About 5% of the children and 2.5% of the adults are diagnosed with ADHD. There are several requirements for a diagnosis:

1. There are at least six symptoms for at least six months. For people older than 17 years old, there need to be five or more symptoms.
2. The symptoms are present before the 12th year of age.
3. The symptoms exist in two or more areas (e.g. school; home).
4. The symptoms interfere with social, school or professional functioning.
5. The symptoms are not better explained by other disorders.

There are three subtypes:

• Predominantly inattentive subtype (i.e. ADD).
  • Careless attention to detail.
  • Problems sustaining attention over time.
  • A poor follow-through (e.g. schoolwork; homework; chores).
  • A poor ability to sustain mental attention (e.g. independent work at school).
  • The child loses necessary materials (e.g. assignment sheets).
  • The child is forgetful.
  • The child is easily distracted.
  • The child is poorly organized.
  • The child does not appear to listen.
• Predominantly hyperactive/impulsive subtype
  
  • The child demonstrates fidgety or squirmy behaviour.
  • The child has problems remaining seated.
  • The child shows excessive motion.
  • The child has problems engaging in quiet play.
  • The child is constantly on the go.
  • The child shows incessant talking.
  • The child blurts out answers or comments (i.e. impulsivity).
  • The child is impatient and has problems with turn-taking (i.e. impulsivity).
  • The child is intrusive to others (i.e. impulsivity).
• Combined subtype.

Children with the inattentive presentation are often misdiagnosed and misunderstood. It is often misinterpreted as a lack of motivation. The children may be characterized by a sluggish information processing style and there are problems with focused or selective attention. These children are unable to filter essential from non-essential details. This lack of attention may result from information overload and the inability to selectively limit the focus of attention. They have poor performance on tests because of this problem with attention and their poor concept of time and time management.

Children with the hyperactive-impulsive presentation experience academic problems due to their impulsive nature. They emphasize speed over accuracy and approach tasks incorrectly because they do not wait for all instructions. They are at social risk due to their impatient nature and they often have poor social skills and difficulties making and maintaining friends. They often gravitate towards other rule-breaking children.

A difficult temperament (1), poor sleep patterns (2), excessive activity (3), irritability (4) and a difficulty soothing the child when they are upset (5) are risk factors in infancy for the development of ADHD. During toddlerhood, the child may demonstrate higher levels of underregulated behaviours and a lack of self-control may persist during the transition to preschool.

The symptom presentation of ADHD differs with age. Inattention symptoms are consistent over time but the hyperactive/impulsive symptoms decrease over time. There is a different ADHD symptom presentation by gender. Females typically have more inattentive symptoms and more internalizing problems while males have more hyperactive/impulsive symptoms. ADHD is more prevalent in males than in females but this may be due to the hyperactivity/impulsivity symptoms being more noticeable than the inattentive symptoms.

There are four biological features of ADHD:

1. 1. 1. 1. Brain structure
            There is less activity in the frontal brain regions (i.e. executive functioning) and more activity in the cingulate gyrus (i.e. focusing of attention).
         2. Genetic transmission
            Half of the children with ADHD have a parent with ADHD and 75% of the aetiology may be contributed to genetic factors.
         3. Neurotransmitters
            There may be low catecholamines (e.g. dopamine; epinephrine; norepinephrine) in children with ADHD and this is associated with attention and motor activity.
         4. Neurocognitive processing
            There may be a dysfunction in executive functioning.

The altered perception of time in ADHD is associated with reductions of dopamine in the basal ganglia. It may also be the result of dysfunction in the parietal lobe. Medication for ADHD (e.g. Ritalin) increases the number of catecholamines in the brain.

ADHD is very comorbid with other disorders (e.g. ODD). At least 62% has a co-occurring disorder and 34% has at least two co-occurring disorders. Symptoms of bipolar disorder and depression may be mistaken for ADHD. Children with bipolar disorder demonstrate rapid shifts of mood compared to lengthy moods for adults, making differential diagnosis very difficult.

