Twin and molecular studies have shown that PTSD is moderately heritable (h2 = 5–34%) [6, 8–10], and research has begun to identify risk loci for PTSD. The Psychiatric Genomics Consortium (PGC)-PTSD Workgroup carried out a Genome-Wide Association Study (GWAS) of PTSD in a multi-ethnic cohort that included over 30,000 PTSD cases and 170,000 controls [9]. The PGC-PTSD workgroup combines genetic information from over 72,000 civilian and military samples to create a large, ancestrally and sex diverse database with approximately 40% of the population being female and 30% of African ancestry [9]. Genome-wide significant variants were identified in those of European (rs345178562, rs9364611) and African (rs115539978) ancestries (EA and AA, respectively), with three additional variants identified in males only (EA males: rs148757321, rs571848662; AA males: rs1421744523). While none of the 6 leading SNPs were replicated in the Million Veteran Program (MVP) cohort, a diverse sample of >165,000 veterans assessed for PTSD with re-experiencing symptoms [10], polygenic risk scores (PRS) derived from the PGC-PTSD study [9] were associated with PTSD re-experiencing symptoms in the MVP [10]. The MVP cohort is also an
