the combined parent- and teacher report for children with ADHD and ODD symptoms (n = 4,517, cross-sectional study, E 3)⁷⁸

1.2.2.1. Work-related accidents (+80% to +130%)¶

According to a systematic review, adults with ADHD had a 1.8- to 2.3-fold higher risk of workplace accidents compared to those without the condition. The association was most pronounced in the manufacturing and construction industries. The review identified noncompliance with safety regulations, impulsive behavior, and distractibility as contributing factors; medication, task rotation, structured feedback, and adjustments to the work environment were described as effective interventions. (Systematic review, k = 29, E 1a)⁷⁹

1.2.2.2. Traffic Accidents and Accident Damage (+23%)¶

A meta-analysis of 16 studies showed: (Meta-analysis, E 1a)⁸⁰

• The risk of accidents among drivers with ADHD was 23% higher (RR 1.23; 95% CI 1.04 to 1.46; RR 1.36 when driving distance was not controlled for)
• This corresponded to the increased risk associated with cardiovascular disease
• People with ADHD apparently drove more frequently than persons without ADHD, which is why the value adjusted for mileage is lower than the raw figure of 23%
• The claim that the risk of accidents is nearly four times higher, based on a study by Barkley et al. (1993), is likely attributable to comorbid ODD and/or CD. It cannot be attributed to ADHD itself.
• People with ADHD were more likely to receive citations for speeding, but not for drunk driving or reckless driving

 

 

1.3. Frequent perpetrators (+150% to +170%) and victims (+80% to +100%) of violence and bullying¶

People with ADHD are at higher risk for:

• Intimate partner violence (Systematic review, E 1a)⁸⁸

  • as the perpetrator:
    • 2.5-fold increased risk (OR 2.5, meta-analysis, k = 6 studies, E 1a)⁸⁹
    • In a Swedish registry study, men with ADHD had a 6.4-fold increased risk (adjusted HR 6.4; 0.6% versus 0.1%) of committing violence against their female partners. Compared with their unaffected siblings, the risk was 3.1 times higher (sibling comparison, E 2b)⁹⁰
    • increased regardless of gender or age (online survey, n = 316, ADHD as determined by screening, E 3)⁹¹
  • as a victim:
    • 1.78-fold increased risk (OR 1.78, meta-analysis, k = 4 studies, E 1a)⁸⁹
    • increased regardless of gender or age (cross-sectional study, E 3)⁹¹

• Sexual Violence

  • as the perpetrator:
    • 2.73-fold increased risk (OR 2.73, meta-analysis, k = 3 studies, E 1a)⁸⁹
  • as a victim:
    • 1.84-fold increased risk (OR 1.84, meta-analysis, k = 6 studies, E 1a)⁸⁹
    • 2.01-fold increased risk (adjusted OR 2.01; Danish birth cohort, children up to age 18, n = 570,351, E 2b)⁹²
    • Frequent victims of physical and non-physical sexual abuse (retrospective self-reports from students in India, N = 5,145, E 3)⁹³

• Child abuse

  • A systematic review of 11 prospective longitudinal studies consistently found an association between child maltreatment and ADHD. The direction of causality remained inconsistent. (Systematic review, E 1a)⁹⁴

• Bullying

  • 2.76- to 2.81-fold increased risk (OR 2.76 to 2.81; parental reports, n = 516, cross-sectional study, E 3)⁹⁵
  • Preadolescents (typically 10- to 12-year-olds) with ADHD reported having been bullied nearly three times as often as children without ADHD (35%; n = 424, cross-sectional study, E 3)⁹⁶
  • Children with ADHD were bullied more frequently (cross-sectional study, E 3)⁹⁷
  • Students with ADHD (grades 4 through 12, U.S., n = 345) were 83% more likely to report having been bullied or threatened, or to feel unsafe at school (PR 1.83) (cross-sectional study, E 3)⁹⁸
  • Children with ADHD were more likely to suffer from anxiety disorders or depression as a result of bullying than people with ADHD (NSCH 2016–2020, n = 71,973, cross-sectional study, E 3).⁹⁷
  • In a nationwide sample of Taiwanese schools, children with ADHD were both more likely to be perpetrators (OR 2.64; 95% CI 1.6 to 4.36) and more likely to be victims (OR 2.60; 95% CI 1.95 to 3.47) of bullying at school. (Epidemiological survey, N = 4,816 children in grades 3, 5, and 7 from 69 schools, n = 388 with ADHD without tic disorders, cross-sectional study, E 3)⁹⁹

Students with ADHD in the U.S. were 7 times more likely to have carried a weapon in the past 30 days than students without a mental disorder (PR 7.02; grades 4 through 12, n = 345, cross-sectional study, E 3).⁹⁸

 

1.4. Higher crime rates (+120% to +800%)¶

The crime rate among persons with ADHD is significantly higher. In a Swedish community sample (n = 101, age 22 years, never treated with stimulants), 19% of the male participants with ADHD and/or developmental coordination disorder had been prosecuted for a criminal offense, compared to none of the people with ADHD and no one in the control group. (Cohort study, E 2b)¹⁰⁰ In a U.S. sample of prison inmates, the top 20% most disruptive inmates accounted for approximately 90% of all rule violations in the correctional system (regardless of gender). An ADHD diagnosis was a predictor of belonging to this group, along with personality disorders, younger age, and substance use. (Cross-sectional study, E 3)¹⁰¹The “normal Pareto distribution” would be 20% / 80%.

Among Danish children with ADHD (n = 206), 47% had been convicted by the age of 31; the risk of a conviction was 5.6 times higher, and the risk of a conviction for a violent crime was 12.0 times higher.¹⁰²

• Risk of imprisonment due to criminal activity
  • 9-fold increased risk (9% vs. 1%; formerly hyperactive boys, follow-up at ages 16 to 23, n = 203). The association was almost entirely mediated by antisocial disorder in young adulthood (cohort study, E 2b)¹⁰³
  • 4.8-fold increased risk (HR 4.8; New Zealand birth cohort, E 2b)¹⁰⁴
  • 2.9-fold increased risk (RR 2.9; meta-analysis, k = 9, n = 15,442, E 1a)¹⁰⁵
• Increase in arrests / detentions
  • 21-fold increased risk in adulthood for boys with a history of hyperactivity and behavioral problems (21% versus 1%) (cohort study, E 2b)¹⁰⁶
  • A 4.18-fold increased risk during adolescence for hyperactive boys with behavioral problems (46% versus 11%). Hyperactive children without behavioral problems did not have an increased risk (cohort study, E 2b)¹⁰⁶
  • 2.4-fold increased risk (OR 2.4; meta-analysis, k = 98, E 1a)¹⁰⁷
  • 2.2-fold increased risk (RR 2.2; meta-analysis, E 1a)¹⁰⁵
  • 2.06-fold increased risk (37% vs. 18%; n = 1,001, self-reported diagnosis, case-control study, E 3)¹⁰⁸
  • Untreated boys aged 10 to 17 with ADHD are 2.02 times more likely to commit a first offense (HR 2.02; 1.52 times more likely when taking stimulants; n = 75,650, cohort study, E 2b)¹⁰⁹
• Criminal convictions
  • 3.3-fold increased risk (RR 3.3; meta-analysis, E 1a)¹⁰⁵
  • Men (HR): (Cohort study, E 2b)¹¹⁰
    • 6.03 times the risk of violent crimes
    • 3.57 times the risk of nonviolent crimes
  • Women (HR): (Cohort study, E 2b)¹¹⁰
    • 10.5 times the risk of violent crimes
    • 4.04 times the risk of nonviolent crimes

Among Swedish long-term inmates with ADHD (n = 30), all reported a lifetime substance use disorder. Amphetamine was the most commonly used drug. (Case-control study, E 3)¹²⁶¹²⁷ Amphetamine is also the active ingredient with the highest effect size for ADHD in adulthood (network meta-analysis: amphetamine SMD -0.79 versus methylphenidate -0.49).¹²⁸

During periods when ADHD medication was taken, the crime rate among people with ADHD was lower than during periods without medication (n = 25,656, cohort study, E 2b)¹³⁰

• by 32% among men (HR 0.68)
• by 41% in women (HR 0.59)

1.5. Co-occurring health problems¶

1.5.1. Mental Illnesses¶

Among 166 adult psychiatric inpatients at a German hospital, a questionnaire-based screening identified ADHD in 59% of them (severe symptoms: 33%). (Cross-sectional study, E 3)¹³⁶

 

1.5.1.1. Neurodegenerative diseases (up to +500%)¶

One review cited a risk of neurodegenerative diseases—particularly Lewy body diseases—that was up to five times higher. (Review, E 1a)¹³⁷
A systematic review (k = 16) found a positive association between ADHD and neurocognitive disorders in 7 studies (overall dementia in 4, Alzheimer’s disease in 3, Lewy body dementia in 2, and mild cognitive impairment in 1 study). Four studies found no association, and five others investigated mechanisms. The absolute risk was low. (Systematic review, E 1a)¹³⁸

 

Scientific: Types of Dementia, Parkinson’s, and Alzheimer’s in Detail

1.5.1.1.1. Dementia (up to +500%)¶

The overall risk of dementia is increased in people with ADHD

• 4-fold (adjusted HR 4.01; unadjusted HR 3.42; Taiwanese cohort study, n = 675 adults with ADHD vs. (E 1a): 2,025 controls, 10-year follow-up, E 2b)¹³⁹ (meta-analysis, E 1a)¹⁴⁰
• 2.8- to 2.9-fold in additional cohort studies (secondary citation from the review by Hedges et al., E 1a)¹⁴⁰
• 2.23 times (German health insurance data, n = 87,394 people with ADHD, cross-sectional study, E 3)¹⁴¹

 

Vascular dementia causes severe cognitive impairment that affects daily functioning and can be diagnosed using imaging techniques. (Meta-analysis, E 1a)¹⁴²
A sixfold increased risk of vascular dementia has been reported among people with ADHD (Tzeng et al. (cohort study, E 2b)¹³⁹, cited in Becker et al. 2023 (meta-analysis, E 1a)¹⁴², independent of other risk factors for vascular dementia such as diabetes, high blood pressure, coronary heart disease, or stroke. The authors of the primary study classified their analysis by type of dementia as unreliable due to the small number of cases per subtype.
The increased risk of vascular dementia may be due to poorer cardiovascular and cerebrovascular health in adults with ADHD. (Meta-analysis, E 1a)¹⁴²

The risk of Lewy body dementia is increased in ADHD (review, E 1a)¹⁴³, although the increase in risk was only 6% in one cohort study (IRR 1.06; secondary citation from the review by Becker et al. (E 1a): 2023 (meta-analysis, E 1a)¹⁴²), whereas the same group of authors reported an up to 5-fold increase specifically for Lewy body disorders in an earlier publication. (Review, E 1a)¹³⁷
Patients with Lewy body dementia were 5.1 times more likely to have had prior ADHD symptoms in adulthood than age-, sex-, and education-matched controls (47.8% vs. 15.1%; OR 5.1) and 4.9 times more likely than patients with Alzheimer’s disease (OR 4.9; case-control study, n = 509, E 3).¹⁴⁴

In a prospective cohort from a cognitive-neurological outpatient clinic, 27 of 161 adults with ADHD developed dementia over a period of up to 15 years, compared with 4 of 109 adults without ADHD. The most common form was Lewy body dementia (20 cases, 19 of which were in the ADHD group). After adjustment, the risk of dementia was 3.33 times higher (95% CI 1.09 to 10.17) and for Lewy body disease, the risk was 54.54 times higher (95% CI 7.48 to 397.50); the very wide confidence interval reflects the small number of cases. Non-amnestic mild cognitive disorder occurred in 67.1% of the ADHD group and in 17.4% of the controls. (Prospective cohort study, N = 270, of whom n = 161 had ADHD, E 2b)¹⁴⁵

1.5.1.1.2. Parkinson’s (up to +421%)¶

Parkinson’s:

• 5.21 times (German health insurance data, n = 87,394 people with ADHD, cross-sectional study, E 3)¹⁴¹
• 1.5 to 2.6 times (cohort studies, review, E 2b)¹⁴²
• 1.33-fold (HR 1.33; n = 13,098, age 50 and older, cohort study, E 2b)¹⁴⁶

People with Parkinson’s disease were 3.65 times more likely to have a pre-existing ADHD diagnosis than matched controls (OR 3.65; 95% CI 2.26 to 10.50; adjusted for age, sex, and comorbidity index). This association is based on 14 versus 5 ADHD diagnoses. The authors initially reported a 2.8-fold increase. (Case-control study using a Taiwanese health insurance sample, N = 21,452, of whom n = 19 had an ADHD diagnosis, E 3) ¹⁴⁷ (Review, E 2b)¹⁴²

Among people with ADHD who also have Parkinson’s, Parkinson’s had developed earlier than among people with Parkinson’s who do not have ADHD. (Cohort study, E 2b)¹⁴⁶

1.5.1.1.3. Alzheimer’s (no significant increase in personal risk; parents of people with ADHD: +55%)¶

Among patients with Alzheimer’s disease, a history of ADHD symptoms in adulthood was no more common than in controls (15.2% vs. (E 1a): 15.1%; case-control study, n = 509, E 3).¹⁴⁴ A systematic review found no significant association between ADHD and Alzheimer’s disease in any cohort or case-control study. (Meta-analysis, E 1a)¹⁴²
Among 212 cognitively intact older adults (ages 55 to 90) without a diagnosis of ADHD, a higher polygenic ADHD risk score (PRS) with greater cognitive decline over 6 years and with biomarkers of Alzheimer’s pathophysiology (cerebrospinal fluid p-tau181, frontoparietal atrophy), particularly in amyloid-positive individuals. (Cohort study, E 2b)¹⁴⁸
In a Swedish multigenerational cohort study (N = 2,132,929), parents of people with ADHD showed a 55% increased risk of Alzheimer’s disease (HR 1.55). The risk was increased to a lesser extent among grandparents, uncles, and aunts. (Cohort study, E 2b)¹⁴⁹

1.5.1.2. Depression (up to +450%)¶

A meta-analysis (k = 24) found a pooled depression rate of 11.3% among children and adolescents with ADHD (girls 20.9%, boys 9.0%). In the 7 case-control studies, the rate was 12%, which was significantly higher than that of neurotypical peers (2%). (Meta-analysis, E 1a)¹⁶⁰

Women with ADHD (n = 13,588) had an increased risk compared with women without ADHD (n = 474,789) after adjustment (cohort study, E 2b)¹⁶¹

• a 14% increase in the incidence of an affective disorder 6 weeks after childbirth
• 21% to 24% for a mood, anxiety, or stress-related Disorder 12 months after giving birth

1.5.1.3. Anxiety Disorders (up to +399%)¶

• A 1.2- to 3.3-fold increased risk of anxiety disorders. (E 4): Lifetime prevalence of 10 to 15% in the general population (clinic information flyer, E 4)¹⁶², 12 to 50% in individuals with ADHD (unpublished presentation, E 4)⁴⁰
• 1.68-fold increased risk of specific phobias (RR 1.68; meta-analysis, children and adolescents, E 1a)¹⁵⁷
• 1.71-fold increased risk of social phobia (RR 1.71; meta-analysis, children and adolescents, E 1a)¹⁵⁷
• 4.99-fold increased risk of agoraphobia (RR 4.99; meta-analysis, children and adolescents, E 1a)¹⁵⁷
• Comorbidities further increase the risk
  • A 16.4-fold increased risk of clinically significant anxiety symptoms (state anxiety) in individuals with ADHD who have experienced a concussion (college athletes, n = 324, cross-sectional study, E 3)¹⁵⁹

1.5.1.4. Epilepsy (+365%)¶

(E 2b): 4.65-fold increased risk (+365%) up to age 33 (cohort study, preprint, E 2b)¹⁵⁶ (Cohort study, preprint, E 2b)⁶⁸ for ADHD diagnoses by age 18 in the Finnish 1987 birth cohort (n = 53,147; preprint). The ADHD prevalence (0.43%) is low due to the fact that ADHD was rarely diagnosed at that time.

1.5.1.5. Eating Disorders, Obesity (up to +260%)¶

• 3.6-fold increased risk of eating disorders (anorexia or bulimia nervosa) among girls with ADHD (5-year follow-up) (cohort study, E 2b)¹⁶³
• Obesity (2-fold risk; secondary citation from a guest article by Barkley, 2019) (guest article in a medical journal, E 4)¹⁶⁴
• ADHD symptoms in early childhood were associated with an increased risk (cohort study, E 2b)¹⁶⁵
  • a high BMI in middle childhood by 19% (OR 1.19) and in adolescence by 14% (OR 1.14)
• A meta-analysis (k = 9, N = 58,296 children and adolescents) found an association between junk food consumption (sweetened beverages, candy) and ADHD symptoms (OR 1.24). The direction of the association remains unclear. (Meta-analysis, E 1a)¹⁶⁶

 

1.5.1.6. Post-Traumatic Stress Disorder, PTSD (+137%)¶

People with ADHD had a 2.37-fold higher risk of post-traumatic stress disorder compared to their siblings who had not been diagnosed with ADHD (HR 2.37; n = 2,082,118). A Mendelian randomization analysis from the same study supported a causal effect of ADHD on PTSD. (Mendelian randomization, E 2b)¹⁶⁷

1.5.1.7. Neurotic Disorders (+112%)¶

(E 2b): 2.12-fold increased risk (+112%) up to age 33 (cohort study, preprint, E 2b)¹⁵⁶ (Cohort study, preprint, E 2b)⁶⁸ for ADHD diagnoses by age 18 in the Finnish 1987 birth cohort (n = 53,147; preprint). The ADHD prevalence (0.43%) is low due to the fact that ADHD was rarely diagnosed at that time.

