The risk of post-traumatic stress disorder (PTSD) following trauma is heritable, with a heritability rate similar to that for major depressive disorder (MDD), a new study reports.
In the largest and most diverse genome-wide association study (GWAS) of PTSD to date, scientists from more than 130 institutions participating in the Psychiatric Genomics Consortium (PGC) have found that genetics accounts for 5-20 per cent of the variability in PTSD risk (varying by sex), which is similar to that for major depression.
Three significant loci were identified, two in European and one in African ancestry analyses. Analyses stratified by sex implicated three additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation (PARK2) was also associated with PTSD.
Analysis demonstrated that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms, although specific loci did not replicate.
Presenting the findings in Nature Communications, the authors said the findings “squarely place PTSD among the other psychiatric disorders in terms of heritability.”
“These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations,” they said.