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In persons with ADHD, the following psychiatric disorders often occur in addition (comorbid), sorted in descending order of frequency with ADHD (in % of people with ADHD) compared to the frequency in non-affected persons.
Adults with the highest 10% of ADHD symptom severity according to ADHD-E were 6.99 times more likely to experience psychological distress than non-affected adults.1
The percentages in the headings indicate the frequency of comorbidity in ADHD. Example: 70 to 80 % of children with ADHD suffer from sleep disorders, compared to 35 to 40 % of children without ADHD.
One study found one or more comorbid mental illnesses in 51.8% of people with ADHD.2
1.1. Sleep disorders in children with ADHD - 70 to 80 % (compared to 35 to 40 % = + 100 %)¶
70 - 80 %3; 73.3 % (28.5 % mild plus 44.8 % moderate and severe),45 twice as common as in unaffected children67
For the treatment of sleep disorders ⇒ Sleep problems with ADHD.
A meta-analysis found that around 33% of people with narcolepsy also have ADHD.8
Narcolepsy is associated with a reduced level of dopamine in the cerebrospinal fluid. This is consistent with the dopamine deficiency found in ADHD. In dogs with narcolepsy, on the other hand, increased dopamine levels were found in the amygdala and increased noradrenaline levels in the oral pontine reticular nucleus. Nevertheless, the dogs respond to stimulants that increase dopamine and noradrenaline.9
Kooij sees sleep disorders (difficulty falling asleep or sleeping through the night) in 43% of people with ADHD.10
For non-affected persons: 2.3 %11
= 5 to 12 times the risk
Nash our experience, the rate of sleep disturbance is significantly higher in adults with ADHD. Of the 670 adults with ADHD (with a medical diagnosis) who took the ADxS.org online symptom test, 69% had sleep problems, compared to 39% of the 159 people with ADHD who said they were not affected (as of March 1, 2022).
A meta-analysis found that around 33% of people with narcolepsy also have ADHD.8
2.1. Developmental motor coordination disorder - 47 %¶
Developmental coordination disorder (DCD) occurs in 47% of people with ADHD.1314
A combination of ADHD and DCD usually represents a more severe phenotype. Despite some shared neuronal features, ADHD and DCD appear to have a separate etiology.14
Diagnostic criteria according to DSM 5:
The learning and execution of coordinated motor skills (if the opportunity to learn the skills is given) is below the level expected for the age.
The motor difficulties significantly impair the activities of daily life and have an impact on school performance, pre-professional and professional activities as well as leisure and play.
The beginning is in the early development phase.
A doctor cannot better explain motor difficulties by intellectual delay, visual impairment or other neurological conditions that affect movement.
The delay is usually in the acquisition of motor skills. Motor milestones are often not delayed.
Frequent accidents, bumping into things, bruises. See also under Symptoms of ADHD.
2.3. Impaired fine motor skills, poor handwriting - 60 %¶
Up to 60% of people with ADHD suffer from impaired fine motor skills, such as poor handwriting.15
3. Affective disorders (depression / dysphoria / dysthymia / mania) - 30 to 61 % (compared to 4.7 to 8.9 % = + 550 %)¶
Dysphoria with inactivity is an original ADHD symptom and not a symptom of depression. Antidepressant treatment of dysphoria with inactivity would be malpractice. ⇒ Depression and dysphoria in ADHD
Of 70 adults with ADHD, 60.7% had had an affective disorder in their lifetime, compared to 25.7% of those not affected 16
according to a large Swedish cohort study in 42.28% (men: 35.60%; women: 40.27%) of adult people with ADHD compared to 4.69% (men: 3.55%; women: 5.87%) of those without.17
according to another cohort study at 29.9 % (over the entire age range) and 55.7 % compared to 24.3 % in a small study of adults16 18
a Norwegian cohort study found major depression in 24.5 % (men: 20.3 % women: 28.8 %) of adult people with ADHD compared to 5.8 % (men: 4 %; women: 7.6 %) of those not affected.19
A simple survey by www.adhs-chaoten.net, in which 73 people with ADHD took part, revealed that a majority suffer from seasonal fall-winter depression.23 This is quite regularly the result of a vitamin D3 deficiency. ⇒ Vitamin D3
In adult people with ADHD: 61.8 %11;
Depression (40 to 60 %)24; 25 %12
Depression (adults with ADHD overall: 21.4 %; women 32.1 %, men 19.8 %; ADHD-I 22.3 %, ADHD-C 17.6 %, ADHD-HI 32.5 %)27
The population prevalence of major depression is 7.8%. People with ADHD have a prevalence of 18.6%, which is 2.4 times higher.28
Adults with the highest 10% of ADHD symptom severity according to ADHD-E are 6.68 times more likely to experience depression than non-affected adults.1
A meta-analysis found depression in people with ADHD and those without:29
in the total population at
8.6 % to 55 % of persons with ADHD compared to 1.2 % to 12.5 % of people without ADHD
in clinical cases with
15.4 % to 39.7 % of persons with ADHD compared to 5.8 % to 39.6 % of people without ADHD
Women with ADHD had a 3.69-fold risk of depression. Women with ADHD who used hormonal contraception (“pill”) had a 5.19-fold risk of depression.30
at 6 %12; (adults with ADHD overall: 6.4 %; women 8.3 %, men 4.7 %; ADHD-I 5.1 %, ADHD-C 8.0 %, ADHD-HI 10.0 %)27 to 4.7 % (over the entire age range)18
In 33.5% of adult persons with ADHD compared to 6.2% of people without ADHD at least once in their lives26
The population prevalence of Bipolar Disorder is 3.1 %. People with ADHD have a prevalence of 19.4 %, which is 6.3 times higher.28
In adult psychiatric clinical patients with ADHD: * 92.2 %31
Aggressive behavior is not an original symptom of ADHD-HI. Aggressiveness can be an expression of stress, but not everyone reacts to stress with aggression, nor does everyone externalize stress.
