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The following psychiatric disorders often occur additionally (comorbidly) in ADHD sufferers, sorted in descending order of frequency in ADHD (in % of ADHD sufferers) 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 those without ADHD.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 ADHD sufferers.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-study found ADHD in around 33% of all people with narcolepsy.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 ADHD sufferers.10
For non-affected persons: 2.3 %11
= 5 to 12 times the risk
In our experience, the rate of sleep disorders 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 who said they were certainly not affected (as of March 1, 2022).
A meta-study found ADHD in around 33% of all people with narcolepsy.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
Depression found
according to a large Swedish cohort study in 42.28% (men: 35.60%; women: 40.27%) of adults with ADHD compared to 4.69% (men: 3.55%; women: 5.87%) of those not affected.16
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 adults17 18
a Norwegian cohort study found major depression in 24.5 % (men: 20.3 % women: 28.8 %) of adults with ADHD compared to 5.8 % (men: 4 %; women: 7.6 %) of those without the disorder.19
A simple survey by www.adhs-chaoten.net, in which 73 affected people took part, revealed that a majority suffer from seasonal fall-winter depression.23 This is regularly the result of a vitamin D3 deficiency. ⇒ Vitamin D3
In adults with ADHD: 61.8%11;
Depression (40 to 60 %)24; 25 %12
At least once in the lifetime of 26.4% of adults with ADHD compared to 16.2% of adults without ADHD26
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
Dysthymia:
Adults with ADHD overall: 7.3 %; women 9.4 %, men 5.4 %; ADHD-I 6.3 %, ADHD-C 7.6 %, ADHD-HI 15 %)27
In 6.1% of adults with ADHD compared to 3.4% of adults without ADHD at least once in their lives26
Bipolar disorders (“manic/depressive”):
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 adults with ADHD compared to 6.2% of those without ADHD at least once in their lives26
In adult psychiatric clinical patients with ADHD: 92.2%28
Adults with the highest 10% of ADHD symptom severity according to ADHD-E are 6.68 times more likely to experience depression than those who are not affected.1
For those not affected: 14.3 %11
Major depression (6 %)25
= 4 to 5 times the risk
In adult ADHD sufferers with the highest 10% of ADHD symptom severity according to ADHD-E: 6.68 times the risk29
Mania 0.15 % (for ADHD over the entire age range)2
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 ADHD-unspecific drugs such as risperidone only reduce aggressiveness but not ADHD symptoms, while MPH (methylphenidate) can alleviate the symptoms of ADHD and ODD in equal measure.33
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.38 The abnormal moods of bipolar disorder are not due to poor self-control and include other DSM-IV mood criteria.
DESR is not associated with an increased risk of bipolar disorder.29
In studies, DESR was found in 44%29 to 55%39 of ADHD sufferers, compared to only 2% of those without the disorder.29
DESR is diagnosed if the affected person scores between 180 and 210 points (on average between 60 and 70 per scale) on the 3 scales anxiety/depression (intense emotions), aggression and attention (impulsivity) of the Child Behavioral Check List (CBCL). 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:40
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), there are hardly any externalizing symptoms such as aggression or oppositional defiant behaviour.41 According to our understanding, the ADHD-I subtype internalizes perceived stress and does not primarily react aggressively.
DESR can therefore only occur in ADHD-HI and ADHD-C sufferers, not in ADHD-I sufferers.
We assume that ADHD-I sufferers 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 ADHD sufferers 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%39; explicitly for ODD: (35%)22
Among ADHD sufferers, 30 to 50 % have comorbid ODD or CD.36
Biedermann quotes an ODD prevalence of 60% in children with ADHD.42 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 ADHD42
ODD 26.1% in Iran among children between 6 and 18 years of age.35
For those not affected: 3.9%11
= 10 times the risk
ODD refers primarily to ADHD-HI (with hyperactivity) and less to ADHD-I sufferers (without hyperactivity), as hyperactivity is an outgrowth of an externalizing stress response pattern, while 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 an ADHD symptom.
Steinhausen describes social behavior disorders on the one hand as the most common comorbidity of ADHD, while43 describes the comorbidity as a subtype of ADHD on page 174.
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). With regard to social behavior disorders, however, this gene polymorphism appears to play a much greater role, 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 ADHD, the MAO-A gene is always mentioned in a subset of affected individuals who also suffer from behavioral disorders.
