Changes in ADHD Symptoms in Adults

The DSM-IV criteria for ADHD describe the symptoms in children and do not specifically address those in adults. (Full text not available to us, E 4)¹
(E 4): The symptoms of ADHD in adults differ significantly from those of ADHD in children. (Full text not available to us, E 4)² (Full text not available to us, E 4)³ In particular, hyperactivity decreases significantly. Symptoms such as inner restlessness, an inability to relax, and the “need to be constantly active” come to the fore.

The following findings were identified regarding mental restlessness in adults:

• In adults with ADHD, racing thoughts and mind wandering (daydreaming) were identified as two separate factors. The “racing thoughts” factor was primarily predicted by emotional lability (β = 0.25, p = 0.03; explained variance of all symptom facets: 20.3%). Mind wandering was not associated with either ADHD symptoms or impairment. The authors view racing thoughts as a plausible explanation for mental restlessness in adults with ADHD. (Cross-sectional study, n = 84, E 3.)⁴
• In adults with more hyperactive ADHD symptoms—but not more inattentive ones—greater variability in thought content was observed, though only when thought control was low (thinking aloud without a specified topic, unintentional digressions in daily life over 7 days) (Cross-sectional study with daily questionnaires via smartphone, n = 91, E 3.)⁵

A twin study reported a linear decline (DSM-IV symptom scale, maternal assessment) among children and adolescents aged 8 to 16 years for: (cohort study, twins, N = 8,395 twin pairs, 8 years, E 2b.)⁶

• Hyperactivity/impulsivity decreased from 6.0 to 2.9 points (roughly halved)
• Inattention: from 5.8 to 4.9 points

However, with regard to inattention, there is also discussion of a change over time toward executive dysfunction. (Narrative review, E 4)⁷

ADHD symptoms decreased in the general population from childhood through middle adulthood. The SDQ score for hyperactivity/inattention declined most sharply before age 8 (by 0.157 points per year, 95% CI 0.144 to 0.170), while DSM-based scores declined most sharply between the ages of 14 and 17 (by 1.32% per year, 1.17 to 1.47). The trends differed significantly across the cohorts. Women consistently had lower scores than men. This gender difference decreased with age because scores declined more sharply among men. (Pooled analysis of 5 birth cohorts, n = 29,519, ages 3 to 45, E 2b.)⁸

Hyperactivity (measured here using infrared motion sensors during the performance of a cognitive control test) was still a better discriminator between affected and unaffected adults than attention problems. Even among people with the predominantly inattentive ADHD-I subtype, significantly increased hyperactivity/motor restlessness was found compared to people without ADHD. (Case-control study, N = 100, n = 40, E 3)⁹

Among 55- to 79-year-olds, the QbTest factors distinguished people with ADHD from those who do not have ADHD as follows: (case-control study, N = 209, n = 97, author(s) employed by the manufacturer, E 3.)¹⁰

• Hyperactivity d = 0.82
• Inattention d = 0.47
• Impulsivity d = 0.15, no distinction

Barkley has compiled a list of typical symptoms of ADHD in adults and verified them through research. Physical hyperactivity decreases significantly, while inner restlessness becomes more apparent. Inattention also decreases significantly.

The following symptoms are most common in adults:

• Inattention (remits less frequently than hyperactivity and impulsivity) (cohort study, n = 128, 4 years, E 2b.)¹²
• Hyperactivity (which remits more frequently than inattention) (cohort study, n = 128, 4 years, E 2b.)¹²
• Impulsivity (remits more frequently than inattention) (cohort study, n = 128, 4 years, E 2b.)¹²
• Emotional overreactivity (more pronounced in adults) (Full text not available to us, E 4)¹³
• Emotional lability (full text not available to us, E 4)¹⁴
• Disorganization (full text not available to us, E 4)¹⁴

Hyperactivity transforms into inner restlessness in adulthood (Barkley). We suspect that this is not so much a transformation as it is that, once the hyperactivity subsides, the symptoms of inner tension become more clearly visible. (ADxS assessment)

Among 128 boys with ADHD, those aged 18 to 20 no longer met the full set of symptoms (syndromic remission, as shown in the figure) for: (Cohort study, n = 128, 4 years, E 2b.)¹²

• Hyperactivity: about 70%
• Impulsivity: about 70%
• ADHD overall (full-spectrum) in over 60% of participants, assessed five times over a 4-year period (cohort study, n = 128, 4 years, E 2b.)¹⁵
• Inattention: about 40%

These figures represent remission rates, not the extent of symptom reduction. Inattention persisted more frequently than hyperactivity and impulsivity across all definitions of remission. (Cohort study, n = 128, 4 years, E 2b.)¹²

(Cohort study, n = 128, 4 years, E 2b.)¹⁵ Inattention, hyperactivity, and impulsivity decreased with age. Inattention also went into remission later than hyperactivity and impulsivity. The proportion of patients in remission depended heavily on the definition used. Only 10% had fewer than 5 symptoms and no impairment (functional remission, GAF above 60) between the ages of 18 and 20. (Cohort study, n = 128, 4 years, E 2b.)¹⁵

However, a reduction in attention problems among adults is consistent with our observations (at least among quite a few people with ADHD). (ADxS experience)

In a nonclinical sample (ages 16 to 54), perseveration errors in a virtual reality test (which are associated with impulsivity) predicted only retrospectively reported ADHD symptoms, but not current ADHD symptoms. (Cross-sectional study, n = 156, E 3.)¹⁶

(E 3): Other sources, however, report that with increasing age,

• an increase in inattention in:
  • Among 55- to 79-year-olds, inattention scores on the QbTest increased with age. It was not demonstrated that this is specific to ADHD; the authors recommended age-adjusted normative values. (Case-control study, N = 209, n = 97, author(s) employed by the manufacturer, E 3.)¹⁰
  • Among adults aged 18 to 62 with ADHD, there was a negative correlation between age and the TOVA attention score (cross-sectional study, retrospective, n = 100, E 3.)¹⁷
  • Adults aged 16 to 50 with ADHD (grouped by decade of life, matched according to the severity of ADHD in childhood) showed an increase in inattention as self-reported (cross-sectional study, n = 439, E 3.)¹⁸
• a decrease (adults aged 16 to 50 with ADHD, grouped by decade of life, matched according to the severity of childhood ADHD) in: (cross-sectional study, n = 439, E 3.)¹⁸
  • all ADHD symptoms as observed by others
  • Deficits in selective attention (neuropsychological test)
  • Deficits in response inhibition (neuropsychological test)

Depressive symptoms increased slightly with age. The authors speculated that accompanying affective symptoms might partly explain the subjectively perceived deterioration. (Cross-sectional study, n = 439, E 3.)¹⁸

Among individuals aged 60 to 94, ADHD was associated with poorer cognitive performance only in the area of attention/working memory (but not in executive functions, processing speed, or memory). After adjusting for depressive symptoms, this association was no longer significant. (Cross-sectional study, N = 231, E 3.)¹⁹

A twin study identified two distinct developmental patterns for hyperactivity/impulsivity and for inattention in children and adolescents (as assessed by parents at ages 8 to 9, 13 to 14, and 16 to 17): (Cohort study, twins, N = 1,450 twin pairs, E 2b.)²⁰

• Hyperactivity/Impulsivity
  • was low, remained low
  • was high, then decreased
• Inattention
  • was low, remained low
  • was high and continued to rise

Combined, these resulted in four groups (low/low, predominantly hyperactive, predominantly inattentive, combined), which were associated with different adjustment problems in early adulthood. (Cohort study, twins, N = 1,450 twin pairs, E 2b.)²⁰

Some changes can also be measured neurophysiologically.

In a cross-sectional study, older adults with ADHD (ages 60 to 75) showed a similarly impaired quality of life as younger adults with ADHD (ages 18 to 45). The only exception was mental health, which was better among the older adults. Compared to non-affected individuals of the same age, quality of life was significantly worse in all areas (large effect sizes). This suggests that there is no significant improvement as adults age; however, as a cross-sectional finding, it does not provide evidence of long-term trends. (Cross-sectional study, N = 158, E 3.)²⁹

Reif, on the other hand, assumes that inattention decreases only slightly, while emotional dysregulation becomes more pronounced in adulthood. (E 4)³⁰
We believe that emotional dysregulation is generally accepted as a normal trait in children (“immaturity”), whereas it is perceived as inappropriate in adults. We therefore wonder whether emotional dysregulation actually increases in adults with ADHD, or whether children with ADHD may already exhibit emotional instability that is still considered acceptable and therefore not recognized as a symptom of ADHD (just as we suspect is the case with internal tension, which becomes apparent in adulthood after physical hyperactivity subsides). We intend to investigate this in greater depth. (ADxS Assessment)

Adults with ADHD exhibited greater emotional dysregulation compared to healthy individuals in terms of: (Meta-analysis, k = 13, N = 2,535, E 3.)³¹

• emotional lability g = 1.20 (95% CI 0.57 to 1.83)
• general emotional dysregulation, g = 1.17 (95% CI 0.70 to 1.64)
• negative emotional reactions g = 1.12 (95% CI 0.57 to 1.68)
• Emotion recognition g = 0.63 (95% CI 0.40 to 0.85)

The severity of ADHD symptoms correlated with general emotional dysregulation (r = 0.54). (Meta-analysis, k = 13, N = 2,535, E 3.)³¹

Older adults with ADHD (mean age 68 years) reported a similar number of ADHD symptoms currently (9.91 out of 18) as they did retrospectively for their childhood (10.43). The ratio of inattention symptoms to hyperactivity/impulsivity symptoms also remained the same and did not change any differently than in peers without ADHD. (Cross-sectional study, retrospective data, N = 231, n = 23, industry-funded, E 3.)³²

The factorial structure of ADHD symptoms in adulthood showed:

