Anterior cingulate cortex and symptom severity in attention-deficit/hyperactivity disorder.

The cause of attention-deficit/hyperactivity disorder (ADHD) has been linked to abnormalities in prefrontal-striatal-cerebellar networks, but the brain-behavioral correlates are relatively equivocal. Children with ADHD and healthy controls underwent MRI and neuropsychological testing. Brain cortical thickness was analyzed for the bilateral rostral and caudal anterior cingulate cortex (ACC). Inhibitory control was assessed with the Stroop Inhibition test, and ADHD symptom severity was assessed with parent and teacher behavioral questionnaires. Brain-behavior relationships were calculated between cortical thickness and behavioral measures with regression models. Children with ADHD had significant cortical thinning in the right rostral ACC but nonsignificant thinning in right caudal, left caudal, or left rostral ACC compared with healthy control children after statistical correction for multiple comparisons. Further, right rostral ACC thickness predicted a significant amount of the variance in parent- and teacher-reported symptoms of ADHD. Exploratory analysis showed that cortical thickness was not related to psychostimulant medication history. Symptoms of ADHD may be related to reductions in cortical thickness in the right anterior attention network, a region implicated in behavioral error detection, impulsivity, and inhibitory control.