ADHD in adults

Author: Ulrich Brennecke
Review: Dipl.-Psych. Waldemar Zdero

ADHD does not, as was assumed until the end of the last millennium,¹ automatically end with adulthood.

ADHD persists into adulthood in around two thirds of people with ADHD who were diagnosed as children. Many show changes in symptoms, while others experience complete remission or remission with fluctuating phases. Up to 90% of persons with ADHD still have residual symptoms or significant limitations in young adulthood compared to people without ADHD. Various reasons for the persistence of ADHD into adulthood are discussed, such as a low socio-economic background, high stress levels in childhood or late traumas. One theory assumes that ADHD already exists in childhood, but is masked by coping mechanisms and only becomes visible in adulthood. Late-onset ADHD, i.e. a first appearance (or at least becoming recognizable) in adulthood, is possible and can occur in up to 10% of ADHD cases, especially in women.
The symptoms of ADHD change in adults compared to children, with hyperactivity decreasing and inner restlessness as well as inattention and organization problems coming to the fore.

Treatment of ADHD in adults often requires lower doses of stimulants compared to children.

• 1. Persistence of ADHD into adulthood
  • 1.1. Types of persistence and their prevalence
    • 1.1.1. Childhood ADHD persists fully into adulthood
    • 1.1.2. Childhood ADHD partially persists into adulthood
    • 1.1.3. Childhood ADHD with full remission
    • 1.1.4. Fluctuating ADHD
  • 1.2. Possible reasons for the persistence of ADHD into adulthood
• 2. Late Onset ADHD
  • 2.1. Late initial diagnosis
    • 2.1.1. Overlooked childhood ADHD: ADHD recognized late
    • 2.1.2. Subclinical childhood ADHD: subclinical late-onset ADHD
  • 2.2. Late first onset: de novo late-onset ADHD
  • 2.3. Very Late-onset ADHD / Senile-onset ADHD in seniors
  • 2.4. Late-Onset ADHD in women
• 3. ADHD symptoms change in adults
• 4. Treatment for adults
• 5. ADHD in old age

1. Persistence of ADHD into adulthood¶

5 % of all children have ADHD (a further 5 % are suspected of having ADHD). In the USA, around 4.4 % of all adults are affected by ADHD.²³ Further studies can be found at Krause.⁴

One large study even found a higher prevalence of ADHD in adults (2.8%) than in children (2.2%).⁵ This could be consistent with the fact that the heritability of adult ADHD may be lower than that of childhood ADHD, meaning that the proportion of environmental influences on the development of ADHD may be higher in adults than in children.⁶

1.1. Types of persistence and their prevalence¶

It is far more the rule than the exception that childhood ADHD persists in adulthood.
It is problematic that many longitudinal studies did not use the original diagnostic scale at follow-up, but the DSM that was current at the time⁷, so that remission rates were influenced by changes in diagnostic scales rather than by changes in symptoms alone.

1.1.1. Childhood ADHD persists fully into adulthood¶

ADHD remains completely persistent throughout life, possibly with altered symptoms, with

• around 66 %⁸⁹
• 50 %¹⁰
• 35 %¹¹¹²
• 32 %⁷
• 22 %¹³
• 4 %¹⁴ (DSM III R to DSM II)

1.1.2. Childhood ADHD partially persists into adulthood¶

A remission of ADHD in the sense of a reduction in the number of symptoms is referred to as partial remission. For most people with ADHD, considerable restrictions remain, for example, with regard to educational and professional success compared to those who are not affected.
The proportion of people with ADHD in childhood who have partially persistent ADHD as adults was put at

• 60 %⁷
• 8 %¹⁴ (DSM III, DSM III R to DSM II)
• 0.23 % for a stable partial remission¹⁰

One study observed in adults whose previous ADHD remitted that only the symptom groups

• Executive problems
• Behavioral problems

were remitted, while

• Hyperactivity/restlessness behavior
• Planning/organizational deficits

persisted.¹⁵

1.1.3. Childhood ADHD with full remission¶

Complete remission in adulthood, without residual symptoms, was found in

• 35 %¹⁶
• 30 %¹⁷¹⁰
• 10 %¹⁷
• 8 %⁷
• 5.7 % within 21 years
  • One study examined adults three times at intervals of 7 and 6 years, from an average age of 34 to an average age of 47, and showed a remission rate of 5.7%.¹⁸
• 0 %¹⁹

1.1.4. Fluctuating ADHD¶

Studies report a fluctuating course of ADHD, with ADHD disappearing (remitting) and reappearing (recurring) several times during development.