One of the arguments in favor of pure comorbidity is that non-ADHD-specific drugs such as risperidone only reduce aggressiveness but not ADHD symptoms, while MPH (methylphenidate) can alleviate the symptoms of ADHD and ODD equally.34
5.1. Deficient emotional self-regulation (DESR) - 44 to 55 %¶
DESR is described as
Self-regulation deficits of physiological arousal caused by strong emotions
Difficulty inhibiting inappropriate behavior in response to positive or negative emotions
Problems with refocusing attention when emotions are strong
Disorganization of behavioral coordination in response to emotional activation
DESR is distinct from the persistent and severe aggressive irritability that is common in pediatric bipolar Disorder.39 The abnormal moods of bipolar Disorder are not based on poor self-control and include other DSM-IV mood criteria.
DESR is not associated with an increased risk of bipolar Disorder.40
In studies, DESR was found in 44%40 to 55%41 of persons with ADHD, compared to only 2% of people without ADHD.40
DESR is diagnosed if the person with ADHD scores between 180 and 210 points on the 3 scales of anxiety/depression (intense emotions), aggression and attention (impulsivity) of the Child Behavioral Check List (CBCL) (on average between 60 and 70 per scale). Scores above 210 points are no longer referred to as DESR, but as more severe forms of affective disorders (mood and behavioral dysregulation disorders). Due to the defined diagnostic criteria of DESR, which cannot be achieved without a high score on the aggression scale, the diagnosis of DESR is likely to be limited to the ADHD-HI subtype, which is phenotypically more likely to react to perceived stress with aggression
The CBCL scale for aggressive behavior:42
Argues or disagrees a lot
Specifies, cuts to
Is crude or mean to others, intimidates them
Requires a lot of attention
Breaks his own things
Breaks things that belong to parents, siblings or others
Does not obey at home
Does not obey at school
Is easily jealous
Easily gets into fights, arguments
Physically attacks others
Screams a lot
Likes to produce or clown around
Is stubborn, grumpy or irritable, is easily annoyed by others
Shows sudden changes in mood and emotion
Talks too much
Likes to tease others
Has outbursts of anger or a hot temper
Threatens, bullies or intimidates others
Is unusually loud
According to our assessment, all question topics are primarily aimed at the ADHD-HI subtype (with hyperactivity), while only question topics 7, 8, 9, 14 and 15 also fit the ADHD-I subtype, but do not specifically ask about possible symptoms of inwardly directed emotional intensity. In the predominantly inattentive subtype (ADHD-I), barely any externalizing symptoms such as aggression or oppositional defiant behaviour occur.43 According to our understanding, the ADHD-I subtype internalizes perceived stress and does not primarily react aggressively.
DESR can therefore only occur in people with ADHD-HI and ADHD-C, not ADHD-I.
We assume that people with ADHD-I also suffer from emotional dysregulation, which just does not or rarely manifests itself as aggression. This perception was confirmed by an ADHD therapist in a personal interview.
Consequently, significantly more than 44 to 55% of all people with ADHD are likely to suffer from emotional dysregulation, although the forms of expression can vary greatly
Here, too, studies would be desirable that take into account the subtypes and the phenotypic expression of intense emotions (ADHD-HI: externalization / ADHD-I: internalization).
5.2. Oppositional Defiant Disorder (ODD) - 26 to 39 % (compared to 3.9 % = + 560 % to + 1440 %)¶
In children with ADHD: 39.3%41; explicitly for ODD: (35%)22
Among people with ADHD, 30 to 50 % have comorbid ODD or CD.37
Biedermann quotes an ODD prevalence of 60% in children with ADHD.44 We consider this to be a translation. In our opinion, this could at best apply when considering only boys with severe ADHD-HI. In addition, the ODD prevalence of boys is given as 55 % and of girls as 30 %, which does not match the overall prevalence. For adults, Biederman cites a prevalence of 30% for the entirety of social behavior disorders in ADHD44
ODD 26.1% in Iran among children between 6 and 18 years of age.36
For those not affected: 3.9%11
= 10 times the risk
ODD refers primarily to people with ADHD-HI (with hyperactivity) rather than ADHD-I (without hyperactivity), as hyperactivity is an outgrowth of an externalizing stress response pattern, whereas ADHD-I is an outgrowth of an inwardly directed stress (playing dead, escaping). ⇒ The subtypes of ADHD: ADHD-HI, ADHD-I, SCT and others
We understand ODD (Oppositonal Defiant Disorder) as a pure comorbidity to ADHD, i.e. not as ADHD symptoms.
