Deactivation of anterior cingulate cortex during virtual social interaction in obsessive-compulsive disorder.

Studies about social functioning in obsessive-compulsive disorder (OCD) are lacking, even though neuroimaging studies and metacognition evaluation results suggest abnormal neural responses during social interactions. This study examined neural responses of OCD patients during handshakes with a virtual avatar. Because of the nature of the handshaking task, we expected that OCD patients with predominantly contamination/washing symptoms (CON) would show different neural responses compared to healthy controls (HCs) and to disease-controlled (NCON) patients. Thirteen CON, 13 NCON, and 18 HC participants performed handshake tasks with clean or dirty virtual avatars while undergoing functional magnetic resonance imaging. During handshakes with a clean avatar, deactivation in the left anterior cingulate cortex was found in CON patients compared to NCON and HC subjects. This cortical deactivation also occurred with dirty-avatar handshakes, but the difference was significant only between the two OCD groups and HC patients. Deactivation in the left anterior cingulate cortex was correlated with both OCD symptom severity and social anxiety traits. This cortical deactivation in OCD, especially in CON patients, suggests that social dysfunction in OCD may be due to interactions between OCD symptoms and impairment in social cognition, including emotional processing.