ADHD persisted throughout life, with periods of remission and recurrence, with

• 63.8% showed fluctuating phases of remission and recurrence during childhood and young adulthood¹¹¹²
  • This study was a follow-up of the MTA study and examined children with ADHD-C a total of 9 times from the beginning (mean age = 8.46) to the end of the follow-up study after 16 years (mean age = 25.12). In 63.8%, the ADHD disappeared in phases (on average 3.58 times) and then reappeared. The fluctuations within a person included an average of 6 to 7 symptoms between the peak and lowest values, especially at a younger age. The ADHD severity in these people with ADHD tended to be moderate. The group with stable persistent ADHD (10.8%) showed an early and persistent risk of affective disorders, substance use problems in adolescence/young adulthood, lower medication adherence and poorer response to treatment in childhood.
  • Protective factors were
    • in the recovery group: very low parental psychopathology
    • in the partial remission group: higher rates of comorbid anxiety
• 10 % to 15 % fluctuating ADHD¹⁰

A study reports on fluctuating intensity of ADHD symptoms in children during the coronavirus lockdown.²⁰

ADHD symptoms recorded in infants aged 24 months showed a moderate stability into preschool age of 56 to 60 %.²¹

A single case with clear adult ADHD-C reported a complete remission following a corona infection. After nine months, the ADHD symptoms slowly returned. It is quite conceivable that diseases alter the dopamine system. Just as certain viral diseases can be a risk for ADHD because they can trigger a dopamine and noradrenaline deficiency, this is also possible in the opposite direction.

Although studies on fluctuating ADHD are rare, fluctuating ADHD could explain the well-known phenomenon that many people with ADHD discontinue their medication, which they initially found very helpful and necessary, after a few years, only to resume it a few years later.

1.2. Possible reasons for the persistence of ADHD into adulthood¶

It is not possible to predict in which persons with ADHD ADHD will disappear in adulthood. Whether persons with ADHD lose their ADHD by the age of 27 is independent of

• The severity of the Disorder²²
• The age at the first onset of ADHD²²
• The IQ of childhood²²
• Behavioral problems in childhood²²
• The severity of ADHD-HI, ODD or CD²²
• The duration of stimulant treatment after adolescence²²

There are various theories as to why childhood ADHD disappears in some adults and persists in others.