• 5 factors of the CAARS 2 (inattention/executive dysfunction, hyperactivity, impulsivity, emotional dysregulation, negative self-concept) with measurement invariance (configurational, threshold, metric, scalar) in self- and raters’ assessments across early (ages 18 to 24), young (ages 25 to 39), and middle adulthood (ages 40 to 64). The latent structure of ADHD thus remained stable into adulthood. (Cross-sectional study, n = 1,684 (self-report), n = 1,606 (rater report), manufacturer-funded, author(s) employed by the manufacturer, E 3.)³³
• In adults aged 50 and older, hyperactivity and impulsivity as separate symptom factors under a general ADHD factor (cross-sectional study, n = 1,562, E 3.)³⁴

(E 2b): ADHD symptoms decreased overall from childhood into adulthood. (Cohort study, n = 471, E 2b.)³⁶ (Narrative review, full text not available to us, E 4.)³⁷ They decreased equally in boys and girls, with the rate of decrease accelerating with age. Girls had slightly more symptoms across all age groups (about 0.1 standard deviations). Comorbid disorders were more stable in girls than in boys. (Cohort study, n = 471, E 2b.)³⁶ However, according to a Greek review, the impairment caused by the Disorder persists. (Narrative review, full text not available to us, E 4.)³⁷

(E 2b): Hyperactivity decreased more markedly from childhood into adulthood than inattention. (Cohort study, n = 141, of whom 101 had ADHD, 5.9 years, E 2b.)³⁸ (Cohort study, n = 1,374, 16 years, E 2b.)³⁹ (Cohort study, n = 186, E 2b.)⁴⁰ (Narrative review, E 4.)⁴¹ (Narrative review, E 4.)⁴² (Narrative review, E 4.)⁴³ (Narrative review, full text not available to us, E 4.)³⁷ (Narrative review, E 4.)⁴⁴

(E 2b): The core symptoms decreased to varying degrees

• From childhood through adolescence (ages 11 to 16), all three were significant, with hyperactivity being the most pronounced, and a decrease (at home) observed for: (cohort study, n = 186, E 2b.)⁴⁰
  • Hyperactivity in self-assessment: d = 0.74
  • Inattention in self-assessment: d = 0.62
  • Impulsivity in self-assessment: d = 0.39
  • Hyperactivity in the maternal assessment: d = 0.34
  • Inattention in the mother’s judgment: d = 0.29
  • Impulsivity in the maternal assessment: d = 0.16
• between the ages of 6 and 20, according to a French review, in terms of the average number of symptoms for: (Narrative review, E 4.)⁴⁴
  • Hyperactivity by 50%
  • Impulsivity by 40%
  • Inattention by 20%

In a population-based birth cohort, symptoms of hyperactivity/impulsivity (combined assessments by mothers at 1.5 to 8 years of age, teachers at ages 6 to 13, and self-reports at ages 10 to 17) decreased overall from ages 1.5 to 17, while inattention symptoms remained constant. Increasing trends were found for: (Cohort study, n = 1,374, 16 years, E 2b.)³⁹

• Hyperactivity/Impulsivity 21.4%
• Inattention 20.2%
• both at the same time: 11.6%

From adolescence to young adulthood, the hyperactive-impulsive symptoms of ADHD improved the most, while inattention barely changed. (Cohort study, n = 141, of whom 101 had ADHD, 5.9 years, E 2b.)³⁸

Inattention persisted more consistently from childhood through young adulthood than hyperactivity and impulsivity. On average, the number of inattention symptoms did not fall below the full diagnostic threshold until the age of 20, whereas the number of hyperactivity and impulsivity symptoms had already fallen below that threshold between the ages of 9 and 11. The persistence of ADHD thus depends more on ongoing inattention than on overt hyperactivity or impulsivity. (Narrative review, E 4.)⁴¹

During the transition from childhood to adulthood, hyperactivity and impulsivity tend to decrease, while inattention, restlessness, disorganization, and executive function deficits persist to a greater extent. (Narrative review, E 4.)⁴²

As children develop, younger children tend to exhibit symptoms of hyperactivity and impulsivity, while in middle childhood, inattention becomes more prominent. In late adolescence and adulthood, inattention persists primarily, while objective signs of motor hyperactivity decrease. More pronounced hyperactivity/impulsivity is more likely to persist in people with ADHD who have severe comorbidities such as substance abuse and antisocial behavior. (Narrative review, E 4.)⁴³

According to a Greek review, physical hyperactivity decreases significantly starting in adolescence and especially in adulthood, while inattention and impulsivity persist. (Narrative review; full text not available to us; E 4.)³⁷

The three DSM-5 symptoms of impulsivity do not adequately capture impulsivity. The UPPS-P scale includes five domains of impulsivity, most of which (negative and positive urgency, lack of planning, lack of perseverance) are elevated in ADHD. The observed decline in impulsivity among adults could therefore be partly attributable to the measurement method. (Comment, E 4.)⁴⁵

According to parental reports, behavioral problems—ranging from hyperactivity in childhood to adolescence—decreased, in some cases more markedly than in the control group (impulsivity/hyperactivity and learning problems decreased only among the hyperactive children). However, on all parental scales, the hyperactive children remained significantly more problematic than the control group (on average, nearly 1 standard deviation). Parental ratings of impulsivity/hyperactivity correlated only weakly over 8 years (r = 0.25). (Cohort study, N = 169, n = 108, 8 years, E 2b.)⁴⁶

(E 2b): People with ADHD rated their symptoms as less severe than their parents did. (Cohort study (follow-up to an RCT), n = 515 with ADHD, n = 258 without ADHD, age 16, E 2b.)⁴⁷ (Cohort study, n = 186, E 2b.)⁴⁰ Young adults with childhood ADHD showed a discrepancy of d = 0.60 compared to the control group. (Cohort study (follow-up to an RCT), n = 515 with ADHD, n = 258 without ADHD, 16 years old, E 2b.)⁴⁷ The adolescents reported their symptoms during childhood and adolescence as less severe than their mothers did, with moderate to large effect sizes during adolescence. (Cohort study, n = 186, E 2b.)⁴⁰ Adults with ADHD tend to downplay the number and severity of their symptoms and complain only about their Consequences. (Narrative review, E 4.)⁴²

(E 2b): Adolescents and adults with ADHD were impaired or symptomatic even when their symptoms fell below the full DSM symptom threshold. The authors considered lower or age-specific criteria to be justified. (Cohort study, n = 140 with ADHD, n = 88 controls, approximately 10 years, E 2b.)⁴⁸ (Cohort study, N = 189, n = 123, 8 years, E 2b.)⁴⁹ (Cross-sectional study, sibling families, n = 9,380, ages 7 to 29, E 3.)⁵⁰ Young women who had ADHD as girls and met only one developmentally-related lower symptom criterion in adulthood were similarly impaired as women with a full DSM-IV diagnosis and significantly more so than women without ADHD. (Cohort study, n = 140 with ADHD, n = 88 controls, approximately 10 years, E 2b.)⁴⁸ The DSM-III-R symptom thresholds were too high for adolescents and excluded 12 to 17% of adolescents with statistically significant childhood ADHD. (Cohort study, N = 189, n = 123, 8 years, E 2b.)⁴⁹ Individuals with a lifetime diagnosis of ADHD continued to exhibit higher ADHD symptom scores than the general population even as young adults, even if they no longer met the full symptom criteria. (Cross-sectional study, sibling families, n = 9,380, ages 7 to 29, E 3.)⁵⁰

(E 3): Among young adults, inattentiveness symptoms in particular predicted impairment. (Cross-sectional study, birth cohort, n = 3,574, E 3.)⁵¹ (Cross-sectional study, birth cohort, n = 4,000, E 3.)⁵² Among individuals in their early 30s, the adult ADHD phenotype was predominantly characterized by inattention. Of the 7 symptoms that independently predicted impairment, 5 were related to inattention. (Cross-sectional study, birth cohort, n = 3,574, E 3.)⁵¹

The best or standard-based symptom thresholds were as follows:

• Inattention
  • with 5 symptoms to predict impairment in 18- to 19-year-olds (cross-sectional study, birth cohort, n = 4,000, E 3.)⁵²
  • with 5 symptoms (along with 4 symptoms of hyperactivity/impulsivity) as a lower developmental criterion in young women with childhood ADHD (cohort study, n = 140 with ADHD, n = 88 controls, approximately 10 years, E 2b.)⁴⁸
  • for 4 symptoms (at least moderate impairment) in individuals around 30 years of age, with low discriminatory power, sensitivity 71%, specificity 59%, AUC = 0.72 (0.70 to 0.74) (Cross-sectional study, birth cohort, n = 3,574, E 3.)⁵¹
• Hyperactivity/Impulsivity
  • with 4 symptoms to predict impairment in 18- to 19-year-olds (cross-sectional study, birth cohort, n = 4,000, E 3.)⁵²
  • for 4 symptoms (along with 5 inattention symptoms) as a lower developmental criterion in young women with childhood ADHD (cohort study, n = 140 with ADHD, n = 88 controls, approximately 10 years old, E 2b.)⁴⁸
  • for 4 symptoms in people around 30 years of age, with low discriminatory power: sensitivity 49%, specificity 60%, AUC = 0.56 (0.53 to 0.59) (Cross-sectional study, birth cohort, n = 3,574, E 3.)⁵¹
• all ADHD symptoms according to DSM-III-R in adolescents, defined as 6 rather than 8 out of 14 symptoms, based on normative values (2 standard deviations above the mean of age-matched controls) (cohort study, N = 189, n = 123, 8 years, E 2b.)⁴⁹ For conduct disorder, the norm-referenced cutoff was 2 rather than 3 symptoms