1.5.1.8. Cognitive impairments¶

In a long-term study of children with ADHD (n = 39), children with subclinical ADHD (n = 79), children with perinatal risks but without ADHD (n = 255), and children without any risk factors (n = 69), the participants were assessed at age 40 in the areas of verbal reasoning, perceptual ability, memory, working memory, attention, executive functions, and processing speed. The results showed: (Cohort study, E 2b)¹⁶⁸

• Participants who had ADHD as children
  • Lower performance in 13 out of 21 metrics
  • 23% showed deficits in three or more cognitive domains (compared with 4 to 6% in the other three groups)
• Participants who had subclinical ADHD as children:
  • lower performance in 5 of the 21 metrics

1.5.1.9. Risk-Taking Behavior¶

(E 1a): Increased risk-taking behavior (cross-sectional study, E 3)¹⁶⁹ ADHD is associated with risk-taking behavior in several areas of life, such as reckless driving, substance use, and unprotected sex. (Review, E 1a)¹⁷⁰

1.5.2. Physical Illnesses¶

• increased risk of most physical illnesses (34 [97 %] of 35 diseases studied), regardless of gender (cohort study, E 2b)¹⁷¹

1.5.2.1. Risk of addiction (up to +761%)¶

• Increased drug use, even without drug dependence: In a U.S. survey of working-age adults (N = 7,044), the use of illicit drugs and the misuse of prescription medications was elevated among individuals with ADHD in all 11 categories examined (AOR 1.63 to 3.33), even among individuals without a substance use disorder (AOR 1.54 to 3.48) (cross-sectional study, E 3)¹⁷²
• (E 1a): Increased alcohol consumption. (Cross-sectional study, E 3)⁴⁶ The majority of studies on ADHD and alcohol abuse found a positive correlation, while a minority found the opposite (review, E 1a).¹⁷³
  • 1.38-fold increased risk of alcohol consumption among adolescents (OR 1.38; +38%; cross-sectional study, n = 4,616, ages 11 to 18, Israel, E 3)¹⁷⁴
  • 1.35-fold increased risk of alcohol use disorder in young adulthood (OR 1.35; 95% CI 1.11 to 1.64; meta-analysis, E 1a)¹⁷⁵
• A 1.5- to 7.9-fold increased risk (+50% to +690%) of substance use disorder in adults, depending on the substance and the severity of the addiction (review, E 1a)¹⁷⁶
• Hyperactivity/attention problems at age 11 were associated with outcomes at age 24 (United Kingdom, ALSPAC) (cohort study, E 2b)¹⁷⁷
  • 4.35 times the risk of severe alcohol use disorder
  • 1.75 times the risk of any alcohol use disorder
  • a 2.09-fold increased risk of symptoms of alcohol dependence
  • a 1.63-fold increased risk of symptoms of alcohol abuse
  • A 2.72-fold increased risk of severe alcohol use disorder, even after adjusting for a comorbid social behavior disorder (95% CI 1.13 to 6.53). No association was found for mild and moderate alcohol use disorders
• (E 1b): More frequent smoking (cross-sectional study, E 3)⁴⁶ (RCT, E 1b)¹⁷⁸ (twin study, E 2b)¹⁷⁹ (cross-sectional study, E 3)¹⁸⁰ (Mendelian randomization, E 2b)¹⁵²
  • 8.61-fold increased risk of nicotine dependence among adolescents with ADHD (HR 8.61; 95% CI 2.44 to 30.34; +761%) (cohort study, E 2b)¹⁸¹
  • 2- to 3-fold increased risk for adolescents (+100 to +200%; Review, E 1a)¹⁸²
  • (E 1a): 2.36-fold increased risk (+136%; meta-analysis, E 1a)¹⁷⁵ (systematic review, E 1a)¹⁸²
  • 2.15-fold increased risk of smoking among adolescents (OR 2.15; +115%) (cross-sectional study, E 3)¹⁷⁴
  • about twice as common among adolescents and 1.5 times as common among adults with ADHD (Review, E 1a)¹⁸³
  • A 1.5- to 1.7-fold increased risk of initiating cigarette, e-cigarette, or other tobacco use among adolescents with 3 or more ADHD symptoms (AOR 1.52 to 1.72; n = 13,572). In cases of asymptomatic ADHD, the risk was not increased (cohort study, E 2b)¹⁸⁴
  • A 1.6-fold increased risk (+60%) of currently smoking at ages 44–45 among individuals with ADHD at age 7 (OR 1.6; 95% CI 1.2 to 2.1) (cohort study, E 2b)¹⁸⁵
  • A study of college students (ages 18 to 26, n = 2,592) found no association between ADHD symptoms and patterns of tobacco use (cohort study, E 2b)¹⁸⁶
  • Conversely, young adult smokers were twice as likely to test positive on the ADHD screening test (ASRS) as nonsmokers (n = 389, cross-sectional study, E 3).¹⁸⁷
• Cannabis
  • Cannabis use disorder is 2.85 times higher (lifetime) and 2.91 times higher (current) (RR; meta-analysis, k = 14; lifetime prevalence among individuals with ADHD: 26.9%, E 1a)¹⁸⁸
  • Increased marijuana use (RCT, E 1b)¹⁷⁸
• Substance Dependence (Addiction) (Review, E 1a)¹⁸⁹
  • 2.27-fold increased risk (OR 2.27; 99.7% CI 1.28 to 3.81; + 127%) of having a substance use disorder between the ages of 19 and 33 among individuals diagnosed with ADHD by age 18 (E 2b) in the Finnish 1987 birth cohort (n = 53,147; preprint, E 2b)¹⁵⁶ (cohort study, preprint, E 2b)⁶⁸. The ADHD prevalence of 0.43% is low because ADHD was rarely diagnosed at that time.
  • A 2.12-fold increased risk of substance use disorder in cases of ADHD that persists into adulthood compared with ADHD that has remitted (OR 2.12; 95% CI 1.53 to 3.17; meta-analysis, k = 36, E 1a)¹⁵⁴
  • 1.77-fold increased risk of substance use disorder among adolescents with ADHD (HR 1.77; 95% CI 1.05 to 3.00) (cohort study, E 2b)¹⁹⁰

1.5.2.2. Sexually Transmitted Diseases (+300%)¶

ADHD is associated with an increased risk of sexually transmitted diseases (systematic review, E 1a).¹⁹¹
Hyperactive children (n = 149) were treated for sexually transmitted diseases four times as often as controls (N = 221, n = 149) by the time they reached a mean age of 20; 16% vs. 4%, cohort study, E 2b).¹⁹²

1.5.2.3. Respiratory diseases (up to +224%)¶

• Respiratory diseases were 2.42 to 3.24 times more common (OR). These associations were explained by shared genetic factors to 60–69% (Sweden, N = 4,789,799, cohort study, E 2b)¹⁷¹, e.g.:
  • Asthma
  • chronic obstructive pulmonary disease

1.5.2.4. Risk of stroke (up to +189%)¶

People with ADHD have an increased risk of stroke.

• In a Mendelian randomization study, a genetic predisposition to ADHD was associated with an increased risk of
  • ischemic stroke by 15% (OR 1.15; 95% CI 1.05 to 1.25) (Mendelian randomization, E 2b)¹⁹³
  • large-artery atherosclerotic stroke by 40% (OR 1.40; 95% CI 1.10 to 1.76) (Mendelian randomization, E 2b)¹⁹³
• Increased risk of acute ischemic stroke or transient ischemic attack in adults with ADHD (HR; Germany, n = 8,943 with ADHD vs. 44,660 controls, 10 years, cohort study, E 2b)¹⁹⁴
  • by 69%
  • by 134% among those aged > 45
  • by 86% in cases of obesity
  • by 118% in cases of hypertension
  • by 189% for dyslipidemia

1.5.2.5. Infections (up to +180%)¶

• Increased incidence of childhood infections (ages 5 to 18; Israel, n = 18,756 with ADHD vs. 37,512 controls, case-control study, E 3)¹⁹⁵
  • Salmonellosis (OR 2.8; 180% more common)
  • Acute respiratory infections (OR 1.4; 40% more common)
  • Acute gastroenteritis (OR 1.3; 30% more common)
  • Urinary tract infections (OR 1.3; 30% more common)
  • All anti-infective drugs were prescribed significantly more often to children with ADHD
  • The number of doctor visits was significantly higher among children with ADHD.

Bacterial or viral infections can also be a contributing factor to ADHD. For more information, see Diseases as ADHD Risk Factors

1.5.2.6. Periodontitis (+129%)¶

Adolescents with ADHD had a 2.29-fold higher risk (HR 2.29; Taiwan; adjusted for smoking, diabetes, and depression) of developing periodontitis later in life compared with control subjects. (Cohort study, N = 178,321, E 2b)¹⁹⁶

1.5.2.7. Fatigue (+118%)¶

Children with ADHD traits (above the screening threshold) at ages 7 and 9 were 2.18 times more likely (OR 2.18; 95% CI 1.33 to 3.56) of suffering from chronic, disabling fatigue by age 18. Children with ASD traits: OR 1.78 (95% CI 1.17 to 2.72; United Kingdom, ALSPAC). (Cohort study, E 2b)¹⁹⁷

1.5.2.8. Tooth Decay (+116%)¶

Children with ADHD symptoms in Spain (n = 3,402, ages 6 to 14) had a higher risk of: (cross-sectional study, E 3)¹⁹⁸

• Tooth decay (OR: 2.16)
• Extraction (OR: 1.42)
• Restoration (OR: 1.47)
• Bleeding gums (OR: 1.64)

The increased risk of tooth decay persisted even when the analysis was limited to families in the middle/upper socioeconomic class and children with low sugar intake, good oral hygiene habits, and regular dental visits.

Chinese children with ADHD (ages 6 to 12) were 1.54 times more likely to have dental caries than age-matched controls (80.8% versus 52.5%) and had a higher median DMFT+dmft caries index (3 vs. 1). The plaque index and modified gingival index were also higher (median 2 vs. 1, respectively), and the proportion of sealed fissures was significantly lower (6.2% vs. 47.3%). In the multivariate analysis, frequent consumption of sweets and methylphenidate use were associated with higher odds of caries; however, the confidence intervals were extremely wide (methylphenidate aOR 39.65; 95% CI 15.79 to 271; sweets aOR 84.54; 95% CI 12.2 to 584), leading the authors themselves to caution against quantification and causal conclusions. A college degree among parents was associated with lower odds of dental caries (aOR 0.10). (Case-control study, n = 130 with ADHD versus 143 controls, E 3)¹⁹⁹

ADHD symptoms in middle childhood (ages 6 to 12) were associated with a 10% increased risk of dental caries in adolescence (OR 1.10; 95% CI 1.01 to 1.20). (Cohort study, E 2b)¹⁶⁵

1.5.2.9. Unhealthy lifestyle (+103%)¶

2.03-fold increased risk of an unhealthy lifestyle among adolescents (OR = 2.03; +103%) (cross-sectional study, E 3)¹⁷⁴

1.5.2.10. Precocious puberty (+101%)¶

(E 2b): ADHD was associated with a 101% increased risk of precocious puberty (aHR 2.01; 95% CI 1.91 to 2.11; Taiwan, N = 3,342,077), particularly among girls. (Cohort study, E 2b)²⁰⁰ For ASD, the risk was increased by 80% (aHR 1.80), again particularly among girls. (Cohort study, E 2b)²⁰¹

1.5.2.11. Childbirth complications in mothers with ADHD (typically +20% to +80%)¶

Mothers with ADHD (45,737 identified pregnant women with ADHD, 42,916 matched pairs) had a 1.2- to 1.8-fold increased risk for most pregnancy and birth complications. Across all 18 complications examined, the range extended from an OR of 1.08 (anemia) to an OR of 2.63 (depressive episode). Only for HPV infection was there no difference (OR 1.03; p = 0.77). (Cohort study, E 2b)²⁰²

In a Danish registry-based cohort of all singleton births from 2010 to 2022, prenatal diagnosis of ADHD in the mother—after adjusting for sociodemographic characteristics, psychiatric history, and somatic comorbidity—was associated with preterm birth (aRR 1.13; 95% CI 1.04 to 1.22), low birth weight (aRR 1.19; 1.09 to 1.30), and bleeding in early pregnancy (aRR 1.15; 1.08 to 1.25). In cases of ADHD diagnosed only after birth, increased rates were found for infections (aRR 1.19), hyperemesis (aRR 1.23), and an Apgar score below 7 (aRR 1.32 to 1.48). ADHD medication during pregnancy was associated, compared with no medication, solely with gestational hypertension (first trimester aRR 1.57; 1.21 to 2.02; continued use aRR 1.39; 1.01 to 1.91). Overall, the increases were small; the authors point to possible residual confounding. (Register-based cohort, N = 741,905 births, of which n = 12,859 had maternal ADHD diagnosed before birth and n = 15,683 after birth, E 2b)²⁰³

1.5.2.12. Atopic dermatitis (+45%)¶

A 45% increased risk of atopic dermatitis in individuals with ADHD (OR 1.45; 95% CI 1.21 to 1.73). Similarly, people with atopic dermatitis were more likely to have ADHD (OR 1.34; 95% CI 1.25 to 1.44; HR 1.42; 95% CI 1.20 to 1.68). The association was strongest in cases of severe atopic dermatitis (OR 2.62; 95% CI 1.76 to 3.92), in cases of multiple concurrent allergic conditions (OR 2.89; 95% CI 1.18 to 7.10), and in cases of concurrent sleep disorders (OR 2.43; 95% CI 2.14 to 2.76). (Meta-analysis of observational studies, k = 49; E 1a)²⁰⁴

1.5.2.13. Gliomas (+15% to +33%)¶

In a Mendelian randomization study, a genetic predisposition to ADHD was associated with a 1.15-fold increased risk of gliomas overall (OR 1.15; 95% CI 1.01 to 1.29; only suggestive) and a 1.33-fold increased risk of non-glioblastoma gliomas (OR 1.33; 95% CI 1.12 to 1.58). (Mendelian randomization, E 2b)²⁰⁵ Gliomas are brain tumors that originate from glial cells.