For ADHD, different problems occur at different ages:

• Preschool
  The most prevalent problems here are behavioural problems and hyperactivity.
• School-age
  The most prevalent problems here are academic problems (1), social problems (2), low self-esteem (3), oppositional behaviour (4) and accidents (5).
• Adolescence
  The most prevalent problems here are planning problems (1), social problems (2), low self-esteem (3), addiction (4), behavioural problems (5) and antisocial behaviour (6).
• Student
  The most prevalent problems here are cognitive under-functioning (1), difficulty finding a job (2), performance anxiety (3), substance abuse (4) and accidents (5).
• Adulthood
  The most prevalent problems here are job-related problems (1), low self-esteem (2), substance abuse (3), accidents (4) and relation problems (5).

People with ADHD get in more accidents due to risk-taking behaviour. Children who receive medication for ADHD are less prone to substance abuse because they develop resilience and they do not self-medicate.

Barkley’s model of ADHD states that a child’s degree of success in behavioural inhibition is central to determining the outcome of working memory (1), self-regulation (2), internalization of speech (3) and reconstitution (4). Deficits in behavioural inhibition result in poor problem-solving strategies based on an inability to integrate and coordinate information generated by the four central processes. This model may explain the hyperattentive-impulsive presentation of ADHD.

According to this model, children with the hyperattentive-impulsive presentation have problems with sustained information and not with selective attention. Sustained attention consists of attention for effortful tasks and contingency-based attention (i.e. self-rewarding attention). Children have fewer problems with contingency-based attention in novel situations giving the false idea that these children are focused when they want to.

The dual pathway model of ADHD states that ADHD is explained by impairment in executive functioning and the motivational and reward system. Executive functions enable goal-oriented behaviour. Motivation does not refer to deliberate motivation.

Executive function is a control process of the brain and includes attention (1), inhibition (2), working memory (3), flexibility (4), planning (5), problem-solving (6), reasoning (7), initiation of action (8) and monitoring of action (9).

A child with executive functioning dysfunction is typically not annoyed by their own behaviour whereas it is frustrating for the teacher. There are several guidelines for helping a child with ADHD in the classroom with executive functioning problems:

• Do not get annoyed.
• Attempt to avoid distractions.
• Make sure that the task is feasible
  
  • Provide structure.
  • Give learning objectives (i.e. primary and secondary).
  • Give clear instructions.
  • Model tasks or indicate steps.
  • Repeat important information.
  • Control whether the child can make independent work.

ADHD is highly prevalent and has a different symptom presentation for everybody. The consequences of the disorder can be great and children with ADHD often show executive functioning problems. This, in turn, often causes academic problems. Parents and teachers can help alleviate some of the problems.

Children with ADHD often have deficits in motivation to perform due to dopaminergic system abnormalities. This means that they have (more) motivation to perform self-rewarding tasks with direct rewards (e.g. videogames) but not for other tasks. Children with these deficits need direct rewards (1), more rewards (2) and higher rewards (3). They take longer to learn new behaviour.

Typically developing children already have optimal performance with feedback only. However, the performance of children with ADHD improves with reward and there is more improvement with higher rewards but the performance of children with ADHD does not normalize, regardless of the reward. Children with ADHD have a decrease in performance over time but the performance over time normalizes when given a high reward. This implies that children with ADHD need more motivation, especially on long tasks.

There are several guidelines for helping a child with ADHD in the classroom with motivational problems:

• Do not get annoyed.
• Make sure that the task is feasible.
• Make sure that there is strong motivation.
  
  • Give direct feedback.
  • Be consistent in giving feedback.
  • Reward more often for longer tasks.
  • Find out what is rewarding for the child.
  • Indicate when movement is permitted.

Every school transition (e.g. other school; other grade) is a challenge for children with ADHD. However, parents and teachers can help by offering feasible tasks and rewards.

There may be a socially disabled subtype for children with ADHD symptoms and a discrepancy between social skills and cognitive ability. Oppositional defiant disorder (ODD) is very common in children with ADHD. It consists of a pattern of negative, hostile and rebellious behaviour. The prevalence of this is 3.3% but it often co-occurs with ADHD. 50% of the children with the combined subtype of ADHD have ODD and 25% of the inattentive type have ODD. There are several requirements for a diagnosis:

1. For at least six months, four or more symptoms of angry or irritable mood (1), argumentative or defiant behaviour (2) or vindictiveness (3).
2. The symptoms cause distress to self or others or it impacts social, school or professional functioning.
3. The symptoms do not exclusively occur during the course of a psychotic, substance use, depressive, bipolar or disruptive mood dysregulation disorder.