(E 3): The prevalence of ADHD was

• as the prevalence of current ADHD: (cross-sectional study, families with siblings, n = 9,380, ages 7 to 29, E 3.)⁵⁰
  • 11.7% among children (ages 7 to 12), DSM-IV-like
  • 9.7% among adolescents (ages 13 to 17), DSM-IV-like
  • 9.2% among 7- to 29-year-olds overall, DSM-IV-like (male-to-female ratio of 2.28 to 1)
  • 6.4% among young adults (ages 18 to 29), DSM-IV-like
  • 3.55% (2.98 to 4.12) among 18- to 19-year-olds in a Brazilian birth cohort according to the DSM-5 (cross-sectional study, birth cohort, n = 4,000, E 3.)⁵²
  • 2.8% among 18- to 19-year-olds in a Brazilian birth cohort according to DSM-IV (cross-sectional study, birth cohort, n = 4,000, E 3.)⁵²
• ASRS scores in the general population that indicate a positive ADHD screening result or are consistent with an ADHD diagnosis: (cross-sectional study, n = 3,443, E 3.)⁵³
  • 6.2% of people aged 47 to 54 (cross-sectional study, n = 2,091, E 3.)⁵⁴
  • 6.2% of people aged 48 to 52
  • 2.2% of people aged 68 to 74, who reported significantly fewer ADHD symptoms than those aged 48 to 52 from the same population

ADHD symptoms were associated with symptoms of depression and anxiety, as well as with poorer employment status, financial stress, poorer relationship quality, health, and well-being—even when only a few symptoms were present. Inattention had a stronger effect than hyperactivity and remained significant after controlling for anxiety and depression. There were no differences between men and women. (Cross-sectional study, n = 2,091, E 3.)⁵⁴

The stability of ADHD subtypes from childhood and adolescence (ages 7 to 19) into young adulthood was low over a 5-year period. Subtype concordance after 5 years was as follows: (cohort study, twins, n = 708, 5 years, E 2b.)⁵⁵

• clinically significant subtypes defined on a population basis: 14.3 to 35.3%
• DSM-IV subtypes: 11.1 to 24.0%

(E 2b): Neuropsychological functions in people with ADHD developed largely in parallel with those of people without ADHD up through young adulthood, resulting in persistent deficits. (Cohort study, n = 53 with ADHD, n = 50 controls, 7 years, E 2b.)⁵⁶ (Cohort study, n = 228, approximately 10 years, E 2b.)⁵⁷ (Meta-analysis, k = 25, E 3.)⁵⁸ From early adolescence (12.8 years) through young adulthood (19.8 years), people with childhood ADHD (CANTAB) caught up only in spatial working memory. In young adulthood, nearly all of the assessed functions remained impaired. The extent of symptom remission did not correlate linearly with the extent of neuropsychological improvement. (Cohort study, n = 53 with ADHD, n = 50 controls, 7 years, E 2b.)⁵⁶ In girls with ADHD, sustained attention and global executive functions improved more significantly than in controls through young adulthood; in contrast, working memory and response inhibition improved only to the same extent, so deficits in these areas persisted. (Cohort study, n = 228, approximately 10 years, E 2b.)⁵⁷ On the Stroop test, people with ADHD aged 9 to 41 were, on average, 1.14 times slower than age-matched peers without ADHD in both the color and color-word conditions. The interference effect was not greater in ADHD, and the age-related maturation of processing speed proceeded at the same rate in people with ADHD and in people without ADHD. (Meta-analysis, k = 25, E 3.)⁵⁸

(E 2b): Executive deficits persisted predominantly in:

• 79% (27 out of 34) of girls with ADHD over the course of 5 years into adolescence (at least 2 impaired executive function tests, Kappa 0.36) (Cohort study, N = 260, n = 138, 5 years, E 2b.)⁵⁹ Girls with ADHD were more severely impaired than controls in all neuropsychological domains except set-shifting
• 69% (18 out of 26) of boys with ADHD from age 7 through young adulthood (at least 2 tests 1.5 standard deviations below controls, Kappa 0.41, p < 0.001, sensitivity 55%, specificity 85%, negative predictive value 75%) (cohort study, n = 85, age 7, E 2b.)⁶⁰ 15 of 59 boys without initial deficits developed new executive function deficits at follow-up

Adults with ADHD performed worse than those without ADHD, particularly on complex attention tasks, in the following areas: (Meta-analysis, k = 25, N = 3,442, E 3.)⁶¹

• Trail Making Test B (focused attention) (k = 9) d = 0.72 (95% CI 0.51 to 0.92)
• CPT confusion error (inhibition) (k = 4) d = 0.61 (95% CI 0.14 to 1.09)
• CPT omission errors (sustained attention) (k = 4) d = 0.49 (95% CI 0.11 to 0.86)
• Stroop color-word card (k = 9) d = 0.47 (95% CI 0.21 to 0.73)
• Number-Symbol Test (k = 12) d = 0.46 (95% CI 0.26 to 0.65)
• Trail Making Test A (simple attention) (k = 11) d = 0.38 (95% CI 0.12 to 0.65)
• Stroop interference (k = 9) d = 0.30 (95% CI 0.07 to 0.53)
• Range (k = 13) d = 0.29 (95% CI 0.07 to 0.50)
• IQ (k = 17) d = 0.25 (95% CI 0.12 to 0.39)
• CPT reaction time (k = 4) d = 0.05 (not significant)

The higher the proportion of men in a study, the greater the difference in Stroop interference (estimated d = 0.81 when 75% of participants were men). Age had no effect on these differences. (Meta-analysis, k = 25, N = 3,442, E 3.)⁶¹

Children with ADHD showed poorer academic performance, impaired attention and impulse control, as well as increased restlessness, task-irrelevant behavior, and vocalizations during a school test compared to controls during adolescence (ages 12 to 20). Selected frontal lobe tests did not distinguish between the groups. Several measures declined with age in both groups, with no interaction between age and group. (Cohort study, N = 160, n = 100, 8 years; full text not available to us; E 2b.)⁶²

In the 8th edition of his textbook on psychiatry (1909–1915), Emil Kraepelin described symptoms of adult ADHD (increased distractibility, inconsistency, and lack of planning in behavior, as well as hyperfocus described as “fixation of attention”) without classifying them as a distinct entity. He presumably attributed milder forms with ADHD-associated mood swings to “manic predisposition” or “constitutional agitation,” and more severe forms with personality and substance use disorders to the “unstable” type (a form of psychopathic personality). The authors speculate that the numerous comorbidities masked the ADHD. (Historical Analysis, E 4.)⁶³

In addition to the core symptoms, adults with ADHD often experience other impairments (including dyspraxia, stimulus discrimination, dysgrammatism, dyslexia, memory, affect modulation, drive, and autonomic stability), which, depending on their personal and professional circumstances, may be more significant for people with ADHD than the core symptoms. (Narrative review, E 4.)⁴²
In adults, problems are also frequently observed in: (Narrative review, E 4.)⁴³

• age-appropriate core symptoms, such as inner restlessness, incessant unfocused mental activity, and difficulty following conversations
• Self-regulation, e.g., impulse control, shifting attention, emotion regulation, task initiation, problem-solving
• Related issues, such as sleep problems and low self-esteem

(E 2b): Hyperactivity in adults with ADHD manifested primarily as internal restlessness, while physical hyperactivity decreased. (Cohort study, N = 119, n = 75, ages 10 to 12, E 2b.)⁶⁴ (Rapid review of qualitative studies, k = 35, E 3.)⁶⁵ (Case-control study with scale validation, n = 40 and n = 347, E 3.)⁶⁶ (Narrative review, E 4.)⁴² (Narrative review, E 4.)⁴³ In qualitative studies, adults with ADHD described hyperactivity less frequently than attention problems, usually as inner restlessness rather than physical hyperactivity or excessive talking. This more subtle form of hyperactivity was reported primarily by women and older adults. Attention problems sometimes occurred only when dealing with topics of no personal interest. (Rapid review of qualitative studies, k = 35, E 3.)⁶⁵

(E 2b): Restlessness was observed in young adults with a history of hyperactivity in the Montreal cohort

• as reported feelings of restlessness in:
  • 64% with an average age of 25 (control group: 29%) (narrative review, secondary citation from Mannuzza & Klein 2000, E 4.)⁶⁷
  • 54.67% in a psychiatric interview at ages 17 to 24, 10 to 12 years after diagnosis, not treated with methylphenidate (controls: 18.18%) (Cohort study, N = 119, n = 75, 10 to 12 years, E 2b.)⁶⁴
  • significantly higher than in the control group (p < 0.0001) in a psychiatric interview conducted when participants were 17 to 24 years old, 10 years after the diagnosis of severe chronic hyperactivity (Cohort study, N = 60, n = 35, 10 years, E 2b.)⁶⁸
• as observed restlessness in:
  • 44% identified by psychiatrists during interviews (control group: 10%) (narrative review, secondary citation from Mannuzza & Klein 2000, E 4.)⁶⁷
  • 40.00% (controls: 6.82%), even though standing up from a chair was rare (cohort study, N = 119, n = 75, ages 10 to 12, E 2b.)⁶⁴
  • higher than in the control group (p < 0.01) (cohort study, N = 60, n = 35, 10 years, E 2b.)⁶⁸

Personality abnormalities (primarily impulsivity and immaturity/dependence) were diagnosed more frequently among young adults who had previously been hyperactive (40.00% versus 22.73%). The authors viewed this as a continuation of childhood impulsivity into adulthood. Only a minority exhibited severe psychopathology or persistent antisocial behavior. (Cohort study, N = 119, n = 75, ages 10 to 12, E 2b.)⁶⁴ In tests of cognitive style, they made more errors (p < 0.04) but were not more impulsive (no shorter reaction time). Their adjustment at work and in their life situations did not differ from that of controls; however, their socialization and well-being were lower (p < 0.02). (Cohort study, N = 60, n = 35, 10 years, E 2b.)⁶⁸

