As predicted, findings indicated that participants with PTSD demonstrated significantly poorer cingulum connectivity, even after accounting for differences in age, depressive symptoms, and trauma exposure. In previous voxel-wise analyses, we observed that individuals with PTSD demonstrated poorer microstructural integrity in posterior aspects of the cingulum (PC) (10). The findings from our prior ROI-based study of the PC suggested that differences between the diagnostic groups may be due in part to genetic factors, particularly, the presence of one or more risk alleles for an FKBP5 SNP that has been closely associated with PTSD risk (rs1360780) (13); findings indicated that those with 2 risk alleles had significantly lower PC FA values as compared to individuals who carried 0 or 1 risk allele.
