Neural and genetic markers of vulnerability to posttraumatic stress symptoms among survivors of the World Trade Center attacks

The article addresses the variability in the way people respond to trauma, in particular describing the neural and genetic processes. It addressed this issue by using functional magnetic resonance imaging (fMRI) to examine the relationship between post-traumatic stress symptomatology (PTSS), a common genetic polymorphism of the serotonin transporter (5-HTT) gene, and neural activity in response to viewing images associated with the 9/11 terrorist attack among a rare sample of high-exposure 9/11 survivors (n=17). Three key findings are reported. First, carriers of the short allele displayed higher levels of PTSS. Second, both PTSS and the presence of the short allele correlated negatively with activity in a network of cortical midline regions (e.g. the retrosplenal and more posterior cingulate corticies [PCC]) implicated in episodic memories and self-reflection when viewing 9/11 versus non-9/11 negative control images. Finally, exploratory analyses indicated that PCC activity mediated the relationship between genotype and PTSS. These results highlight the role of PCC in distress following trauma.