Students with ADHD reported significantly higher levels of internal restlessness on the Internal Restlessness Scale (IRS) than students without ADHD (mean 112.25 versus 76.00, p < 0.0001, η² = 0.43). The scale showed a retest reliability of 0.89 (0.80 in the ADHD group) and a four-factor structure with factors for: (Case-control study with scale validation, n = 40 and n = 347, E 3.)⁶⁶

• internal distractibility
• inner restlessness
• internal impulsivity
• internal disorganization

A German review identified the following as core symptoms of ADHD in adults: (Narrative review, E 4.)⁷²

• Attention in Cases of Understimulation
• chronic (internal) restlessness
• Impulsivity
• disorganized behavior
• Emotion regulation

The extent of psychosocial impairment depends on symptom severity, psychiatric comorbidities (such as substance use disorder or depression), and the level of psychosocial support. If ADHD persists into adulthood, it may be mild and appear as a variation of normal personality traits (“erratic, spirited”) or retain the severity of a disorder that significantly impairs daily functioning. (Narrative review, E 4.)⁷²

(E 3): Emotional dysregulation was common among adults with ADHD. (Case-control study, n = 514, E 3.)⁷³ (Rapid review of qualitative studies, k = 35, E 3.)⁶⁵ (Narrative review, E 4.)⁷⁴ It is absent from the diagnostic criteria. (Rapid review of qualitative studies, k = 35, E 3.)⁶⁵ (Narrative review, E 4.)⁷⁵ Neither ICD-10 nor DSM-IV nor DSM-5 lists it as a core symptom. (Narrative review, E 4.)⁷⁵ In qualitative studies, it manifested as extreme reactions to conflict or criticism, anxiety, and tension. (Rapid review of qualitative studies, n = 35, E 3.)⁶⁵ Emotional dysregulation occurs in adults with ADHD about as frequently as the core symptoms. (Narrative review, E 4.)⁷⁴

During the transition from childhood to adulthood, disorders in affect regulation become more pronounced. (Narrative review, E 4.)⁴² Emotional lability becomes an increasing burden that can dominate the clinical picture. (Narrative review, E 4.)⁴³

Adults with ADHD who met the criteria for: (case-control study, n = 514, E 3.)⁷³

• Inattention 98.7%
• Hyperactivity 91.1%
• Disorganization 85.8%
• Impulsivity 78.4%
• Emotional dysregulation (WRAADDS) 70.5%

Symptoms of emotional dysregulation (disorders in temper control, affective lability, and emotional hyperreactivity according to Wender-Reimherr) can be reliably and validly assessed in adults with ADHD and constitute an independent factor in the psychopathology of adult ADHD. (Narrative review, E 4.)⁷⁵

(E 2b): Emotional dysregulation or emotional impulsivity had independent significance beyond the core symptoms for:

• Impairments in 7 out of 10 areas of life, including overall impairment as well as occupational, academic, criminal, traffic-related, and financial impairments (emotional impulsivity, hyperactivity in childhood with ADHD persisting into adulthood, mean age 27 years, who reported more emotional impulsivity than those without persistence and than controls) (cohort study, N = 210, n = 135, full text not available to us, E 2b.)⁷⁶
• Predicting an ADHD diagnosis (case-control study, n = 514, E 3.)⁷³
• greater ADHD severity, independent of comorbidities (case-control study, n = 514, E 3.)⁷³ Comorbid mental disorders exacerbated emotional dysregulation but did not fully explain it
• social problems (narrative review, E 4.)⁷⁴

(E 4): Pharmacological and psychotherapeutic treatments reduce emotional dysregulation. (Narrative review, E 4.)⁷⁵ It responds to pharmacological and psychotherapeutic treatment along with inattention and hyperactivity/impulsivity. (Narrative review, E 4.)⁷⁴ The authors see this as evidence that emotional dysregulation may be a core feature of ADHD. (Narrative review, E 4.)⁷⁴

Adults with ADHD were more likely to use maladaptive emotion regulation strategies than individuals without ADHD. Emotional dysregulation was associated with symptom severity, executive functions, psychiatric comorbidities, and even criminal convictions. Different patterns of brain activity were observed during emotion processing. The evidence base was sparse and heterogeneous. (Systematic review, k = 22, E 3.)⁷⁷

The association between ASD and ADHD symptoms changed over the lifespan and was strongest during adolescence. The correlation between ASD and ADHD symptoms was as follows: (Narrative review with empirical analysis of 17,173 paired symptom assessments, ages 0 to 84, E 4.)⁷⁹

• Toddlers (8 months to 2 years) r = 0.06
• Preschoolers (ages 3 to 4) r = 0.24
• Children (ages 5 to 11) r = 0.51
• Adolescents (ages 12 to 18) r = 0.60
• young adults (ages 19 to 30) r = 0.50
• Middle-aged adults (ages 31 to 55) r = 0.50
• older adults (ages 56 to 84) r = 0.39

The authors hypothesize that social adaptation and executive functions are most important during the transition to adulthood, and that the weaker correlations observed in childhood and old age correspond to more diffuse symptoms resulting from executive functions that are still differentiating or, conversely, becoming less differentiated. (Narrative review with empirical analysis of 17,173 paired symptom assessments, ages 0 to 84, E 4.)⁷⁹

The instability associated with ADHD—in terms of moving, relationships, and jobs—did not decrease from early to middle adulthood but rather increased, most markedly among those aged 40 to 52. (Registry study, N = 3,448,440, n = 31,081, manufacturer-funded, author(s) employed by the manufacturer, E 2b.)⁸⁰

(E 3): Adults with ADHD frequently exhibited—or exhibited more—excessive mind wandering than those without ADHD. (Systematic review, k = 9, E 3.)⁸¹ (Case-control study, 2 samples, n = 199, of whom 122 had ADHD, industry-funded, E 3.)⁸² (Cross-sectional study, n = 255, E 3.)⁸³ (Case-control study, n = 53, of whom 25 had ADHD, E 3.)⁸⁴ ADHD is frequently associated with spontaneous mind wandering. The evidence base is limited; of the 9 included studies, 8 involved adults. (Systematic review, k = 9, E 3.)⁸¹ Half of the adults with ADHD (ages 18 to 55) exhibited pronounced mind wandering (127 out of 255, MWQ total score of 24 or higher). (Cross-sectional study, n = 255, E 3.)⁸³

(E 3): Mind wandering was associated with greater functional impairment. (Systematic review, k = 9, E 3.)⁸¹ (Case-control study, 2 samples, n = 199, of whom 122 had ADHD, industry-funded, E 3.)⁸² (Cross-sectional study, N = 1,484, n = 198, E 3.)⁸⁵ (Cross-sectional study, n = 255, E 3.)⁸³ Beyond the core symptoms, excessive mind wandering explained additional variance in: (Cross-sectional study, N = 1,484, n = 198, E 3.)⁸⁵

• Well-being increased from 10% to 15% (Mind Excessively Wandering Scale)
• Functional impairment R²Δ = 0.024, accounting for 82.4% of the variance beyond the core symptoms, independent of inattention and hyperactivity/impulsivity (case-control study, 2 samples, n = 199, of whom 122 had ADHD, manufacturer-funded, E 3.)⁸²
• Impairment increased from 53.4% to 55.3% (Mind Excessively Wandering Scale)

Women and men with ADHD did not differ in terms of mind wandering. Men with ADHD reported more inattention and lower well-being. (Cross-sectional study, N = 1,484, n = 198, E 3.)⁸⁵ The Mind Excessively Wandering Scale (MEWS) showed an internal consistency of over 0.9, as well as a sensitivity and specificity of 0.9 each for the diagnosis of ADHD. (Case-control study, 2 samples, n = 199, of whom 122 had ADHD, manufacturer-funded, E 3.)⁸²

Compared to people with low levels of mind wandering, adults with ADHD and pronounced mind wandering had: (cross-sectional study, n = 255, E 3.)⁸³

• more symptoms of inattention and hyperactivity (p < 0.0001)
• Impaired executive functions (BRIEF-A)
• more comorbid psychopathology (ASR, p ≤ 0.001)
• greater emotional dysregulation (p < 0.001)
• lower quality of life

Mind wandering (MWQ) was correlated with the following in adults with ADHD: (cross-sectional study, n = 41, E 3.)⁸⁶

• two inattention items (careless errors, difficulty following instructions) with a combined rs = 0.45 (p = 0.004)
• Inattention rs = 0.38 (p = 0.02)
• Total symptom score rs = 0.34 (p = 0.03)
• Hyperactivity rs = 0.17 (p = 0.28), not significant

These two items identified individuals with high levels of mind wandering with an AUC of 0.71. The authors describe mind wandering as “internal distractibility.” (Cross-sectional study, n = 41, E 3.)⁸⁶

Mind wandering and emotional lability predicted symptom severity in adults with ADHD. Mind wandering led to more severe ADHD symptoms via emotional lability, while poor sleep quality exacerbated mind wandering. (Cross-sectional study, serial mediation analysis, n = 81, industry-funded, E 3.)⁸⁷

Unmedicated adults with ADHD showed the following differences from those without ADHD in everyday life (Experience Sampling): (Case-control study, n = 53, of whom 25 had ADHD, E 3.)⁸⁴

• a greater tendency toward mind wandering (trait)
• more episodes of mind wandering and mind blanking
• less intentional and less frequently structured, coherent wandering of the mind
• increased drowsiness

In both groups, mind wandering and mental blankness were associated with increased sleepiness. The self-reported tendency toward mind wandering was strongly associated with the severity of inattention, impulsivity, and hyperactivity. (Case-control study, n = 53, of whom 25 had ADHD, E 3.)⁸⁴

