Anterior cingulate cortex volume reduction in patients with panic disorder

Aim: Recent neuroimaging studies have suggested that the anterior cingulate cortex (ACC) has an important role in the pathology of panic disorder. Despite numerous functional neuroimaging studies that have elucidated the strong relationship between functional abnormalities of the ACC and panic disorder and its symptoms and response to emotional tasks associated with panic disorder, there has been no study showing volumetric changes of the ACC or its subregions. Methods: To clarify the structural abnormalities of ACC and its subregions, the combination of region of interest (ROI) and optimized voxel-based morphometry (VBM) methods were performed on 26 patients with panic disorder, and 26 age and sex-matched healthy subjects. In the ROI study, ACC was divided into four subregions: dorsal, rostral, subcallosal and subgenual ACC. Results: The results of the manually traced ROI volume comparison showed significant volume reduction in the right dorsal ACC. VBM also showed a volume reduction in the right dorsal as well as a part of the rostral ACC as a compound mass. Conclusions: Both manual ROI tracing and optimized VBM suggest a subregion-specific pattern of ACC volume deficit in panic disorder. In addition to functional abnormalities, these results suggest that structural abnormalities of the ACC contribute to the pathophysiology of panic disorder.