Attention Deficit Hyperactivity Disorder

Synonyms: Hyperkinetic disorder, attention deficit disorder (ADD)

Attention deficit hyperactivity disorder is a persistent pattern of inattention and/or hyperactivity and impulsivity that is more frequent and severe than is typically observed in individuals at a comparable level of development. The ICD-10 classification uses the term hyperkinetic disorder for a more restricted diagnosis. It differs from the DSM-IV classification in that all three problems of attention, hyperactivity, and impulsiveness must be present.

Either 1 or 2:

1. Inattention: at least six of the following symptoms persisting for at least 6 months to a degree that is maladaptive and inconsistent with developmental level:
   • Often fails to give close attention to details or makes careless mistakes in schoolwork or other activities.
   • Often has difficulty sustaining attention in tasks or play activities.
   • Often does not seem to listen to what is being said to him or her.
   • Often does not follow through on instructions and fails to finish schoolwork chores or duties in the workplace (not due to oppositional behaviour or failure to understand instructions).
   • Often has difficulty organising tasks or activities.
   • Often avoids or strongly dislikes tasks (such as schoolwork or homework) that require sustained mental effort.
   • Often loses things necessary for tasks or activities, e.g. school assignments, pencils, books, tools or toys.
   • Often easily distracted by extraneous stimuli.
   • Often forgetful in daily activities.
2. Hyperactivity/impulsivity: at least six of the following symptoms of hyperactivity or impulsivity for at least 6 months to a degree that is maladaptive and inconsistent with developmental level:
   • Hyperactivity:
     • Often fidgets with hands or feet and squirms in seat.
     • Leaves seat in classroom or in other situations in which children are expected to remain seated.
     • Often runs about or climbs excessively in inappropriate situations (in adolescents or adults this may be limited to feelings of restlessness).
     • Often has difficulty playing or engaging in leisure activities quietly.
     • Is often on the go or often acts as if driven by a motor.
     • Often talks excessively.
   • Impulsivity:
     • Often blurts out answers to questions before the questions have been completed.
     • Often has difficulty waiting in line or awaiting his or her turn in games or group situations.
     • Often interrupts or intrudes on others.

• Onset no later than 7 years of age.
• Symptoms must be present in two or more situations, e.g. at school, at home and/or at work.
• The disturbance causes clinically significant distress or impairment in social, academic and/or occupational functioning.
• Does not occur exclusively during the course of a pervasive developmental disorder, schizophrenia or other psychotic disorder, and is not better accounted for by a mood disorder, anxiety disorder, dissociative disorder or personality disorder.¹

• Combined type: inattention and overactivity or impulsiveness (similar to hyperkinetic disorder).
• Predominantly inattentive type.
• Predominantly hyperactive-impulsive type.

• ADHD affects 8-12% of children.¹
• Three times more boys than girls are affected.
• More common in lower socioeconomic groups.
• The disorder is more common in first-degree relatives of affected children and studies of twins suggest a significant genetic contribution. There are a number of genes that are thought to have a small effect, e.g. DRD4 and DRD5, but it is unlikely that any individual genes have a large effect.¹
• ADHD is commoner in learning-disabled children, and if there has been prenatal exposure to cannabis.^2,3 Other environmental risk factors include obstetric complications and family conflict.¹

• ADHD is a part of a spectrum of disorders.
• 70% also have other conditions such as generalised or specific learning difficulties (e.g. dyslexia, language disorders, autistic spectrum disorder), dyspraxia, Tourette's or tic disorder.
• Oppositional defiant disorder or conduct disorder is present in most children with ADHD, 20% have coexistent mood disorder, 25% coexistent anxiety disorder, and 20% specific developmental disorders such as dyslexia or dyspraxia.⁴

• Anxiety
• Depression
• Drugs, e.g. anticonvulsants, antihistamines, β-agonists, antisocial conduct disorder, disinhibited attachment disorder (seen in children who have passed through many adoption/foster placements and who have been unable to develop healthy attachments or friendships).

• Parents and affected children need a great deal of explanation and support. There is a great deal of unproven advice available for parents and it is very important that time is taken to properly explain and discuss the diagnosis and appropriate treatments.
• Caffeine containing beverages are best avoided.
• Hypoallergenic diets (e.g. no tartrazine) are controversial and unproven.
• Some researchers have shown a deficiency in essential fatty acids in a subgroup of ADHD patients and tried supplementation.⁵

Drugs

• Recent evidence suggests the best medications are better that the best behavioural regimes and, in most cases, combined treatment is no better than medication alone.⁶
• Methylphenidate is the most commonly used medical treatment, although it is not licensed for children under 6 years of age. Dexamfetamine tends to be reserved for children who do not respond to methylphenidate. Atomoxetine is also licensed for the management of attention deficit hyperactivity disorder in children and adults.
• Methylphenidate, atomoxetine and dexamfetamine are all recommended as possible treatments for children or adolescents with ADHD. Treatment with methylphenidate, atomoxetine or dexamfetamine should only be started after a specialist who is an expert in ADHD has thoroughly assessed the child or adolescent and confirmed the diagnosis. Once treatment has been started it can be continued and monitored by a GP.⁷ Treatment often needs to be continued into adolescence, and may need to be continued into adulthood.
• The dose is gradually titrated upward while monitoring for effectiveness and side effects. Insomnia, loss of appetite and weight loss are relatively common side effects.
• Follow-up and monitoring: should include baseline physical review (height, weight and general health), medication review for both efficacy, safety and compliance and a review of the child's functioning at school, at home, socially and psychologically. Monitoring should include regular feedback from parents, teachers and others in close contact with the child.
• When a child receiving methylphenidate shows improvement and the condition appears stable, treatment can be suspended periodically in order to assess the need for continuation of therapy.⁷
• There is some evidence that tricyclic antidepressants can benefit patients with ADHD, particularly with behavioural symptoms. However, the evidence is less convincing than for the psychostimulants.⁸

Psychosocial treatments

• Cognitive behavioural therapy, behaviour modification and intensive contingency treatment have been used. The latter two treatments are more effective than cognitive behavioural therapy in improving behaviour and academic performance.⁹
• Although there is little evidence to show that combined treatments of medication plus psychotherapy are more effective than with medication alone, combined treatments may have an effect on other symptoms such as anxiety and may improve social skills.
• Family therapy without medication may help to develop structure in the family, help to manage children's behaviour, and may help families cope with distress from the presence of the disorder. family therapy is an effective intervention for children with ADHD. However there is no strong evidence that family therapy is an effective intervention for children with ADHD.¹⁰
• Underlying learning difficulties will require additional individual or small-group remedial instruction.
• Other allied health professionals may be involved. Occupational therapists can provide specific programmes for handwriting or gross motor difficulties. Speech therapists may be required for language difficulties.

Alternative treatments

• Many of the alternative treatments that have been promoted are not supported by clinical trials.¹¹

Of all children diagnosed as having ADHD, more than 70% continue to meet the criteria for ADHD in adolescence, and up to 65% of adolescents may continue to meet the criteria in adulthood.¹²