The largest and most diverse study of PTSD genetics has identified 43 genes that appear to have a role in causing the disorder.
The analysis of genetic data from more than 1.2 million people also pinpointed 95 locations on the genome associated with the risk of developing PTSD. This includes 80 locations that had not yet been identified in previous research.
The findings, published the journal Nature Genetics, confirm previous research on the genetic underpinning of PTSD and provides new targets for future research into prevention and treatment strategies.
“This discovery firmly validates that heritability is a central feature of PTSD based on the largest PTSD genetics study conducted to date and reinforces there is a genetic component that contributes to the complexity of PTSD,” says Caroline Nievergelt, co-first and corresponding author on the study and a professor in the department of psychiatry at the University of California, San Diego.
Globally, 3.9% of the population develop PTSD at some point in their lifetime, with significant variation in prevalence across countries. PTSD can develop following a traumatic event of ongoing exposure to trauma, with individuals experience symptoms such as: re-experiencing the event; avoidance and numbing; cognitive or mood changes; and hyperarousal.
In the new study, researchers from the PTSD working group within the Psychiatric Genomics Consortium compiled data from 88 different genome-wide association studies. These use genetic data from large groups of people to look for associations between regions of the genome and the chance of developing a condition or trait.
The dataset included information from more than 1.2 million individuals of European ancestry (including about 140,000 with PTSD), about 50,000 of African ancestry (including about 12,000 with PTSD), and about 7,000 of Native American ancestry (about 2,000 with PTSD).
“It’s exciting that we see the exponential increase in loci with increases in sample size, [which] we see for other disorders,” says senior author Karestan Koenen, an institute member of the Broad Institute of MIT and Harvard, and professor of psychiatric epidemiology at Harvard, in the US.
“This is a milestone for PTSD genetics.”
They also identified 43 genes that appear to play a role in causing PTSD, including those that affect neurons, neurotransmitters (which allow neurons to communicate with each other), ion channels (which allow ions to pass in and out of cells), synapses, and the endocrine and immune systems.
“For the first time, we are approaching a genetic architecture for PTSD, which both validates prior understanding of some of the critical biology underlying trauma-related disorders, while also pointing towards exciting and novel new targets and mechanisms,” says Kerry Ressler, Chief Scientific Officer at McLean Hospital and professor of psychiatry at Harvard Medical School.
“These data are an important first step in next generation approaches to novel interventions for PTSD.”
