Symptom development in children by age and frequency

The symptoms of ADHD vary according to age, from infancy to adulthood.
In infancy, early symptoms such as restlessness, increased activity and sleep problems may indicate an increased risk of ADHD.
Symptoms in infancy include distractibility, chaotic play behavior and motor problems.
In preschool age, ADHD-I can show anxious and withdrawn behavior, while hyperactive and impulsive behavior is already noticeable in ADHD-HI.
At school age, other ADHD symptoms are added, such as attention problems, learning difficulties, emotional and social problems.
In adolescence, ADHD can be associated with increased risk-taking behavior and addiction.
In adulthood, earlier hyperactivity decreases and inner restlessness becomes more visible. Affective comorbidities such as depression or anxiety disorders can also occur. ADHD can also first manifest itself in adulthood, particularly in women from their late 30s onwards.

Non-affected people also have individual ADHD symptoms. However, people with ADHD have significantly more ADHD symptoms than people without ADHD. However, the diagnosis is not only based on the presence of certain symptoms, but also on their intensity and long-term presence in various areas of life. It is important to distinguish ADHD from temporary stress or strain.

Many of the symptoms listed below are basically typical for children. Nevertheless, naming them is relevant, because the difference lies in the degree of occurrence, which in ADHD clearly exceeds that of peers. The mere occurrence of more severe symptoms compared to peers is not a compelling reason to make a diagnosis. Some children have developmental delays that disappear over time. Nevertheless, these should be observed at an early stage without pathologizing them so that timely intervention can be made if they become severe enough to require support or treatment. For preschool children, one of the most effective forms of treatment is training the parents to interact appropriately with the child and to develop an understanding of the child’s individual problems.

• 1. Symptom development of ADHD-HI (with hyperactivity) by age
  • 1.1. Infancy - early symptoms of ADHD
  • 1.2. Infant age (1 - 3 years)
  • 1.3. Preschool age (4 - 6 years)
    • 1.3.1. ADHD-I at preschool age (without hyperactivity)
    • 1.3.2. ADHD at preschool age (with hyperactivity)
  • 1.4. School years (6 to 15 years)
    • 1.4.1. ADHD-I at school age (without hyperactivity)
    • 1.4.2. ADHD-HI at school age (with hyperactivity)
  • 1.5. Adolescence (from 15 years)
  • 1.6. Adulthood
• 2. Symptom frequency and symptom intensity in ADHD
• 3. Ethnic and cultural differences

1. Symptom development of ADHD-HI (with hyperactivity) by age¶

1.1. Infancy - early symptoms of ADHD¶

One study was able to distinguish those with a high genetic risk of ADHD (older siblings or parents with ADHD) from those without a genetic risk of ADHD in children at 1 month of age based on behavior (primarily increased activity and impulsivity and more frequently reported behavior and temperament problems).¹

The following early symptoms in infants correlate with an increased risk of ADHD in later years:

• Restlessness, hypermotoric
  • Restlessness((
    • Approx. 60 % of children show extreme restlessness²
    • Restlessness at 6 months correlated with ADHD symptoms at 37 and 54 months, independent of the early symptom of shortened sleep duration³
  • Uninterrupted urge to move²
  • Inexhaustible energy⁴
  • No crawling, early walking⁵
  • Restless, unbalanced⁵
  • Playing time shortened⁵
  • Difficulties in establishing a calm waking state⁴
• Sleep
  • Unstable wake and sleep rhythm²
  • Superficial sleep, wide awake⁵
  • Short sleeper⁴
    • Normal sleepers before 18 months showed significantly fewer ADHD symptoms at 37 months than long-term short sleepers³
  • Regulatory problems (excessive crying, sleep or feeding problems) that were co-occurring (multiple) or persistent at 5, 20 or 56 months of age predicted increased internalizing (p = .001), externalizing (p = .020) and overall behavioural problems (p = .001), especially more depressive (p = .012), somatic (p = .005), avoidant (p < .001) and antisocial personality problems (p = .006) than in children who never had regulatory problems. The risk of an ADHD diagnosis was increased (p = .017), especially of the hyperactive/impulsive subtype (p = .032). IQ was not correlated.⁶
• Crying, screaming
  • Particularly frequent, persistent and shrill crying²⁴
  • Insatiable crying at times⁵
  • Regulatory problems (excessive crying, sleep or feeding problems) that were co-occurring (multiple) or persistent at 5, 20 or 56 months of age predicted increased internalizing (p = .001), externalizing (p = .020) and overall behavioural problems (p = .001), especially more depressive (p = .012), somatic (p = .005), avoidant (p < .001) and antisocial personality problems (p = .006) than in children who never had regulatory problems. The risk of an ADHD diagnosis was increased (p = .017), especially of the hyperactive/impulsive subtype (p = .032). IQ was not correlated.⁶
• Feeding problems
  • Drinking problems⁵⁴
  • Hot eater⁴
  • Frequent colic⁴
  • Regulatory problems (excessive crying, sleep or feeding problems) that were co-occurring (multiple) or persistent at 5, 20 or 56 months of age predicted increased internalizing (p = .001), externalizing (p = .020) and overall behavioural problems (p = .001), especially more depressive (p = .012), somatic (p = .005), avoidant (p < .001) and antisocial personality problems (p = .006) than in children who never had regulatory problems. The risk of an ADHD diagnosis was increased (p = .017), especially of the hyperactive/impulsive subtype (p = .032). IQ was not correlated.⁶
• Cleanliness education often delayed²
• Language development often delayed²
• Stroking is not enjoyed⁵
• Frequent skin allergies⁵
• Higher level of negative affect (already at the age of 3 months)⁷
  • The results for positive affect did not reach statistical significance
  • Simultaneous observation of the progression of positive and negative emotionality can generate additional information
  • Negative affect only correlated with ADHD symptoms in childhood if moderate, stable or low positive affect was present at the same time