Steinhausen describes disorders of social behavior on the one hand as the most common comorbidity of ADHD,45 describes the comorbidity on the other hand on page 174 as a subtype of ADHD.
Apart from the fact that sleep disorders are likely to be significantly more common, we do not consider ODD to be a subtype due to the delimitability of the genetic basis.
A specific polymorphism of the MAO-A gene is cited as a genetic contributory cause of both social behavior disorders and ADHD (in each case as one of several interacting specific genes). However, this gene polymorphism seems to play a much greater role with regard to social behavior disorders, as it is mentioned much more frequently there and ADHD can also manifest itself without the involvement of this gene (through the interaction of other genes). In the case of ADHD, the MAO-A gene is always mentioned in a subset of people with ADHD who also suffer from behavioral disorders.
A further argument in favor of pure comorbidity is that non-specific ADHD medications such as risperidone only reduce aggressiveness but not ADHD symptoms, while MPH (methylphenidate) can alleviate the symptoms of ADHD and ODD equally.34
ODD does not correlate with any of the symptom circuits of the dual / triple pathway model, so at least in this respect it has a different neurological basis.46
Symptoms Oppositional defiant disorder (ODD):
Frequent and persistent defiance or disobedience towards authority figures
Quarrelsome and easily irritated or annoyed
Deliberate attempts to annoy others or behave vindictively
Difficulty following rules and displaying a pattern of negative, hostile and defiant behavior
5.3. Disorders of social behavior / Conduct Disorder (CD)¶
Around 10 % for those not affected52
= 3 times the risk
Anxiety disorders and ADHD seem to reinforce each other. Treating anxiety or AD(HS also reduces the symptoms of the other Disorder.53
Generalized anxiety disorder tripled and a half the risk of ADHD, while ADHD quadrupled the risk of generalized anxiety disorder.54
40 to 85% of children with an anxiety disorder also had ADHD55
9.2. Anxiety disorders in adults - 44 % (compared to 4.9 %)¶
An anxiety disorder was found in 44.65% (men: 37.02%; women: 55.74%) of adults with ADHD compared to 4.89% (men: 3.64%; women: 6.19%) of people without ADHD, according to a large Swedish cohort study.17 A Norwegian register study found a prevalence of 22.2 % (men: 18.2 %; women: 26.3 %) of adult people with ADHD compared to 5 % (men: 3.3 %; women: 6.7 %) of those not affected.19
Other sources cite a prevalence of 42 % or 20 to 60 % in adults with ADHD24; 19 % anxiety disorders and 15.5 % phobic disorders12
In adult psychiatric clinical patients with ADHD: 25%49 to 28.6%31
Of 70 adults with ADHD, 34.3% had an anxiety disorder in their lifetime, compared to 25.7% of the 70 unaffected16
Anxiety disorders and ADHD seem to reinforce each other. Treating anxiety or AD(HS also reduces the symptoms of the other Disorder.53
For non-affected persons: 2 %25
= 3 to 12 times the risk
Of 70 adults with ADHD, 2.9% had a generalized anxiety disorder in their lifetime, compared to 1.4% of the 70 unaffected16
9.2.2. Social phobia - 5 to 29.3 % (compared to 3.5 to 10 %)¶
Adults with ADHD overall: 3.5 %; women 2.5 %, men 4.4 %; ADHD-I 3.3 %, ADHD-C 3.0 %, ADHD-HI 7.5 %27
Of 70 adults with ADHD, 18.6% had social phobia in their lifetime, compared to 10% of the 70 unaffected16
Social anxiety disorder was found in 22.8% of adult persons with ADHD compared to 6.6% of non-affected people at least once in their lifetime.26
The population prevalence of social phobia is 7.8%. People with ADHD have a prevalence of 29.3%, which is almost 3.8 times higher.28
9.2.3. Panic disorder - 1.9 to 4.3 % (compared to 2.9 %)¶
Adults with ADHD overall: 1.9 %; women 2.9 %, men 2.4 %; ADHD-I 2.1 %, ADHD-C 2.5 %, ADHD-HI 7.5 %27
Of 70 adults with ADHD, 4.3% had a panic disorder in their lifetime, compared to 2.9% of the 70 unaffected16
At least once in the lifetime of 22% of adult persons with ADHD compared to 7% of people without ADHD26
The population prevalence of panic disorder is 3.1%. People with ADHD have a prevalence of 8.9%, which is almost 3 times higher.28
6.1.1. Substance abuse - 21.9% to 35% (compared to 2.9% to 3.6%)¶
According to a large Swedish cohort study, substance misuse (SUD) was found in 35.12% (men: 39.44%; women: 30.88%) of adult people with ADHD compared to 3.61% (men: 4.40%; women: 2.79%) of non-affected people.17
A Norwegian cohort study found substance abuse in 21.9% (men: 27.5% women: 16.2%) of adult people with ADHD compared to 2.9% (men: 3.6%; women: 2.1%) of those without.19
Another Norwegian cohort study found no association between ADHD and alcohol or drug abuse,57 as well as an earlier study,58 which found increased alcohol and drug abuse in people with ADHD only in the presence of additional externalizing disorders.
