Images show focal decrease in GM volume in 16 patients with MS and OCD compared with 15 patients with MS without psychiatric disorders (CG). Clusters of decreased GM volume (red/yellow) are overlapped with a rendered brain. Clusters that are significant at P < .05 (2-sample t test; false discovery rate corrected) are observed in the right inferior frontal gyrus (Z = 2.71; coordinates: 48, 14, −30), inferior temporal gyrus (Z = 3.30, coordinates: 50, −24, −28) and middle temporal gyrus (Z = 2.90, coordinates: 54, −4, −26).