Women may be at a higher genetic risk for developing post-traumatic stress disorder (PTSD) compared to men. This study is the largest twin-sibling study on PTSD conducted to date. While both men and women are genetically susceptible to PTSD, the underlying genetic risk may be stronger in women.

I’ve linked to the news release in the post above. In this comment, for those interested, here’s the link to the peer reviewed journal article:

https://psychiatryonline.org/doi/10.1176/appi.ajp.20230104

From the linked article:

A new study published in the American Journal of Psychiatry has revealed that women may be at a higher genetic risk for developing post-traumatic stress disorder (PTSD) compared to men. This study, led by researchers from Virginia Commonwealth University and Lund University, is the largest twin-sibling study on PTSD conducted to date. The findings suggest that while both men and women are genetically susceptible to PTSD, the underlying genetic risk may be stronger in women.

For their study, the researchers analyzed data from over 16,000 twin pairs and more than 376,000 sibling pairs from Swedish national health and population registries. This large sample allowed them to explore both the genetic and environmental components of PTSD in a way that previous studies, with smaller sample sizes, could not.

The study’s findings revealed that PTSD is moderately heritable, with genetic factors accounting for approximately 35% of the risk in women and 29% in men. This means that while both sexes inherit some genetic susceptibility to PTSD, the genetic contribution is stronger in women. This quantitative difference in heritability suggests that women have a higher genetic risk for developing PTSD compared to men, even after accounting for environmental factors.

Moreover, the study found evidence for qualitative differences in the genetic risk for PTSD between men and women. Although many of the same genes contribute to PTSD in both sexes, some genes appear to have sex-specific effects. This qualitative difference indicates that the genetic architecture of PTSD is not entirely the same in men and women, which could explain part of the observed disparity in PTSD prevalence.

I’d guess it would be related to something Robert Sapolsky was saying in an interview about estrogen increasing susceptibility to stress, as well as women having some predisposition to ruminate.