There were significant interactions between the effects of the COMT and BDNF genotypes in the regions of left cuneus (η2 = 10%), left middle temporal gyrus (η2 = 11%), right inferior occipital gyrus (η2 = 10%), and bilateral putamen (right: η2 = 13%; left: η2 = 8%) in all participants, irrespective of PTSD diagnosis (Fig. 3 and Supplementary Table S3). Here, BDNF is linked to post-traumatic stress disorder.