• Children with ADHD from a low socio-economic background benefited more from special school support than children from higher socio-economic backgrounds.²³ In our view, this indicates that families with a low socio-economic status are less able to compensate for their children’s deficits. This is likely to apply to all mental health problems.
• A study of stress exposure in children with ADHD found that severe stress exposure in childhood and adolescence was associated with severe ADHD-HI or ADHD-I progression into adulthood, while children with low stress exposure often showed remitting ADHD (all subtypes).²⁴ A large cohort study in Sweden confirms this²⁵
• Another study found an up to 11.8-fold increase in trauma in late-onset ADHD. Neurophysiologically, late-onset ADHD did not differ from ADHD in people with ADHD who had had it since childhood. However, the effects were significantly stronger. At the same time, 1/3 of the late-onset ADHD sufferers were no longer diagnosed with ADHD after one year.²⁶ The latter could also be an indication of a high rate of misdiagnosis.
  • Puberty is associated with a strongly altered dopaminergic innervation in the PFC. The PFC is particularly vulnerable to dopaminergic stimulation during this time. This explains the fluctuating behavior of adolescents between the poles of novelty seeking and strong withdrawal. The strong dopaminergic vulnerability in this developmental phase further explains the dangers of alcohol and drug abuse or excessive media consumption. These can cause permanent disorders of the dopamine system, which increases the risk of impulsivity, addiction or psychosis.²⁷
    Prolonged cortical maturation in the frontoparietal network has a favorable effect on the final performance of the brain, while acceleration, e.g. through too much dopaminergic stimulation, has an unfavorable effect.²⁸ In both ADHD and giftedness, the maturation of the brain is slowed down.
    See ⇒ Giftedness and ADHD In the section ⇒ Differential diagnosis of ADHD in the chapter ⇒ Diagnostics
• Anxiety symptoms at the age of 15 make mental disorders in early adulthood much more likely²⁹
  • Anxiety disorder: 4.9-fold
  • Depression: 4.8-fold
  • ADHD, ASD or developmental disorder: 3.4-fold
    This could be a further indication that middle adolescence represents a second particularly vulnerable developmental window alongside early childhood.
• One theory assumes a post-maturation of brain functions. However, not every delay in brain maturation is also a sign of ADHD. In the case of giftedness, there is a delay in the development of the cortex that corresponds exactly to the delay until the first cortex thickness maximum occurs in ADHD.
  ⇒ ADHD and giftedness.
• Another theory is that certain regions of the brain take on compensatory tasks so that the child’s ADHD deficits can be corrected as a result.³⁰
• Another model assumes that certain childhood ADHD deficits persist throughout life.³⁰
• A study of adults with persistent ADHD found an imbalance between the connections in the brain within the default mode network on the one hand and those between the default mode network and the areas that support attention and cognitive control on the other. These differences did not exist in adults whose ADHD was remitted.³¹³²
• A comparison of partially remitted and non-remitted adolescents found a significantly lower activation of the vlPFC in partial remission. This improvement in vlPFC efficiency correlated with performance on a go/no-go task and was intermediate between ADHD diagnosis and normal controls.³³
• A gene analysis study found four genome-wide significant loci for childhood ADHD and one for late onset ADHD. Elevated polygenic risk scores for ADHD (ADHD-PRS) were found in persistent ADHD. Childhood ADHD showed greater genetic overlap with hyperactivity and autism as well as the highest burden of rare protein truncating variants in evolutionarily restricted genes. Late onset ADHD, on the other hand, showed greater genetic overlap with depression and no increased burden of rare protein-truncating variants.⁹

In adults with persistent ADHD, a thinner cortex correlated with more severe symptoms.³⁴

2. Late Onset ADHD¶

The term late onset is used in English-language specialist literature to describe a later onset of ADHD that only began to develop in childhood.

The majority of the study literature uses the term late-onset for a late first diagnosis (in adulthood) that did not exist in previous examinations between the ages of 7 and 17 (DSM IV) or 12 and 17 (DSM 5), without distinguishing whether or not individual symptoms were present in the first 6 or 11 years.
As we understand it, this collides with the DSM and ICD system, for which the time of diagnosis is completely irrelevant as long as several (= at least 2 of the 18) symptom characteristics had already occurred by the age of 6 years (DSM IV) or 11 years (DSM 5).
The term late onset therefore does not describe anything special, as DSM and ICD quite naturally assume that symptom severity can change with age.

The term “de novo late onset” was coined by Liu et al. for full-blown ADHD that develops without several symptoms already being present in the first 6 or 11 years.³⁵ A late diagnosis, which according to DSM and ICD was accompanied by some (but not enough for a diagnosis) symptoms in childhood, is referred to as “subthreshold late onset ADHD” (subclinical late-onset ADHD). We consider the term “late-diagnosed ADHD”⁹, i.e. late-diagnosed ADHD, to be more appropriate.
However, some studies (e.g. Moffitt et al. 2015³⁶ also use the term late-onset in the sense of a “de novo late-onset”, which shows that the term is not only misleading for us (in the earlier presentation).

