To conclude, we found that, compared to similarly traumatized individuals without PTSD, those with PTSD demonstrated significantly poorer structural and functional connectivity in a hippocampal-prefrontal pathway previously demonstrated to be critical to basic emotion on as well as cognitive functioning (Sexton et. al., 2009). Participants with PTSD who carried two risk alleles for a putatively functional FKBP5 polymorphism demonstrated the poorest cingulum connectivity compared to the other diagnostic and genotype groups. This is of clinical interest; given that the cingulum is a highly heritable white matter pathway (14), altered connectivity for this tract may serve as a marker of risk for the development of anxious psychopathology. In summary, our findings indicate that cingulum connectivity is an attractive intermediate neural phenotype for PTSD, as well as other mood and anxiety disorders. Abnormalities in this pathway are likely to be heritable, and may predict vulnerability for the development of this disorder following exposure to a traumatic stressor.