A further argument in favor of pure comorbidity is that ADHD-unspecific drugs such as risperidone only reduce aggressiveness but not ADHD symptoms, while MPH (methylphenidate) can alleviate the symptoms of ADHD and ODD in equal measure.33
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.44
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)¶
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 adults with ADHD compared to 3.61% (men: 4.40%; women: 2.79%) of those without the disorder.16
A Norwegian cohort study found substance abuse in 21.9 % (men: 27.5 % women: 16.2 %) of adults with ADHD compared to 2.9 % (men: 3.6 %; women: 2.1 %) of those without the disorder.19
Another Norwegian cohort study found no link between ADHD and alcohol or drug abuse,48 as well as an earlier study,49 which found increased alcohol and drug abuse in ADHD sufferers only in the presence of additional externalizing disorders.
However, these studies clearly contradict the vast majority of specialist literature, which reports a significant increase in the risk of ADHD.
Of 70 adults with ADHD, 17.1% had experienced substance misuse in their lifetime, compared to 2.9% of those not affected17
SUD sufferers showed an ADHD prevalence of 21%.50
Among 153 addicts (98.7% men) at a clinic in India, 33% were found to have ADHD. The prevalence of ADHD varied for certain addictions:51
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.
Substance abuse begins on average 3 years earlier in ADHD sufferers52
Appropriate medication (especially methylphenidate) reduces the likelihood of addiction or substance abuse in ADHD.
ADHD sufferers with comorbid cocaine addiction showed a significant reduction in addictive behavior when treated with stimulants, corresponding to a reduction in ADHD symptoms.53
6.1.2. Smoking - 40 to 45 % (compared to 22 to 25 %)¶
27% of women and 32% of men in the total population aged 18 and over58
= 1.6 times the risk
Adults with ADHD-HI: plus 100 % compared to non-affected persons59
ADHD medication, nicotine (smoking) and zinc block the dopamine transporters (DAT) (which are elevated in ADHD) and thus reduce their overactivity60
6.1.3. Alcohol dependence (30 to 39 % compared to 5 to 15 %) / alcohol abuse¶
In adults with ADHD between 30 %25, 25 to 44 %59 and 38.9 %26
although we assume that these data refer to psychiatric inpatients with ADHD.
A large Norwegian cohort study found no link between ADHD and alcohol or drug abuse,48 as well as an earlier study,49 which found increased alcohol and drug abuse in ADHD sufferers only in the presence of additional externalizing disorders.
In adult psychiatric clinical patients with ADHD, one study found alcohol dependence in 4.1%.28
For those not affected: 5%25 to 14.6%26
= 6 to 8 times the risk
Conversely, among n = 153 alcoholics, 43% were diagnosed with ADHD in childhood and 22% with persistent ADHD.61 Another study found an ADHD diagnosis in 19% of 100 adult alcoholics in India.62
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 dependency in their lifetime, compared to 2.9% of those not affected17
6.1.4. Substance-related addictions in general - 7.8 %¶
In adults with ADHD: 7.8 %11, 20 %25 to 50 to 60 %6364
For those not affected: 1.9 %11 to 5 %2564
= 4 to 12 times the risk
According to another source, the lifetime prevalence of psychoactive substance use in ADHD is 52%, compared to 24% in those not affected.65
Of 70 adults with ADHD, 11.4% had a substance dependence in their lifetime, compared to 0% of the 70 unaffected people17
ADHD was found in 11.2% of all adult addiction patients who consumed intravenous opiods or intravenous/intranasal benzodiazepines. The ADHD rate was higher among women (15.3 %) than among men (10.3 %).69
With ADHD, the risk of substance dependence (addiction) is 2 to 3 times higher than for those not affected.70
With ADHD, the risk of nicotine dependence is up to 9 times higher than in those not affected.70
People with ADHD are just as likely to suffer from addiction 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%). At 2.4%, problematic gambling behavior is 4 times more common among ADHD sufferers than among those without the disorder (0.6%).72
Another study found gambling addiction in 1.54% of adults with ADHD compared to 0.39% of those without ADHD 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.73
7. Restless legs (RLS, akathisia) - 11 to 44 % (vs. 2.6 to 15.3 %)¶
A meta-study 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%.74
A study of children with ADHD (aged 6 to 16) found RLS in 33.3%.75 Other sources speak of 44%.76 A smaller study of adults with ADHD found RLS in 20%, with comorbid RLS aggravating the ADHD symptoms.77
Kooij sees RLS in 30 % to 40 % of ADHD sufferers.10