Common behaviour in ODD is a bad mood (1), arguing with adults (2), not obeying rules (3), aggression (4), destructive temper tantrums (5), irritating others on purpose (6), blaming others (7), being quickly irritated by others (8) and being vengeful (9). For children younger than five years, this behaviour needs to occur on most days. For children older than five years this behaviour needs to occur at least once a week.

What is normal naughty behaviour changes over the course of development. For example, temper tantrums are common in toddlerhood and naughty behaviour is common in preschool when the child’s goals are blocked (e.g. getting the ball). Problem behaviour is often seen in preschool years but is often unlearned over time.

Aggression in the preschool years is an important predictor of aggression in later life. There are three pathways to problem behaviour and delinquency:

1. Authority conflict pathway
   This starts with stubborn behaviour which starts before the age of 12. This develops into defiance and disobedience and then into authority avoidance (e.g. truancy). This can merge with the other pathways.
2. Overt pathway
   This starts with minor aggression (e.g. bullying; annoying others) and develops into physical fighting and, lastly, violence.
3. Covert pathway
   This starts with minor covert behaviour (e.g. shoplifting) and develops into property damage and, lastly, serious delinquency (e.g. fraud; burglary).

The different pathways can overlap as it develops. There are several predictors of problem behaviour and these predictors are hereditary, rather than aggression itself.

• Problem behaviour at a young age.
• The male sex.
• Attention problems.
• Hyperactivity.
• A difficult temperament.
• A low resting heart rate.
• A low serotonin level.
• A low IQ.
• Limited pro-social emotions.

The environment plays an important role in the development of aggression. There are several family characteristics in the case of child aggression:

• Inconsistent application of rules.
• Physical and harsh punishment.
• Lack of warmth, sensitivity and monitoring.
• A low SES, unsafe environment and little social network.

There is often an attraction to peers with similar behaviour. If a child shows problem behaviour, this leads to many short-term relationships and many conflicts.

The learning theory states that problem behaviour is learned as a result of wrong instructions (1), wrong examples (2), endorsement of wrong behaviour (3) and through coercive interactions (4). Overlearned activities require very little active cognitive processing which makes it possible to do something else at the same time (e.g. driving and talking).

Coercive interactions consist of interactions where behaviour is enforced on one another and little attention is paid to prosocial behaviour. A coercive cycle can be parent-driven or child-driven. Coercive sequences are not pathological by themselves. A lot of the aversive events (e.g. attack) are positively reinforced by the victim (e.g. give up bicycle; cry), leading to an increase in the probability of future aversive events on the victim. Peers and siblings may be an important source of positive reinforcement, especially for physical aggression (e.g. hitting).

Coercion may be overlearned. The effects of reinforcement and punishment contingencies in family interaction sequences may be automatic. This means that this interaction is not mediated by thought or expectancies. Family therapy is very difficult because the coercion process is automatic.

 It may be useful to bring the overlearned aspects of the coercion process in the open. This can be done by This can be done by providing clearly stated directives in a neutral affect and follow-up with positive reinforcement for cooperation and small negative sanctions for non-compliance.

The contingency theory states that everybody changes their behaviour to match the changes in contingencies one experiences in their social environment. The contingencies may operate outside of family members’ awareness or intention, meaning that they may result in increasing reliance on aversive behaviour as a means of influence and control. This may lead to extended conflict which escalates in intensity.

Negative reciprocity is more likely when one member of a family engages in coercive behaviour (e.g. when the mother engages in aversive behaviour, the child is more likely to also respond negatively). This leads to a sequence that increases coercion:

1. Frequent aversive behaviour sets up reinforcement contingencies.
2. The contingencies are followed by increases in chains of aversive behaviour (i.e. repeated aversive behaviours by multiple family members).
3. The aversive behaviours are accompanied by outbursts of negative emotion.

The presence of negative affect increases the risk and longer chains of aversive events are more likely to escalate in intensity. The negative reinforcement contingency that accompanied an aversive exchange is more powerful and resistant to extinction than positive reinforcement. This may shape aversive behaviour.

Infants may use negative contingencies to teach caregiving skills to family members (e.g. crying as an aversive behaviour). The differences in reactions of both the infant and the parents influence the risk for persistent involvement in coercive social processes (e.g. time spent crying before the caregiver picks up the infant). In most families, teaching the child to use words and positive behaviour gradually replaced coercion but it can persist to early childhood. Coercive behaviour peaks around the age of 3 (e.g. temper tantrums of toddlers).

