Alteration of fractional anisotropy and apparent diffusion coefficient in obsessive–compulsive disorder: A diffusion tensor imaging study

BackgroundAbnormalities of fractional anisotropy (FA) have been reported in previous diffusion tensor imaging (DTI) studies in patients with obsessive–compulsive disorder (OCD). However, there are some inconsistencies in the results and the apparent diffusion coefficient (ADC) has not been investigated. The goal of this study was to investigate white matter abnormalities and water diffusivity, as reflected by FA and ADC, using DTI in patients with OCD.MethodsFifteen patients with OCD and 15 healthy volunteers underwent DTI. Voxelwise analysis was used to compare FA in white matter and ADC in gray matter/white matter of the two groups.ResultsCompared with healthy volunteers, the patients had higher FA in the bilateral semioval center extending to the subinsular white matter; and a higher ADC in the left medial frontal cortex. There were no areas with a significantly lower FA or ADC in patients compared with healthy volunteers.ConclusionsA significantly higher FA was found in regions associated with the emotion of disgust and a trend for a higher ADC was found in a region associated with the regulation of emotions. These findings suggest that neurocircuits involved in disgust processing may play an important role in the pathophysiology of OCD.