One study found periodic limb movement disorder (PLMS) (more than 5/hour) in 10% of ADHD sufferers.78 Another study found 66% of all 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.79 A meta-study found no evidence of more frequent PLMS in ADHD.80
In adult psychiatric clinical patients with ADHD, 25.5% showed RLS28
A large cohort study found a strong correlation between restless legs and ADHD.81
Independent of ADHD, RLS occurs in around 2% of all children and adolescents, and in 0.5 to 1% in a moderate to severe form. In adults, it affects 5 to 10 %. In 25% of those affected, the disorder begins between the ages of 10 and 20.82 Other sources cite a prevalence of RLS of up to 8%.83
In 70% of those affected, 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).83
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-HI83
Iron is a cofactor for tyrosine hydroxylase, an enzyme that is essential for dopamine synthesis. ADHD and RLS both frequently show reduced iron levels. Lower S-ferritin levels in ADHD sufferers correlate with more severe ADHD-HI symptoms. Children with ADHD and RLS showed lower ferritin levels than children with ADHD without RLS.848586 However, other studies did not find reduced S-ferritin levels in ADHD8788
In RLS, the severity correlates more clearly with a reduced S-ferritin level.8990 particularly in children.91 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.92 Adults with RLS show a low iron status in the cerebrum.93
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.84
An RC study found improved ADHD symptoms in children with ADHD and low ferritin levels when given iron (80 mg/day).94
7.2. adenosine for RLS and ADHD
Restless legs could be caused by a downregulation of adenosine A1 receptors as a result of iron deficiency.95
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, albeit 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.968397
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, with regard to both ADHD and RLS.98
Around 10 % for those not affected102
= 3 times the risk
Anxiety disorders and ADHD appear to reinforce each other. Treating anxiety or ADHD also reduces the symptoms of the other disorder.103
Generalized anxiety disorder tripled and a half the risk of ADHD, while ADHD quadrupled the risk of generalized anxiety disorder.104
9.2. Anxiety disorders in adults - 44 % (compared to 4.9 %)¶
According to a large Swedish cohort study, 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 those without ADHD.16 A Norwegian register study found a prevalence of 22.2 % (men: 18.2 %; women: 26.3 %) of adults with ADHD compared to 5 % (men: 3.3 %; women: 6.7 %) of those without ADHD.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%99 to 28.6%28
Of 70 adults with ADHD, 34.3% had an anxiety disorder in their lifetime, compared to 25.7% of the 70 unaffected people17
Anxiety disorders and ADHD appear to reinforce each other. Treating anxiety or ADHD also reduces the symptoms of the other disorder.103
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 unaffected people17
Social anxiety disorder was found in 22.8% of adults with ADHD compared to 6.6% of those without ADHD at least once in their lives.26
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 unaffected people17
At least once in the lifetime of 22% of adults with ADHD compared to 7% of adults without ADHD26
Specific phobias were found in 35.8% of adults with ADHD compared to 14.6% of those without ADHD at least once in their lives26
10. Autism spectrum disorders (ASD) - 3.6 to 21% (compared to 0.40 to 1.85%)¶
A meta-study 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.105106
Similarly, 21.6% of autism spectrum disorder sufferers were found to have comorbid ADHD.107 Another source mentions 85% comorbid ADHD in people with ASD.106
A recent study found previously undiagnosed ASD in 27 of 103 children (85% boys) with ADHD without intellectual impairment.108
In a large study, girls with autism who also had ADHD showed significantly stronger symptoms of ADHD, learning disorders and ODD than boys with ASD and ADHD.109
A cohort study mentions 3.6% (over the entire age range).18
Other sources do not provide % figures.5110
Source111 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%).112
ADHD and ASD share two genes that are known as risk genes.110 There are considerations that ADHD and autism could have further common genetic roots.113 Among other things, dopaminergic neurotransmission disorders are suspected in ASD,114 while there is evidence of such disorders in ADHD.
Around 50% of those affected by autism 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 5.111
There are indications that ADHD and autism have common genetic roots.113 Among other things, dopaminergic neurotransmission disorders are suspected in ASD,115 while there is evidence of such disorders in ADHD.