People with ADHD typically describe excessive, spontaneous mind wandering (their thoughts drifting away from the current task) as a state of constant mental activity lacking thematic stability and consistency in content. According to the mind-wandering hypothesis, altered deactivation of the default mode network (DMN, the brain’s resting-state network that is active during inward-directed attention) and its disrupted interaction with the executive control network lead to excessive mind wandering, which underlies the symptoms and impairments of ADHD. The processes that normally regulate mind wandering (context regulation, sensory decoupling, salience thresholds) are deficient in ADHD. Mind wandering could be an endophenotype of ADHD. (Narrative review, E 4.)⁸⁹

(E 3): ADHD and mind wandering were linked

• as increased mind wandering compared to controls in:
  • Adolescents with ADHD (average age 15 years), excessive mind wandering d = 0.82 (cross-sectional study, N = 156, n = 80, E 3.)⁹⁰ Older adolescents with ADHD had higher scores than younger ones (r = 0.24); no age-related correlation was found in the control group. Whether this reflects an increase in mind wandering over the course of adolescence remains unclear without longitudinal data
  • Adults with ADHD, showing a decline as working memory load increases, but not as demands on sustained attention increase (deficient context regulation) (case-control study, N = 56, n = 27, E 3.)⁹¹ Controls remained task-focused under all conditions. The performance differences between the groups were no longer significant after controlling for the frequency of mind wandering
  • Students with ADHD (ages 20 to 32), including when compared to control subjects with equally poor and good task performance (case-control study, N = 69, n = 23, E 3.)⁹² The two control groups did not differ from one another. Increased mind wandering is therefore an independent characteristic of ADHD and not merely a consequence of poor performance on the main task.
  • Women with ADHD, borderline personality disorder (BPD), or both experience more frequent and intense spontaneous mind wandering; after controlling for depression and anxiety, this difference remained significant only for ADHD compared with controls (case-control study using experience sampling, N = 98, n = 28, E 3.)⁹³
  • Students with high levels of inattention (subclinical, with hyperactivity/impulsivity within the normal range), in everyday life, during a sustained attention task (SART), and while reading, with poorer text comprehension (experimental study, n = 90, of whom 46 had high levels of inattention, E 3.)⁹⁴
• as an increase in mind wandering associated with more ADHD symptoms in:
  • young adults in the general population, in the laboratory and in everyday life (cross-sectional study using experience sampling, n = 105, E 3.)⁹⁵ Mind wandering was perceived as more disruptive (r = 0.31). Lower meta-awareness of one’s own mind wandering partially mediated this relationship. Individuals with few ADHD symptoms viewed disruptive mind wandering as useful (strategic), whereas those with many ADHD symptoms did not.
  • Students (ages 18 to 29): mind wandering (Mind Excessively Wandering Scale) for five of six symptom dimensions (all except impulsivity), β = 0.15 to 0.22; additionally, more self-reported rumination (rumination) (cross-sectional study, N = 4,679, E 3.)⁹⁶
• not effective or less effective for:
  • Excessive mind wandering (MEWS) and ADHD symptoms in young adults; correlation not significant (cross-sectional study, N = 53, n = 17, E 3.)⁹⁷
  • the MEWS score for adults with ADHD compared to a clinical control group: 20.5 versus 22.3 points (cross-sectional study, N = 53, n = 17, E 3.)⁹⁷
  • More frequent freely moving thoughts associated with more ADHD symptoms; predictive value not confirmed in adults in the general population (r = 0.09, not significant) (cross-sectional study, n = 225, E 3.)⁹⁸
  • Daydreaming (IPI Daydreaming Frequency Scale) among college students; other symptom dimensions: β = -0.03 to 0.04 (not significant); SCT, however, β = 0.59 (cross-sectional study, N = 4,679, E 3.)⁹⁶

In ADHD, spontaneous mind wandering was also more intense than in BPS and in cases of comorbid ADHD with BPS. Negative thought content was elevated only in BPS and comorbid BPS (but no longer significant after controlling for depression and anxiety). Spontaneous mind wandering is thus a transdiagnostic phenomenon; however, in ADHD it is a core process, whereas in BPS it tends to be a consequence of anxiety and depression. (Case-control study using experience sampling, N = 98, n = 28, E 3.)⁹³

Experimentally induced low mood increased mind wandering in the SART only among students with high levels of inattention, combined with a more ruminative response style. Working memory capacity did not differ and did not influence the effects. (Experimental study, n = 90, of whom 46 had high levels of inattention, E 3.)⁹⁴

Spontaneous (unintentional), but not intentional, mind wandering was associated with ADHD symptoms. This was true in two large nonclinical samples of young adults and among college students diagnosed with ADHD. (Cross-sectional study, N = 2,708, n = 69, E 3.)⁹⁹ The association with ADHD symptoms (ASRS, semipartial correlation) was as follows: (Cross-sectional study, N = 2,708, n = 69, E 3.)⁹⁹

• spontaneous mind wandering: sr = 0.47 and 0.40, respectively
• intentional mind wandering: sr = 0.03 (not significant) or 0.07

Among adults without a diagnosis of ADHD, spontaneous mind wandering was associated with inattentive traits only in a more difficult version of the task (SART), whereas it was associated with hyperactive and impulsive traits regardless of task difficulty. Mind wandering is therefore not specific to inattention. The authors therefore consider it unsuitable as a diagnostic criterion for inattention. (Experimental cross-sectional study, n = 80, E 3.)¹⁰⁰

Among students, the associations between ADHD symptoms and daydreaming, as well as reflective and ruminative brooding, weakened after controlling for SCT and internalizing symptoms. SCT was independently associated with more mind wandering and both forms of brooding. The association between ADHD and mind wandering may therefore be less robust than previously assumed. (Cross-sectional study, N = 4,679, E 3.)⁹⁶

(E 3): Excessive or excessive mind wandering was correlated with: (Cross-sectional study, N = 156, n = 80, E 3.)⁹⁰

• Problems with emotion regulation, r = 0.77 (adolescents)
• Anxiety rs = 0.578 (young adults, MEWS) (cross-sectional study, N = 53, n = 17, E 3.)⁹⁷
• Impulsivity r = 0.55 (adolescents)
• Depression rs = 0.469 (young adults, MEWS) (cross-sectional study, N = 53, n = 17, E 3.)⁹⁷
• Inattention r = 0.38 (adolescents)
• Hyperactivity/impulsivity r = 0.33 (adolescents)

Attention lapses in ADHD were more akin to “mind blanking” than to “mind wandering.” In a Go/No-Go task, children with ADHD who were not taking medication (ages 6 to 12) reported more mind blanking, at the expense of both focused and wandering thoughts. Children treated with methylphenidate had levels of “mind blanking” comparable to those of the control group but tended to show more wandering thoughts rather than more focus. A similar pattern was found in young adults with subclinical ADHD. (Case-control study, 2 studies, n = 80 children, n = 40 young adults, 15 of whom had subclinical ADHD, E 3.)¹⁰¹

In a 20-minute sustained attention test, adults with ADHD showed a steeper increase in rare slow reactions (ex-Gaussian parameter τ, attention lapses) as the task duration increased compared to those without ADHD. They also performed worse on measures of selective and divided sustained attention. After controlling for the increase in τ, the group differences for divided attention—and, to some extent, for selective attention—disappeared. The increase in τ correlated with self-reported ADHD symptoms. (Case-control study, n = 48, including 24 with ADHD, E 3.)¹⁰²

Adults with ADHD recognized facial expressions (anger, fear, disgust, surprise) just as accurately as those without ADHD, but on average took nearly 200 ms longer to make a correct decision. This was also true for adults with autism and for the control condition, suggesting a general slowing of processing. Mind wandering in ADHD was associated with overall processing speed and was independent of the severity of ADHD and autism symptoms. Emotional dysregulation and functional impairment distinguished adults with ADHD or autism from non-affected individuals, but not from one another. (Case-control study, N = 103, n = 43, E 3.)¹⁰³

Young adults with ADHD drove at a higher average speed in the driving simulator, applied the gas pedal more frequently, and pressed the gas and brake pedals more forcefully. In the overall sample, more mind wandering was associated with greater pressure on the gas pedal and higher maximum speed. (Case-control study, N = 87, n = 16; full text not available to us, E 3.)¹⁰⁴

Questionnaires on mind wandering in ADHD include the Mind Excessively Wandering Scale (MEWS), which measures the frequency, intensity, and negative consequences of excessive mind wandering; its Brazilian Portuguese version demonstrated satisfactory semantic equivalence to the original (validation study, n = 40, E 3.)¹⁰⁵, as well as a validated questionnaire on mind wandering (4FMW, 16 items, 4 factors), which distinguished young adults with probable ADHD from controls. (validation study, E 3.)¹⁰⁶

(E 3): Maladaptive daydreaming (excessive, distressing immersion in complex fantasy worlds) was associated with ADHD or ADHD symptoms. (Cross-sectional study, n = 83, E 3.)¹⁰⁷ (Cross-sectional study, N = 447, E 3.)¹⁰⁸ (Cross-sectional study, n = 848, full text not available to us, E 3.)¹⁰⁹

Among adults with ADHD, 20.5% met the proposed criteria for maladaptive daydreaming. This subgroup exhibited higher levels of depression and loneliness, as well as lower self-esteem, than people with ADHD who did not engage in maladaptive daydreaming. The authors view maladaptive daydreaming as a distinct disorder from ADHD that, in some cases, might better explain ADHD-like symptoms. (Cross-sectional study, n = 83, E 3.)¹⁰⁷

People with maladaptive daydreaming reported significantly more ADHD symptoms than controls, with differences observed in: (cross-sectional study, N = 447, E 3.)¹⁰⁸

• Total ADHD symptoms (ASRS) d = 0.89
• Inattention d = 0.85
• Impulsivity d = 0.48

