Landmark Study Identifies Six Genetic Markers of PTSD Risk

By Dr. Douglas Williamson and Cameron Cucuzzella

Man in military uniform looking down with head in handsAn international team of researchers including faculty from Duke Psychiatry recently identified interesting genes linked with posttraumatic stress disorder (PTSD). Although it’s well-known that PTSD is influenced by genetic factors, common genetic risk variants for this disorder have not been robustly identified until now. 

In collaboration with the Psychiatric Genetics Consortium, Duke Psychiatry faculty members Drs. Douglas Williamson, Jean Beckham, Nathan Kimbrel, and Rajendra Morey have published a report in Nature Communications titled, “International Meta-Analysis of PTSD Genome-Wide Association Studies Identifies Sex- and Ancestry-Specific Genetic Risk Loci.” This landmark study identifies specific genes involved in the development of PTSD that suggest a common link with age-related neurodegenerative disease. 

PTSD is the most seriously impairing and commonly occurring disorder that occurs after exposure to traumatic events such as combat, accidents, sexual/physical assault and natural disasters. In the United States, an estimated seven percent of the general population and 29 percent of veterans of the recent wars in Iraq and Afghanistan have suffered from a lifetime episode of PTSD. Due to the high prevalence of this disorder, there’s a significant public need to better understand the biological mechanisms underlying PTSD risk. This improved understanding could contribute both to PTSD treatment and prevention.

Through analysis of 30,000 PTSD cases of both active-duty service members and war veterans, this genome-wide association study identified several significant loci, or positions of genes on their associated chromosomes, that are associated with PTSD. Among the loci identified is a gene with mutations known to cause Parkinson’s disease. Additionally, the investigators also identified an association between PTSD and a gene linked to neurocognition and dementia. Results from this report are consistent with findings that PTSD shares common variant risk with other psychiatric disorders, specifically major depression and schizophrenia. 

“These findings underscore the role of genetics in conferring susceptibility for PTSD and highlight areas of the genome requiring further research to unlock our understanding of the biological mechanisms underlying PTSD,” says Williamson. “Extending from these genetic associations, as part of the Consortium to Alleviate PTSD, we are actively identifying some of the biological mechanisms that contribute to the risk to develop PTSD as well as the mechanisms underlying the successful response to treatment.”

Unlike studies that have examined smaller groups of subjects, this study identifies genes that may be altered in people who are at higher risk for developing PTSD following a traumatic event. Furthermore, these genetic discoveries identify new targets for developing effective treatments to improve the lives of those with this debilitating condition.

Read the full report.