1.2. Infant age (1 - 3 years)¶

• Distractibility⁴
• Chaotic and destructive, less goal-oriented play behavior²
• Sleep problems
  • Sleep-through problems in toddlers 1 to 3 years old were a stronger predictor of later ADHD than sleep duration.⁸
  • Sleep disorders⁴
  • Regulatory problems (excessive crying, sleep or feeding problems) that were co-occurring (multiple) or persistent at 5, 20 or 56 months of age predicted increased internalizing (p = .001), externalizing (p = .020) and overall behavioural problems (p = .001), especially more depressive (p = .012), somatic (p = .005), avoidant (p < .001) and antisocial personality problems (p = .006) than in children who never had regulatory problems. The risk of an ADHD diagnosis was increased (p = .017), especially of the hyperactive/impulsive subtype (p = .032). IQ was not correlated.⁶
• Gross motor problems
  • Often falls over his own legs⁹
  • Mouth motor skills noticeable⁹
    • Mouth is often open
    • Drools easily
  • Desire for violent movements⁴
  • Constantly on the move⁴
  • Sometimes very skillful motor skills⁴
• Playing time shortened⁹
  • Changes employment frequently
  • Does not finish the game
• Learning problems
  • No learning gain through negative experiences²
  • Learns to dress with difficulty⁹
  • Language development delayed⁹¹⁰
  • Conversion problems⁹
  • Adaptation problems⁹
• Can’t wait⁹
  • Until it is your turn
• Sensitivity changes
  • Highly sensitive or hyposensitive to external stimuli⁹
• Novelty Seeking
  • Stimulation hunger⁴
  • Enormously curious⁴
  • Daring, increased risk of accidents⁴
• ADHD-HI specific:
  • Group incompetence and disruptive behavior, outsider role²
  • Constant fidgeting and interrupting in the chair circle²
  • Strong urge to move leads to danger to self and others²
  • No awareness of danger²
  • Impulsiveness
    • Impulsivity at age 2 correlated with ADHD symptoms at age 3.¹¹
  • Irritability
    • Significant irritability at 3 years of age was predictive of clinical diagnoses
      • At the age of 6 years (depression, oppositional behavior disorder and functional impairment. Irritability also correlated with parental depression and anxiety)¹²
      • At age 9 (current and lifetime anxiety disorders at age nine, current and lifetime generalized anxiety disorder and current separation anxiety, depressive symptoms, disruptive behavior, major functional impairment, and use of outpatient treatment)¹³
      • Between the ages of 12 and 15 (internalizing and externalizing disorders in adolescence, anxiety and depressive symptoms as well as major functional impairments, in particular poorer peer relations, poorer physical health, use of antidepressants)¹⁴
  • Emotional dysregulation
    • Aggression
      • Increased aggression²
      • Little tyrant⁴
      • Destruction of games and toys⁴
    • Anger
      • Frequent / uncontrollable fits of rage²⁴
    • Affect spasms⁴
    • Affectively unstable, mostly pronounced defiant phase⁴
• ADHD-I specific:
  • Remarkably calm and well-behaved⁹
  • Overanxious, clinging, very affectionate⁹
• A meta-analysis found a predictive power of symptoms in the first 36 months for later ADHD in childhood:¹⁵
  • Activity level (k = 18) in infancy and toddlerhood correlated moderately with ADHD (ADHD-C only)
  • Sustained attention correlated moderately negatively with ADHD (all subtypes)
  • Negative emotionality correlated moderately with ADHD (all subtypes)