2.1. Late initial diagnosis¶

Various long-term studies show that ADHD can also be diagnosed for the first time in adulthood. Depending on the study, this occurs in 0.4% to 10% of ADHD cases. For example, a study of young adults with ADHD found that only 12.6% had already been diagnosed with ADHD in childhood.³⁷
However, this already corresponds to the definition according to DSM 5 or ICD 11, neither of which require that ADHD may only be diagnosed for the first time up to a certain age.

In the case of late first-time diagnosis, a distinction must be made as to whether the symptoms were already so severe in childhood that an ADHD diagnosis could have been given (overlooked diagnosis), whether the symptoms in childhood were not sufficient for this and the symptoms only intensified later, or whether all ADHD symptoms developed for the first time after the age limits specified by the DSM and ICD (de novo late-onset ADHD).
There is evidence that late-diagnosed ADHD differs substantially from childhood ADHD. While childhood ADHD showed a higher genetic overlap with hyperactivity and autism and the highest burden of rare protein-shortening variants in evolutionarily restricted genes, late-diagnosed ADHD was found to have a greater genetic overlap with depression and no increased burden of rare protein-shortening variants⁹

2.1.1. Overlooked childhood ADHD: ADHD recognized late¶

Many people with ADHD who are diagnosed with ADHD for the first time in adulthood already had sufficiently many and severe symptoms in childhood to receive an ADHD diagnosis at that time.
In the last millennium, only a few doctors and psychologists were familiar with ADHD.
We suggest the term “late seen ADHD” or “late recognized ADHD” for this case and in German “spät erkanntes ADHD”.

2.1.2. Subclinical childhood ADHD: subclinical late-onset ADHD¶

Adults who receive an ADHD diagnosis for the first time do not necessarily have to have had diagnosable ADHD in childhood. It is sufficient that some (at least 2) symptoms were already present by the age of 6 (DSM IV, ICD 10) or 11 (DSM 5, ICD 11). This corresponds to the normal definitions of DSM and ICD.
In order to distinguish this case from those in which at most one or no ADHD symptom was recognizable in childhood (de novo late-onset), the term “subthreshold late onset ADHD” (subclinical late-onset ADHD) coined by Liu et al. seems useful to us.

There is now clear evidence from extensive cohort studies in various countries that ADHD can also “appear” for the first time in adulthood.³⁸ One study showed that in children with ADHD, the symptoms disappeared in up to 95% of people with ADHD in adulthood, while a significant proportion of adults with ADHD did not “have” full-blown ADHD as children³⁹

Population-based longitudinal studies show that in a subset of people with ADHD, ADHD symptoms first increase after childhood and they first meet the criteria for ADHD in later adolescence or early adulthood.^{354041424313374445} One study found 45% of people with ADHD who were first diagnosed as adults did not have full-blown ADHD in childhood. They showed lower hyperactivity/impulsivity symptoms and higher education. We see both as indications of a higher probability of an overlooked diagnosis in childhood with good coping skills. In addition, higher resilience is conceivable due to various protective factors.⁴⁶
In a study of 7 to 9-year-old children with subclinical psychiatric disorders, 37% had developed a full-blown Disorder after 3 years.⁴⁷

The data from Agnew-Blaits et al. using a twin cohort study¹³ give an impression of the development of ADHD symptoms in

• Non-affected persons
• People with childhood ADHD and later remitting ADHD
• People with ADHD with persistent childhood ADHD
• (subthreshold) Late-onset ADHD

The symptoms of the respective group at the age of 5 to 12 years are compared with the symptoms at the age of 18 years (n = 2,040):

