[The hyperactive child]

Hyperactivity in childhood is a frequent complaint from parents and teachers. It is a subjective disorder that needs precise evaluation by specific scales and tests as well as by complete familial and personal anamnesis. If hyperactivity is associated with attentional deficit and impulsivity, is precocious and permanent, resulting in maladaptative behaviours the diagnosis of ADHD can be concluded. Neuropsychological, pharmacologic, brain-imaging studies implicate dopamine and norepinephrine neurotransmitter systems in fronto-striatal circuitry in the pathophysiology of the disorder with predominant genetic factors. ADHD is a chronic condition with symptoms experienced over a lifetime and with large comorbidity. It needs a specific therapeutic approach.