However, these studies clearly contradict the vast majority of specialist literature, which reports a significant risk increase in ADHD.
Of 70 adults with ADHD, 17.1% had experienced substance misuse in their lifetime, compared to 2.9% of those without16
People with ADHD showed an ADHD prevalence of 21%.59
Among 153 addicts (98.7% males) at a clinic in India, 33% were found to have ADHD. The prevalence of ADHD was different for certain addictions:60
47.6 % of people with cannabis addiction
38.8 % of people who use tobacco/smoke
33% of people with cocaine addiction and
21.5 % of people with alcohol dependence.
For people with ADHD, substance abuse begins on average 3 years earlier61
Appropriate medication (especially methylphenidate) reduces the likelihood of addiction or substance abuse in ADHD.
People with ADHD with comorbid cocaine addiction showed a significant reduction in addictive behavior when treated with stimulants, corresponding to a decrease in ADHD symptoms.62
6.1.2. Smoking - 40 to 45 % (compared to 22 to 25 %)¶
In adult persons with ADHD: 40%63 to 42%6465 to 44.8%26
Compared to 22.6%26 to 26% of those not affected (2005),66 therefore a 61% increased risk (regardless of medication).
In adult psychiatric clinical patients with ADHD are dependent on nicotine
27% of women and 32% of men in the total population aged 18 and over67
= 1.6 times the risk
Adult persons with ADHD-HI: plus 100 % compared to non-affected people68
ADHD medication, nicotine (smoking) and zinc block the dopamine transporters (DAT) (which are elevated in ADHD) and thus reduce their overactivity69
6.1.3. Alcohol dependence (30 to 39 % compared to 5 to 15 %) / alcohol abuse¶
In adult persons with ADHD between 30 %25, 25 to 44 %68 and 38.9 %26
although we suspect that these data refer to psychiatric inpatients with ADHD.
A large Norwegian cohort study found no association between ADHD and alcohol or drug abuse,57 as well as an earlier study,58 which found increased alcohol and drug abuse in people with ADHD only in the presence of additional externalizing disorders.
In adult psychiatric clinical patients with ADHD, one study found alcohol dependence in 4.1%.31
For those not affected: 5%25 to 14.6%26
= 6 to 8 times the risk
Conversely, among n = 153 alcoholics, 43% were found to have childhood ADHD and 22% were found to have persistent ADHD.70 Another study found an ADHD diagnosis in 19% of 100 adult alcoholics in India.71
Alcohol / substance abuse: Adults with ADHD overall: 1.6 %; women 1.1 %, men 2.0 %; ADHD-I 0.9 %, ADHD-C 2.5 %, ADHD-HI 2.5 %27 to 18.1 %22.6 %26 compared to19.3 % for those not affected26
Of 70 adults with ADHD, 8.6% had an alcohol dependence in their lifetime, compared to 2.9% of those without16
6.1.4. Substance-related addictions in general - 7.8 %¶
In adult persons with ADHD: 7.8 %11, 20 %25 to 50 to 60 %7273
For those not affected: 1.9 %11 to 5 %2573
= 4 to 12 times the risk
According to another source, the lifetime prevalence of psychoactive substance use in people with ADHD is 52%, compared with 24% in people without the disorder.74
Of 70 adults with ADHD, 11.4% had a substance dependence in their lifetime, compared to 0% of the 70 unaffected16
ADHD was found in 11.2% of all adult addiction patients who used intravenous opiods or intravenous/intranasal benzodiazepines. The ADHD rate was higher among women (15.3 %) than among men (10.3 %).78
With ADHD, the risk of substance dependence (addiction) is 2 to 3 times higher than for those not affected.79
With ADHD, the risk of nicotine dependence is up to 9 times higher than in those not affected.79
Persons with ADHD are about as likely to be addicted as relatives who are not affected by ADHD.
