Posttraumatic stress disorder (PTSD) is a worldwide public health problem and of particular concern to the US military. While PTSD can be attributable to a range of traumatic events, the nature and intensity of traumatic events experienced by some military personnel result in particularly high prevalence among US military veterans1. Published PTSD genome-wide association studies (GWAS) have identified genomewide-significant risk loci2–4; however these studies have tended to be small and underpowered for a trait as complex as PTSD. The largest to date was a meta-analysis undertaken by the Psychiatric Genomics Consortium (PGC)5. While there have been promising possible gene identifications, there are none yet that are both significant and replicated.
