the effects of the catecholomethyltransferase val158met polymorphism on white matter connectivity in patients with panic disorder background the catecholomethyltransferase comt gene val158met polymorphism rs4680 has been found to be associated with various psychiatric phenotypes including panic disorder considering the probable genetic influence of comt on the pathogenesis of panic disorder and white matter connectivity the present study investigated white matter connectivity using diffusion tensor imaging in relation to the comt genotype in panic disordermethods twentysix patients with panic disorder and twentysix age and gendermatched healthy controls participated in this study brain magnetic resonance scans and genotype analysis for comt rs4680 were conducted panic disorder severity scale albany panic and phobia questionnaire and anxiety sensitivity inventoryrevised were assessed tractbased spatial statistics tbss were used for image analysisresults there was no significant difference in white matter analysis between panic disorder and healthy controls however tbss analysis showed increased fractional anisotropy fa in posterior thalamic radiation posterior and superior corona radiata superior longitudinal fasciculus and sagittal stratum all located in the right hemisphere in comt aaag genotype group compared to gg genotype in panic disorder voxelwise correlational analysis revealed the symptom severity scores are correlated with the fa in white matter tracts that previously showed significant group differences between aaag and gg genotypes in comt aaag genotype group while no significant correlation was found in gg genotype grouplimitations the sample size in each group was small hence further studies with larger numbers of patients are needed to confirm our findingsconclusions these data suggested that comt rs4680 could affect the white matter connectivity in panic disorder