Differential neural network of checking versus washing symptoms in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is clinically heterogeneous. The aim of this study was to investigate differential neural responses to a symptom provocation task in drug-free patients who have predominantly aggression/checking symptoms (Checkers) and patients with contamination/washing symptoms (Washers). We compared the Checkers (n = 10) and the Washers (n = 12) separately to normal controls during the symptom provocation tasks using fMRI (functional magnetic resonance imaging). Moreover, we performed correlative analysis in each OCD group between brain activation and symptom severity. The Checkers showed hypoactivation in the left caudate and left anterior cingulate cortex (ACC) compared to the normal controls and a positive correlation between activated brain areas and symptom severity in the left ACC. The Washers showed hyperactivation in several bilateral cortico-cerebellar regions and a positive correlation between symptom severity and the bilateral fronto-temporal gyrus. We suggest that the caudate and ACC are associated with checking rituals and that large cortical brain regions are related to washing rituals.

► Obsessive-compulsive disorder (OCD) is clinically heterogeneous. ► This study aimed to identify the neural network related to symptom subtypes. ► We investigated drug-free OCD patients using functional magnetic resonance imaging. ► “Checking” symptoms are associated with the caudate and anterior cingulate cortex. ► “Washing” symptoms are related to the bilateral cortico-cerebellar regions.