PTSD Risk Might Be Genetic

Genetics may play role in PTSD risk after trauma

After a traumatic event, some people develop post-traumatic stress disorder (PTSD), and some don’t. The reason why might be found in your genes.

That’s according to a new study from researchers at the Harvard T.H. Chan School of Public Health. In a study of 20,730 people around the world, these researchers found evidence that genetics may play a role in PTSD risk — particularly in women.

“We know from lots of data — from prisoners of war, people who have been in combat, and from rape victims — that many people exposed to even extreme traumatic events do not develop PTSD. Why is that?” ” said senior study author Dr. Karestan Koenen, PhD, professor of psychiatric epidemiology at the Harvard T.H. Chan School of Public Health, in a press release. “We believe that genetic variation is an important factor contributing to this risk or resilience.”

PTSD is a mental disorder in which patients often re-experience a traumatic event that initially triggered the disorder. Patients with PTSD face a higher risk of suicide, substance abuse and other problems, according to past research.

An estimated 8 percent of Americans, or 24.4 million, have PTSD at any given moment — a figure PTSD United points out is roughly equal to the population of Texas.

Dr. Koenen and colleagues found that, like other psychiatric disorders, PTSD risk may be at least partly affected by genetics. Looking at genomic data for patients in 11 ethnically diverse studies, these researchers found that genetic factors may account for around 29 percent of European American women’s risk of developing PTSD.

silhouette of man and woman arguingFor men, the apparent role of genetics in PTSD risk was much smaller — estimated at almost zero, in fact. The study authors proposed that this could be the result of gender and culture differences in reporting of PTSD symptoms like depression and anxiety. They said research on this topic would likely be worthwhile.

Another key finding in this study: Genetic risk for other mental health problems, such as schizophrenia, bipolar disorder and major depressive disorder, appeared to be linked to patients’ genetic risk for PTSD. Those who had a higher genetic risk of other mental disorders also had a raised genetic risk for PTSD.

The study’s first author, Laramie Duncan, a psychiatry and behavioral sciences instructor at Stanford University, said PTSD is preventable and this study’s findings may improve doctors’ ability to care for patients who might be at risk.

“There are interventions effective in preventing PTSD shortly after a person experiences a traumatic event,” Duncan said in a press release. “But they are too resource-intensive to give to everyone. Knowing more about people’s genetic risk for PTSD may help clinicians target interventions more effectively and it helps us understand the underlying biological mechanisms.”

This study was published in the journal Molecular Psychiatry.

The Psychiatric Genomics Consortium PTSD Working Group, National Institute of Mental Health, Cohen Veterans Bioscience, One Mind and The Stanley Center for Psychiatric Research funded this research. Several study authors disclosed ties to pharmaceutical companies and health-related organizations.

References:
Molecular Psychiatry, “Largest GWAS of PTSD (N =20 070) yields genetic overlap
with schizophrenia and sex differences in heritability”
http://www.nature.com/mp/journal/vaop/ncurrent/full/mp201777a.html
Harvard T.H. Chan School of Public Health, “Study finds first molecular genetic evidence of PTSD heritability”
https://www.hsph.harvard.edu/news/press-releases/molecular-genetic-evidence-ptsd-heritability/
PTSD United, “PTSD Statistics”
http://www.ptsdunited.org/ptsd-statistics-2/

Story by: Alex Lindley | Medically reviewed by: Dr. Robert Carlson, M.D.