People with ADHD have more than double the risk of developing a gambling addiction (5.3% compared to 2.4%). Problem gambling behavior is 4 times more common among persons with ADHD (2.4%) than among people without ADHD (0.6%).81
Another study found gambling addiction in 1.54% of adult persons with ADHD compared to 0.39% of non-affected people at least once in their lifetime.26
One study found that gene variants that correlate with substance use can causally increase the risk of ADHD.82
7. Restless legs (RLS, akathisia) - 11 to 44 % (vs. 2.6 to 15.3 %)¶
A meta-analysis found RLS in 11 to 42.9 % of children with ADHD and in 20 - 33.0 % of adults with ADHD. In the general population, RLS was found in 2.6 to 15.3%.83
A study of children with ADHD (aged 6 to 16) found RLS in 33.3%.84 Other sources speak of 44%.85 A smaller study of adults with ADHD found RLS in 20%, with comorbid RLS aggravating ADHD symptoms.86
Kooij sees RLS in 30 % to 40 % of people with ADHD.10
One study found 10% of people with ADHD had a disorder of periodic limb movements (PLMS) (more than 5/hour).87 Another study found 66% of children with ADHD had a PLM index greater than 5/hour, which is a marker for RLS, while no ADHD non-affected individuals had an elevated PLM index.88 A meta-analysis found no evidence of more frequent PLMS in ADHD.89
In adult psychiatric clinical patients with ADHD, 25.5% showed RLS31
A large cohort study found a strong correlation between restless legs and ADHD.90
Irrespective of ADHD, RLS occurs in around 2% of all children and adolescents, and in 0.5 to 1% in moderate to severe form. In adults, it affects 5 to 10 %. In 25% of people with ADHD, the disorder begins between the ages of 10 and 20.91 Other sources cite a prevalence of RLS of up to 8%.92
In 70% of people with ADHD, one parent is also affected.
A genetic link between RLS and ADHD has not yet been established. It is conceivable that the BTBD9 gene, which is associated with iron stores, could be involved.
69.4 % of children and adolescents with RLS have sleep disorders (compared to 39.6 % of those not affected), 80.6 % have a history of “growing pains” (compared to 63.2 % of those not affected).92
Common causes of RLS and ADHD
7.1. iron deficiency in RLS and ADHD
There is increasing evidence that iron deficiency (S-ferritin level < 12 ng/ml) underlies common pathophysiological mechanisms in patients with RLS and patients with ADHD-HI92
Iron is a cofactor for tyrosine hydroxylase, an enzyme that is essential for dopamine synthesis. ADHD and RLS both often show decreased iron levels. Lower S-ferritin levels in people with ADHD correlate with more severe ADHD-HI symptoms. Children with ADHD and RLS showed lower ferritin levels than children with ADHD without RLS.939495 However, other studies did not find decreased S-ferritin levels in ADHD9697
In RLS, the severity correlates more clearly with a reduced S-ferritin level.9899 particularly in children.100 It is possible that impaired transport of iron from the serum into the cerebrospinal fluid and of iron into the dopaminergic cells leads to a reduced iron concentration in the cerebrum.101 Adults with RLS show a low iron status in the cerebrum.102
Children with ADHD and a predisposition to RLS appear to represent a subgroup at particular risk for severe ADHD-HI symptoms, and iron deficiency may contribute to the severity of ADHD symptoms.93
An RC study found improved ADHD symptoms in children with ADHD and low ferritin levels when given iron (80 mg/day).103
7.2. adenosine for RLS and ADHD
Restless legs could be caused by downregulation of adenosine A1 receptors as a result of iron deficiency.104
Adenosine is closely linked to dopamine. Adenosine receptors are found throughout the brain in the vicinity of dopamine receptors and sometimes form receptor heteromers with them. Adenosine could also be involved in ADHD, although more likely via an excessive adenosine effect on adenosine A2A receptors. Adenosine inhibits dopamine, adenosine antagonists such as caffeine (coffee, cola, black tea) and theobromine (cocoa) therefore increase dopamine.
More on this in the article => Adenosine
7.3. treatment of RLS in ADHD
The problem with the comorbidity of restless legs and ADHD is that ADHD medications (although also dopaminergic) do not work against RLS and RLS medications such as L-dopa (although also dopaminergic) do not work against ADHD.10592106
Prolonged treatment with L-dopa often leads to a worsening of RLS symptoms.
Simultaneous administration of L-dopa and stimulants may cause increased side effects.
A single case report documented a good response of a 6-year-old boy with ADHD and RLS, who was also an MPH nonresponder, to the dopamine agonist ropinirole, in terms of ADHD as well as RLS.107
10. Autism Spectrum Disorders (ASD) - 3.6 to 21% (vs. 0.40 to 1.85%)¶
A meta-analysis reported that autism spectrum disorders were found in 15% to 21% of children and adolescents with ADHD, and that ADHD-affected children with ASD showed more severe ADHD symptoms than children without ASD.108109
Similarly, 21.6% of persons with ADHD were found to have comorbid ADHD.110 Another source mentions 85 % comorbid ADHD in persons with ADHD.109
A recent study found previously undiagnosed ASD in 27 cases of 103 children (85% boys) with ADHD without intellectual impairment.111
Girls with autism who also had ADHD showed significantly stronger symptoms of ADHD, learning disabilities and ODD than boys with ASD and ADHD in a large study.112
A cohort study mentions 3.6% (over the entire age range).18
Other sources do not provide % figures.5113
Source114 DSM-IV still stipulated that ADHD and autism spectrum disorders should not be diagnosed as comorbid. This was changed in DSM 5.
