What is ADHD?

ADHD is a common mental health disorder that starts during child development but frequently persists throughout adolescence and into the adult years. Common symptoms include inattention, distractibility, disorganisation, over activity, restlessness, impulsiveness and mood lability; and these may lead to considerable clinical and psychosocial impairments. ADHD is often seen at a high rate in people with other significant clinical problems including substance abuse, unstable mood states, anxiety, depression, forensic cases and emerging or developed personality disorder. ADHD is often associated with specific learning difficulties and is a common problem in higher education.

ADHD is a clinical syndrome defined in the DSM-IV and ICD-10 (hyperkinetic disorder) by high levels of hyperactive, impulsive and inattentive behaviours beginning in early childhood, persistent over time, pervasive across situations and leading to clinically significant impairments. The disorder is common in the population with prevalence estimates in the UK around 3-4% (Ford, Goodman & Meltzer, 2003). Follow-up studies of ADHD in children find that the disorder frequently persists into adult life, with around 15% retaining the full diagnosis by the age of 25 years, and a further 50% in ‘partial remission’ with some of the symptoms persisting and leading to continued impairments in daily life. A recent review and meta-analysis estimated world prevalence of ADHD in adults to average 2.5% or higher (Simon, Czobor, Balint, et al, 2009), with around 1% expected to fall in the most severe group requiring immediate treatment.