1.3. Preschool age (4 - 6 years)¶

1.3.1. ADHD-I at preschool age (without hyperactivity)¶

• Often anxious⁹
• Often unsafe⁹
• Learning difficulties
  • Problems listening⁹
  • Slow comprehension⁹
  • Often believes he cannot cope with the task⁹
  • Slow language acquisition, confuses letters⁹
• Gross motor skills
  • Conspicuous oral motor skills⁹
  • Speaks indistinctly⁹
  • Does not like to paint or do handicrafts⁹
  • Motor problems⁹
  • Difficulties learning to swim⁹
  • Difficulties learning to ride a bike
  • Balance problems
  • Activities slowed down or too fast⁹
• Fine motor skills impaired¹⁶
• Withdrawn social behavior
  • Often plays alone⁹
  • Little contact with children of the same age⁹
  • Withdrawal tendencies in groups⁹
    • Kindergarten
    • Circle of chairs
  • Gets bored quickly⁹
• Often loses and forgets things⁹
• Regulatory problems (excessive crying, sleep or feeding problems) that were co-occurring (multiple) or persistent at 5, 20 or 56 months of age predicted increased internalizing (p = .001), externalizing (p = .020) and overall behavioural problems (p = .001), especially more depressive (p = .012), somatic (p = .005), avoidant (p < .001) and antisocial personality problems (p = .006) than in children who never had regulatory problems. The risk of an ADHD diagnosis was increased (p = .017), especially of the hyperactive/impulsive subtype (p = .032). IQ was not correlated.⁶

1.3.2. ADHD at preschool age (with hyperactivity)¶

• Motor hyperactivity
  • Motor restlessness⁹
  • Always on the move⁹
• Impulsiveness
  • Gets excited quickly and strongly⁹
  • Reacts spontaneously and rashly⁹
  • Asks a lot⁹
    • Often does not wait for answers⁹
  • Does not adhere to rules⁹
    • Often forgets rules again¹⁷
  • Grumbles quickly⁹
• Attention problems
  • Often only become apparent at an older age (school years)
  • Cannot listen for long⁹
  • Forgets quickly⁹
  • Loses a lot⁹
• Aggression
  • Often as a comorbidity
  • Especially in case of uncertainty⁹
• Gross motor skills
  • Conspicuous oral motor skills¹⁸
  • Language problems
    • Speaks indistinctly⁹
    • Stammer⁹
    • Difficulties with some consonants
  • Does not like to paint or do handicrafts¹⁸
  • Holds pens cramped⁹
  • Presses too hard⁹
  • Coloring or cutting out shapes makes it difficult⁹
  • Difficulties learning to swim
  • Difficulties learning to ride a bike
  • Balance problems
• Fine motor skills impaired¹⁶
• Social behavior
  • Strong sense of justice⁹
  • High ambition in sports and games⁹
  • Often wants to determine⁹
  • Eager for social services⁹
  • Quickly offended¹⁹
    • Rejection Sensitivity
• Impatience
  • With itself⁹
  • With others⁹
• Wets more frequently⁹
  • More often during the day than at night
• Sleep
  • Frequently falling asleep late⁹
  • Needs little sleep⁹
• Executive function problems at preschool age
  • Correlated with more externalizing and attention symptoms, but fewer internalizing symptoms at the age of 8 to 13 years²⁰
  • Similar for an older age group²¹

1.4. School years (6 to 15 years)¶

ADHD symptoms are now becoming fully apparent.²

Sleep problems at the age of 8 to 9 years increased the risk of ADHD at the age of 10 to 11 years by 18 to 20%²²

1.4.1. ADHD-I at school age (without hyperactivity)¶

• Emotional problems
  • Often anxious⁹
  • Often unsafe⁹
  • Dares to do nothing⁹
  • Rejection Sensitivity
    • Easily offended⁹
    • Cries quickly⁹
    • Emotionally sensitive⁹
    • Poorly tolerates criticism⁹
    • Feels unloved⁹
    • Feels misunderstood⁹
• Attention and learning difficulties
  • Problems listening⁹
  • Easily distractible⁹
  • Forgets a lot⁹
  • Overhears a lot⁹
  • Unfocused⁹
    • Unless something is of particular interest
  • Dreamy⁹
  • Slowly⁹
  • Inflexible thinking⁹
  • Takes a very long time to do homework⁹
  • Cannot do homework alone⁹
• Gross and fine motor problems
  • Writing problems
  • Coloring unclean⁹
  • Speaks indistinctly⁹
• Social behavior
  • Is easily annoyed⁹
  • Can defend himself badly⁹
  • Delayed development of social maturity⁹
  • Gets bored quickly⁹
• Often loses and forgets things
• Somatization tendencies
  • Frequent headaches⁹
  • Frequent abdominal pain⁹

