This is the largest neuroimaging study conducted on cortical measures in OCD to date. We found that the parietal cortex was consistently implicated both in adult and pediatric OCD, which is consistent with prior VBM and FreeSurfer studies (12; 25). Lower cortical thickness of the inferior parietal cortex in adult OCD patients compared to controls is in accordance with results reported by Kuhn et al. (10) and the OBIC consortium (12). Lower cortical thickness of the inferior and superior parietal cortex in children with OCD is a novel finding. The only other study of cortical thickness in pediatric OCD found lower cortical thickness of another parietal region, the supramarginal gyrus (29). Other imaging studies have reported lower gray matter volume in the parietal lobe, especially in the angular gyrus of the inferior parietal lobe in children and adults with OCD (25; 30).