Among students, maladaptive daydreaming was associated with ADHD symptoms (r = 0.335) and decreased with age (r = −0.231). (Cross-sectional study, n = 848; full text not available to us; E 3.)¹⁰⁹

Dissociative absorption (complete immersion in mental imagery or external stimuli to the point of blocking out the surroundings) could be distinguished from ADHD symptoms and mind wandering through factor analysis. ADHD symptoms and mind wandering, on the other hand, could not be completely separated from one another. The author considers it possible that a tendency toward absorption may be misdiagnosed as ADHD. (Cross-sectional study, n = 303, E 3.)¹¹⁰

Racing thoughts are a distinct symptom in adults with ADHD. (Cross-sectional study, n = 263, of whom 182 had ADHD, 30 had ADHD and a bipolar disorder, E 3.)¹¹⁷ Racing thoughts are not listed as an ADHD symptom in the DSM or ICD. (Selective review, E 4.)¹¹⁸

Racing thoughts were more common in adults with ADHD compared to:

• Higher scores (Racing and Crowded Thoughts Questionnaire, RCTQ) (Narrative review, E 4.)¹¹⁹
• higher among patients with manic episodes (RCTQ) (Narrative review, E 4.)¹¹⁹
• higher in hypomanic episodes (narrative review by our own working group, E 4.)¹²⁰
• Higher rates of inattentive-type ADHD, hypomania, and euthymic bipolar disorder in the combined-type ADHD group (RCTQ) (cross-sectional study, n = 263, of whom 182 had ADHD, 30 had ADHD and bipolar disorder, E 3.)¹¹⁷
• Hypomania in the inattentive type of ADHD without distinction (RCTQ) (cross-sectional study, n = 263, of whom 182 had ADHD, 30 had ADHD and a bipolar disorder, E 3.)¹¹⁷
• Higher prevalence of euthymic bipolar disorder among individuals with the inattentive type of ADHD (RCTQ) (cross-sectional study, n = 263, of whom 182 had ADHD, 30 had ADHD and bipolar disorder, E 3.)¹¹⁷

In cases of euthymic bipolar disorder, racing thoughts were similarly pronounced as in non-affected individuals. (Narrative review by our own working group, E 4.)¹²⁰

(E 3): Racing thoughts increased in adults with ADHD in the evening and at bedtime, were most pronounced before falling asleep, and correlated with the severity of insomnia. (Cross-sectional study, n = 263, of whom 182 had ADHD and 30 had ADHD and bipolar disorder, E 3.)¹¹⁷ (Narrative review, E 4.)¹¹⁹ They were associated with anxiety (cross-sectional study, n = 263, of whom 182 had ADHD, 30 had ADHD and bipolar disorder, E 3.)¹¹⁷ (Narrative review, E 4.)¹¹⁹, as well as cyclothymic temperamental traits (cross-sectional study, n = 263, of whom 182 had ADHD, 30 had ADHD and bipolar disorder, E 3.)¹¹⁷ and mood instability. (Narrative review, E 4.)¹¹⁹ Racing thoughts and intrusive thoughts are closely linked to mixed depression, can be distinguished from rumination, and are also associated with ADHD and insomnia. (Narrative review, E 4.)¹¹⁹

Racing thoughts are not specific to bipolar disorder. The most important distinguishing feature remains the episodic course of bipolar disorder as opposed to the lifelong course of ADHD symptoms; however, this is not always clear-cut clinically. (Narrative review by our own working group, E 4.)¹²⁰ According to one study, flight of ideas or racing thoughts were present in: (Selective review, E 4.)¹¹⁸

• about 60% of adults with ADHD and bipolar disorder
• 20% of adults with ADHD alone

Rapid thinking is therefore more closely associated with bipolar disorder than with ADHD. (Selective review, E 4.)¹¹⁸

Adults with ADHD, with ADHD and bipolar disorder (euthymic), and with hypomania switched between semantic fields (switches) more frequently than non-affected individuals during the free-flowing speech task, while using the same number of words. The authors view this semantic overactivation as a common mechanism underlying racing thoughts in both ADHD and bipolar disorder. (Case-control study, n = 115, of whom 37 had ADHD; full text not available to us, E 3.)¹²¹ (E 3): In hypomania, lexical search in word fluency was based more on sound similarity than on semantic proximity; increased phonological clustering was found only in hypomania. (Case-control study, n = 115, including 37 with ADHD; full text not available to us, E 3.)¹²¹ (Narrative review by our own research group, E 4.)¹²⁰

Racing thoughts and rumination mediated the association between ADHD symptoms and symptoms of depression and anxiety in adults. The direct effects of ADHD symptoms on depression and anxiety were not significant. (Cross-sectional study, online survey of the general population, n = 289, E 3.)¹²² Significant indirect effects were found for: (Cross-sectional study, online survey of the general population, n = 289, E 3.)¹²²

• Hyperactivity/impulsivity via racing thoughts linked to anxiety: b = 0.50 (95% CI 0.32 to 0.7)
• Hyperactivity/impulsivity via racing thoughts to depression: b = 0.43 (95% CI 0.27 to 0.65)
• Hyperactivity/impulsivity versus rumination on depression: b = 0.42 (95% CI 0.27 to 0.59)
• Hyperactivity/impulsivity versus rumination on anxiety: b = 0.23 (95% CI 0.14 to 0.36)
• Inattention due to racing thoughts on anxiety: b = 0.18 (95% CI 0.06 to 0.32)
• Inattention due to racing thoughts and depression: b = 0.16 (95% CI 0.06 to 0.30)

Inattention did not affect depression or anxiety through rumination. (Cross-sectional study, online survey of the general population, n = 289, E 3.)¹²²

Students who exhibited a stronger tendency to maximize their decisions (seeking the best possible option) and greater regret also reported more ADHD symptoms and greater inner restlessness. (Cross-sectional study, N = 275, E 3.)¹²³ The correlations were as follows: (Cross-sectional study, N = 275, E 3.)¹²³

• inner turmoil and remorse r = 0.37
• inner restlessness and maximization r = 0.35
• ADHD symptoms and remorse r = 0.33
• ADHD symptoms and maximization: r = 0.26

Internal restlessness (cognitive restlessness) was significantly more pronounced among students who used stimulants without a prescription than among non-users (η² = 0.069). (Cross-sectional study, N = 807, E 3.)¹²⁴

Sluggish Cognitive Tempo (SCT, now known as Cognitive Disengagement Syndrome, CDS) is more strongly associated with ADHD symptoms in adults than in children. (Meta-analysis, k = 73, N = over 19,000, E 3.)¹²⁵ According to the state of research as of 2014, SCT is likely an attention disorder distinct from ADHD, which overlaps with ADHD in about half of cases. The two large studies in adults available at that time confirmed the findings in children. SCT has its own symptom dimensions and comorbidities, likely its own—albeit less severe—areas of impairment, and possibly its own cognitive deficits, causes, and course-related risks. Barkley proposed renaming SCT “Concentration Deficit Disorder.” (Comment, E 4.)¹²⁶

(E 3): SCT correlated

• involving inattention:
  • r = 0.72 in adults (meta-analysis, k = 73, N = over 19,000, E 3.)¹²⁵
  • r = 0.67 for students (2 cross-sectional studies, N = 840, n = 72, E 3.)¹²⁷
  • r = 0.66 for students (cross-sectional study, N = 6,167, E 3.)¹²⁸
  • r = 0.63 for children (meta-analysis, k = 73, N = over 19,000, E 3.)¹²⁵
• with hyperactivity/impulsivity: (meta-analysis, k = 73, N = over 19,000, E 3.)¹²⁵
  • r = 0.46 for adults
  • r = 0.32 for children
  • r = 0.02 (not significant) among college students (cross-sectional study, N = 6,167, E 3.)¹²⁸
• with additional characteristics: (meta-analysis, k = 73, N = over 19,000, E 3.)¹²⁵
  • Impairment (overall, social, academic) r = 0.38 to 0.44
  • Age r = 0.11

(E 3): SCT was a factor related to ADHD but distinct from it among students and adults (cross-sectional study, N = 6,167, E 3.)¹²⁸, in which the Barkley Adult ADHD Rating Scale-IV (BAARS-IV) identified one of four correlated but distinct factors (SCT, inattention, hyperactivity, impulsivity) (2 cross-sectional studies, N = 840, n = 72, E 3.)¹²⁷, distinguishable from inattention in a reliable 5-item SCT scale among Japanese adults. (Cross-sectional study, N = 429, n = 26, E 3.)¹²⁹ Self-reports and parental assessments of ADHD in young adulthood showed only low to moderate agreement, which supports the inclusion of multiple raters in the diagnosis of ADHD in adults. (Cross-sectional study, N = 6,167, E 3.)¹²⁸

Among adults who came in for an ADHD evaluation, an SCT scale based on self- and raters’ assessments yielded three factors (slow/daydreaming, sleepy/sluggish, low initiative/perseverance). (Cross-sectional study, n = 124, E 3.)¹³⁰

(E 3): Adults with ADHD had higher SCT scores than individuals without ADHD, as assessed by others, even after controlling for comorbidity (cross-sectional study, n = 124, E 3.)¹³⁰, and among Japanese adults, this was true even after controlling for ADHD and internalizing symptoms, when compared to college students and adults without ADHD. (Cross-sectional study, N = 429, n = 26, E 3.)¹²⁹

(E 3): In adults, SCT was associated with the following factors in addition to ADHD symptoms:

