Abnormal Corpus Callosum Integrity in Bipolar Disorder: A Diffusion Tensor Imaging Study

Objective Abnormalities in the anterior interhemispheric connections provided by the corpus callosum (CC) have long been implicated in bipolar disorder (BD). In this study, we used complementary diffusion tensor imaging methods to study the structural integrity of the CC and localization of potential abnormalities in BD. Methods Subjects included 33 participants with BD and 40 healthy comparison participants. Fractional anisotropy (FA) measures were compared between groups with region of interest (ROI) methods to investigate the anterior, middle, and posterior CC and voxel-based methods to further localize abnormalities. Results In ROI-based analyses, FA was significantly decreased in the anterior and middle CC in the BD group (p< .05). Voxel-based analyses similarly localized group differences to the genu, rostral body, and anterior midbody of CC (p< .05, corrected). Conclusion The findings demonstrate abnormalities in the structural integrity of the anterior CC in BD that might contribute to altered interhemispheric connectivity in this disorder.