Abstract

&NA; Attention‐deficit/hyperactivity disorder, a syndrome involving inattention, impulsivity, and hyperactivity, was originally thought to occur only in children. It is now a recognized condition throughout life in some individuals. For a valid diagnosis, the onset of symptoms should occur before age 7. Dysfunction of catecholamine neurotransmission is implied by the clinical improvement induced by stimulants. Positron emission tomography studies reveal reduced glucose metabolism in the basal ganglia and sometimes in the frontal cortex. Excessive cortical slowing is documented on the electroencephalogram. Twin studies show a familial, genetic influence. Data from multiple sources are necessary for a diagnosis, and rating scales are particularly useful for the adult syndrome. Older individuals typically manifest disorganization and impulsivity more than hyperactivity. Stimulant drugs are the principal forms of treatment for all ages, but bupropion is favored for patients with substance abuse history.