1.4.2. ADHD-HI at school age (with hyperactivity)¶

• Social behavior
  • Integration into the class group very difficult²
• Aggression
  • Hits frequently, is often beaten by others²
• Risk behavior
  • Can assess dangers poorly⁹
  • 85 % of accidents on the way to school²
• Attention problems become recognizable for the first time
  • From the age of 7 at the earliest
  • Up to the age of 14, 15 years
• Motor hyperactivity
  • Motor restlessness⁹
  • Always on the move⁹
  • Fidgets a lot⁹
• Gross motor skills
  • Poor power metering⁹
• Impulsiveness
  • Gets excited quickly and strongly⁹
  • Reacts spontaneously and rashly⁹
  • Interrupts others
  • Answers before the question is finished⁹
  • Is often loud⁹
• High sensitivity
  • Is often sensitive to noise itself¹⁷
• Attention problems
  • Often only become apparent at an older age (school years)
  • Cannot listen for long⁹
  • Forgets quickly⁹
  • Loses a lot⁹
  • Concentration span limited
    • Frequently switches back and forth between tasks / activities⁹
  • Often paints on the side
  • Difficulties starting homework⁹
  • Interrupts homework frequently⁹
  • Good powers of observation⁹
    • Notices a lot⁹
    • Can see through others well⁹
• Learning problems
  • Makes mistakes again and again
  • Does not learn from mistakes⁹
• Gross motor skills
  • Conspicuous oral motor skills¹⁸
  • Language problems
    • Speaks indistinctly⁹
    • Stammer⁹
    • Difficulties with some consonants
  • Does not like to paint or do handicrafts¹⁸
  • Holds pens cramped⁹
  • Presses too hard⁹
  • Coloring or cutting out shapes makes it difficult⁹
  • Difficulties learning to swim
  • Difficulties learning to ride a bike
  • Balance problems
• Emotional dysregulation
  • Rejection Sensitivity
    • Quickly feels unfairly treated⁹
• Social behavior
  • Strong sense of justice⁹
    • Altruistic behavior
  • Often wants to determine⁹
  • Gets on worse with peers than with younger or older people⁹
• Collects useless things⁹
• Sleep
  • Often fall asleep late

1.5. Adolescence (from 15 years)¶

• Motor hyperactivity is reduced²
• Inner and outer restlessness⁹
• Impulsiveness and reduced attention remain²
• Orientation towards socially marginalized groups²
• Risk of developing an addiction²
• Willingness to engage in high-risk behavior²
• Frequent accidents²
• Drop in performance under stress⁹
• Organizational problems⁹
• Low determination⁹
• Spotty handwriting⁹

1.6. Adulthood¶

• Barely any motor hyperactivity, instead inner restlessness, feeling driven²³
• Attention problems subside somewhat
• Emotional problems / affective comorbidities on the rise
  • Depression
  • Anxiety disorders
• Increased risk of addiction, Disorders in social behavior²⁴
• Anxiety symptoms, alcohol problems²⁵
• Criminal offenses ²⁶
• Increased tendency to have accidents²⁷
• Worse professional position²⁸

2. Symptom frequency and symptom intensity in ADHD¶

ADHD is not diagnosed by the presence of a specific type of symptom that is exclusive to ADHD (categorical), but by the set of symptoms that can originate from ADHD and their intensity (dimensional).²⁹³⁰

• In a collection of symptoms presented by Barkley³¹
  • Non-affected people often experience 1 to 2 of the 18 symptoms on average, i.e. around 5 %
  • On average, people with ADHD often have 12 of the 18 symptoms mentioned, i.e. around 66%.³¹
• In the online test we designed ourselves ⇒ ADHD online tests
  have
  • According to their own assessment, people with ADHD who were not affected had an average of just under 8 out of 32 possible symptoms (25 %)
  • Subjects with a confirmed ADHD diagnosis around 24 of the 32 possible symptoms (75 %)
• Hardly any person with ADHD has all the symptoms “often”, and it is barely possible to typify which symptoms occur more frequently together.

The symptoms must occur over a longer period of time and in several areas of life. They usually first become apparent before the age of 12. However, more and more cases of late onset ADHD are being recognized in which there were no sufficiently severe symptoms in adolescence to justify a diagnosis. This mainly affects women in their late 30s.
The fact that symptoms must persist for longer and in different areas of life serves to distinguish ADHD as a permanent disorder from symptoms of merely temporary (stress) exposure to temporary stressors.

3. Ethnic and cultural differences¶

When adults diagnose ADHD in children, the different ethnic and cultural backgrounds should be taken into account.³²