Kim GW, et al. - Differential gray matter (GM) and white matter volume alterations were assessed between healthy controls and patients with obsessive-compulsive disorder (OCD) and generalized anxiety disorder (GAD) with the aid of voxel-based morphometry (VBM). A substantially decreased GM volume in the medial prefrontal cortex (mPFC) was shown among patients with GAD versus patients with OCD. The medial prefrontal cortex (mPFC) volume abnormality was related to anxiety disorder in patients with GAD instead of OCD.