1.5.2.14. Type 2 diabetes mellitus (+10%)¶

In a Mendelian randomization study, a genetic predisposition to ADHD was associated with an approximately 10% increased risk of type 2 diabetes mellitus (OR 1.10; 95% CI 1.02 to 1.18), primarily mediated by a higher BMI, more television viewing, and lower educational attainment. (Mendelian randomization, E 2b)

1.5.2.15. Slightly Elevated Blood Pressure in Older Adults¶

ADHD symptoms in childhood (age 7) were associated with an average increase of 3.5 mmHg in systolic blood pressure and 2.2 mmHg in diastolic blood pressure at ages 44–45 (n = 8,016, cohort study, E 2b).¹⁸⁵

1.5.2.16. Higher risk of COVID-19, more severe course of the disease¶

In a Mendelian randomization study, a genetic predisposition to ADHD increased the risk of hospitalization due to COVID-19 (OR 1.36; 95% CI 1.10 to 1.69), while a genetic predisposition to Tourette syndrome increased the risk of a critical course of COVID-19 (OR 1.14; 95% CI 1.04 to 1.25). (Mendelian randomization, E 2b)²⁰⁶

1.5.2.17. Complications Following Spinal Surgery Vary by ADHD Subtype¶

Adolescents with idiopathic scoliosis who underwent dorsal spondylodesis showed varying clinical courses in the 90 days following surgery, depending on their ADHD subtype. Among those with hyperactive-impulsive ADHD, emergency department visits (OR 1.89) and urinary tract infections (OR 1.54) were more common than among matched controls without ADHD. In inattentive ADHD, adverse events overall (OR 0.59), mild adverse events (OR 0.52), transfusions (OR 0.50), and readmissions (OR 0.49) were less common. Across all forms of ADHD combined, there were more emergency department visits (OR 1.58) and urinary tract infections (OR 1.41), as well as fewer transfusions (OR 0.73). (retrospective database study, N = 14,466 adolescents who underwent surgery, of whom n = 908 had hyperactive-impulsive ADHD and n = 409 had inattentive ADHD, matched 1:4, E 2b)²⁰⁷

1.5.2.18. Short stature¶

• Children with ADHD had an odds ratio nearly four times higher for short stature in 4th grade; they grew more slowly from kindergarten through 4th grade and gained less BMI (n = 7,603). Longer duration of ADHD medication use was associated with shorter height and slower growth. (Cohort study, E 2b)²⁰⁸

1.6. Increase in Teenage Pregnancies (+130% to +520%)¶

• A Taiwanese registry study (n = 7,505 adolescents with ADHD, 30,020 controls) found that ADHD was associated with a 2.3-fold increased risk of pregnancy before age 20 (HR 2.30) and a 1.27-fold increased risk of pregnancy by age 30. Long-term ADHD medication was associated with a 31% lower risk of early pregnancy (HR 0.69). (Cohort study, E 2b)²¹⁰

• 6.2-fold increased risk of giving birth as a teenager (15.3% vs. 2.8%; OR 6.23; registry study, n = 384,103 first-time mothers, E 2b)²¹¹

• 38% of the hyperactive participants in the Milwaukee study were already parents by young adulthood, compared with 4% of the control group. (Cohort study, E 2b)¹⁹²

• Parenting and ADHD (Danish registry cohort study, N = 2,698,052, E 2b)²¹²

  • between the ages of 12 and 16
    • 3.62 times higher risk for women with ADHD 3.62 times
    • 2.30 times the risk for men with ADHD
  • between the ages of 17 and 19
    • 1.94 times the risk for women with ADHD
    • 2.27 times the risk for men with ADHD

Age at First Child for Parents with ADHD: Parents with ADHD were more likely to have their first child between the ages of 18 and 23, but less likely to do so between the ages of 24 and 30 and between 31 and 38. Over the age range of 18 to 38 years, the probability of a first birth was reduced (men OR 0.92; women OR 0.90); after taking relationship status into account, the association reversed (men OR 1.07; women OR 1.09). Comparisons between siblings yielded similar results. (Finnish registry cohort of birth cohorts from 1982 to 1993, N = 759,430, E 2b)²¹³

1.7. Educational Disadvantages¶

• Poorer educational opportunities (Mendelian randomization, E 2b)¹⁵²
  • According to their parents, 94% of children with clinically significant ADHD symptoms on the parent questionnaire (SDQ) were impaired in the classroom, and 73 to 82% were impaired at home (U.S. population sample, n = 10,255, ages 4 to 17, cross-sectional study, E 3)²¹⁴
  • 32% of the hyperactive participants in the Milwaukee Study did not graduate from high school (12th grade) (cohort study, E 2b)¹⁹². 3.7-fold odds (OR 3.7; 95% CI 2.0 to 7.0) of not graduating from high school (meta-analysis, k = 98, E 1a)¹⁰⁷
• Poorer academic performance
  • An analysis of Swedish registries of 657,720 school leavers found that people with ADHD (n = 29,128) had poorer academic performance than people without ADHD (total score of 136.8 versus 211.0 out of a maximum of 320 points). 37.6% versus 10.7% did not meet the requirements for upper secondary school (AOR 4.70). (Register-based study, N = 657,720, E 2b, E 2b)²¹⁵
• University degrees were 27% less common (19% vs. 26%; adults with a self-reported ADHD diagnosis, n = 500, compared with 501 controls, case-control study, E 3)¹⁰⁸
• High school graduation rates were 11% lower (83% vs. 93%) (case-control study, E 3)¹⁰⁸
• Poorer academic performance among students with childhood ADHD symptoms (India, n = 5,145, cross-sectional study, E 3)⁴⁶
• Bachelor’s degree (less common) (systematic review, k = 6, E 1a)²¹⁶
• Increased school absenteeism (medication-treated ADHD, Scotland, n = 766,244, cohort study, E 2b)²¹⁷
  • up to 10 years: +7%
  • Ages 11 to 14: +24%
  • Ages 15 and older: +23%
• Increased school suspensions (ADHD treated with medication) (cohort study, E 2b)²¹⁷
  • total: 5.79 times
  • 4.97 times higher in the quintile with the highest level of deprivation
  • 14.75 times higher in the quintile with the lowest level of deprivation
  • 5.4 times higher among boys
  • 9.42 times higher for girls

In a Norwegian registry cohort of n = 8,051 children and adolescents with ADHD, 32.8% of mothers and 31.8% of fathers had only a primary school education, compared with an average of 7.9% in the clinics’ catchment areas. (Cohort study, E 2b)²²⁰

In a Norwegian registry study, the average grade at the end of compulsory schooling for children with ADHD was 1.11 standard deviations lower than that of children without ADHD. After adjusting for demographic factors, the difference remained at 0.87 standard deviations; after adjusting for comorbid mental disorders, it was 0.82; after accounting for previous academic performance, it was 0.54; and when compared to biological siblings, it was 0.60. The relative academic deficit was 22% greater among girls than among boys and 39% greater among children of highly educated parents than among children of parents without a high school diploma; in absolute terms, however, it was smaller in the latter group. The academic deficit was observed across all school subjects. (Register-based cohort with sibling comparison, N = 344,152, of whom 4.0% had ADHD, E 2b)²²¹

1.8. Career Disadvantages and Loss of Income¶

• A systematic review of 6 longitudinal studies found lower labor force participation following childhood ADHD. The authors rated the quality of the evidence as low. (Systematic review, E 1a)²¹⁶
• A systematic review found that childhood ADHD was consistently associated with lower educational attainment, lower occupational status, more unstable employment, and poorer work performance, as well as lower annual income, more frequent receipt of public assistance, and an increased risk of homelessness. These findings were independent of gender, history of medication use, and symptom persistence; older studies found fewer occupational impairments. (Systematic review, n = 19 longitudinal studies from 35 publications, E 2b)²²²
• Persistent ADHD at age 25 was associated with a 3.71-fold higher odds of being neither in education nor employment (NEET; OR 3.71; 95% CI 2.06 to 6.67), and a 2.07-fold higher odds of experiencing multiple adverse social outcomes (OR 2.07; 95% CI 1.47 to 2.93). 25% of people with persistent ADHD exhibited more than one such outcome, compared with 11% of people with mild ADHD symptoms. No robust association was found for ADHD limited to childhood (NEET OR 1.20; not significant). These associations remained consistent across gender, household income of the family of origin, and after adjusting for childhood comorbidities. (ALSPAC birth cohort, N = 6,439, E 2b)²²³
• Job turnover increased by 59% (5.4 versus 3.4 jobs over 10 years; comparison among currently employed individuals) (case-control study, E 3)¹⁰⁸
  • In a Japanese hospital sample (n = 335), women with ADHD were less likely to be employed full-time than men with ADHD. (Cross-sectional study, E 3)²²⁴
• Employment rate decreased by 28% (52% compared to 72%) (case-control study, E 3)¹⁰⁸
• Twice the odds of unemployment (OR 2.0; 95% CI 1.0 to 3.9; meta-analysis, k = 98, E 1a)¹⁰⁷
• Three times the risk of losing a job (review article, E 1a)⁸²
• Higher layoff rate: 1.1 vs. 0.3 jobs/period²²⁵
  • (E 2b): Hyperactive participants in the Milwaukee Study had been expelled more frequently than controls by early adulthood (cohort study, E 2b)¹⁹² (Secondary citation from Oehler 2009: 1.1 versus 0.3 discharges; not verified) (Unpublished presentation, E 4)²²⁵
• Frequent job changes (secondary citation from Oehler 2009: 2.7 vs. 1.3 jobs; not verified) (unpublished presentation, E 4)²²⁵. In Swedish registry data, 1.03-fold (IRR 1.03; N = 3,448,440), increasing with age (cohort study, E 2b)²²⁶
• (E 2b): Poorer performance evaluations by employers (cohort study, E 2b)¹⁹² (Unpublished presentation, E 4)²²⁵
• Not in employment, education, or training 6 months after leaving school (ADHD treated with medication, Scotland) (cohort study, E 2b)²¹⁷
  • total: 1.39 times
  • Boys: 1.40 times
  • Girls: 1.59 times
• Adults with ADHD reported a loss of work productivity amounting to 31.6% of their working hours, while respondents without ADHD reported a loss of 19.9% (WPAI; U.S. online survey, n = 8,432 with and n = 273,936 without a self-reported ADHD diagnosis; no significance test reported, E 3)²²⁷
  • Absenteeism: 10.7% vs. 5.87%
  • Presenteeism: 28.4% vs. 18.0%
  • Impairment of daily activities: 36.5% vs. 23.3%

In a Norwegian registry-based cohort of n = 8,051 children and adolescents with ADHD, the annual income of mothers was 28,374 USD and the fathers’ at 54,900 USD, compared to an overall average of 48,019 USD for women and men in the clinics’ catchment areas. (Cohort study, E 2b)²²⁰

Among U.S. Marine Corps recruits, there was less than a 3-percentage-point difference in promotions, demotions, deployments, and early discharges between people with ADHD (2.0% to 3.2% of the sample) and people not with ADHD; despite high statistical power, these differences were not statistically significant. People with ADHD who were treated fared better than people with ADHD who were not treated. (Two registry cohorts, N = 51,845 and N = 161,507, propensity score-adjusted, E 3)²²⁹

1.9. Reduced quality of life¶

• (E 2b): Reduced quality of life (cross-sectional study, E 3)¹⁶⁹ (cohort study, E 2b)²³⁰

• (E 1a): Reduced health-related quality of life: PedsQL difference of 7.65 points among 4- to 17-year-olds (n = 4,194, cohort study, E 2b)²³⁰; d = 0.72 among children with ADHD not receiving medication (n = 100 vs. 100, cross-sectional study, E 3)²³¹; lower KIDSCREEN scores among 11- to 17-year-olds with ADHD (KiGGS Wave 2, n = 6,599, review, E 1a)²³²; among adults with ADHD symptoms (ASRS) (cohort study, E 2b)²³³

• (E 3): In a survey of 500 adults with a self-reported ADHD diagnosis and 501 controls matched by age and sex (n = 1,001), the proportion of those who were completely satisfied with one area of life was lower among people with ADHD in six out of seven areas. (Case-control study, E 3)¹⁰⁸ (Unpublished presentation, E 4)²³⁴

  • Family life: 47% vs. 68% (p ≤ 0.001)
  • Partnership: 47% vs. 58% (p ≤ 0.001)
  • Social life: 38% vs. 58% (p ≤ 0.001)
  • Social integration: 25% versus 27% (not significant)
  • Health and fitness: 23% compared with 39% (p ≤ 0.001)
  • Working life: 22% versus 40% (p ≤ 0.001)
  • Achievement of life goals: 26% versus 39% (p ≤ 0.05)

• 72% of people with ADHD reported that ADHD had permanently affected their lives. (Case-control study, E 3)¹⁰⁸

• (E 1a): Adults in the top 10% of ADHD symptom severity (ADHD-E) had, compared to people with ADHD and lower symptom severity, a

  • A 4.1-fold increase in the relative risk of low overall life satisfaction (RR 4.10; 95% CI 3.14 to 5.35) and a
  • A 3.3-fold increased risk of insufficient social support (RR 3.30; 95% CI 2.34 to 4.65) (secondary citation from Schmidt, Petermann 2011). (Book chapter, E 4)²³⁵ (Review, E 1a)²³²

• Individuals with a combination of symptoms (according to the ASRS) showed the greatest impairment in physical quality of life and the highest depression scores. (Cohort study, E 2b)²³³

  • Combined presentation was most severely impaired for PCS (physical HRQoL) and MDI (depression)

According to their parents, adolescents with childhood ADHD had fewer close friends (d = 0.57) and experienced more rejection from their peers (d = 1.06; d = 0.71 according to teacher reports) than adolescents without ADHD (ages 13 to 18, n = 211, of whom 111 had ADHD; cohort study, E 2b).²³⁶

A meta-analysis of studies using the PedsQL compared the health-related quality of life of children and adolescents with and without ADHD from the perspectives of both the children and their parents. The disadvantage was moderate in the physical domain and large in the psychosocial domains (emotional, social, school). There was no significant difference between parents’ and children’s assessments. As age increased, the scores were lower across all domains. (Meta-analysis, k = 9 studies in the review, of which 7 were included in the meta-analysis, E 1a)²³⁷

1.10. Divorces/separations more common (+7% to +87%)¶

• Divorces
  • increased by 87% (28% vs. 15%; adults with a self-reported ADHD diagnosis, n = 1,001, case-control study, E 3)¹⁰⁸
  • In a Japanese hospital sample (n = 335), women with ADHD were more likely to be divorced than men with ADHD. (Cross-sectional study, E 3)²²⁴
• Relationship instability in Swedish registry data was 1.07 times higher (IRR 1.07; N = 3,448,440) and was more pronounced among women with ADHD (cohort study, E 2b)²²⁶
• 3- to 5-fold increased risk of separation and divorce (presentation slides, no longer available, E 4)⁴⁰

In a Norwegian registry-based cohort of n = 8,051 children and adolescents with ADHD, 47.0% of the mothers and 46.8% of the fathers were married, compared with 60.4% of the mothers in the clinics’ catchment areas. (Cohort study, E 2b)²²⁰

 

1.11. More frequent moves (+135%)¶

Adults with ADHD moved 2.35 times as often as those without the condition (IRR 2.35; 95% CI 2.32 to 2.37; Swedish registry study, N = 3,448,440, E 2b).²²⁶

1.12. Depression Among Parents of Children with ADHD Has Increased (+335%)¶

Parents of children with ADHD (screening instrument) were 4.35 times more likely to have depression than parents of children without ADHD (OR 4.35; 95% CI 2.68 to 7.07; cross-sectional study, n = 2,497 elementary school students, ages 6 to 13, China, E 3).²³⁸

Even undiagnosed ADHD in a child placed a strain on the family. In a survey of Canadian and U.S. parents, parenting stress was highest in families with diagnosed ADHD, followed by families with undiagnosed ADHD and those with a diagnosis but no current clinical symptoms. The quality of parental cooperation was lower in families with undiagnosed ADHD and in those with a diagnosis but no clinical symptoms than in families without ADHD; family quality of life was highest in families without ADHD. (Cross-sectional survey, n = 253 parents of 6- to 17-year-olds, E 3)²³⁹
In the German KiGGS cohort, financial worries, parenting problems, and conflicts with the child predicted both inattention and hyperactivity symptoms as well as a parent-reported ADHD diagnosis. Four or more types of parental stress were associated with a higher likelihood of both characteristics. The study is a cross-sectional study and does not determine the direction of the association. (Cross-sectional analysis of the KiGGS cohort, Wave 2, n = 4,596, E 3)²⁴⁰

In the Australian longitudinal study LSAC, ADHD in children was associated with poorer mental health among their primary caregivers (mean difference on the Kessler 6 scale: -1.31; 95% CI -2.44 to -0.18). There was no longer a difference in parents’ health-related quality of life once their mental health was taken into account. Children’s behavioral problems and financial hardship were associated with lower parental quality of life, while a good marital relationship and higher education were associated with better quality of life. (Cross-sectional analysis of a population-based longitudinal study, children aged 11 to 12 years, E 3)²⁴¹

1.13. Homelessness¶

Among homeless children and adolescents, the prevalence of ADHD was 22.8% (95% CI 12.9 to 34.4%). It increased with age: among participants aged 12 and older, the prevalence was 43.1% (95% CI 26.5 to 60.4%), compared with 13.1% (95% CI 4.3 to 25.6%) among younger participants. Heterogeneity was very high (I² = 98%; individual values 1.6% to 64.5%). (Meta-analysis, k = 13, N = 2,878, mean age 12.0 years, E 1a)²⁴²

1.14. More frequent contact with child and youth services (+436%)¶

In a Norwegian registry study, 32.7% of children and adolescents with ADHD had been in contact with child and youth welfare services, compared with 6.1% of the general population. The risk of out-of-home placement was 7.3 times higher (aOR 7.3; 95% CI 5.2 to 10.2), and the risk of receiving supportive services was 6.3 times higher (aOR 6.3; 95% CI 5.1 to 7.7). Among people with ADHD who had contact with support services, comorbid social behavior disorders and prior criminal convictions were more common, as were unmarried parents and parents with lower income and educational attainment. (Register-based cohort, n = 8,051 with ADHD, 18 years of follow-up, E 2b)²⁴³

1.15. Increased Risks for Children of Parents with ADHD¶

In a Swedish registry study, children of parents with ADHD had higher rates of most of the 24 adverse outcomes examined: psychiatric disorders (HR 1.49 for intellectual disability to 4.47 for ADHD), behavioral outcomes (HR 1.08 for falls to 1.82 for exposure to violence), and somatic diseases (HR 1.04 for type 1 diabetes to 2.47 for sleep disorders). After adjusting for the children’s own ADHD, the associations persisted, except for intellectual disability and epilepsy. Rates were elevated for both maternal and paternal ADHD and were highest for people with both types of ADHD. (Register-based cohort, N = 1,164,580; matched n = 56,853 with parental ADHD compared to 544,716, E 2b)²⁴⁴

1.16. Consequences of a Late ADHD Diagnosis, Especially in Women¶

In a Welsh registry cohort, women diagnosed with ADHD between the ages of 12 and 25 had higher rates of health care utilization and poorer mental health, educational, and socioeconomic outcomes during adolescence and early adulthood than women diagnosed between the ages of 5 and 11 (OR 1.39 to 4.96) and than women without ADHD (OR 1.54 to 23.98). Even in childhood, those diagnosed later exhibited health and academic difficulties compared to women without ADHD (OR 1.07 to 9.02). Among women, several of these disadvantages were more pronounced than among men. (Register-based cohort, n = 13,593 with ADHD, of whom 2,680 were female, compared with 578,793 without ADHD, E 2b)²⁴⁵

In a French survey of people with ADHD diagnosed in adulthood, 47% described their journey to diagnosis as difficult to very difficult. The authors attributed this to ongoing controversies, misconceptions, and misinformation—even within the medical community—and described the consequences of misdiagnoses as serious. Nevertheless, the late diagnosis was predominantly experienced by people with ADHD as a relief because it resolved their self-blame for past experiences, led to more appropriate treatment, and consequently resulted in reduced reliance on other medical treatments. (Survey, n = 201, supplemented by 8 individual interviews, cross-sectional study, E 3)²⁴⁶

A systematic review of ADHD across the lifespan in women found that girls and women are often diagnosed late or incorrectly, putting them at increased risk for anxiety disorders, depression, and unhealthy coping strategies. Hormonal fluctuations exacerbated symptoms, particularly during puberty, the peripartum period, perimenopause, and in older age. The authors conclude that there is a need for gender-specific diagnosis and treatment. (integrative review, k = 10 studies and 1 guideline, publications from January 2023 to April 2025, E 1a)²⁴⁷

1.17. Stigmatization¶

Adults with ADHD reported self-stigmatization (internalized), perceived, public, and structural stigmatization. More severe ADHD symptoms were associated with greater internalized stigmatization, which in turn was associated with functional impairment, lower self-esteem, and a lower quality of life. Perceived stigmatization made it more difficult to seek help, take medication, and disclose the diagnosis; however, it showed no significant association with quality of life. Public stigmatization was the most frequently studied, particularly in academic settings. Only a few studies were found on structural stigmatization, none of which used quality of life as an outcome measure. (Systematic review, k = 17, E 1a)²⁴⁸

In a representative Australian survey, people with mental health conditions reported experiencing discrimination most frequently (E 3)²⁴⁹

• in social life (43.6%; 95% CI 41.2 to 45.9
• within the family (41.4%; 39.1 to 43.7) and
• when making or maintaining friendships (41.0%; 38.7 to 43.3).