Another study examined the Pelotas birth cohort of n = 5,249 individuals born in Pelotas, Brazil, in 1993 through age 18 to 19 years, with 81.3% of the cohort participating in the study.⁴⁸
At the age of 11, 393 (8.9%) were found to have ADHD. Most of the people with ADHD were male (63.9%).
At 18 to 19 years of age, 492 (12.2%) met all DSM-5 criteria (excluding age at onset). After excluding comorbidities, a prevalence of 6.3% (256) remained. Whether women predominated (according to the wording) or were in the minority (according to 39%) is unclear to us.
Both groups had higher levels of traffic accidents, criminal behavior, incarceration, suicide attempts and comorbidities in adulthood.
However, only 60 children (17.2%) with ADHD still had ADHD at 18 to 19, and only 60 young adults (12.6%) with ADHD had ADHD at 11.
The results indicate a discontinuity of ADHD and a possible late-onset ADHD. As many as 77.4% of 18 to 19-year-old persons with ADHD did not have full-blown ADHD at the age of 11 or earlier.

Several long-term studies over 20 to 40 years show that ADHD in children and ADHD in adults often affect separate groups of people. In adults, gender participation was also balanced, while in children there was still a male predominance. This could also indicate a separation of the groups of people.^4950515253

The updated European consensus on the treatment and diagnosis of ADHD in adults from 2018⁵⁴ points out that many people with ADHD have a poor memory and therefore have difficulty remembering events and details of their childhood and that there are reports of adults documenting the first onset of symptoms after the age of 12.⁵⁵⁵⁶

One publication reports that the severity of ADHD should be milder if it occurs later.⁴² This is in contrast to reports that late-diagnosed women in particular tend to have more severe symptoms with strong comorbidity (depression, anxiety).⁵²
The risk of being (diagnosed with) ADHD for the first time in adulthood also appears to be related to comorbidities. (ADHD)-typical comorbidities existing in childhood seem to increase the risk of developing ADHD in old age - just as (which has been known for some time) ADHD in childhood increases the risk of developing typical comorbidities in adulthood.⁵⁷⁵⁸

A long-term study found that of 318 children with birth problems, at age 40 those who had developed ADHD as a child were only 21% ADHD, but had poorer educational attainment, more ADHD symptoms and executive problems. Those who had attention problems as a child but not full-blown ADHD had 6.6% ADHD at age 40; those who did not show attention problems as a child had 6% ADHD. Controls without birth problems had 1.6% ADHD at 40.⁵⁹ Accordingly, around 6 to 6.6 % of those children with birth problems and 1.6 % of those without birth problems could be diagnosed with ADHD for the first time at the age of 40.

2.2. Late first onset: de novo late-onset ADHD¶

Whether there is an ADHD in which no ADHD symptoms were detectable in childhood is controversial.
Barkley argues - rightly in our view - that symptoms do not necessarily have to occur in childhood or adolescence, but can also appear for the first time up to the end of brain development (around 23 years).
Findings based on the Dunedin cohort study, which lasted over four decades, go even further. This found a prevalence of ADHD in childhood of 6% and in adults of 3%. However, it further found that the childhood ADHD and adult ADHD groups barely overlapped, and that many people with adult ADHD had shown no signs of ADHD in childhood and adolescence.³⁶ The authors interpret the results as an indication of the existence of two syndromes with different developmental trajectories.
In view of the fact that ADHD is a syndrome that can arise from hundreds or even thousands of different causes, we believe that the different developmental trajectories could possibly also represent different sources of environmental influence. It is conceivable that certain environmental toxins or diseases contributed at different times. To determine this, a study of several birth cohorts from different countries could be helpful.

If the age by which the first symptoms must have appeared is set at 16, 99% of people with ADHD are covered, according to one study.⁶⁰
This means that every hundredth case of ADHD still has its first symptoms after the age of 16. Assuming a prevalence of 8% for ADHD, this would mean 64,000 people in Germany, and at 5%, 40,000 people would have de novo late-onset ADHD after the age of 16.
It is usually found that at least one symptom was highly pronounced in adolescence.⁶¹

