Aims: Previous morphometric studies using magnetic resonance imaging (MRI) have revealed structural brain abnormalities in obsessive–compulsive disorder (OCD). The aim of the present study was to investigate the alterations in brain structure of patients with OCD using a voxel-based morphometry (VBM) method.
Methods: Sixteen patients with OCD free of comorbid major depression, and 32 sex- and age-matched healthy subjects underwent MRI using a 1.5-T MR scanner. OCD severity was assessed with the Yale–Brown Obsessive–Compulsive Scale (mean ± SD: 22 ± 7.6; range: 7–32). MR images were spatially normalized and segmented using the VBM5 package (http://dbm.neuro.uni-jena.de/vbm/). Statistical analysis was performed using statistical parametric mapping software.
Results: Significant reductions in regional gray matter volume were detected in the left caudal anterior cingulate cortex and right dorsal posterior cingulate cortex in the patients with OCD as compared to healthy controls (uncorrected, P < 0.001). No significant differences in white matter volumes were observed in any brain regions of the patients. No significant correlation between Yale–Brown Obsessive–Compulsive Scale score and regional gray matter or white matter volume was observed.
Conclusions: Regional gray matter alteration in the dorsal cingulate cortex, which is suggested to play a role in non-emotional cognitive processes, may be related to the pathophysiology in OCD.