• deficits in executive functioning in daily life (validation study, N = 3,172, E 3.)¹³¹, and in young adults even beyond anxiety and depression (cross-sectional study, n = 158, E 3.)¹³², more pronounced in adults with ADHD and additional SCT than in those with ADHD without SCT, even after controlling for ADHD symptom severity (cross-sectional study, n = 106, manufacturer-funded, E 3.)¹³³, beyond ADHD and internalizing symptoms, only among those treated with stimulants (n = 48) (cross-sectional study, n = 102, E 3.)¹³⁴
• functional impairment (validation study, N = 3,172, E 3.)¹³¹, in many areas of life (cross-sectional study, n = 158, E 3.)¹³², more pronounced in adults with ADHD and additional SCT than in those with ADHD without SCT (cross-sectional study, n = 106, manufacturer-funded, E 3.)¹³³, as a lower level of functioning in adults who sought evaluation for ADHD (cross-sectional study, n = 124, E 3.)¹³⁰
• emotional dysregulation (validation study, N = 3,172, E 3.)¹³¹, more pronounced in adults with ADHD and comorbid SCT than in those with ADHD without SCT (cross-sectional study, n = 106, manufacturer-funded, E 3.)¹³³
• Anxiety and depression among students, after controlling for ADHD symptoms and sociodemographic characteristics, as well as among students with a confirmed ADHD diagnosis (internalizing symptoms) (2 cross-sectional studies, N = 840, n = 72, E 3.)¹²⁷
• poorer academic performance (including grade point average) or academic impairment, even among students with a confirmed ADHD diagnosis (2 cross-sectional studies, N = 840, n = 72, E 3.)¹²⁷
• poorer learning strategies among young adults (cross-sectional study, n = 158, E 3.)¹³²
• Suicidal behavior among college students, beyond depression and other psychological symptoms (cross-sectional study, N = 1,704, E 3.)¹³⁵ ADHD symptoms were no longer associated with suicidal behavior after controlling for internalizing symptoms

Adults with ADHD and co-occurring SCT showed slower neuropsychological latencies (CANTAB, WAIS) and different strategy selection as cognitive load increased. The authors view SCT as a distinct subgroup of adults with ADHD. (Cross-sectional study, n = 106, industry-funded, E 3.)¹³³

In adults with ADHD, SCT correlated with inattention as well as dimensionally measured depression and anxiety, but not with clinical diagnoses of depression or anxiety. (Cross-sectional study, n = 102, E 3.)¹³⁴

Among adults with ADHD (ages 18 to 38), three SCT profiles were identified (mild, moderate, severe). (Cross-sectional study, latent class analysis, N = 349, n = 213, E 3.)¹³⁶ Moderate and severe SCT differed from minimal SCT in terms of: (Cross-sectional study, latent class analysis, N = 349, n = 213, E 3.)¹³⁶

• increased anxiety and depression
• more persistent inattention
• greater disruption to one’s career and personal relationships

In adults, a continuum ranging from hypoactivity (SCT) to hyperactivity was observed, with inattention showing a U-shaped relationship to it (small proportion of variance). (Cross-sectional study, N = 1,398, E 3.)¹³⁷

Among college students (ages 17 to 25), inattention and SCT were the strongest predictors of self-reported problems with executive functions. Inattention was the strongest predictor of problems with time management and motivation, while SCT was the strongest predictor of problems with self-organization and problem-solving. Only SCT (not inattention) was associated with problems with emotion regulation. (Cross-sectional study, N = 298, E 3.)¹³⁸

(E 3): Self-reported symptoms were not associated with objective test performance among students; neither was a high SCT score associated with objectively slower performance on time-limited tests (cross-sectional study, N = 253, E 3.)¹³⁹ nor were inattention and SCT associated with performance on laboratory tests (visual working memory, Stroop Test, Conners’ CPT-II). (Cross-sectional study, N = 298, E 3.)¹³⁸

13% of students had high SCT scores (5 or more symptoms), often without concurrently high ADHD, anxiety, or depression scores. Of all symptom groups, SCT explained the largest independent proportion of variance for problems related to executive functions (34%) and, on par with depression, for functional impairment (29%). Students with high SCT scores, with or without high ADHD scores, were more severely impaired and had more executive function problems than controls. (Cross-sectional study, N = 458, E 3.)¹⁴⁰ In contrast, in another study, high SCT scores almost never occurred in isolation among students. After ruling out ADHD, depression, anxiety, poor sleep, and risky substance use, 4.8% of the people with ADHD remained. (Cross-sectional study, N = 910, E 3.)¹⁴¹

(E 3): Additional CDS symptoms were found in:

• 41.3% of Iranian students with ADHD (screened using BAARS-IV, confirmed via a structured clinical interview), met criteria for CDS (cross-sectional study, n = 690, full text not available to us, E 3.)¹⁴² Students with ADHD and CDS showed deficits in planning and attention control (Stroop, WCST, Tower of London)
• 40% of individuals with probable ADHD in a sample of adults without known mental illness had elevated CDS symptoms (cross-sectional study, N = 1,024; full text not available to us, E 3.)¹⁴³ Conversely, 60% of individuals with elevated CDS symptoms had an increased risk of ADHD

Among adults, inattention and SCT symptoms (Sluggish Cognitive Tempo, such as daydreaming, slowed processing, and drowsiness) were associated with higher levels of perceived stress, whereas hyperactivity/impulsivity were not. Beyond age, gender, education, depression, and anxiety, ADHD symptoms accounted for an additional 10% of the variance in perceived stress. (Cross-sectional study, n = 983, E 3.)¹⁴⁴ The standardized regression weights were as follows: (Cross-sectional study, n = 983, E 3.)¹⁴⁴

• Inattention β = 0.24
• SCT β = 0.12
• Additional executive criteria proposed by Barkley, Murphy, and Fischer: β = 0.04 (not significant)
• Hyperactivity/Impulsivity β = -0.01 (not significant)

(E 4): Hyperactivity and impulsivity improve with age, while inattention is more persistent in adolescence among most people with ADHD (Narrative Review, E 4.)¹⁴⁵ —for hyperactive symptoms across the entire lifespan, whereas inattentive symptoms do not decrease (Narrative Review, E 4.)¹⁴⁶ —for hyperactive symptoms with age. (Narrative Review, E 4.)¹⁴⁷ Many adults therefore meet the criteria for the inattentive subtype but not for the combined subtype. Impulsivity occurs less frequently, but its consequences are more severe in adulthood (such as the financial consequences of impulsive decisions rather than impulsively taking away toys). (Narrative review, E 4.)¹⁴⁶

For children with persistently high ADHD symptoms from 3rd through 12th grade, the focus was on: (Cohort study, n = 413, E 2b.)¹⁴⁸

• hyperactivity in childhood
• In 6th grade: inattention and hyperactivity
• in 9th and 12th grade: inattention

In long-term studies of hyperkinetic children, the following conditions persisted into young adulthood despite intensive pharmacotherapy and psychotherapy: (Narrative review, E 4.)¹⁴⁹

• an increase of more than 80% in distractibility
• Over 70% with attention disorders
• 60% increase in motor restlessness

(E 4): In adulthood, disorganization and emotional dysregulation often accompany the core symptoms of ADHD or become more prominent. (Narrative review, E 4.)¹⁵⁰ (Narrative review, E 4.)¹⁵¹ (Narrative review, E 4.)¹⁴⁷ The core symptoms present in childhood reappear in altered forms in adulthood. Common manifestations include disorganization in professional and personal life, emotional disorders, and stress intolerance, as well as residual symptoms of specific learning disorders (dyslexia, dyscalculia, dysgraphia). (Narrative Review, E 4.)¹⁵¹ The vast majority of people with ADHD have psychiatric comorbidities. Developmental psychopathological changes and age-related comorbidity must be taken into account in the diagnostic process. (Narrative review, E 4.)¹⁵⁰ The phenotype changes over the lifespan and is moderated by high comorbidity. (Narrative review, E 4.)¹⁴⁷

Young adults with childhood ADHD (MTA sample) described their symptoms as context-dependent. They fared better in activities that were stressful and challenging, new and involving multitasking, busy and fast-paced, physically demanding, or practically or intrinsically interesting. In such situations, high energy levels sometimes became a strength. Choosing appropriate work and educational settings could help reduce the burden of symptoms in adulthood. (Qualitative study, n = 125, E 3.)¹⁵²

Some child psychiatric disorders change their symptomatology as individuals transition into adulthood. Hyperkinetic children frequently developed antisocial disorders, delinquency, and alcoholism in adulthood. (Narrative review, E 4.)¹⁵³ In a 9-year follow-up study, the HKS group and the control group differed in the following respects: (Cohort study, n = 100, 9 years, secondary citation from Remschmidt & Herpertz-Dahlmann 1989, E 2b.)¹⁵³

• antisocial behavior: 27% versus 8%
• Substance abuse: 19% compared to 7%

Both were four times as common in cases of persistent HKS as in cases of resolved HKS. (Cohort study, n = 100, 9 years, secondary citation from Remschmidt & Herpertz-Dahlmann 1989, E 2b.)¹⁵³

(E 3): Younger adults reported more ADHD symptoms than older adults. (Cross-sectional study, n = 852, E 3.)¹⁵⁴ (Cross-sectional study, network analysis, N = 8,506, E 3.)¹⁵⁵ Among adults (ages 18 to 50 and older), age and gender had only minor effects on self-reported ADHD symptoms. There was no difference between 18- to 29-year-olds and 30- to 49-year-olds; both groups reported more symptoms than those over 50 (small effect sizes). An exception was hyperactivity as defined by ICD-10, for which there was no age effect. (Cross-sectional study, n = 852, E 3.)¹⁵⁴ The network structure of ADHD and SCT symptoms did not differ between young adults (ages 18 to 25) and older adults (ages 26 to 64), nor did it differ between the sexes. (Cross-sectional study, network analysis, N = 8,506, E 3.)¹⁵⁵ The mean number of symptoms was higher among young adults for: (Cross-sectional study, network analysis, N = 8,506, E 3.)¹⁵⁵