However, they experienced the greatest stress due to (E 3)²⁴⁹

• Discrimination in job searches and in the workplace
• when dating
• in romantic relationships
• when looking for an apartment, as well as
• when receiving social benefits

People with ADHD or depression reported experiencing distress in more areas of life than people with anxiety disorders or severe mental illnesses. 67.7% (65.5 to 69.9) perceived stigmatization and discrimination as worse than the mental illness itself. (Representative population survey, N = 6,032, of whom n = 2,613 had a mental illness or high levels of psychological distress; not ADHD-specific, E 3)²⁴⁹

In a randomized video experiment, students rated a young woman more negatively when she displayed visible ADHD symptoms; they liked her less and wanted less contact with her. The additional information that she was taking prescribed stimulants did not lead to any further significant negative evaluation. The authors conclude that visible symptoms, rather than medication, are the primary trigger for stigmatization. (Randomized video experiment with four conditions, n = 314 students, E 2b)²⁵⁰

2. Protective Effects of ADHD Treatment¶

In observational studies, ADHD medications were associated with lower risks of ADHD symptoms and related consequences. A qualitative systematic review of 40 pharmacoepidemiological registry studies found that ADHD medication was associated with short-term relative risk reductions ranging from 9% to 58% for injuries, traffic accidents, educational outcomes, and substance use disorders. (Systematic review, E 1a)²⁵¹

In the majority of 40 registry studies, ADHD medications were shown to have a protective effect with regard to (review with meta-analysis, k = 40, E 1a):²⁵²

• Mood Disorders
• Suicidal tendencies
• Crime
• Substance Use Disorders
• Accidents and Injuries
• traumatic brain injuries
• Traffic accidents
• Educational Outcomes

In the meta-analyses (k = 21), the protective effect on academic performance, accidents and injuries, and mood disorders was statistically significant. (Meta-analysis, E 1a)²⁵² In contrast, a systematic review of 9 observational studies (n = 12,269 children and adolescents, ages 6 to 18) found no robust evidence that methylphenidate improves academic performance under real-world conditions. Three of the four studies with the lowest risk of bias found no effect. (Systematic review, E 1a)²⁵³

Treatment for ADHD improved long-term outcomes compared with untreated ADHD for 55 of 76 outcome measures examined (72%) from 48 studies; however, these outcomes generally did not reach the level seen in individuals without ADHD (systematic review, k = 351, E 1a).⁵ When broken down by area, the following improvement rates were found:

• Driving: 100%
• Obesity: 100%
• Self-esteem: 90%
• Social functioning: 83%
• Academic performance: 71%
• Drug use/addiction: 67%
• Antisocial behavior: 50%
• Use of support services: 50%
• Work: 33%

For the last four areas mentioned—those showing a weak response—European studies demonstrated a benefit in 86% (6 out of 7) of the outcome measures, while North American studies did so in 50% (11 out of 22). The authors attributed this to differences in study design. (Systematic review, k = 351, E 1a)⁵

A meta-review of 231 systematic reviews and meta-analyses on ADHD found strong evidence of short-term symptom reduction through medication, particularly stimulants; however, there was only limited evidence that medication mitigates adverse life outcomes (educational attainment, employment, substance abuse, injuries, suicides, criminality, and comorbid mental and physical disorders). There was little evidence regarding adverse effects following long-term use. The authors assessed the strength of evidence for nonpharmacological treatments as inconsistent. (Meta-review of systematic reviews and meta-analyses, k = 231, E 1a)²⁵⁴

2.1. Reduced premature mortality (–19% to –25%), fewer suicide attempts (–17% to –72%)¶

MPH use was associated with a 19% lower overall mortality rate among 68,096 children and adolescents with ADHD (ages 4 to 17, Taiwan) (AHR 0.81, 95% CI 0.67 to 0.98). A delayed start of MPH treatment was associated with a 5% higher mortality rate (AHR 1.05), while a longer duration of treatment was associated with a 17% lower mortality rate (AHR 0.83). (Cohort study, E 2b)²⁵⁵
Starting ADHD medication within three months of diagnosis was associated with a 21% lower overall mortality rate over two years (HR 0.79, 95% CI 0.70 to 0.88). (E 2b): Mortality from unnatural causes was 25% lower (HR 0.75, 0.66 to 0.86), while mortality from natural causes showed no significant change (target study emulation, Swedish registry cohort, N = 148,578, E 2b, E 2b).²⁵⁶ A British cohort study (18,637 patient-years on stimulants or atomoxetine, 7 deaths) found no increased risk of sudden cardiac death with ADHD medication, but did find an increased suicide rate among 11- to 14-year-olds compared to the general population. (Cohort study, E 2b)²⁵⁷

In several large observational studies, ADHD medications (primarily stimulants) were associated with a lower risk of suicide attempts: (Review, E 1a)²⁵⁸

Individual studies on mortality and suicide attempts

• 17% (suicidal behavior, IRR 0.83, 95% CI 0.78 to 0.88; target study emulation, n = 148,581, E 2b)²⁵⁹
• 19% (stimulants; comparison of periods when the same individuals were taking medication versus periods when they were not, HR 0.81) (cohort study, E 2b)⁴¹
• 24% compared with people with ADHD who are not receiving medication (RR 0.76, 95% CI 0.58 to 1.00; stimulants RR 0.72) (meta-analysis, E 1a)²⁶⁰
• 31% compared with periods when people with ADHD were not taking medication (RR 0.69, 0.49 to 0.97; stimulants RR 0.75) (meta-analysis, E 1a)²⁶⁰
• 31% (population-based comparison, OR 0.69) and 39% (comparison of months on medication versus months without medication among the same individuals, OR 0.61) across all age groups; for stimulants, 28% (OR 0.72); for non-stimulants, no significant effect (OR 0.94; U.S., n = 3,874,728, cohort study, E 2b)²⁶¹
• 38% (suicidal thoughts or attempts, stimulants vs. no medication, adjusted HR 0.62, 95% CI 0.57 to 0.67; vs. non-stimulants, HR 0.70; n = 797,189, cohort study, E 2b)²⁶²
• 59% for MPH use lasting 90 to 180 days (HR 0.41) (cohort study, E 2b)²⁶³
• 72% among those taking MPH for more than 180 days (HR 0.28; Taiwan, n = 84,898, under 18 years of age, cohort study, E 2b)²⁶³
• Methylphenidate for ADHD was associated with a reduction in the previously elevated risk of suicide attempts to baseline levels after 90 days (IRR 6.55 in the 90 days prior to treatment initiation, 3.91 during the first 90 days, 1.35 with continued use; Hong Kong, n = 25,629, self-controlled case series study, E 2b).²⁶⁴
• For a duration of use ranging from 1 to 90 days, ADHD medication was not associated with a reduction in risk (RR 0.91, n.s.; meta-analysis of observational studies, E 2b, E 1a)²⁶⁰
• (E 2b): Non-stimulants showed no significant reduction in suicidality (HR 0.96, corresponding to 4%, not significant (cohort study, E 2b)⁴¹; OR 0.94, not significant (cohort study, E 2b)²⁶¹)

A Swedish registry study examined all n = 221,714 adolescents and adults (ages 16 to 65) who had received an ADHD diagnosis between 2006 and 2021. Compared with periods when these medications were not taken, the use of the following ADHD medications was associated with a lower risk of suicide attempts or suicides: (cohort study, E 2b)²⁶⁵

• Dexamphetamine: reduced by 31% (aHR 0.69)
• Lisdexamfetamine: reduced by 24% (aHR 0.76)
• Combination therapy: reduced by 15% (aHR 0.85)
• Methylphenidate: reduced by 8% (aHR 0.92)

Increased risk of subsequent suicidal behavior:

• Atomoxetine: 20% increase (aHR 1.20, 95% CI 1.04 to 1.39)
• Guanfacine: increased by 65%
• Clonidine: increased by 92%

Among adolescents and young adults with ADHD and comorbid substance use disorder, ADHD medication was associated with a 30% lower mortality rate (adjusted HR 0.70; 95% CI 0.65 to 0.75) as well as fewer hospitalizations, fewer emergency room visits, a lower risk of suicidal thoughts and suicide attempts (RR 0.74 to 0.82), and more consistent use of psychiatric services (RR 1.23). Stimulants performed better than non-stimulants (fewer hospitalizations, accidental overdoses, and suicidal thoughts and attempts; RR 0.63 to 0.79). However, in cases of comorbid substance use disorder, stimulants were prescribed less frequently (RR 0.63; 95% CI 0.62 to 0.63). (Retrospective cohort study based on U.S. treatment data from 2007 to 2024, N = 1.23 million 15- to 25-year-olds with ADHD, of whom n = 288,159 had a substance use disorder, propensity score matching, E 2b)²⁶⁶

ADHD medication reduced the following compared to periods without medication: (Quebec Registry Cohort 2000–2021, N = 217,192 individuals aged 1 to 24 with ADHD, E 2b)²⁶⁷

• overall mortality by 39% (aHR 0.61; 95% CI 0.48 to 0.76)
• accidental injuries
  • that led to emergency department treatment, by 25% (aHR 0.75; 0.74 to 0.77)
  • that led to hospitalization decreased by 29% (aHR 0.71; 0.68 to 0.75)
• Stimulants were associated with lower mortality and fewer injuries
• Non-stimulants and the simultaneous administration of both result in fewer injuries

In a multinational self-controlled case series analysis, the risk of a first episode of self-harm was

• highest during the 90 days prior to the start of ADHD medication (pooled adjusted IRR 2.58; 95% CI 2.12 to 3.13)
• lower during the first 90 days of use (1.78; 1.23 to 2.57)
• the lowest as treatment progressed (1.27; 1.01 to 1.60).

The authors interpret this as evidence that untreated ADHD—rather than medication—is the primary driver of self-harm. The results were consistent across all five databases. (Self-controlled case series from databases in Hong Kong, New Zealand, South Korea, Taiwan, and the United Kingdom, 2001 to 2020, N = 461,024 on ADHD medication, of whom n = 6,847 had a first episode of self-harm, self-controlled case series study, E 2b)²⁶⁸

In a meta-analysis of 48 observational studies on psychotropic medications and suicide-related outcomes, methylphenidate was associated with a lower risk of suicide-related events in patients with depression (OR 0.45; 95% CI 0.29 to 0.69); the same was true for personality disorders, where lisdexamfetamine also showed a reduced risk. For schizophrenia spectrum disorders, methylphenidate showed no association in either direction (p > 0.05). For ADHD as the primary diagnosis, a pooled analysis was not possible because only one suitable study was available per medication. (Systematic review with meta-analysis of observational studies, k = 48, N = 6,489,573, E 1a)²⁶⁹

2.2. Fewer Accidents and Injuries¶

2.2.1. Fewer injuries and traumatic brain injuries (-43% to -73%)¶

(E 1a): ADHD medication was associated with fewer emergency room visits due to unintentional injuries among people with ADHD, both as children and as adolescents (OR 0.64 to 0.72; registry study, n = 1,968,146, E 2b).²⁷⁰ (meta-analysis, E 1a)²⁷¹

Dose-dependent individual findings regarding injuries

• a 43.5% lower prevalence of injuries at age 12 (95% CI 18.1 to 69.0; Danish cohort, 4,557 children with ADHD, E 2b)²⁷²
• Traumatic brain injuries decreased
  • by 51% at an MPH dose of more than 84 daily doses per year (HR 0.49, 95% CI 0.47 to 0.51), with a dose-dependent reduction at lower cumulative doses (HR 0.76 and 0.88, respectively; Taiwan, n = 124,438, cohort study, E 2b)²⁷³
  • up to 73% (HR 0.27, 95% CI 0.20 to 0.38; Sweden, n = 9,421, cohort study, E 2b).²⁷⁴

A German study using two representative samples (the KiGGS questionnaire and health insurance data) found no significant effect of medication on the incidence of accidents (OR 1.28, 95% CI 0.93 to 1.77; OR 0.97, 95% CI 0.93 to 1.01). In the logistic regression analysis of the health insurance sample, medication remained a weak predictor (Exp(B) 1.10; p = 0.002). The authors considered this part of their analysis to be exploratory. (Cross-sectional study, E 3)²⁷⁵

2.2.2. Fewer traffic accidents (-12% to -58%)¶

• fewer traffic accidents (Review, E 1a)²⁷⁶

  • 12% (IRR 0.88; target study emulation, n = 148,581, E 2b)²⁵⁹
  • 38% among men (OR 0.62; emergency department visits due to traffic accidents, n = 2,319,450, cohort study, E 2b)²⁷⁷
  • 42% among women (OR 0.58) (cohort study, E 2b)²⁷⁷

• 58% fewer serious traffic accidents among men (HR 0.42, 95% CI 0.23 to 0.75); no significant effect among women (Swedish registry study, n = 17,408 adults, E 2b)²⁷⁸

• A health economic model (funded by the manufacturer) was based on a 43% lower probability of accidents in a driving simulator when taking a once-daily sustained-release amphetamine formulation (Dyanavel XR) compared with placebo, as demonstrated in an RCT. (RCT, E 1b)²⁷⁹

  • With medication costs of $80 per 30 days, the lifetime savings amounted to:
    • $332,660 compared to people with ADHD who have not been treated
    • $194,278 compared to people with ADHD receiving standard treatment (standard treatment: a combination of short-, medium-, and long-acting stimulants and non-stimulants)

• (E 1a): improved driving performance (systematic review, E 1a)²⁸⁰ s in the simulator (book chapter, E 4)²⁸¹

2.2.3. Fewer injuries (-53%)¶

Methylphenidate reduced the risk of injuries in adults with ADHD

• by 53% when taken for more than 3 months (cohort study, E 2b)⁵⁴
• by 35.5% when taken for less than 3 months (cohort study, E 2b)⁵⁴

Atomoxetine reduced the risk of injuries in adults with ADHD

• by 26% when taken for more than 3 months (cohort study, E 2b)⁵⁴

2.2.4. Fewer fractures (-32% to -86%)¶

Every medication used to treat ADHD reduced the risk

• of total fractures (cohort study, E 2b)²⁸²
  • by 39% to 74%, according to 6 cohort studies, with no difference between stimulants and non-stimulants (systematic review, E 1a)²⁸³
  • by 32% to 41% in a self-controlled case series (comparison of treatment phases with the 6 months prior to the start of MPH; Hong Kong, n = 2,023, systematic review, E 1a)²⁸³
  • by 60.4 to 86.2% (limb fractures) (cross-sectional study, E 3)⁵⁷

Treatment of ADHD with methylphenidate reduced the risk

• a 60.4% reduction in limb fractures (OR 0.396; retrospective cross-sectional study, n = 754 children aged 6 to 18 years, E 3)⁵⁷

• a 23% reduction in total fractures with use for at least 180 days (aHR 0.77, 95% CI 0.63 to 0.94; no significant effect with shorter duration of use; Taiwan, n = 6,201, cohort study, E 2b)²⁸⁴