In the total population, ASD occurs in 1 in 54 boys (1.85%) and in 1 in 252 girls (0.40%).115
ADHD and ASD share two genes that are known as risk genes.113 There are considerations that ADHD and autism could have further common genetic roots.116 Disorders of dopaminergic neurotransmission are suspected in ASD, among other things,117 while there is evidence of such disorders in ADHD.
Around 50% of people with ADHD have ADHD as a comorbidity.
The fact that ADHD could not be diagnosed in autism according to DSM IV speaks against empirical experience and is therefore omitted in DSM 5.114
There are indications that ADHD and autism have common genetic roots.116 Disorders of dopaminergic neurotransmission are suspected in ASD, among other things,118 while there is evidence of such disorders in ADHD.
21. Impulse control disorder, impulse control disorder - 19.6 % (vs. 6.1 %)¶
The population prevalence of impulse control disorder is 6.1%. People with ADHD have a prevalence of 19.6%, which is around 3.2 times higher.28
Total adults 2.6 %; women 2.9 %, men 3.7 %; ADHD-I 1.2 %, ADHD-C 5.0 %, ADHD-HI 12.5 %27
11. Adjustment disorders - 18.9 % (compared to 3 %)¶
Adjustment disorders are described as reactions to a one-off or ongoing stressful life event.
Types of adjustment disorders are:
Short depressive reaction
Prolonged depressive reaction (up to 2 years)
Mixed anxiety and depressive reaction
With predominant impairment of other feelings
With predominant Disorder of social behavior
With mixed disorders of emotions and social behavior
One study found that 6.6% of children between the ages of 7 and 11 had learning-specific partial performance disorders. Reading difficulties were found in 4%, dyscalculia in 3.6% and a weakness in written expression in 1.8%. Approximately 63% of children with learning-specific partial performance disorders had one or more comorbid diagnoses, with ADHD being the most common comorbidity at 54.9%. Boys were more frequently affected.120
13.1. Reading difficulties (dyslexia) - 8 to 40 % (compared to 5.6 %)¶
There is evidence that reading impairment with ADHD shows different connectivity in the brain than reading impairment without ADHD.122
One study found only weak evidence of concordant neurophysiological changes in ADHD and dyslexia.123
65 to 70 % of all children with dyslexia are said to have functional binocular disorders:124
Oculomotor dysfunctions (OMD) (9 %)
Fixation impaired
Subsequent movements impaired
Horizontal eye saccades impaired
Dysfunctional binocular vision (DBS) (16%)
Heterophoria
Suppression
Convergence insufficiency
Accommodative dysfunction
Fusion insufficiency
Stereopsis insufficient
DBS and OMD (51 %)
Neither DMS nor OMD (24 %)
13.2. Spelling difficulties (agraphia, dysgraphia) - 12 to 40 %¶
12 - 27 %119, 25 - 40 %39, 40 %50
Also for adults with ADHD.125
15. Bipolar Disorders - 4.5 to 35.5 % (vs. 0.2 to 3.6 %)¶
Bipolar Disorder was found in
14.29% (men: 9.95%; women: 18.95%) of adult persons with ADHD compared to 0.72% (men: 0.53%; women 0.91%) of people without ADHD (large Swedish cohort study)17
10.9 % (men: 8.9 % women: 12.9 %) of adult people with ADHD compared to 1.3 % (men: 1.1 %; women: 1.6 %) of those not affected.19
6 %12; (adults with ADHD overall: 6.4 %; women 8.3 %, men 4.7 %; ADHD-I 5.1 %, ADHD-C 8.0 %, ADHD-HI 10.0 %)27
5.1% of adult psychiatric clinical patients with ADHD31
In 2.4 million people examined, 9250 bipolar disorders were observed. If an ADHD disorder was already present, the risk of bipolar disorder increased 12-fold over a lifetime; if ADHD and an anxiety disorder were previously present, the risk increased 30-fold compared to people without ADHD and without an anxiety disorder.129
People with ADHD have an ADHD prevalence of:
60 % (meta-analysis of twenty studies with n = 2,722 PBD patients (average age = 12.2 years)130
A meta-analysis found Bipolar Disorder in people with ADHD and non-affected people:29
in the total population at
4.48 % to 35.5 % of persons with ADHD compared to 0.2 % to 3.6 % of people without ADHD
in clinical cases with
7.4 % to 80 % of persons with ADHD compared to 2 % to 19.5 % of people without ADHD
One study found evidence of overlap between the genetic causes of bipolar and ADHD, particularly in early-onset bipolar (under the age of 21),134 another study also found genetic overlap between bipolar and ADHD.135
16. Eating disorders - Loss of Control Eating Syndrome (LOC-ES) - 7.5 to 11.4 % (vs. 1.4 %)¶
12-fold increased risk in people with ADHD-HI.136137
A cohort study of Iranian children and adolescents found an increased prevalence of ADHD of 7.5% among people with ADHD.138
A very large study found the risk of bulimia or anorexia increased 18.3-fold with ADHD.139
Of 70 adults with ADHD, 11.4% had social phobia in their lifetime, compared to 1.4% of the 70 unaffected16
Appetite disorders in adults with ADHD: 21 %
Disordered eating was 40% more common in adolescents with ADHD.140
17. Personality disorders (in adults) - 11.5 % to 33.2 % (compared to 0.9 % to 1.4 %)¶
Personality disorders are generally not yet diagnosed in children.