The degree to which child coercive behaviours persist depends on the effectiveness of parents’ use of contingencies. The preschool period can be a period of growth in coercion, depending on parental skills and child temperament. There are three stages in the sequence of coercive behaviours:

1. 1. 1. 1. Stage 1: the family (i.e. infancy and toddlerhood)
            There can be coercive interactions between the infant and the mother. As the child ages, more family members are involved and it increases in intensity. At this point, several coercive processes may begin to run simultaneously. There is a progression to a wider variety of coercive behaviours shaped by reinforcement contingencies during family interactions. This stage includes negative reinforcement for coercive behaviours.
         2. Stage 2: the deviant peer group (i.e. school age through adolescence)
            The reinforcement contingencies are positive (1), are provided by peers (2) and shape more covert forms of aggression (3). Friends’ reinforcement accounts for a lot of variance of adolescent rule-breaking or deviant talk (i.e. deviancy training by peers). The contribution of deviant peers could begin as early as school entry.
         3. Stage 3: peer deviancy training
            Deviant peers shape increasingly deviant behaviour through both negative and positive reinforcement. There are significant contributions to the coercion process by both the family and the coercive peer group.

Children who started aggressive and oppositional behaviour early in development were more at risk for police arrests and to become chronic offenders than late starters. Risk for police arrest increases as children move through the stages of coercion.

The macro-level of coercion describes the reactions people have when confronted by some form of antisocial behaviour (e.g. rejection of peer that shows antisocial behaviour). It is also associated with changes in the form of deviant behaviour that evolve from people’s reactions to antisocial behaviour.

As children move to stage three, they come into contact with a subgroup of peers who are even more extreme. They will combine elements of stage 1 with those of stage 2. There is a drop in positive parenting and monitoring as the family becomes increasingly coercive. These children drift into increasingly deviant environments through reinforcement.

The Parent Management Training-Oregon model (PMTO) is suitable for treatment and prevention of antisocial behaviour. It leads to more effective parenting (1), less child externalizing problems (2), less maternal depression (3), higher SES (4) and lower deviant peer association (5). The work-struggle hypothesis refers to the relationship between therapists and clients where the therapist suggests change and the client resists it.

The social interaction learning model (SIL) states that ongoing coercive behaviour is governed by its positive and negative reinforcement contingencies and not cognitive processes. This seems to be supported. A reduction in coercion is typically associated with a growth in positive parenting. Coercion and a lack of positive parenting contribute to growth in deviancy.

The information processing theories differentiate between reactive aggression and proactive aggression. According to these theories, reactive aggression is caused by rejection experiences. There is an aggressive experience (1), this leads to selective attention to threatening information (2), this leads to a negative interpretation of other people’s behaviour (3), this leads to anger (4), this leads to a difficulty in regulating the anger (5) which, in turn, again leads to an aggressive experience.

Proactive aggression is caused by observational learning and reinforcement of aggressive behaviour. The child has dominance and revenge goals (1), limited social skills (2) and an overestimation of approval of others on aggressive behaviour (3) and this leads to proactive aggression.

Aggression always has a reason. It is typically an expression of dissatisfaction or distress and can be the result of depression (1), anxiety (2), overestimation of situation (3), cognitive dissonance (4) or relationships with others (5). It is a coping style.

Psychoeducation can help families to communicate better. It consists of learning how to bear the feeling (1), communicate about emotions (2), learning to talk about difficult subjects when calm (3) and understanding the roots of the anger (4).

For the assessment of ADHD, a semi-structured interview is useful. It is important to use multiple informants (1), obtain information concerning other areas of diagnostic concern (e.g. depression) (2) and it may be useful to have a cognitive assessment to evaluate deficits in specific areas (3).

Treatment alternatives for ADHD depend on the comorbid features (1), symptoms (2) and the nature and extent of functional impairment (3). The interventions can be applied at home (1), at school (2) or in interactions with peers (3). Stimulant medication is more effective than behavioural therapy in alleviating core symptoms of the disorder but there are no long-term differences.

Anxious children with ADHD may benefit equally well from behaviour therapy compared to medication. Parent training can improve parenting skills (1), reduce parental stress (2), reduce core symptoms of ADHD (3) and reduce non-compliance (4).