• stress fractures (fatigue fractures)

  • by 22.4% (crude rate 0.45% vs. 0.58%; adjusted OR 0.64), with the rate among MPHs actually lower than that among those not affected (0.54%) (retrospective study, E 2b)²⁸⁵
  • 16% lower than in those not affected (OR 0.84; not significant) (meta-analysis, E 1a)⁵⁹

• traumatic fractures (accidental fractures)

  • the same value as for those not affected (OR 1.00) (meta-analysis, E 1a)⁵⁹
  • about half the rate observed in those without ADHD (men, Israeli recruits aged 18 to 25; fracture rate 4.8 to 5.8% with MPH compared to 10.4% without ADHD and 16.4% with untreated ADHD; no corresponding effect observed in women) (cohort study, E 2b)²⁸⁶
  • People with ADHD had a 17% higher risk of fracture than people without ADHD (OR 1.17). Among people treated with non-stimulant medications, the increased risk was 37% (OR 1.37). (Meta-analysis, E 1a)⁵⁹

• (E 1a): a 15% reduction in unintentional injuries (cohort study, E 2b)²⁸⁷ or a relative risk of 0.88 (meta-analysis, n = 13,254, E 1a)²⁸⁸

• by 73% in cases of traumatic brain injury (cohort study, E 2b)²⁸⁷

• from poisoning (self-controlled case series study, E 2b)²⁸⁹

• a 9% decrease in injury-related emergency room visits (self-controlled case series study, E 2b)²⁹⁰

• burns in children and adolescents with ADHD (n = 90,634, cohort study, E 2b)²⁹¹

  • by 57% among those who had been taking MPH for 90 days or longer (aHR 0.43)
  • by 30% among those who had been taking MPH for less than 90 days (aHR 0.70)

Treatment of ADHD with atomoxetine reduced the risk

• a 86.2% reduction in limb fractures (OR 0.138; retrospective cross-sectional study, n = 754, E 3)⁵⁷

2.2.5. Typical Recovery Time for a Concussion¶

The prolonged recovery from concussion symptoms associated with ADHD was not observed in athletes with ADHD who were being treated with stimulants. These athletes also had an increased risk of sustaining a concussion. (Cohort study, E 2b)⁶²

2.2.6. Fewer emergency room visits (-28% to -46%)¶

ADHD medication reduced emergency room visits among children with ADHD (cohort N = 710,120, of whom n = 4,557 had ADHD, E 2b)²⁷²

• by 28% (at age 10)
• by 46% (at age 12)

2.2.7. Reduced Antibiotic Use¶

In a Finnish registry study (n = 66,146 people with ADHD of all age groups, 4:1 matched controls), the proportion of people with ADHD prescribed broad-spectrum penicillins in the second year following an ADHD diagnosis decreased from 11.1% to 7.0% compared to the previous year; the proportion prescribed beta-lactamase-sensitive penicillins from 5.6% to 4.5%, and the proportion of those prescribed ophthalmic antibiotics from 6.1% to 4.4%. Among controls, these prescriptions also decreased (broad-spectrum penicillins from 9.2% to 6.1%). A more pronounced decline compared with controls was observed primarily among children aged 0 to 5 years. (Cohort study, E 2b)²⁹²

2.2.8. Mild Bladder-Bowel Dysfunction¶

Bladder-bowel dysfunction (BBD) is a combined disorder of bladder and bowel function. Children with ADHD and BBD (n = 122) had higher BBD scores than children with BBD but without ADHD (n = 300). Within the ADHD group, children not taking ADHD medication had more severe baseline BBD scores (by 13.4 points) than children taking ADHD medication, but only in the subgroup treated exclusively with urological therapy. When additional medication was used to treat BBD, there was no difference between the groups. (Cohort study, E 2b)²⁹³

In Sweden, ADHD medication use was correlated over the entire period from 2006 to 2020, regardless of age or gender, with: (Swedish registry study, self-controlled case series, N = 247,420, ages 4 to 64, E 2b)²⁹⁴

• 19% to 23% reduction in self-harm (IRR 0.77; 95% CI 0.73 to 0.81 to IRR 0.85; 0.82 to 0.88)
• 11% to 13% fewer unintentional injuries (IRR 0.87; 0.84 to 0.89 to IRR 0.93; 0.91 to 0.95)
• 13% to 29% fewer traffic accidents (IRR 0.71; 0.67 to 0.77 to IRR 0.87; 0.83 to 0.91)
• A 16% to 27% reduction in crime (IRR 0.73; 0.71 to 0.75 to IRR 0.84; 0.82 to 0.85)

While the prevalence of prescriptions rose from 0.6% to 2.8%, the association with unintentional injuries, traffic accidents, and crime weakened (p for trend < 0.01 in each case). Changes in the age and gender distribution of those treated did not fully explain this weakening association for unintentional injuries and traffic accidents. (E 2b)²⁹⁴

A Norwegian registry study estimated the effect of ADHD medication on injuries using prescribing patterns—which vary widely across clinics—as an instrumental variable. Compared with the general population, people with ADHD had an increased risk of injury (RR 1.35; 95% CI 1.30 to 1.39), with this risk being higher among girls and women (RR 1.47; 1.38 to 1.56) than among boys and men (RR 1.23; 1.18 to 1.28). For the subgroup with milder or atypical symptoms, whose treatment status depended on clinical preference, there was no causal evidence of a protective effect of the medication on injuries overall. Only for injuries treated in emergency departments was an effect of the medication observed over time. (Norwegian registry study with instrumental variable analysis, n = 8,051, diagnosis at ages 5 to 18 years, follow-up up to 4 years, E 2b)²⁹⁵

2.3. Fewer sexually transmitted diseases and teenage pregnancies (up to a 41% decrease)¶

• People with ADHD are more likely to have sexually transmitted diseases (systematic review, E 1a)¹⁹¹
  • ADHD medications were associated with a 30% (short-term use, HR 0.70) to 41% (long-term use, HR 0.59) reduced risk in men. No protective effect was observed in women (n = 89,490, cohort study, E 2b)²⁹⁶
• Fewer teenage pregnancies (long-term medication: HR 0.69 for pregnancy under age 20) (cohort study, E 2b)²¹⁰

 

2.4. Fewer comorbidities¶

Several of the studies presented below found that ADHD medications were associated with a lower prevalence of the following comorbidities. Among children and adolescents with ADHD and comorbidities, combination therapy or MPH alone was more effective than other forms of treatment (n = 1,919, cross-sectional study, E 3).²⁹⁷
A Norwegian cohort study of n = 8,051 children and adolescents (ages 5 to 18) with a first-time diagnosis of ADHD found that ADHD medication (87.5% MPH, 11.5% ATX, 0.9% amphetamine preparations) in regression analyses: a rate of substance use disorders that was up to 51% lower (years 1–2), a 36% lower rate of psychotic disorders (Year 8), and a 22% lower rate of reactive disorders; at the same time, it found up to a 30% higher rate of social behavior disorders, a 48% higher rate of tic disorders, and, after 9 years, a 7% higher rate of any comorbidity. (Cohort study, E 2b)²²⁰ A limitation to consider is that the study design could not distinguish between the medication and non-medication groups based on the severity of ADHD. Medication correlates with higher severity. Furthermore, people who have already experienced that medication can help them are likely to be more willing to undergo an additional diagnosis in the event of further problems. Amphetamine-based medications were significantly underrepresented.

(E 2b): The instrumental variables analysis of the same cohort, which estimates effects only among patients “on the treatment borderline” (for whom prescribing depended on the clinic’s preference), found that medication nearly eliminated the occurrence of reactive (stress-related) disorders in girls during the first two years of follow-up and reduced the incidence of tic disorders in boys by up to 89% during the first three years. (Cohort study, E 2b)²⁹⁸ No other benefits or harms were observed (editorial on the study, E 4).²⁹⁹

2.4.1. Fewer anxiety disorders (-85%)¶

In a 10-year follow-up study of 140 boys with ADHD, treatment with stimulants (for an average of 6 years) was associated with an 85% reduction in the risk of multiple anxiety disorders (≥ 2 anxiety disorders) (HR 0.15). (Cohort study, E 2b)³⁰⁰

2.4.2. Fewer social behavior disorders and ODD (-48% to -79%)¶

In a 10-year follow-up study of 140 boys with ADHD, treatment with stimulants (for an average of 6 years) was associated with a reduced risk of (cohort study, E 2b)³⁰⁰

• Conduct Disorder (CD) by 79% (HR 0.21)
• ODD (Oppositional Defiant Disorder) by 79% (HR 0.21)

Long-term MPH use (> 1 year) was associated with a 48% reduced risk of CD and ODD in children and adolescents with ADHD compared with short-term use (< 1 year) (HR 0.52). (Cohort study, E 2b)³⁰¹

2.4.3. Reduced depression (-20% to -78%)¶

ADHD medications were associated with a reduced risk of depression:

• 42% reduction 3 years after taking the medication (HR 0.58; n = 38,752, cohort study, E 2b)³⁰²
• by 20% while taking the medication (HR 0.80) (cohort study, E 2b)³⁰²
• by 20% (RR 0.80; meta-analysis, k = 33, children and adolescents, E 1a)¹⁵⁷
• Long-term use of MPH (> 1 year) in children and adolescents with ADHD compared to short-term use (< 1 year) was associated with a 30% reduction (HR 0.70) (cohort study, E 2b)³⁰¹
• Stimulant treatment (average duration of 6 years) in a 10-year follow-up study of 140 boys with ADHD reduced the risk by 78% (HR 0.22) (cohort study, E 2b)³⁰⁰
• Among 25 pregnant women with ADHD, those who stopped taking their ADHD medication exhibited more severe depressive symptoms than those who continued taking it (cohort study, E 2b)³⁰³

In the same Finnish registry study that examined lower antibiotic use, the proportion of adults with ADHD who were prescribed SSRIs decreased from 21.7% to 16.5% in the second year following their ADHD diagnosis, while it increased slightly among the control group (from 5.7% to 6.2%). (Cohort study, E 2b)²⁹²

Among adolescents and young adults aged 10 to 24 with ADHD and comorbid major depression, stimulants were associated with more favorable clinical outcomes compared with non-stimulants (adjusted HR 0.49 to 0.68 for suicidality, initiation of antipsychotic treatment, initiation of mood stabilization, and intensive use of the healthcare system). Bupropion achieved results comparable to those of stimulants for suicidality and the initiation of mood stabilization. Following a diagnosis of depression, fewer stimulants were newly prescribed (RR 0.92; 95% CI 0.91 to 0.93) and more non-stimulants, particularly bupropion (RR 3.75; 3.58 to 3.92). (Retrospective cohort study using electronic health records from the U.S., N = 1,026,253 with ADHD, of whom n = 223,665 had major depression; after propensity score matching, n = 159,259 per cohort, E 2b)³⁰⁴

2.4.4. Fewer cases of Parkinson’s disease (-37% to -75%)¶

People with ADHD over the age of 50 who received amphetamine medications (n = 13,930 vs. 13,848) showed a 37 to 45% reduced risk of Parkinson’s disease (HR 0.59 to 0.55 after 2 to 6 years). Higher doses (> 5 mg) were associated with a greater reduction in risk than lower doses. Among women, the risk was reduced by about 75% (HR 0.24 to 0.28); among men, the reduction was not statistically significant. (Cohort study, E 2b)³⁰⁵

2.4.5. Psychoses (up to -36%)¶

(E 2b): Long-term MPH use (> 1 year) was not associated with a 17% reduced risk of psychotic disorders in children and adolescents with ADHD compared with short-term use (< 1 year) (HR 0.83; 95% CI 0.52 to 1.32; not significant). (Cohort study, E 2b)³⁰¹ In the Norwegian cohort (n = 8,051), ADHD medication was associated with a 36% reduction in psychotic disorders after 8 years, as shown in regression analyses. (Cohort study, E 2b)²²⁰

For disorders on the schizophrenia spectrum, the following was found: (Swedish registry study with within-person comparison, N = 131,476, E 2b)³⁰⁶

• Lisdexamfetamine
  • An 11% reduced risk of hospitalization or death overall (aHR 0.89; 95% CI 0.84 to 0.94)
  • A 30% reduction in somatic hospital admissions (aHR 0.70; 0.58 to 0.84)
• Atomoxetine
  • A 13% reduced risk of hospitalization due to psychosis (aHR 0.87; 0.78 to 0.98).
• Methylphenidate
  • 4% increase in overall risk (aHR 1.04; 1.01 to 1.08)
  • An 8% increase in overall risk with daily doses of 95 mg or more (aHR 1.08; 1.03 to 1.14)
  • A 6% increase in overall risk when taken without a concomitant antipsychotic (aHR 1.06; 1.01 to 1.12)
• There was no increase in cardiovascular hospitalizations.

The authors therefore consider ADHD medication to be safer for schizophrenia spectrum disorders than is generally assumed. (Swedish registry study with within-subject comparison, N = 131,476, E 2b)³⁰⁶

In a Finnish registry study using instrumental variable analysis (prescription propensity of the respective hospital district), long-term methylphenidate treatment (30 mg/day) showed, in the overall sample,

• Unchanged risk of non-affective psychosis (risk difference after 1 year: -0.14; 95% CI: -0.85 to 0.42; after 4 years: -0.15; -0.49 to 0.11).
• Risk of psychosis is lower among those diagnosed before age 13
  • after 3 years, -0.24 (-0.45 to -0.03; p = 0.03;
  • after 4 years, -0.21 (-0.48 to -0.07; p = 0.02).
• For those diagnosed during adolescence, the instrumental variable was too weak for the same analysis.

Of 3,956 people with ADHD, 2,728 (69.0%) were prescribed methylphenidate at least once. 222 (5.7%) were diagnosed with non-affective psychosis by the end of the follow-up period, at a mean age of 22.16 years (SD 2.39). (Finnish registry study using instrumental variable analysis, birth cohorts from 1987 to 1997, N = 697,289, of whom n = 3,956 had ADHD, E 2b)³⁰⁷

2.4.6. Decrease in psychiatric hospitalizations (-7% to -26%)¶

A Swedish registry study examined all n = 221,714 adolescents and adults (ages 16 to 65) who had been diagnosed with ADHD between 2006 and 2021.
ADHD medications reduced the risk of psychiatric hospitalization while being taken compared to periods when they were not taken: (cohort study, E 2b)²⁶⁵

2.4.7. Bipolar Disorders¶

In the same 10-year longitudinal study of 140 boys with ADHD, the risk of bipolar disorder was not significantly altered with stimulant treatment (HR 0.47; p = 0.063). (Cohort study, E 2b)³⁰⁰

In bipolar disorder, stimulant medication administered in addition to antipsychotics or mood stabilizers showed the following results compared to periods during which only antipsychotics or mood stabilizers were used: (Swedish registry study from 2006 to 2021 with within-person comparisons, N = 17,971, mean follow-up 8.9 years, E 2b)³⁰⁸

• 11% fewer psychiatric hospitalizations (aHR 0.89; 95% CI 0.85 to 0.93)
• 25% fewer substance-use-related admissions (aHR 0.75; 0.70 to 0.81)
• A 10% reduction in hospitalizations or death overall (aHR 0.90; 0.87 to 0.93)
• A 7% decrease in mania-related hospitalizations (aHR 0.93, not significant)
• No change in somatic hospital admissions (aHR 1.00, not significant)

A reduction in psychiatric hospitalizations was observed for lisdexamfetamine (aHR 0.81; 0.75 to 0.87) and methylphenidate (aHR 0.92; 0.88 to 0.97), but not for atomoxetine. (E 2b)³⁰⁸

2.4.8. Dementia¶

In a prospective Israeli cohort of individuals born between 1933 and 1952, 730 of 109,218 participants (0.7%) received a diagnosis of ADHD in adulthood. Of these, 96 (13.2%) developed dementia, compared with 7,630 of 108,488 (7.0%) without an ADHD diagnosis (adjusted HR 2.77; 95% CI 2.11 to 3.63; p < 0.001; unadjusted HR 3.62; 2.92 to 4.49). In contrast, among people with ADHD who received psychostimulants, there was no significant increase in the risk of dementia. (prospective cohort study, N = 109,218, follow-up 2003 to 2020, E 2b)³⁰⁹

A narrative review interprets the available findings to suggest that stimulants such as methylphenidate and amphetamine derivatives may reduce the risk of dementia by normalizing dopaminergic tone, promoting cortical plasticity, and reducing oxidative stress. The authors explicitly describe these data as preliminary; randomized trials to confirm a protective effect are still pending. (Narrative review, no quantitative data, E 1b)³¹⁰

2.5. Less periodontitis (-58%)¶

Atomoxetine was associated with a 58% reduced risk of later periodontitis in adolescents with ADHD (HR 0.42; only n = 290 atomoxetine users, 16,211 people with ADHD compared with 162,110 controls, cohort study, E 2b).¹⁹⁶

2.6. Reduced substance use (-15% to -50%)¶

ADHD medications were associated with a lower:

• Tobacco use (case-control study, E 3)³¹¹

  • Smoking rate reduced by about half (OR 0.54; OR 0.44 with consistent treatment; meta-analysis, k = 14, n = 2,360, E 1a)³¹²
  • less frequent early-onset smoking (systematic review, E 1a)¹⁸²

• Substance abuse (RCT, E 1b)³¹³

  • by 15% (IRR 0.85; n = 148,581, cohort study, E 2b)²⁵⁹
  • by 31% (HR 0.69; n = 38,753, cohort study, E 2b)³¹⁴
  • in terms of the proportion of people with ADHD who are unaffected (untreated people with ADHD: HR 2.6 compared to controls) (cohort study, E 2b)³¹⁵

• (E 1b): Alcohol consumption (case-control study, E 3)³¹¹ (RCT, E 1b)³¹³

• Cannabis use (case-control study, E 3)³¹¹

• (E 1b): Use of illegal drugs (case-control study, E 3)³¹¹ (RCT, E 1b)³¹⁶

  • In men with ADHD and amphetamine dependence who had been released from prison (n = 54), OROS-MPH (up to 180 mg/day) increased the proportion of amphetamine-negative urine samples in an RCT (median 23% versus 14% with placebo) and prolonged the time to first relapse (25 versus 16 days) (RCT, E 1b)³¹⁶

A meta-analysis (n = 2,565) found neither an increased nor a decreased risk associated with ADHD medications. (Meta-analysis, E 1a)³¹⁷

• Alcohol abuse or dependence reduced by 20% (11 studies, over 1,300 participants; OR 0.80)
• 34% increase in nicotine abuse or dependence (6 studies, 884 participants; OR 1.34)
• 3% reduction in cannabis abuse or dependence (9 studies, over 1,100 participants; OR 0.97)
• 10% increase in cocaine abuse or dependence (7 studies, 950 participants; OR 1.10)

Cocaine use was reduced by 192% to 546% in an RCT involving adults with ADHD and cocaine use disorder who received sustained-release mixed amphetamine (60 or 80 mg) (OR for cocaine-free weeks: 2.92 and 5.46, respectively; abstinence in the past 3 weeks: 30.2% versus 7.0% with placebo) (RCT, E 1b)³¹⁸

(E 1a): A meta-analysis of 6 studies involving n = 1,034 participants found that participants treated with stimulants had a 1.9-fold reduced risk of developing a substance use disorder (alcohol and drugs) later in life, with a stronger effect observed during follow-up through adolescence (OR 5.8) than through adulthood (OR 1.4). (Meta-analysis, E 1a)³¹⁹ (Book chapter, E 4)³²⁰
Another meta-analysis (k = 17; n = 2,155; ages 15 to 65) found that, among individuals with ADHD and substance use disorders, medication treatment resulted in lower craving (SMD 0.27) compared to placebo, higher abstinence rates (SMD 0.33), and lower substance use (SMD 0.41). Consumption decreased for tobacco (SMD 0.44), cocaine (SMD 0.44), and amphetamine (SMD 0.51), but not for cannabis (SMD 0.17). The authors found stimulants and non-stimulants to be superior to placebo but were unable to conduct an active-ingredient-specific analysis due to the heterogeneity of the studies. (Meta-analysis, E 1a)³²¹

Among opioid-dependent pregnant women with ADHD (n = 3,247, of whom 5% were taking psychostimulants), stimulant medication was associated with (cohort study, E 2b)³²²

• 81% higher rate of buprenorphine use (a medication used for opioid withdrawal; aRR 1.81)
• 61% less frequent methadone use (aRR 0.39)
• A 23% lower likelihood of discontinuing buprenorphine treatment once started (aHR 0.77)
• 50% fewer hospitalizations due to substance use disorders (OR 0.50)

In cases of cannabis use disorder, ADHD medications influenced the risk of addiction-related hospitalization:

• 15% lower for ADHD medication overall (aHR 0.85; 95% CI 0.81 to 0.88)
• 26% lower with lisdexamfetamine (aHR 0.74; 0.69 to 0.79)
• 10% lower with methylphenidate (aHR 0.90; 0.86 to 0.94)
• 15% lower with combination medication for ADHD (aHR 0.85; 0.75 to 0.96)
• Antipsychotics (aHR 1.12), antidepressants (aHR 1.09), and benzodiazepines (aHR 1.14), on the other hand, increased the risk, while mood stabilizers had no effect.

The authors attribute the benefit more to the treatment of underlying psychiatric disorders than to a direct effect on cannabis use disorder. (Swedish registry study from 2006 to 2021 with within-person comparison, N = 51,947 with first-episode cannabis use disorder, E 2b)³²³

Among adults who received psychostimulants or atomoxetine, the rate of stimulant-related hospitalizations in the six months following the start of treatment was lower than in the six months prior:

• 21% among individuals with a pre-existing stimulant use disorder, RR 0.79 (95% CI 0.62 to 0.99)
• 16% among individuals with a pre-existing stimulant use disorder, RR 0.84 (0.70 to 1.02)

Of the 132,666 patients treated, 3,161 (2.4%) had a history of stimulant use disorder. The results were comparable across genders, age groups, and drug classes and remained consistent in sensitivity analyses using 8-, 12-, and 52-week time periods. (Swedish registry study with within-person comparison, N = 132,666, 2008 to 2021, E 2b)³²⁴

2.7. Fewer diseases related to thermoregulation (-44%)¶

In a cohort study (n = 69,446 per group after matching, ages 6 to 24, 1-year follow-up), stimulants were associated with a 44% reduction in the overall risk of heat-related illnesses (RR 0.56). (Cohort study, E 2b)³²⁵ The reduction was significant for dehydration (RR 0.56) and rhabdomyolysis (OR 0.56), but not for heat stroke, heat syncope, heat exhaustion, or sunstroke. The study examined

• Dehydrogenation
• Hyperthermia
• Heatstroke
• Heat syncope
• Heat cramps
• Heat exhaustion
• Heat-induced fatigue
• Heat edema
• Rhabdomyolysis
• Sunstroke

2.8. Reduced nearsightedness (-39%)¶

Children with ADHD who received ADHD medications (MPH, atomoxetine, or clonidine) had a 39% lower risk of myopia (nearsightedness; aHR 0.61). Two ADHD medications reduced the risk more significantly (aHR 0.28) than a single ADHD medication (aHR 0.50). (Cohort study, E 2b)³²⁶
The risk of myopia in untreated children with ADHD was 22% higher than in children without ADHD (aHR 1.22). (Cohort study, E 2b)³²⁶

2.9. Decrease in overall hospitalizations (-16% to -38%)¶

A Swedish registry study examined all n = 221,714 adolescents and adults (ages 16 to 65) who had been diagnosed with ADHD between 2006 and 2021.
ADHD medications reduced the risk of nonpsychiatric hospital admission while being taken, compared to periods when they were not being taken: (cohort study, E 2b)²⁶⁵

• Amphetamine-based medications: reduced by 38% (aHR 0.62, p = 0.002)
• Lisdexamfetamine: reduced by 36% (aHR 0.64, p < 0.001)
• Combination therapy: reduced by 33% (aHR 0.67, p < 0.001)
• Dextroamphetamine: reduced by 28% (aHR 0.72, p < 0.001)
• Methylphenidate: reduced by 20% (aHR 0.80, p < 0.001)
• Modafinil: reduced by 19% (aHR 0.81, p = 0.05)
• Atomoxetine: reduced by 16% (aHR 0.84, p < 0.001)
• Guanfacine: increased by 2% (p = 0.85, not statistically significant)
• Clonidine: increased by 5% (p = 0.68, not statistically significant)

Children and adolescents with ADHD and comorbid autism began medication later than people with ADHD alone (12 to 14% started more than 12 months after diagnosis, compared with 7 to 8%), they discontinued treatment more frequently within three months (16% versus 12%) and switched medications more frequently within three years (an average of 2.6 switches). In a comparison within the same individual—examining the year before versus the year after the start of treatment—the alternative ADHD medications, after adjusting for multiple testing, did not differ significantly from MPH in terms of inpatient psychiatric admissions, accidental injuries, or specialist treatments for substance use, depressive, or anxiety disorders. (Swedish registry study, n = 24,117 with ADHD and autism (AuADHD), n = 79,830 with ADHD alone, initial diagnosis 2007–2018, follow-up through 2021, E 2b)³²⁷

2.10. A decrease in cases of precocious puberty (-37%)¶

MPH was associated with a 37% reduction in the risk of precocious puberty, which is twice as common in children with ADHD as in those without the condition (aHR 0.63; ADHD without medication: aHR 2.01). (Cohort study, E 2b)²⁰⁰

2.11. Lower rates of obesity (14.7% to 33.6% compared with 41.2%)¶

Among adults with ADHD, the following had obesity: (U.S. cross-sectional survey, N = 481, combination group n = 34, cross-sectional study, manufacturer-funded, E 3).²²⁷

• 41.2% of adults with ADHD (BMI ≥ 30) who are not taking medication
• 33.6% of those treated with immediate release stimulants
• 31.0% of those treated with sustained release stimulants
• 14.7% of people with ADHD treated with a combination of sustained-release and immediate release stimulants

The following were of normal weight (BMI 18.5 to 25): (U.S. cross-sectional survey, N = 481, combined group n = 34, cross-sectional study, manufacturer-funded, E 3).²²⁷

• 27.2% of those not taking medication
• 36.2% of those treated with immediate release stimulants
• 39.7% of those treated with sustained release stimulants
• 44.1% of people with ADHD receiving combination therapy
• The BMI distribution differed significantly only between the group receiving combined treatment and the group not receiving medication (p = 0.005).

2.12. Less reduction in brain volume¶

Children with ADHD had smaller brain volumes than the control group (total brain volume: 3.2% decrease; cerebellum: 3.5% decrease). Children with ADHD who had not previously received medication showed more pronounced reductions (total brain—5.8%, cerebellum – 6.2%, white matter – 10.7% compared to controls; white matter – 8.9% compared to children with ADHD receiving medication). Children with ADHD who were on medication differed from controls in all measures of gray matter (-3.4% to -6.6%), in the caudate nucleus (-4.3%), and in the cerebellum (-3.6%), but in no measure of white matter. The frontal lobe showed the smallest Effect sizes of all regions. The study did not find any selective prefrontal findings. Developmental trajectories were largely parallel between patients and controls, which the authors interpreted as evidence of an early, non-progressive cause independent of stimulant treatment. (Case-control study, E 3)³²⁸

2.13. Rarely a victim of violence, bullying, and abuse¶

Male adolescents with ADHD who were treated with MPH were less likely to be victims of bullying/cyberbullying (physical victimization, isolation, destruction of property by others, and sexual victimization), were less likely to destroy others’ property, and were less likely to exhibit bullying behavior (as perpetrators). (Cross-sectional study, E 3)³²⁹

People with ADHD who were treated with MPH or ATX were less likely to experience abuse than people with ADHD who were untreated (aHR 1.47 versus 1.80 for ADHD overall, in each case compared with controls). (Cohort study, E 2b)³³⁰

A combined ADHD and violence treatment program was associated with a reduction in intimate partner violence among 209 perpetrators of intimate partner violence who had ADHD; this reduction was primarily linked to a decrease in ADHD symptoms (no control group). (Cohort study, E 2b)³³¹

Among children with ADHD who were receiving methylphenidate and were also experiencing physical abuse, the risk of abuse was: (Self-controlled case series based on electronic health records from Hong Kong, n = 1,064 children aged 5 to 16 years, self-controlled case series study, E 2b)³³²

• highest shortly before the start of treatment (+349%) (IRR 4.49; 95% CI 3.76 to 5.36)
• normalized after the start of treatment (corresponding to the risk during periods without medication, -10%) (IRR 0.90; 0.63 to 1.29)
• reduced by 37% as treatment continued

This is consistent with the assumption that MPH treatment reduces the risk of becoming a victim of physical abuse.

2.14. Lower crime rate (-32% to -41%)¶

ADHD medications reduced the crime rate while they were being taken:

• by 41% in women (HR 0.59; n = 25,656, cohort study, E 2b)¹³⁰

• 33% to 38% fewer minor offenses among adolescents on ADHD medication during periods of high medication adherence compared to periods of low medication adherence (HR 0.67 for at least 3 months, HR 0.62 for at least 6 months). SSRIs (as control medication) had no effect, nor was there any evidence of reverse causality. The reduction ranged from 16% to 55% depending on gender, stimulant versus non-stimulant medication, and type of offense. (Registry study, n = 18,234 adolescents aged 12 to 18, E 2b)³³³

• by 32% in men (HR 0.68) (cohort study, E 2b)¹³⁰

• 30% fewer incarcerations (HR 0.70; 95% CI 0.60 to 0.80) during periods of active ADHD medication (Danish registry study, n = 4,231 with ADHD, n = 19,595 controls, follow-up until a mean age of 22.0 years) ³³⁴ SSRIs: no significant effect

• 20% fewer convictions (HR 0.80; 95% CI 0.70 to 0.90) during periods of active ADHD medication (Danish registry study, n = 4,231 with ADHD, n = 19,595 controls, follow-up until a mean age of 22.0 years)³³⁴ SSRIs: no significant effect

• 25% for male adolescents: Boys with ADHD between the ages of 10 and 17 who are treated with stimulants have a 1.52-fold risk of committing a first offense, compared to a 2.02-fold risk for those not treated with stimulants (in each case compared to those without ADHD). For repeat offenses, only a slight difference was observed (HR 1.09 versus 0.97); among treated girls aged 10 to 17, the risk of recidivism was increased (HR 1.26) (cohort study, E 2b)¹⁰⁹

• 13% regardless of sex (IRR 0.87; n = 148,581, cohort study, E 2b)²⁵⁹

• particularly in the case of crimes committed on impulse (violent and public order offenses; no effect on premeditated crimes) (cohort study, E 2b)³³⁵

• (E 1b): lower recidivism rate among former offenders (violent recidivism while using psychostimulants, HR 0.62) (RCT, E 1b)³¹³ (cohort study, E 2b)³³⁶. The evidence from prison studies is limited (systematic review, E 1a)³³⁷

2.15. Improved Academic Performance and Educational Outcomes¶

ADHD medications are associated with better academic performance:

• In a Swedish registry study (n = 657,720), a three-month course of ADHD medication was associated with (cohort study, E 2b)²¹⁵
  • a total score that is 9.35 points higher (scale: 0 to 320)
  • a 20% lower odds of not being admitted to upper secondary school (OR 0.80)
• Test scores for people with ADHD while they were taking medication were 4.8 points (scale: 1 to 200) higher than during the period when they were not taking medication (within-person comparison of 930 individuals with multiple test results). (Cohort study, E 2b)³³⁸
• Partial or complete discontinuation of ADHD medication was associated with a significantly lower grade point average at graduation compared to continuous treatment (teacher ratings: −0.18 SD; exam scores: −0.22 SD) (cohort study, E 2b)³³⁹
• ADHD medication was associated with slightly better test scores in math (SMD 0.063) and reading (0.071). For English (SMD 0.037), the effect was not significant. The authors assessed the average long-term effect as clinically irrelevant. (Cohort study, E 2b)³⁴⁰

In a U.S. cross-sectional survey (n = 481), adults with ADHD who were taking stimulants were more likely to hold an associate’s, bachelor’s, or graduate degree (56.1% to 58.9%) than people with ADHD who were not taking medication (41.3%). The difference was not statistically significant. (Cross-sectional study, E 3)²²⁷

In a 10-year follow-up study of boys with ADHD (U.S.), the cumulative risk of repeating a grade by age 21 was 26% among those receiving stimulant treatment, compared with 63% among those not receiving stimulants (HR 0.25) (cohort study, E 2b)³⁰⁰

Adults with ADHD (n = 20) showed reduced motivation to exert themselves cognitively or physically when not taking medication. Amphetamine medication increased motivation equally in both areas to a level close to that of healthy control subjects (n = 24, experimental crossover study, E 2b).³⁴¹

In contrast, a Norwegian registry study designed as an emulated target study found only minor long-term effects on academic performance. The initiation of ADHD medication was associated with standardized mean differences of 0.037 (English; 95% CI -0.003 to 0.076), 0.063 (math; 0.016 to 0.111), and 0.071 (reading; 0.030 to 0.111) in national eighth-grade tests. The authors considered these effects to be clinically insignificant. (Simulated target study based on registry data, n = 8,548 children with ADHD, born between 2000 and 2007, E 2b)³⁴²

In a Canadian analysis of administrative data, students with ADHD who were taking long-acting stimulants in grades 9 through 12: (Retrospective analysis of administrative data, n = 15,544 on long-acting stimulants, n = 27,880 untreated, n = 204,681 without ADHD; author employed by the manufacturer, E 2b)³⁴³

• better report card grades (estimated value of -4.93 compared to -6.19 for untreated ADHD; reference: group without ADHD)
• Better results on statewide standardized tests (percentile rank of -9.20 compared to -11.50)
• Fewer days of absence across all grade levels (absenteeism rate: -3.33 compared to 7.96)
• a higher probability of graduating from high school (odds of not graduating: 1.39 versus 2.22)
• a higher probability of transitioning to further education (odds of not transitioning: 0.77 versus 1.42).
• A gap between them and their peers without ADHD persisted across all areas.