The following prevalence rates were found in adults:
11.5 % (men: 9.1 % women: 13.6 %) of adult people with ADHD compared to 1.4 % (men: 1.1 %; women: 1.7 %) of those not affected.19
33.2 % in adult persons with ADHD11 to 80.3 % in adult outpatients with ADHD141
For non-affected persons: 0.6 %11
= 50 times the risk
0.31 % to 33.8 % of persons with ADHD compared to 0 % to 3.9 % of people without ADHD
in clinical cases with
21.9 % to 65.95 % of persons with ADHD compared to 6.6 % to 34.4 % of people without ADHD
17.1. Antisocial PS - 18 % (compared to 2 to 3.5 %)¶
One study found antisocial personality disorder in 18% of people with ADHD-HI with hyperactivity compared to 2% of those without.142.
Other sources cite 37.1 %14342 .
One study found Antisocial PS in 18.9% of adult persons with ADHD compared to 3.5% of non-affected people at least once in their lifetime.26
Of 30 prison inmates with ADHD-HI, 96% also had antisocial personality disorder.
In contrast, 20 non-prison ADHD-HI affected people and 18 non-affected people (without ADHD) were not found to have Antisocial Personality Disorder.Interestingly, amphetamines are the drugs most commonly used by prison inmates affected by ADHD-HI.67 Amphetamines are known to be a highly effective medication for ADHD.
For domestic violence offenders who had ADHD, ADHD treatment reduced domestic violence far more significantly than domestic violence interventions.144
17.2. Borderline PS / Emotionally unstable PS - 18 to 33 % (vs. 1 to 5 %)¶
Adults with ADHD are said to have BPD in 18.3% of cases145
A population study found that 33.7% of people with ADHD also had borderline personality disorder (BPD) (compared to 5.2% in the general population).26
A Swedish cohort study found a 19.4-fold risk of comorbid borderline personality disorder in people with ADHD.146 3.9 % of the more than 2 million people examined had an ADHD diagnosis (women 3.0 %, men 4.8 %), 0.5 % had BPD (women 0.8 %, men 0.1 %). People who had an ADHD diagnosis also had an increased risk of BPD:
Identical twins: n = 9,130 , OR = 11.2 (Among 9,130 twins, the risk of BPD was 11.2 times higher if the other twin had ADHD)
Fraternal twins: N = 17,350, OR = 1.0
Full siblings: n = 2,211,396, OR = 2.4
Maternal half-siblings: n = 332,486, OR = 1.4
Half-siblings on the paternal side: n = 331,080; OR = 1.5
Cousins Parents Full siblings:n = 6,456,848; OR = 1.5
Cousins Maternal parents Half-siblings: n = 472,212; OR = 1.3
Cousins Paternal parents Half-siblings: n = 466,836; OR = 1.2
The risk of a BPD diagnosis if the person with ADHD had ADHD themselves or a full sibling was:146
19.1 times higher in women (OR = 19.1)
21.8 times higher in men (OR = 21.8)
People with ADHD in childhood were 14% more likely to be diagnosed with BPD later in life.147
One study found avoidant PS in 10.6% of adult persons with ADHD compared to 2.1% of non-affected people at least once in their lifetime.26
In adult psychiatric clinical patients with ADHD: 31.6 %31
One study found compulsive PS in 19.3% of adult persons with ADHD compared to 7.8% of non-affected people at least once in their lifetime.26
40,7 %14342
In adult psychiatric clinical patients with ADHD: 10.2 %31
15,7 %14342
One study found Dependency PS in 3.1% of adult persons with ADHD compared to 0.4% of non-affected people at least once in their lifetime.26
In adult psychiatric clinical patients with ADHD: 18.4 %31
15.7 %14342
One study found Narcissistic PS in 25.2% of adult persons with ADHD compared to 5.7% of non-affected people at least once in their lifetime.26
14,3 %14342
One study found Histrionic PS in 10.7% of adult persons with ADHD compared to 1.6% of non-affected people at least once in their lifetime.26
17.11. Schizotypal PS - 22.4 % (compared to 3.5 %)¶
8,6 %42
One study found Schizotypal PS in 22.4% of adult persons with ADHD compared to 3.5% of non-affected people at least once in their lifetime.26
Former names: Borderline schizophrenia, latent schizophrenic reaction, pseudoneurotic schizophrenia
6.4 %42
One study found schizoid PS in 9.2% of adult persons with ADHD compared to 2.9% of non-affected people at least once in their lifetime.26
18. Behavioral disorders / social disorders (aggression, antisocial behavior, oppositional defiant behavior) - 1.5 to 20.2 % (compared to 4.3 %)¶
Conduct disorder (CD): Adults with ADHD total: 1.2%; females 0.7%, males 1.7%; ADHD-I 0.3%, ADHD-C 1.0%, ADHD-HI 10.0%27
Another study found Conduct Disorder in 20.2% of adult persons with ADHD compared to 4.3% of non-affected people at least once in their lifetime.26
Oppositional defiant behavior (ODD): Adults with ADHD overall: 0.7 %; women 0.0 %, men 1.7 %; ADHD-I 0.0 %, ADHD-C 1.5 %, ADHD-HI 5.0 %27
Reduced cortisol levels have been reported in ADHD in conjunction with aggression disorders.152
Externalizing stress reactions are associated with lower basal cortisol levels and a reduced cortisol response to acute stress.