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 disorder 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%. Around 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.117
13.1. Reading difficulties (dyslexia) - 8 to 40 %¶
There is evidence that reading difficulties with ADHD show different connectivity in the brain than reading difficulties without ADHD.119
One study found only weak evidence of concordant neurophysiological changes in ADHD and dyslexia.120
65 to 70 % of all children with dyslexia are said to have functional binocular disorders:121
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 %116, 25 - 40 %38, 40 %100
Also for adults with ADHD.122
15. Bipolar disorders - 4.5 to 35.5 % (compared to 0.2 to 3.6 %)¶
Bipolar disorder was found in
14.29% (men: 9.95%; women: 18.95%) of adults with ADHD compared to 0.72% (men: 0.53%; women 0.91%) of those without ADHD (large Swedish cohort study)16
10.9 % (men: 8.9 % women: 12.9 %) of adults 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 ADHD28
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.126
Bipolar sufferers have an ADHD prevalence of:
60 % (meta-analysis of twenty studies with n = 2,722 PBD patients (average age = 12.2 years)127
A meta-study found bipolar disorder in ADHD sufferers and non-sufferers:30
in the total population at
4.48 % to 35.5 % of ADHD sufferers compared to 0.2 % to 3.6 % of non-sufferers
in clinical cases with
7.4 % to 80 % of ADHD sufferers compared to 2 % to 19.5 % of non-sufferers
One study found evidence of overlap between the genetic causes of bipolar and ADHD, particularly in early-onset bipolar (under the age of 21),131 another study also found genetic overlap between bipolar and ADHD.132
16. Eating disorders - Loss of Control Eating Syndrome (LOC-ES) - 7.5 to 11.4 % (vs. 1.4 %)¶
12-fold increased risk in ADHD-HI sufferers.133134
A cohort study of Iranian children and adolescents found an increased prevalence of ADHD of 7.5% among those affected by eating disorders.135
A very large study found the risk of bulimia or anorexia to be 18.3 times higher with ADHD.136
Of 70 adults with ADHD, 11.4% had social phobia in their lifetime, compared to 1.4% of the 70 unaffected people17
Appetite disorders in adults with ADHD: 21%
Disordered eating was 40% more common in adolescents with ADHD.137
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 adults with ADHD compared to 1.4 % (men: 1.1 %; women: 1.7 %) of those not affected.19
33.2 % in adults with ADHD11 to 80.3 % in adult outpatients with ADHD138
For non-affected persons: 0.6 %11
= 50 times the risk
0.31 % to 33.8 % of ADHD sufferers compared to 0 % to 3.9 % of non-sufferers
in clinical cases with
21.9 % to 65.95 % of ADHD sufferers compared to 6.6 % to 34.4 % of those not affected
17.1. Antisocial PS - 18 % (compared to 2 to 3.5 %)¶
One study found antisocial personality disorder in 18% of ADHD-HI sufferers with hyperactivity compared to 2% of non-affected individuals.139.
Other sources cite 37.1 %14040 .
One study found antisocial PS in 18.9% of adults with ADHD compared to 3.5% of those without the disorder 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 and 18 non-affected (without ADHD) inmates were not found to have Antisocial Personality Disorder.Interestingly, amphetamines are the drugs most commonly used by ADHD-HI-affected prison inmates.58 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.141
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 cases142
A population study found that 33.7% of ADHD sufferers 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.143 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 with 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 affected person or a full sibling had ADHD was:143
19.1 times higher in women (OR = 19.1)
21.8 times higher in men (OR = 21.8)
14% of those affected who had ADHD in childhood were later diagnosed with BPD.144
One study found avoidant PS in 10.6% of adults with ADHD compared to 2.1% of non-affected individuals at least once in their lifetime.26
In adult psychiatric clinical patients with ADHD: 31.6 %28
15.7 %14040
One study found narcissistic PS in 25.2% of adults with ADHD compared to 5.7% of non-affected individuals at least once in their lifetime.26
6.4 %40
One study found schizoid PS in 9.2% of adults with ADHD compared to 2.9% of those without ADHD 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 overall: 1.2 %; women 0.7 %, men 1.7 %; ADHD-I 0.3 %, ADHD-C 1.0 %, ADHD-HI 10.0 %27
Another study found Conduct Disorder in 20.2% of adults with ADHD compared to 4.3% of those without ADHD 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.149
Externalizing stress reactions are associated with lower basal cortisol levels and a reduced cortisol response to acute stress.
Disturbances in 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:150
People with epilepsy 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 adults with epilepsy also had ADHD.151
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%.152
Some anti-seizure medications can cause or worsen ADHD symptoms as a side effect, while some ADHD medications can increase the risk of seizures.153
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 adults 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
21. Impulse control disorder, impulse control disorder - 2.6 %¶
Total adults 2.6 %; women 2.9 %, men 3.7 %; ADHD-I 1.2 %, ADHD-C 5.0 %, ADHD-HI 12.5 %27
Around 30% of all patients with ADHD have tics or Tourette’s syndrome, while around half of all patients with a tic disorder or TS also have ADHD.155
The population prevalence of tic disorders is around 5%156
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.160 They found a comorbidity of ADHD in 26.7% of people with Messi syndrome.
A meta-study of 57 investigations found a correlation between ADHD and162
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), although this was mediated by comorbid depression, irritability and anxiety, not by ADHD itself.163
A study examined 450 children. 14% of them bit their nails. Among these were found:165
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 disorder at 6.7 %
profound developmental disorders at 3.2 %.
38. Mental disorders in relatives of ADHD sufferers - 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 ADHD-HI sufferers, the risk of severe psychiatric disorders was significantly increased compared to matched control subjects without relatives with ADHD-HI:166
ADHD-HI: 6.87-fold risk
Autism spectrum disorder: 4.14 times the risk
Bipolar disorders: 2.21 times the risk
Major depressive disorder: 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 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 ↥