2.16. Improved Ability to Work and Income¶

Adults taking a combination of sustained-release and immediate-release stimulant medications were more likely to be employed full-time (52.9%) than people with ADHD who do not take medication (33.3%) (U.S. cross-sectional survey, n = 481, E 3).²²⁷
23.5% (with and without intellectual disabilities), 38.3% (without intellectual disabilities), 39.7% (with intellectual disabilities), and 53.5% (not taking medication) of the people with ADHD were unemployed. (Cross-sectional study, E 3)²²⁷
Of the 20 former inmates with ADHD who were followed up and had participated in a 52-week methylphenidate study, 15 had been released after 3 years. Of these, 10 (67%) were employed, mostly full-time. (RCT, E 1b)³¹³

People with ADHD who take stimulant medication have (differences not significant) (cross-sectional study, E 3)²²⁷

• 58.8% to 65.2% have a household income between $25,000 and $150,000 per year (people with ADHD: 50.9%)
• 14.7% to 26.2% had a household income of less than $25,000 per year (people with ADHD: 34.2%)

A Swedish registry-based study found: (Registry cohort, N = 12,875 working-age adults with ADHD born between 1958 and 1978, follow-up from 2008 to 2013; authors employed by the manufacturer, E 2b)³⁴⁴

• if the patient has taken ADHD medication in the past 2 years
  • A 10% lower risk of long-term unemployment (at least 90 days of unemployment in the following year) (adjusted RR 0.90; 95% CI 0.87 to 0.95).
    • only in women (RR 0.82; 0.76 to 0.89)
    • not among men (RR 0.96; 0.91 to 1.01)
  • in women, this increased with the duration of treatment (p < 0.001 for the trend).
    • 1 to 6 months; RR 0.86
    • 18 to 24 months; RR 0.72.
• During periods of medication use, the same individuals
  • 11% lower long-term unemployment than during periods without medication (RR 0.89; 0.85 to 0.94).

A Danish case-control study using registry data from 1995 to 2016 and involving at least 10 years of follow-up found no association between adherence to ADHD medication and the completion of an educational program by age 30. Adherence was associated with a less favorable employment status at age 30, which the authors attribute to the severity of psychiatric comorbidity as a confounder. People with ADHD had higher overall direct healthcare costs, more psychiatric comorbidities, and more concomitant medications than the controls, who were matched 1:4 by age, sex, and place of residence. (Danish case-control study using registry data, E 3)³⁴⁵

In a U.S. cross-sectional analysis of the Medical Expenditure Panel Survey from 2013 to 2019, adults with ADHD who were receiving stimulant treatment and those who were not did not differ in terms of employment status in the adjusted models. Those receiving stimulant treatment were more likely to report social limitations (OR 3.16; 95% CI 1.50 to 6.69) and were less likely to be physically active (OR 0.29; 0.13 to 0.66). In the subgroup analysis, patients who adhered to their medication regimen were more likely to be self-employed than those who did not adhere (OR 2.10; 1.15 to 3.82). The authors note the cross-sectional design of the study and call for longitudinal studies. (U.S. cross-sectional study, n = 1,290, weighted 2,468,186, E 3)³⁴⁶

2.17. Common Types of Commercial Health Insurance¶

Had commercial (private) health insurance instead of government-provided insurance or no insurance coverage (U.S. cross-sectional survey, n = 481; relative differences calculated by the author based on the source data, E 3):²²⁷

• 44.7% of people with ADHD who are not taking medication
• 56.4% of people with ADHD treated with immediate release stimulants (+26.2%)
• 65.2% of people with ADHD treated with sustained-release stimulants (+45.9%)
• 79.4% of people with ADHD treated with a combination of sustained-release and immediate release stimulants (+77.6%)

Due to the cross-sectional design, a selection effect (easier access to medication for those with private insurance) cannot be distinguished from the medication’s effect. The study was funded by Purdue Pharma. (Cross-sectional study, E 3)²²⁷

2.18. Improved Quality of Life¶

In a cross-sectional study (n = 100 children with ADHD, ages 6 to 12, 42 of whom were receiving medication), children with ADHD who were not taking medication reported a lower health-related quality of life than healthy children (d = 0.72). Children receiving medication differed from healthy children only in the “family” domain (d = 0.53). The benefit of medication was significant in the “school” domain (d = 0.39). (Cross-sectional study, E 3)²³¹

 

A meta-analysis of five randomized, placebo-controlled discontinuation studies (n = 1,463) found a decline in quality of life following randomized discontinuation of medication in children and adolescents (SMD = 0.21), but not in adults (SMD = 0.02, n.s.). (Meta-analysis, E 1a)³⁴⁷ Since only patients with prior symptomatic remission were included, the value reflects the effect in responders.

In the ABCD cohort, in which children aged 9 to 10 were supported for five years, half of the children with ADHD took medication during that period. The self-reported trajectories of family conflicts, prosocial behavior, and school experiences could each be classified into three categories (stable and favorable, worsening, and low but improving). Classification was more strongly associated with social and structural characteristics (ethnic discrimination, gender, insurance status, background, and parents’ relationship and employment status) than with medication-taking patterns. Only the use of non-stimulant medications was associated with less favorable outcomes compared to the exclusive use of stimulants. (U.S. longitudinal cohort study, 5-year follow-up, E 2b)³⁴⁸

A component network meta-analysis of 113 RCTs in adults found that stimulants and atomoxetine were the only treatments with short-term efficacy for core symptoms, as confirmed by both self- and raters’ assessments (stimulants SMD -0.39; 95% CI −0.52 to −0.26 and −0.61; −0.71 to −0.51; atomoxetine −0.38; −0.56 to −0.21 and −0.51; −0.64 to −0.37, respectively). According to the authors, the medications were not effective for other endpoints, such as quality of life. They describe the evidence regarding longer-term outcomes as insufficiently studied. Atomoxetine was less well tolerated than placebo (OR 1.43; 1.14 to 1.80), as was guanfacine (OR 3.70; 1.22 to 11.19). (Systematic review with component network meta-analysis, k = 113 randomized controlled trials, N = 14,887 adults, E 1b)³⁴⁹

In a two-year prospective observational study of children and adolescents aged 6 to 18 with ADHD and complex comorbidities (autism spectrum disorder 31%, autistic traits 24%, oppositional symptoms 59%, anxiety 32%, reading, spelling, or language disorder 16%, borderline intellectual disability 17%) showed improvement with individually tailored medication: (Prospective observational study over 2 years, n = 128; no control group, E 2b)³⁵⁰

• the overall clinical impression (SMD as Cohen’s d: 2.28, strong)
• ADHD symptoms (SMD 2.06, strong)
• the “everyday functioning” subscale in the parental assessment was rated as moderate to strong (total score 0.73; learning 0.40; family 0.67).
• Comorbid symptoms, particularly oppositional behavior, depression, and anxiety, improved after just one year.
• Of the 128 participants, 29 (23%) dropped out; of these, 7 did so due to adverse effects, 7 because they moved, and 6 because they no longer needed the medication.
• The most common side effects were loss of appetite, depressed mood, anxiety, irritability, and fatigue.

2.19. Long-term follow-up 18 years after multimodal treatment in childhood¶

Among adults who had received multimodal ADHD treatment (behavioral therapy and/or stimulants) between the ages of 6 and 10, mixed results were found on average 17.7 years later (n = 70 of the original 75, 93% male, ages 22 to 32; no untreated control group, comparison with population norms; the individual results are derived from subsamples of varying sizes: clinical interview n = 44, SCID-II n = 41, questionnaires n = 43 to 55). (Cohort study, E 2b)³⁵¹

 

In the Dutch NeuroIMAGE cohort, adults with childhood ADHD differed after more than 12 years depending on their history of stimulant use during childhood (early and intensive, n = 46; late and moderate n = 63, no stimulants n = 34) in none of the 51 outcome measures across seven domains (psychiatric status, behavior and emotions, school and work, daily functioning, neurocognition, physical health, and use of health care services). Only callous-unemotional traits were more favorable in the treated groups, which may also reflect baseline differences. (Cohort study, n = 143 adults with childhood ADHD out of 324 children followed up, E 2b)³⁵²

2.20. Number of patients needed to treat¶

How many children with ADHD need to be treated with stimulants to prevent one of the following Consequences by young adulthood (Number Needed to Treat, NNT; two naturalistic 10-year follow-up studies of boys and girls, n = 265; Driving simulation: RCT with lisdexamfetamine, n = 61)? (RCT, E 1b)³⁵³ The results did not differ by gender:

• 3 people with ADHD treated = 1 case of repeating a grade avoided
• 3 people with ADHD treated = 1 case of ODD (Oppositional Defiant Disorder) prevented
• 3 people with ADHD treated = 1 case of conduct disorder prevented
• 3 people with ADHD treated = 1 prevented case of at least two anxiety disorders
• 4 people with ADHD treated = 1 case of severe depression prevented (major depression with severe impairment)
• 4 people with ADHD treated = 1 collision avoided in the driving simulator (6 weeks of lisdexamfetamine versus placebo)
• 5 people with ADHD treated = 1 case of bipolar disorder prevented
• 6 people with ADHD treated = 1 person prevented from becoming a smoker
• 10 people with ADHD treated = 1 case of addiction prevented (after adjusting for age: 43)

 

2.21. Improved Adherence to Medication in Type 2 Diabetes¶

Among adults with type 2 diabetes and ADHD, ADHD medication was consistently associated with better adherence to diabetes medication; over a 5-year period, the odds of poor adherence were 0.45 (95% CI 0.30 to 0.67), with consistent findings across all participating countries. ADHD alone was not associated with poorer adherence (pooled odds ratios after 1, 2, and 5 years: 1.01; 1.03; and 1.12), but it was in men (after 5 years, OR 1.23; 1.11 to 1.37). The authors conclude that appropriately treated ADHD does not impair treatment adherence in type 2 diabetes. (Cohort study using population-based databases from seven countries, 2010 to 2020, N = 3,643,197 adults starting oral diabetes medication, of whom n = 88,339 had ADHD, E 2b)³⁵⁴

3. Financial Consequences of ADHD¶

An initial diagnosis at an older age was associated with higher costs for the healthcare system and society than an early diagnosis (Review article; secondary citation of Buitelaar et al. 2022, based on Daley et al. (E 1a): 2019, E 1a).³⁵⁵ (Sibling comparison, E 2b)³⁵⁶

3.1. Treatment Costs for ADHD¶

Treatment costs are the direct costs of therapy, medication, and doctor’s visits for the purpose of ADHD diagnosis and treatment.

The following figures were cited as the annual costs of drug treatment:

3.2. Health Care Costs Associated with ADHD¶

In addition to the direct costs of treating ADHD itself, healthcare costs also include the additional medical expenses associated with comorbidities resulting from ADHD (e.g., substance use disorders) and the increased risk of accidents.

3.2.1. Germany:¶

A routine analysis of statutory health insurance (GKV) data (DAK, diagnoses from 2019/2020; n = 10,033 people with ADHD, 30,093 controls) found that children and adolescents in Germany with newly diagnosed ADHD had total healthcare costs that were 1,505 EUR higher in the first year after diagnosis compared to matched peers of the same age without ADHD (2.86 times higher). (E 2b): Age and comorbidities were significantly associated with costs. (Routine data analysis, E 2b)³⁶⁰ (Cost analysis with a control group, E 2b)³⁶¹

Healthcare costs exceeded 4,000 EUR per person in the year of the initial diagnosis. Comorbidities, healthcare utilization, and costs were already high prior to the initial diagnosis and declined over the following 4 years. Only 32% were initially prescribed ADHD medication; the highest rates of comorbidities and costs were found in this group, suggesting that prescriptions were primarily issued to people with ADHD who were most severely affected. Analysis of German health insurance data (InGef database, approximately 5 million insured individuals from over 60 statutory health insurance plans) that tracked adults for 4 years each before and after their initial ADHD diagnosis. The median age at diagnosis was 35 years; 60% were men. (Retrospective longitudinal analysis of claims data, cohort study, E 2b)³⁶²

The annual healthcare costs for individuals with ADHD were 1,500 EUR higher than those for age- and gender-matched individuals without ADHD (analysis of German health insurance data, approximately 4 million insured individuals per year). The main cost drivers were inpatient treatment, psychiatrists, and psychotherapists. Mood disorders, anxiety disorders, substance use disorders, and obesity occurred significantly more frequently among individuals with ADHD; the resulting additional costs amounted to up to 2,800 EUR annually. Costs increased with age and were slightly higher for women than for men. Among 18- to 30-year-olds, costs dropped significantly—particularly for stimulants and psychiatric care—and rose again after age 30. The authors interpret this, together with the decline in administrative prevalence starting at age 17, as a gap in care during the transition to adulthood. (Health insurance data analysis, n = 25,300 people with ADHD compared to 25,300 age- and sex-matched controls; cost analysis with a control group, E 2b)³⁶³

A meta-analysis of health care costs for children with ADHD found weighted mean direct medical costs of $5,319 per year, compared with $1,152 for children without ADHD—a difference of $4,167. The range of annual healthcare costs per person with ADHD was between $722 and $11,555 (for people without ADHD, $179 to $3,646), and from a societal perspective, between $162 and $18,340 (without ADHD, $0 to $2,540). Children with ADHD utilized more pharmaceutical, psychiatric, and special education services; at the same time, one of the included studies found that unmet health care needs were twice as common among them. Few studies were available on productivity losses, but those that did exist identified them as a significant cost driver. (Meta-analysis, k = 32, E 1a)³⁶⁴

3.2.2. Other Countries¶

3.3. Costs for Family Members in Cases of ADHD¶

Family-related costs are the expenses incurred by parents or legal guardians due to the additional burden resulting from the people with ADHD.

A Danish registry study (data through 2016) found that the annual additional direct and indirect costs, including transfer payments, amounted to 7,997 EUR per partner of an adult person with ADHD. (Cohort study, E 2b)³⁶⁵

A U.S. longitudinal study surveyed parents—when their children were between 14 and 17 years old—about the family burden incurred throughout childhood (direct behavioral costs excluding treatment costs, as well as indirect costs resulting from the burden on caregivers). Families of children with ADHD bore a cost of $15,036 per child (2017 prices), more than five times that of control families ($2,848; n = 56 versus n = 30). The difference persisted after controlling for intelligence, oppositional symptoms, and behavioral problems. (Cohort study, E 2b)³⁸¹

A systematic review of European cost studies (1990 to 2013), applied to the Netherlands (2012 prices), calculated total annual costs for ADHD ranging from 9,860 to 14,483 EUR per child or adolescent (ages 7 to 17) with ADHD. (Cross-sectional study, E 3)³⁷¹ Of this amount, losses in productivity among family members accounted for 1,358 to 3,208 EUR (14% to 22%).

For people with ADHD, the total societal costs for 2018 were reported to be $14,092 per person. (Descriptive Cost Analysis, E 3)³⁷⁷
(E 3): Caregivers of adults with ADHD spent an additional 0.8 hours per week on ADHD-related care compared to caregivers in the general U.S. population. (Descriptive cost analysis, E 3)³⁷⁷ (Survey report, E 3)³⁸² (Survey report, E 3)³⁸³ This resulted in additional annual costs of $6.6 billion. (Descriptive cost analysis, E 3)³⁷⁷

A systematic review of 19 studies estimated annual ADHD-related additional costs in the U.S. (in 2010 USD) ranging from 143 to 266 billion USD (own calculation: 0.95% to 1.77% of U.S. GDP in 2010). (Review, E 1a)³⁸⁴ This figure included spillover costs borne by family members of individuals with ADHD, ranging from $33 billion to $43 billion (0.22% to 0.29% of U.S. GDP; author’s calculation).

An early U.S. estimate put the total ADHD-related additional costs for the year 2000 at 31.6 billion USD. Of this amount: (case-control analysis of claims data, people with ADHD aged 7 to 44 and their relatives under age 65, E 3)³⁸⁵

• $14.2 billion in other healthcare costs incurred by family members
• $12.1 billion in other health care costs for people with ADHD
• $3.7 billion due to lost work time among people with ADHD and their adult family members
• $1.6 billion for ADHD treatment itself

Healthcare costs for family members thus exceeded those for people with ADHD. The calculation is based on billing data from a single large company for the years 1996 through 1998, extrapolated using published prevalence and treatment rates; the authors themselves describe it as preliminary and unadjusted for comorbidities.

3.4. Educational Costs Associated with ADHD¶

A systematic review of European cost studies (1990 to 2013), extrapolated to the Netherlands (2012 prices), calculated total annual costs for ADHD ranging from 9,860 to 14,483 EUR per child or adolescent (ages 7 to 17) with ADHD. (Cross-sectional study, E 3)³⁷¹ Of this amount, educational costs accounted for 6,141 EUR (42% to 62%).

