Attention deficit hyperactivity disorder (ADHD) is a heterogeneous behavioural syndrome characterised by the core symptoms of:
- hyperactivity
- impulsivity
- inattention
- while these symptoms tend to cluster together, some people are predominantly hyperactive and impulsive, while others are principally inattentive
- two main diagnostic criteria are in current use
- the International Classification of Mental and Behavioural Disorders 10th revision (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5)
- both systems require that symptoms are present in several settings such as school/work, home life and leisure activities
- symptoms should be evident in early life, if only in retrospect; for ICD-10, by age 7 years and for DSM-5, by age 12 years
- ADHD may persist into adult life
- prevalence rates for ICD-10 (identifying hyperkinetic disorder) are 1 to 2% in childhood. Under the previous, less stringent DSM-IV criteria, childhood prevalence rates were 3 to 9% and these may increase under the new DSM-5 criteria
- causes of ADHD are not fully understood but a number of risk factors are associated with the condition
- genetic factors can have an influence, with family members frequently affected
- the diagnosis of ADHD in older family members such as parents may have previously been missed and should be considered
- both the ICD-10 and DSM-5 require the presence of functional impairment due to symptoms of ADHD, with the symptoms adversely affecting psychological, social and/or educational/ occupational functioning
- the impact of ADHD may vary considerably in its severity, which is best judged by considering the level of impairment, pervasiveness, and familial and social context
- for some people, symptoms may be limited to certain settings and cause minimal impairment in a limited number of domains (for example, ability to complete schoolwork, work tasks, avoiding common hazards and forming positive interpersonal relationships)
- in other people, multiple symptom areas (hyperactivity, inattention and impulsivity) are present in multiple settings, and this causes significant impairment across multiple domains
- symptoms and impact can also change over time. For some people, symptoms and impairment may be reduced through environmental modifications, such as a modified school curriculum or choice of employment
- symptoms of ADHD can overlap with those of other related disorders
- common coexisting conditions in children include disorders of mood, conduct, learning, motor control, language and communication, and anxiety disorders; in adults, they include personality disorders, bipolar disorder, obsessive-compulsive disorder and substance misuse
Drug treatment for children and young people with ADHD should always form part of a comprehensive treatment plan that includes psychological, behavioural and educational advice and interventions (1). Medication for ADHD should only be prescribed after expert advice:
- when a decision has been made to treat children or young people with ADHD with drugs, healthcare professionals:
- methylphenidate (either short or long acting) should be offered as the first line pharmacological treatment for children aged 5 years and over and young people with ADHD
- consider switching to lisdexamfetamine for children aged 5 years and over and young people who have had a 6-week trial of methylphenidate at an adequate dose and not derived enough benefit in terms of reduced ADHD symptoms and associated impairment
- dexamfetamine should be considered for children aged 5 years and over and young people whose ADHD symptoms are responding to lisdexamfetamine but who cannot tolerate the longer effect profile
- atomoxetine or guanfacine should be offered to children aged 5 years and over and young people if:
- they cannot tolerate methylphenidate or lisdexamfetamine or
- their symptoms have not responded to separate 6-week trials of lisdexamfetamine and methylphenidate, having considered alternative preparations and adequate dose
Drug treatment for adults with ADHD should always form part of a comprehensive treatment programme that addresses psychological, behavioural and educational or occupational needs
- following a decision to start drug treatment in adults with ADHD, lisdexamfetamine or methylphenidate are options as first-line pharmacological treatment
A systematic review (2) found:
- very low-certainty evidence that extended-release methylphenidate compared to placebo improved ADHD symptoms (small-to moderate effects) measured on rating scales reported by participants, investigators, and peers such as family members
- methylphenidate had no effect on 'days missed at work' or serious adverse events, the effect on quality of life was small, and it increased the risk of several
adverse effects
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