Attention-deficit/hyperactivity disorder: Perspectives from neuroimaging

Attention-deficit/hyperactivity disorder (ADHD) is a common childhood behav ioral disorder most often characterized by inattentiveness, impulsivity, an d hyperactivity. Current etiologic theories suggest that ADHD stems from ab normalities in dopaminergic and possibly noradrenergic brainstem nuclei tha t act to regulate a cortico-striato-thalamo-cortical network, believed to b e critical for executive functions and the regulation of behavioral respons es such as arousal, attention, and inhibition. Noninvasive structural and f unctional neuroimaging techniques provide a new avenue for exploring the va lidity of these theories. Despite their limitations, neuro imaging studies have provided a unique and otherwise inaccessible, biological perspective o f ADHD. Collectively, the studies reviewed here reveal that dysfunction in arousal, behavioral inhibition, and attention associated with ADHD may resu lt from structural abnormalities in frontostriatal regions that in turn res ult in diminished activity essential for normal function. (C) 2000 Wiley-Li ss, Inc.