Dopamine D1 receptor binding in the anterior cingulate cortex of patients with obsessive–compulsive disorder

Functional neuroimaging studies in patients with obsessive–compulsive disorder (OCD) suggest there is a hyperactivation of the anterior cingulate cortex (ACC) during provocation of symptoms and conflict–inhibition tasks. Since dopamine, acting through D1 receptors is suggested to modulate ACC activity, we hypothesised that there would be an altered D1 binding potential (BP) in the ACC of OCD patients. Using [11C]-SCH23390 and positron emission tomography, we report significantly reduced D1 BP in seven drug-free OCD patients compared with matched healthy controls. These findings suggest mesocortical dopamine inputs via D1 receptors may play a role in the aetiology of OCD.