How war-related acute stress affects behaviour

Washington, July 20 (ANI): People confronted with acute stress, say rocket attacks, tend to dissociate from threats instead of becoming more vigilant, according to Tel Aviv University researchers.

The study, led by Prof. Yair Bar Haim of TAU's Department of Psychology, appears in the American Journal of Psychiatry.

This research overturns accepted convention and may lead to better understanding of the mechanisms underlying acute stress reactions, Prof. Bar Haim said.

He said: "Our study is important because it's the first to show the effects of war-related acute stress in real time."

It also has significant implications for the understanding of other known PTSD ((post-traumatic stress disorder) triggers, such as rape or motor vehicle accidents.

Using fMRI and other imaging techniques, Prof. Bar Haim investigated neural mechanisms related to anxiety disorders and how people respond cognitively to stress. He also studied how people process threats when they are under severe stress. His previous studies, both at Tel Aviv University and through the U.S. National Institutes of Health, looked at neural, genetic and molecular factors related to threat processing in the brain, and these gave Prof. Bar Haim and his team a context to infer what happens in the brain when behavioral data on acute stress situations is collected.

In the most recent study, he looked at Israelis close to the firing zone, near the border with Gaza, where they had been living with the daily stress of rocket threats for eight years. The threat became more severe during the war. While his test subjects completed various computer tasks to test behavior, Dr. Bar Haim monitored processes at the deeper, unseen levels of the brain.

He found that subjects under acute stress developed symptoms of post-trauma and most often manifested a dissociative state rather than one of hypervigilance. Most important for clinical applications, the researchers found that the symptoms produce a measurable effect - a neuromarker - that may be used to predict who are the individuals most at risk for developing chronic PTSD following a traumatic event.

Prof. Bar Haim claims this is the first study in the scientific literature to describe real-time effects of war-related stress on its victims. In the previous literature, scientists assumed that people under stress would become more vigilant to threats, rather than disengaging.

"This calls for some revision of the foundations of the stress-PTSD model," he said. (ANI)