Contrast sensitivity in children with and without attention deficit hyperactivity disorder symptoms.

Dopamine regulation may play a role in attention-deficit hyperactivity disorder (ADHD). Visual contrast sensitivity has been proposed as a measure of retinal dopamine that may predict frontal lobe dopamine levels. Individuals with disorders involving dopamine dysregulation (e.g., Parkinson's disease, Phenylketonuria) have shown poor contrast sensitivity. In this study, 110 6- to 13-year-old children with and without ADHD completed a task measuring visual contrast sensitivity. As predicted, contrast sensitivity was significantly worse in children with ADHD-Combined Type than controls. Contrast sensitivity was significantly correlated with inattention and hyperactivity. However, unlike many neuropsychological studies of ADHD, only hyperactivity accounted for unique variance.