Toward a pathophysiology of attention-deficit/hyperactivity disorder.

Converging insights into attention-deficit/hyperactivity disorder (ADHD) support the notion that ADHD is best characterized behaviorally as a disorder of self-regulation or executive functioning. Anatomic neuroimaging studies suggest that the relevant regulatory circuits include the prefrontal cortex and the basal ganglia, which are modulated by dopaminergic innervation from the midbrain and by stimulant medications. The emerging model proposed in this review encompasses a developmental perspective into this common condition.