Women are twice as likely as men to develop post-traumatic stress disorder, but the factors contributing to this disparity have largely remained unsettled. A research team led by Virginia Commonwealth University and Lund University in Sweden conducted the largest twin-sibling study of PTSD to date to shed light on how genetics may play a role.
Their results, published in the American Journal of Psychiatry, are the first to demonstrate that women have a higher genetic risk for the disorder compared with men.
By analyzing health data from over 16,000 twin pairs and 376,000 sibling pairs, the research team discovered that heritability for PTSD was 7 percentage points higher in women (35.4%) than in men (28.6%). They also found evidence that the genes that make up the heritable risk for PTSD vary between the two sexes.
The researchers say their findings could inform strategies for PTSD prevention and intervention following a traumatic event, as well as help address stigmas related to women’s mental health.
Women are at higher risk for developing PTSD than men, even when controlling for the type of trauma, income level, social support and other environmental factors. Some of the theories as to why that is have frankly been unkind to women, such as attributing the sex difference to a weakness or lack of ability to cope, said Ananda B. Amstadter, Ph.D., a professor in the VCU School of Medicine’s departments of Psychiatry and Human and Molecular Genetics and lead author of the study.
I think this study can help move the narrative that people can have an inherited biological risk for PTSD, and that this genetic risk is greater in women.
Nearly 70% of the global population is exposed to at least one traumatic event in their lifetime, such as physical or sexual assault, a motor vehicle accident, exposure to combat or a natural disaster. About 6% of those who are exposed to trauma develop PTSD. Amstadter’s research focuses on understanding the conditions that might increase or decrease a person’s risk of experiencing PTSD, particularly how a person’s genes impact their risk.
