Gene plays role in risk for trauma stress disorder

By Will Dunham

WASHINGTON (Reuters) - A gene that helps regulate the body's response to stress can make certain people more apt to develop post-traumatic stress disorder than others exposed to similar trauma, researchers said on Tuesday.

PTSD is an anxiety disorder that can appear after a person experiences a terrifying event such as physical abuse, rape, military combat, war, torture, accidents and disasters.

The study involved 900 people, primarily low-income blacks, who sought general medical care at an Atlanta hospital. Many had experienced childhood physical or sexual abuse.

After genetic screening of these people, the researchers focused on a gene called FKBP5, which helps control hormones released in response to stress.

Among the people who had experienced the childhood abuse, those with certain variants of the gene were more likely to develop symptoms of PTSD after a trauma in adulthood. People with other variants were less likely to have such symptoms, even after a trauma in adulthood.

The researchers said that while this study involved people with trauma as civilians, the findings may be applicable to others who may develop PTSD in wartime such as combat troops.

Many U.S. troops returning from the wars in Iraq and Afghanistan, for example, are being diagnosed with PTSD.

"When humans face stressful or traumatic situations like combat or car accidents, our bodies have responses to stress that help prepare us to respond -- the fight, flight or freeze response that helps us keep ourselves safe," Rebekah Bradley of the Emory University School of Medicine in Atlanta, one of the researchers, said in an interview.