A systematic review of 19 studies estimated annual ADHD-related additional costs in the U.S. (in 2010 USD) ranging from 143 to 266 billion USD (own calculation: 0.95% to 1.77% of U.S. GDP in 2010): (Review, E 1a)³⁸⁴

3.5. Increased Social Benefits¶

A Danish registry study (data through 2016) found that people with ADHD and their partners were more likely to receive social benefits (sick pay or disability benefits). (Cohort study, E 2b)³⁶⁵

At age 25, people with persistent ADHD were 2.72 times more likely to receive social benefits than people with mild ADHD symptoms (OR 2.72; 95% CI 1.62 to 4.57). For ADHD that was limited to childhood, there was no statistically significant difference (OR 1.38; not significant). (ALSPAC birth cohort, N = 6,439, E 2b)³⁸⁷

3.6. Indirect Consequences of ADHD¶

The available cost estimates do not fully capture the indirect costs. A scoping review of 45 studies on the costs of illness among children and adolescents up to age 24 with obesity, asthma, or ADHD (8 of which focused on ADHD) found that while all studies accounted for absenteeism, only 31.1% assessed unpaid work and only 13.3% assessed reduced productivity while at work (presenteeism). 88.9% captured indirect costs incurred by caregivers, and 51.1% also captured productivity losses among the children and adolescents themselves, of which 47.8% assigned a monetary value to these losses. A more standardized methodology would be helpful. (Scoping review of health cost studies, n = 45, including 8 on ADHD; search conducted through October 16, 2024, E 1a)³⁸⁸

3.6.1. Increased absenteeism, unemployment, and disability¶

For people with ADHD, the total societal costs for 2018 were reported to be $14,092 per person with ADHD (manufacturer-funded model calculation). (Descriptive Cost Analysis, E 3)³⁷⁷
Of this, the following accounted for

• Additional costs due to unemployment: 54.4% (7,661 USD per person with ADHD)
  • Adult men with ADHD were 2.1 times more likely to be unemployed than those without the condition. Their unemployment rate was thus 22.1 percentage points higher.
  • Adult women with ADHD were 1.3 times more likely to be unemployed than those without the condition. Their unemployment rate was thus 9.7 percentage points higher.
  • The annual additional costs in the United States totaled $66.8 billion ( $55.8 billion for men and $11 billion for women with ADHD). This represents 0.325% of GDP (own calculation, 2018 U.S. GDP).
• Productivity losses: 23.4% (US$3,299 per person with ADHD) (Descriptive Cost Analysis, E 3)³⁷⁷
  • 13.6 workdays of ADHD-related absences
  • 21.6 workdays lost due to ADHD while at work
  • Lost productivity costs due to ADHD amounting to $28.8 billion ($19.9 billion for men and $8.9 billion for women with ADHD). This represents 0.14% of GDP (own calculation, 2018 U.S. GDP).
  • ADHD was associated with 35.0 days of lost work productivity per year (U.S. workers aged 18 to 44, n = 3,198; 4.2% with ADHD). The loss was distributed as follows (cross-sectional study, E 3)³⁸⁹
    • Blue-collar workers: 55.8 days
    • Service occupations: 32.6 days
    • Technical occupations: 19.8 days
    • Academic/liberal professions (professional): 12.2 days
  • Extrapolated, this amounted to 120 million lost workdays, or 19.5 billion USD in human capital, annually (2005). (Cross-sectional study, E 3)³⁸⁹
  • Employees with ADHD were 3.8 times more likely to be absent due to “unofficial” absences (4.33 vs. 1.13 days) (cohort study, E 2b)³⁷³
  • 22.1 days of annual productivity loss (WHO World Mental Health Survey, 10 countries, n = 7,075 employed individuals, cross-sectional study, E 3)³⁹⁰

 

A Swedish registry study (compulsory school graduates from 1998 to 2008, n = 1.2 million) found among people with ADHD: (cohort study, E 2b)³⁹¹

• 12.2 additional days of unemployment per year (based on 252 working days, this would be 4.84%; own calculation)
• 19-fold increase in the odds of receiving a disability pension (OR 19.0)
  • In most cases, the inability to work was attributable to comorbid intellectual disabilities and developmental disorders; therefore, in our assessment, these conditions are only partially amenable to improvement through more consistent treatment.

In a German case-control study (70 adults clinically diagnosed with ADHD compared with 70 controls matched for age and sex), 28.6% of the people with ADHD were unemployed, compared with 22.9% of the controls (not statistically significant due to the small sample size, p = 0.44). (Case-control study, E 3)³⁹²

 

A Swedish registry study of young adults with a first diagnosis of ADHD between the ages of 19 and 29 found the following over the next 5 years compared with matched individuals without ADHD:

• 10.2 times the risk of receiving a disability pension (HR 10.2; 95% CI 9.3 to 11.2)
• A 2.7-fold increased risk of sick leave lasting more than 90 days (HR 2.7)
• A 1.7-fold increased risk of unemployment lasting more than 180 days (HR 1.7).

Compared to siblings without ADHD, there was

• 9.0 times the risk of receiving a disability pension
• 2.5 times the risk of being on sick leave for more than 90 days
• 1.0 times the risk of being unemployed for more than 180 days

Comorbidities accounted for about one-third of the association with disability benefits and a smaller proportion of the associations with the other outcomes. (Register-based cohort, n = 9,718, E 2b)³⁹³

21% of the same cohort received a disability pension within 5 years. Their risk was elevated regardless of gender: (register cohort, n = 9,718, E 2b)³⁹⁴

• 1.54 times higher among those who were younger at the time of diagnosis (HR 1.54)
• 1.97 times for fewer than 10 years of schooling (HR 1.97)
• 2.54 times if there is no earned income at the start (HR 2.64)
• 2.48 times for sick leave lasting more than 90 days (HR 2.48)
• 2.16 times higher in cases of comorbid schizophrenia or psychosis (HR 2.16),
• 1.87 times higher in cases of comorbid AS (HR 1.87)
• 1.37 times higher in cases of comorbid anxiety disorder (HR 1.34)

Among young workers in Sweden (ages 19 to 29), 20% of people with ADHD and 59% of people without ADHD did not experience a single day of unemployment, sick leave, or disability benefits in the 5 years following their initial ADHD diagnosis. The incidence rate of such days was 2.7 to 3.1 times higher among those with ADHD; after adjusting for sociodemographic and health-related characteristics, it was 1.4 to 1.7 times higher. There were no significant differences across sectors (manufacturing, construction, trade, finance, health and social services, education). (Register-based cohort, n = 6,030 with ADHD compared with 10 matched controls each, E 2b)³⁹⁵

3.6.2. Premature Mortality¶

For adults with ADHD, the total societal costs for 2018 were reported to be $14,092 per person with ADHD. (Descriptive Cost Analysis, E 3)³⁷⁷
In a Danish cohort (n = 1.92 million), the overall mortality rate among individuals with ADHD was doubled (MRR 2.07), and 4.25 times higher among those diagnosed in adulthood. After excluding comorbid ODD, CD, and substance use disorders, the MRR was 1.50. Accidents were the most common cause of death. (Cohort study, E 2b)³⁹⁶
Schein et al. based their cost analysis on an annual mortality rate for adults with ADHD that was approximately 50% higher and, based on this, calculated a total societal loss of productivity for 2018 of approximately 3.2 billion USD (0.016% of 2018 GDP; own calculation). (Descriptive Cost Analysis, E 3)³⁷⁷

 

3.6.3. Income Disparities Among People with ADHD¶

3.6.3.1. Decreased household income (from -16.1% to -24.4%), lower net worth (up to -75%, projection)¶

A long-term study spanning approximately 20 years involving 604 participants (364 with childhood ADHD, 240 controls) showed that, at age 30, people with ADHD had lower incomes and were more financially dependent on their parents than people without ADHD. This was true even when the DSM criteria were no longer met. (E 2b): When extrapolated over their working lives, men with ADHD had a lifetime income that was $1.27 million lower and net worth at retirement that was up to 75% lower than that of non-affected individuals (projection, not observed). (Cohort study, E 2b)⁴⁰¹ In addition, adults with ADHD who had not been diagnosed or treated during childhood earned less than their unaffected same-sex siblings and incurred 20,134 EUR higher costs per person in 2010 (n = 460 pairs of siblings, sibling comparison, E 2b).³⁵⁶

A Swedish registry study (compulsory school graduates from 1998 to 2008, n = 1.2 million) found that people with ADHD had an annual income that was 17% lower. (Cohort study, E 2b)³⁹¹

3.6.3.2. Taxes and social security contributions resulting from reduced income¶

To date, we are aware of only one study that calculated the resulting loss of tax and social security revenue for Germany.
The estimated lifetime net tax and social security revenue for a person born in 2010 who does not have ADHD was found to be approximately 80,000 EUR higher than that of a person with untreated ADHD. For the 2010 birth cohort (n = 31,844 people with ADHD), this amounted to 2.5 billion EUR. ADHD interventions that resulted in a modest improvement in educational attainment led to fiscal benefits through higher tax revenues over the individual’s lifetime.
For every euro spent on a new ADHD intervention, 1.39 EUR in discounted net tax revenue and 3.02 EUR in discounted gross tax revenue were calculated. (Cohort study, E 2b)⁴⁰⁵ A methodological study explains the fiscal analysis framework from the government’s perspective without providing ADHD figures for Germany.⁴⁰⁶

A second study by the same research group estimated the loss of lifetime earnings in Germany resulting from lower educational attainment at an average of 92,000 EUR per person with ADHD. For a single birth cohort of 31,864 people with ADHD diagnosed in childhood, this resulted in a societal loss of 2.93 billion EUR. The authors’ cost-benefit analysis showed that even a moderately effective intervention justifies substantial investment. The figures are based on model assumptions derived from human capital theory, not on observed income trajectories. (Model calculation for Germany) (Cohort study, E 2b)⁴⁰⁷

 

3.7. Total Economic Costs¶

(E 1a): A systematic review on the monetization of health outcomes in children, based on Pelham et al. (2007),(Review, E 1a)⁴⁰⁸ estimated the discounted lifetime costs of a case of ADHD lasting from age 5 to 17 in the United States—including healthcare, education, and criminal consequences—at $182,045 (2015 prices). (Systematic review, E 1a)⁴⁰⁹

An Australian study estimated the total social and economic costs of ADHD in 2018–2019 at $12.76 billion (range: $8.40 billion to $17.44 billion), with an annual cost per person with ADHD of $15,664. (Cross-sectional study, E 3)⁴¹⁰ Of the total financial costs, the following were attributable to

• Productivity costs: 81%
• Welfare losses due to tax and transfer distortions (deadweight losses) 11%
• Health care costs: 4%
  The loss in well-being was further estimated at 5.31 billion USD.

4. ADHD treatment is economically beneficial: reduced need for treatment, lower healthcare costs (-56% to -82%)¶

Of 29 complete health economic analyses, nearly all of those that compared medication or psychotherapy with no treatment, a placebo, or usual care found that the treatment had a favorable cost-benefit ratio. The cost-effectiveness of stimulants in children and adolescents is best documented. Evaluations involving adults, psychosocial interventions, long-term follow-up, and no manufacturer funding are rare (Systematic Overview, k = 29, E 2b; Systematic Review, E 1a)⁴¹⁸

An Israeli model estimated the costs per adult person with ADHD—resulting from lower educational attainment, higher rates of criminal involvement, traffic accidents, and substance abuse, at $289,969, and the cost of optimal treatment from childhood through adulthood at $41,667. This resulted in a cost-benefit ratio of 7.02; assuming treatment success in only half of the cases, the ratio was 3.51. The calculation is based on an assumed adult prevalence of 4% and on estimates from the literature, not on individual follow-up data. (Model calculation for the Israeli population; cross-sectional study, E 3)⁴¹⁹

4.1. Economic Benefits of ADHD Medication¶

A manufacturer-funded model estimate, based on a driving simulator study, (43% fewer collisions with a once-daily sustained release amphetamine formulation compared to placebo) estimated the lifetime accident-related cost savings at an assumed drug cost of $80 per 30 days (RCT, manufacturer-funded, E 1b)²⁷⁹

• $332,660 compared to people with ADHD who have not been treated
• $194,278 compared to standard treatment (a combination of short-, medium-, and long-acting stimulants and non-stimulants)

A systematic review of comprehensive health economic analyses from 2010 to 2020 identified 10 studies of moderate to good quality on ADHD, including 8 on medications and 2 on psychosocial interventions. Parent training programs for younger children were cost-effective, as were various combinations of stimulants and non-stimulants for children, in each case measured against the willingness-to-pay thresholds specified in the original studies. (Systematic review, k = 12, of which 10 on ADHD, E 1a)⁴²⁰

A review of model-based health economic analyses on developmental disorders identified 12 studies, 6 of which focused on ADHD. Four reported cost savings, three reported an improvement in quality of life, and three reported an increase in costs. Most studies used a societal perspective in their calculations; none assessed the impact on families and caregivers. (Scoping review, k = 12, of which 6 focused on ADHD, E 1a)⁴²¹

In the U.S. MTA study, treatment costs varied by a factor of 4. Medication was the least expensive option, followed by behavioral therapy and a combination of the two. Medication was more effective and more expensive than standard community-based care, but more cost-effective than combination therapy and behavioral therapy alone. For children with multiple comorbidities, combination treatment was more cost-effective—measured in terms of cost per additional normalized child—under certain assumptions. (Randomized trial, N = 579 children with ADHD-C aged 7 to 9.9 years, 14 months of treatment, E 1b)⁴²²

In a sequential randomized trial, one school year of treatment that began with low-dose behavioral modification (large-group parent training) cost $961, compared to $1,669 when it began with a low dose of stimulants, regardless of whether the initial treatment was later intensified or supplemented with the other treatment modality. Since the results of the main study showed that starting with behavioral modification was equally effective or more effective, the authors consider this treatment approach to be the more cost-effective option. (Randomized study with sequential assignment, N = 146 children, E 1b)⁴²³

In contrast, a health economic analysis of actual care practices in the Netherlands found no statistically significant differences in costs and outcomes between children who were treated with medication and those who were not. The probability that medication treatment is cost-effective was 55% at a willingness-to-pay threshold of 80,000 EUR per quality-adjusted life year and 36% at 20,000 EUR. The authors interpret this as a lack of clear evidence for the cost-effectiveness of medication under real-world conditions. (Prospective observational study over 12 months, N = 209 children aged 5 to 12 years, of whom n = 108 received medication and n = 101 did not, propensity score matching, E 2b)⁴²⁴

A review of cost-effectiveness studies found that, in 2004, methylphenidate had cost-utility ratios ranging from 15,509 to 27,766 USD per quality-adjusted life year gained. In the included studies, children with ADHD incurred annual medical costs that were $503 to $1,343 higher than those of matched controls, while adults with ADHD incurred costs ranging from $4,929 to $5,651, compared with $1,473 to $2,771 for matched controls. (Review, k = 22 studies, including conference abstracts and reports, E 3)⁴²⁵

Among people with ADHD who had been taking oral stimulants for at least 3 months, those with low or moderate adherence had, after adjustment, significantly more absences from work as well as higher absenteeism-related and total indirect costs than those with high adherence (p < 0.01 in each case). (Online survey, N = 602 adults with a self-reported ADHD diagnosis, of whom n = 395 had low or moderate adherence and n = 207 had high adherence; authors employed by the manufacturer, E 3)⁴²⁶

A Markov model based on the MTA data projected the 14-month study period forward by 10 years and evaluated the treatments based on how many years of life they prevented from being lost to serious crime. The annual cost to society of a serious offense was USD 12,370 per year. The net present value was

• $95,449 for medication (cost: $0.62 per day)
• $88,553 for behavioral therapy ($3.18 per day)
• $90,536 for the combination (medication and behavioral therapy) ($3.53 per day)
• $98,660 for standard community care (cost: $0.52 per day)

Accordingly, all three active treatment conditions performed worse than the control condition as long as crime prevention was the only benefit factor considered. The estimates remained stable for willingness-to-pay thresholds ranging from 0 to 50,000 USD. (Model calculation based on N = 448 children aged 7 to 10 from the MTA study, E 3)⁴²⁷

4.2. Economic Benefits of Non-Pharmacological Treatment for ADHD¶

For two behavioral therapy programs for children with predominantly inattentive ADHD, the total costs per child were $1,559 for the program integrated through the home and school (CLAS), $710 for parent training alone, and $0 for usual care. The additional costs per resolved case were $3,997 (CLAS versus standard care), $3,227 (parent training versus standard care), and $4,994 (CLAS versus parent training). After streamlining the CLAS program, the cost difference compared to parent training decreased to $29 per resolved case. The cost of CLAS was significantly lower than the annual cost of an unresolved ADHD case. (Randomized trial, E 1b)⁴²⁸

4.3. Economic Benefits of Measures for Caregivers¶

According to a review of 20 health economic analyses from high-income countries (6 on ADHD, another 5 on behavioral problems including ADHD), interventions for caregivers of children with developmental disorders showed:

• 9 studies found the intervention to be cost-effective
• 5 as cost-effective

Methodological weaknesses primarily concerned cost data collection, outcome measurement in children, and the chosen time horizon. (Scoping review, k = 20, of which 11 were ADHD-related, E 1a)⁴²⁹