• SCT 3.12 versus 2.22 symptoms
• Inattention: 2.54 symptoms compared to 1.80 symptoms
• Hyperactivity/impulsivity: 2.24 versus 1.63 symptoms

Increased CDS symptoms (above the 95th percentile of the sample) decreased with age (OR 0.94 per year of age, 95% CI 0.92 to 0.95) and were more common in women (6.37% versus 4.32%, OR 1.46, 1.17 to 1.83). (Cross-sectional study, N = 8,075, E 3.)¹⁵⁶ The proportion with elevated CDS symptoms was as follows: (Cross-sectional study, N = 8,075, E 3.)¹⁵⁶

• Ages 15 to 17: 9.14% (95% CI 6.97 to 11.91)
• Ages 18 to 24: 6.00% (5.38 to 6.69)
• Ages 25 to 34: 5.43% (4.51 to 6.53)
• Ages 45 to 55: 1.62% (0.55 to 4.6)
• Ages 35 to 44: 1.20% (0.47 to 3.05)

(E 3): ADHD symptoms were associated with poorer cognitive performance, including slower processing speed. (Meta-analysis, k = 115, N = 24,909, E 3.)¹⁵⁷ (Cross-sectional study, population cohort, N = 2,091, E 3.)¹⁵⁸ The association between ADHD inattention and poorer cognitive performance (processing speed, sustained attention, immediate recall, working memory) was stronger the younger the sample was. For hyperactivity/impulsivity, age moderated only the associations with response inhibition and sustained attention. The authors view this as evidence of delayed rather than abnormal brain maturation. (Meta-analysis, k = 115, N = 24,909, E 3.)¹⁵⁷ Among 47- to 54-year-olds in the general population, ADHD symptoms were negatively associated with reaction time, processing speed, task switching, mental flexibility, and a measure of overall cognitive function. These effects were already evident in the subclinical range. Inattention and hyperactivity had opposing effects on some tasks. (Cross-sectional study, population cohort, N = 2,091, E 3.)¹⁵⁸

Adults with ADHD exhibit similar deficits in executive functions as children with ADHD in the following areas: (Narrative review, full text not available to us, E 4.)¹⁵⁹

• Reaction inhibition
• Planning skills
• cognitive flexibility
• Fluency
• Working memory, including spatial working memory as well as logical and visual memory

(E 3): Among adults with ADHD, the following exhibited emotional dysregulation or emotional lability:

• 72 to 90% (Narrative review, secondary citation from Moukhtarian et al. (2018), E 4.)¹⁶⁸
• 34 to 70% (Narrative review, secondary citation from Pérez-Hernández et al. (2024), E 4.)¹⁶⁹
• 67.52% (emotional instability and/or impulsivity cluster) among newly diagnosed individuals, which is roughly the same proportion as those with inattention/disorganization (61.38%) (cross-sectional study, n = 460, E 3.)¹⁷⁰
• 31.1% of 718 (emotional lability according to CAARS) (cross-sectional study, n = 718, E 3.)¹⁷¹

Factor analyses of adults with ADHD revealed distinct emotional factors:

• in the WRAADDS, an emotional factor (temperament, affective lability, emotional hyperreactivity) alongside the attention/disorganization factor (validation study, N = 882, n = 762, manufacturer-funded, E 3.)¹⁷²
• In a 7-factor model (robust RMSEA = 0.07) for newly diagnosed individuals, positive affect, negative affect, self-concept problems, and emotion regulation skills were identified as independent, interrelated factors alongside inattention, hyperactivity, and impulsivity (cross-sectional study, n = 213, E 3.)¹⁷³
• Among newly diagnosed individuals, 20 self-report questionnaires assessed emotional instability and impulsivity across five symptom clusters (in addition to hyperarousal, inattention/disorganization, and sleep problems) (cross-sectional study, n = 460, E 3.)¹⁷⁰

Emotional dysregulation was particularly closely associated with self-concept problems and, to some extent, with impulsivity/emotional lability. The authors view emotional dysregulation as a primary symptom of ADHD in adults. (Cross-sectional study, n = 213, E 3.)¹⁷³ Emotional dysregulation was most common in the combined type. (Cross-sectional study, n = 460, E 3.)¹⁷⁰ Childhood maltreatment accounted for variance in: (Cross-sectional study, n = 460, E 3.)¹⁷⁰

• emotional instability 10.6%
• Impulsivity 4.5%
• Sleep problems 2.4%

(E 3): Emotional symptoms and emotional dysregulation contributed to functional impairment in adults with ADHD. (Cross-sectional study, n = 460, E 3.)¹⁷⁰ (Cross-sectional study, N = 176, n = 146, E 3.)¹⁷⁴ (Systematic review, k = 33, N = approx. 2,678, E 3.)¹⁷⁵ (Narrative review, secondary citation via Moukhtarian et al. (2018), E 4.)¹⁶⁸ Emotional dysregulation predicts impairments in social, academic, and occupational domains independently of other ADHD symptoms. (Narrative review, secondary citation of Moukhtarian et al. (2018), E 4.)¹⁶⁸ Sleep problems also contributed significantly to functional impairment. (Cross-sectional study, n = 460, E 3.)¹⁷⁰ Emotional symptoms were directly linked to ADHD in adults and severely impaired family life, social life, work, and organization. (Cross-sectional study, N = 176, n = 146, E 3.)¹⁷⁴ They mediated the relationship between core symptoms and impairment in: (Cross-sectional study, N = 176, n = 146, E 3.)¹⁷⁴

• Impulsivity and Family Life, Covered in Full
• Inattention and Social Life, Covered in Full
• Inattention and work/organization, partially addressed

Studies using Ecological Momentary Assessment (EMA, repeated real-time data collection in everyday life) measured fluctuations in emotional dysregulation in ADHD. These fluctuations were associated with negative affect and functional impairment, regardless of age. Participation rates ranged from 60 to 99 percent. (Systematic review, k = 33, N = approx. 2,678, E 3.)¹⁷⁵ Adults with ADHD exhibited more intense and unstable negative emotions (including anger and irritability) in everyday life than controls. This high emotional lability persisted even after controlling for stressful daily events, suggesting an endogenous component. (Secondary citation via Poetar & Nistor 2026, E 3.)¹⁷⁵

Adults with ADHD exhibited greater emotional dysregulation (median DERS score of 118 versus 65.5) and greater uncertainty in reflective functioning (mentalization, the understanding of one’s own and others’ mental states) compared to controls. In a mediation analysis, the relationship between ADHD symptom severity and emotional dysregulation was indirect, mediated by reflective function; the direct effect was not significant. (Case-control study, N = 80, n = 40, E 3.)¹⁷⁶

Emotional symptoms are common and persistent among children, adolescents, and adults with ADHD. Emotional impulsivity and deficits in emotional self-regulation may be specific enough to serve as diagnostic criteria, whereas irritability should not be considered a symptom of ADHD. There is no uniform definition of these constructs. (Narrative review, industry-funded, E 4.)¹⁷⁷

Among adults with ADHD and emotional lability (31.1%), 29.6% reported having had emotional lability (WURS) in childhood, compared with 5.5% of adults with ADHD who did not have emotional lability. (Cross-sectional study, n = 718, E 3.)¹⁷¹ The odds ratios for emotional lability in adulthood were as follows: (Cross-sectional study, n = 718, E 3.)¹⁷¹

• emotional instability in childhood OR 6.18 (3.69 to 10.67)
• current psychiatric comorbidity: OR 2.39 (1.53 to 3.79)
• combined subtype (versus inattentive subtype) OR 1.73 (1.18 to 2.55)
• physical abuse OR 1.66 (0.99 to 2.77), p = 0.05
• ADHD in the family history: OR 1.65 (1.15 to 2.37)
• female gender OR 1.29 (0.88 to 1.88), not significant

The association between ADHD symptoms and emotional problems (symptoms of depression and anxiety) increased from early childhood through early adulthood. (Twin study, N = 10,738 twin pairs, 19 years, E 2b.)¹⁷⁸ The phenotypic correlation was as follows: (Twin study, N = 10,738 twin pairs, 19 years old, E 2b.)¹⁷⁸

• early adulthood (age 21) r = 0.52 (0.49 to 0.54)
• early adolescence (age 12) r = 0.51 (0.49 to 0.53)
• middle childhood (ages 7 to 9) r = 0.34 (0.32 to 0.36)
• early childhood (ages 2 to 4) r = 0.30 (0.28 to 0.32)

For inattention, the correlation increased from r = 0.14 (early childhood) to r = 0.49 (early adulthood). For hyperactivity/impulsivity, it peaked in middle childhood (r = 0.24) and declined to r = 0.12 by early adulthood. Genetic overlap contributed significantly to the association in all phases. In early and middle childhood, there was also a negative (protective) causal effect of ADHD symptoms on emotional problems, which stemmed primarily from hyperactivity/impulsivity and waned after adolescence. (Twin study, N = 10,738 twin pairs, 19 years, E 2b.)¹⁷⁸

Among adolescent girls, irritability predicted later hyperactive-impulsive symptoms (β = 0.26, p < 0.001), while in young adult women, inattention predicted later irritability (β = 0.49, p < 0.05). A random forest model (machine learning) predicted impulsive symptoms in adolescent girls based on irritability with an accuracy rate of 86%. (Longitudinal study, n = 148 adolescents and n = 124 young adults, E 2b.)¹⁷⁹

40% of adults with ADHD (30 out of 75) met the symptom criteria for oppositional defiant disorder (ODD). They had more comorbid disorders, poorer functioning, and lower life satisfaction. The improvement in ODD symptoms during treatment was mediated by the improvement in ADHD symptoms and was more pronounced with dexamfetamine than with paroxetine. (Secondary analysis of an RCT, n = 81, manufacturer-funded, E 3.)¹⁸¹