Attention deficit hyperactivity disorder in adulthood.

A behavioural syndrome of childhood characterised by overactivity, excitability, and explosive behaviour has been recognised since the turn of the last century and is now thought to be, at certain ages, the most common disorder of childhood. The disorder is now recognised in the terminology of ICD-10 as ‘‘hyperkinetic disorder’’, and in DSM-IV as ‘‘attention deficit hyperactivity disorder’’ (AD/HD). The cardinal features of overactivity and impaired attention should be pervasive—that is, evident in more than one situation, and observable before the age of six (ICD-10) or seven years (DSMIV), though they are usually evident well before that. DSM-IV subclassifies AD/HD into predominantly inattentive, predominantly hyperactive–impulsive, and combined subtypes; ICD-10 insists on the presence of both inattention and hyperactivity for a diagnosis of hyperkinetic disorder.