Post-traumatic stress disorder (PTSD) is one of the most common psychiatric disorders, affecting some eight million adults at some point in their lifetime in the United States alone. Despite this, it is not clear why only some people who experience a traumatic event go on to develop PTSD. Some researchers have suggested that the disorder is only a social construct, but previous studies have hinted that genetics has some role. Now a new study confirms a clear biological basis for PTSD.
In the largest and most diverse genetic study of PTSD to date, scientists from more than 130 institutions participating in the Psychiatric Genomics Consortium (PGC) have found that PTSD has as strong of a genetic component as other psychiatric disorders. Genetics, they write in Nature Communications, accounts for between five and 20 percent of the variability in PTSD risk following a traumatic event.
The study team also reports that, like other psychiatric disorders and many other human traits, PTSD is highly polygenic, meaning that it is associated with thousands of genetic variants throughout the genome, each making small contributions to the disorder. Six genomic regions (“loci”) harbor variants that were strongly associated with disease risk, providing some clues about the biological pathways involved in PTSD.
“Based on these findings, we can say with certainty that there is just as much of a genetic component to PTSD risk as major depression and other mental illnesses,” said Dr. Karestan Koenen, an associate member of the Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard, a professor of psychiatric epidemiology in the Harvard T.H. Chan School of Public Health, and senior author on the study.Tags: Friday Letter Submission, Publish on October 18