Furthermore, it cannot be denied that there are environmental influences that can trigger or intensify ADHD symptoms even in adulthood. More on this under Physical ADHD risk factors And Psychological ADHD risk factors in the chapter Development.
This would be consistent with the heritability of adult ADHD being lower than that of childhood ADHD. This would indicate that the proportion of environmental influences on the development of ADHD could be higher in adults than in children.⁶⁶² However, this is contradicted by the fact that the heritability of ADHD in adults was only lower in self-assessment studies, and that self-assessment was generally associated with a reduced assessment of genetic causes.^6364656667 Differences in the heritability of ADHD depending on the assessment method were also found between parent rating (82%), teacher rating (60%) and self-assessment (48%) in 12-year-old twins.⁶⁶

Regardless of this, it is of no use to adult persons with ADHD if they are denied treatment in adulthood because some ADHD symptoms were not identified in childhood. There are no reports that the usual treatment methods (especially stimulants) are less effective or less frequent in late-onset ADHD. In this respect, special observation by the attending physician may make sense, but refusing treatment would be a breach of the doctor’s duty of care. We see this in particular if treatment is refused in adulthood solely on the basis of a lack of primary school certificates, although the symptoms show a full ADHD picture.

One study examined 239 participants in the MTA study who had not been diagnosed with ADHD as children and 97 of whom showed ADHD symptoms as young adults:⁶⁸
32 also showed the subjective stress required for a diagnosis.
Of these 32, 12 had been diagnosed with ADHD by one of the diagnostic sources at the time, but not by all sources, so no diagnosis was made due to this disagreement.
Of the remaining 21, the current symptoms of 3 resulted from substance abuse.
Of the remaining 18, 9 already had other diagnoses of other disorders. In 5 cases, the symptoms were primarily attributed to the other disorder.
Of the 13 cases whose elevated ADHD symptoms and impairments first appeared in adolescence, 7 were excluded whose symptoms were reported only by a teacher or a teacher and themselves.
This brings the study to 6 cases (2.5% of the comparison group without ADHD at baseline) with de novo late-onset ADHD in adolescence.
In our opinion, the study underestimates the prevalence of late-onset ADHD, as on the one hand it excluded those in whom even one source reported ADHD symptoms as a child, and at the same time it also excluded those in whom only one source reported symptoms in adolescence. Due to this double exclusion, the actual late-onset prevalence is likely to be higher.
The study does, however, reliably establish that there is a group of people with late-onset ADHD in late adolescence, even when viewed critically.⁶⁹

2.3. Very Late-onset ADHD / Senile-onset ADHD in seniors¶

A study of 488 consecutive patients admitted to a special outpatient clinic for dementia found ADHD in 7 patients who were initially suspected of having an early form of Alzheimer’s dementia. These 7 persons with ADHD of “very late onset ADHD” or “senile onset ADHD” had four characteristics in common:⁷⁰

• significantly younger (< 65 years) than the overall study population
• predominantly inattention-related symptoms
• latent manifestation
• stressful life event before the manifestation (stress experience)

2.4. Late-Onset ADHD in women¶

In women, an ADHD diagnosis that only occurs in adulthood is relatively common. While many more boys than girls are diagnosed in childhood, the ratio is (almost) balanced in adulthood.⁵³
Women with a late diagnosis in particular suffer from the most severe symptoms and often comorbidities such as anxiety disorders or depression, which are a typical consequence of ADHD that has gone untreated for a long time.
On the other hand, women are more susceptible to developing emotional disorders that start later (on average in adolescence), such as depression, dysthymia, various anxiety disorders or eating disorders. Sex hormones are often discussed as possible causes.⁷¹
A high oestrogen level alleviates deficits in learning and memory.⁷² This could possibly explain why ADHD symptoms are often not detectable in girls during their school years and only become more apparent in women from the age of 35.

One possible mechanism that could explain late onset, particularly in women, is a masking of estradiol, which declines with age, particularly menopause, and may then reveal executive problems. Early life stress may have lasting effects on those serotonergic circuits that underlie executive functions and are unmasked by the loss of estradiol at menopause.⁷³

3. ADHD symptoms change in adults¶

The DSM IV criteria for ADHD describe the symptoms of children and not specifically those of adults.⁷⁴
The symptoms of ADHD in adults change considerably compared to those of ADHD in children.⁷⁵⁷⁶ Hyperactivity in particular is significantly reduced. Symptoms such as inner restlessness, inability to relax and “constantly having to be active” come to the fore.