Disorders of stress hormone levels, especially cortisol, are extremely common in ADHD. ⇒ Cortisol in ADHD
A meta-analysis of 63 studies with N = 1,073,188 people from 17 countries found:153
People with ADHD have an ADHD prevalence of 22.3% (12.7% for the ADHD-I subtype).
People with ADHD have an epilepsy prevalence of 3.4%.
One study found that 35% of adult people with ADHD also had ADHD.154
In adults with psychogenic non-epileptic seizures (PNES), ADHD was found in 63.6%, while in adults with epileptic seizures (ES), ADHD was found in 27.8%.155
Some anti-seizure medications can cause or worsen ADHD symptoms as a side effect, while some ADHD medications can increase the risk of seizures.156
The prevalence of epilepsy in the general population is 0.5 to 1 %.
A Norwegian cohort study found schizophrenia in 3.4 % (men: 4.2 % women: 2.5 %) of adult people with ADHD compared to 0.8 % (men: 0.9 %; women: 0.6 %) of those not affected.19
Another study found a prevalence of ADHD of 0.9% across the entire age range18
About 30% of all patients with ADHD have tics or Tourette syndrome, while about half of all patients with a tic disorder or TS also have ADHD.158
The population prevalence of tic disorders is around 5%159
Messi syndrome is characterized by a strong urge to collect useless objects with a tendency to litter the living environment. A strong coincidence with ADHD is discussed. For an overview of the literature, see Kuwano et al.163 They found a comorbidity of ADHD in 26.7% of people with ADHD.
A meta-analysis of 57 studies found a correlation between ADHD and165
Suicide attempts (OR 2.37)
Suicidal thoughts (OR 3.53)
Suicide plans (OR 4.54)
Suicide (OR 6.69).
According to the study, suicide is between 2.37 and 6.69 times more common in people with ADHD than in those without the disorder.
Another study found increased suicidality in children and adolescents with ADHD (OR 1.1), but this was mediated by comorbid depression, irritability and anxiety, not ADHD itself.166
A study examined 450 children. 14% of them bit their nails. Among these were found:168
ADHD at 74.6 %
Oppositional defiant behavior at 36
Separation anxiety at 20.6 %
Enuresis at 15.6 %
Tic disorders at 12.7 %
Obsessive-compulsive disorder at 11.1
mental retardation at 9.5 %
major depressive disorders at 6.7 %
profound developmental disorders at 3.2 %.
38. Mental disorders in relatives of people with ADHD - 6.8-fold¶
An analysis of the entire Taiwanese population in 2010 examined 220,966 parents of children with ADHD-HI (according to ICD-9, which did not recognize ADHD-I), 174,460 siblings of children with ADHD-HI, and 5,875 children of parents with ADHD-HI. Among these relatives of people with ADHD-HI, the risk of severe psychiatric disorders was significantly increased compared to matched control subjects without relatives with ADHD-HI:169
ADHD-HI: 6.87-fold risk
Autism spectrum disorder: 4.14 times the risk
Bipolar disorders: 2.21 times the risk
Major depressive disorders: 2.08 times the risk
Schizophrenia: 1.69 times the risk
This can be understood as an indication of common genetic causes. However, it is also theoretically conceivable that this could be explained by the immunological consequences of (primarily viral) infections (which are more frequently transmitted between close relatives). See the chapter ⇒ Immune system and behavior.
Similarly, similar external life circumstances and similar dysfunctional behavior patterns and stressful experiences are likely to be shared more frequently among close people. These mechanisms can complement each other.
Nishino, Sakai (2016): Modulations of Ventral Tegmental Area (VTA) Dopaminergic Neurons by Hypocretins/Orexins: Implications in Vigilance and Behavioral Control In: Monti, Pandi-Perumal, Chokroverty (Herausgeber) (2016): Dopamine and Sleep: Molecular, Functional, and Clinical Aspects, 65-90, 75 ↥
