Attention-deficit/hyperactivity disorder: a neuropsychiatric disorder with childhood onset.

Attention-deficit/hyperactivity disorder (ADHD) is characterized by attentional problems such as hyperkinesia, restlessness and disturbances in timing. Environmental psychosocial factors interact with a genetic predisposition in causing measurable biological impairment. It is a common, persistent disorder of childhood that may change in manifestation with development from preschool through adult life. Untreated, it predisposes children to psychiatric and social pathology later in life. Unlike other psychiatric disorders of childhood, it can be successfully treated.