One study reports a linear decline in hyperactivity from 6 to 2.9 points between the ages of 8 and 16.⁷⁷ Inattention only fell from 5.8 to 4.9 points in the same period.
However, another study shows that hyperactivity - measured here using infrared movement sensors during the performance of attention tests - is a better discriminator than attention problems, even in adults. Even in people with ADHD-I, a predominantly inattentive subtype, hyperactivity / restlessness of movement was found to be significantly higher than in non-affected people.⁷⁸

Barkley has drawn up a list of typical symptoms of ADHD in adults and verified it through research. Physical hyperactivity decreases significantly, inner restlessness becomes more visible. Inattention also decreases significantly.

The following symptoms predominate in adults:

• Inattention (reduced by up to 40% compared to children)
  Attention problems decrease by up to 40% in adults compared to children and adolescents (the decrease is thus less than that of the other main symptoms).⁸⁰ These figures are taken from the data in Biedermann’s publication. We cannot understand why the specialist literature interprets them differently. However, the decline in attention problems in adults that can be read from the data is consistent with our perception (at least for some people with ADHD). One study reports a linear decline in inattention from 5.8 to 4.9 points between the ages of 8 and 16.⁷⁷
  Other sources, however, report an increase in inattention at the age of⁸¹⁸² and consistent attention problems and executive problems from working memory between the ages of 60 and 94, some of which stemmed from depression.⁸³
• Hyperactivity (reduced by up to 60 % compared to children)
  Hyperactivity transforms into inner restlessness in adulthood (Barkley) and decreases by up to 60% compared to children / adolescents⁸⁴⁷⁷ We suspect that this is not so much a transformation, but that the symptoms of inner tension become more visible after the hyperactivity has subsided.
• Impulsiveness (reduced by up to 60 % compared to children)
  According to various sources, impulsivity is said to decrease by up to 60% compared to children / adolescents⁸⁴⁸⁵⁷⁷
  Another study found no change in impulsivity with age.⁸¹
• Emotional overreactivity (increased in adults)⁸⁶
• Affect lability⁸⁷
• Disorganization⁸⁷

One study found four patterns of hyperactivity and inattention between childhood and adulthood:⁸⁸

• Hyperactivity
  • was low, stay low
  • was high, decreased
• Inattention
  • was low, remained low
  • was high, continued to rise

Some changes can also be measured neurophysiologically.

The problems and quality of life impairments of older adults with ADHD are similar to those of younger adults with ADHD, according to a study. This suggests that there is no long-term improvement with further ageing during adulthood.⁹⁵

Reif, on the other hand, assumes that inattention decreases only slightly, while emotional dysregulation becomes stronger in adulthood.⁹⁶
We believe that emotional dysregulation is a more accepted trait in children (“immaturity”), whereas it is perceived as inappropriate in adults. We therefore wonder whether emotional dysregulation is actually increasing in adults with ADHD or whether emotional imbalance is already present in children with ADHD, but is still perceived as acceptable and therefore not as an ADHD symptom - as we suspect is the case with inner tension, which is perceived in adulthood after physical hyperactivity decreases. We want to research this in more detail.

4. Treatment for adults¶

In adults, significantly lower amounts of stimulants are usually required to correct the dopamine and noradrenaline deficit in the reinforcement system and in the dlPFC, which could be related to the fact that the excess of dopamine transporters compared to children apparently partially regresses.
A (starting) dosage of stimulants as for children would therefore be medical malpractice. Irrespective of this, stimulant treatment should always be started with dosages of 2.5 mg / below the smallest packaging dosage sizes.

5. ADHD in old age¶

There are only a few studies on the symptoms, diagnosis and treatment of ADHD in older adults.⁹⁷