Israeli researchers used genetic and psychological testing to identify factors that reduce the risk of developing post-traumatic stress disorder (PTSD). The groundbreaking Tel Aviv University study focused on infantry soldiers in the Israel Defense Forces.

The onset of PTSD is unpredictable. Because it depends on the unforeseeable occurrence of traumatic events, it is difficult to identify preventative or causative factors. Scientists typically turn to patients who have already developed PTSD to study the disorder, but that means they can’t draw comparisons to their psychological state prior to experiencing trauma.

But by turning to recruits prior to any developing signs of anxiety, Prof. Yair Bar-Haim and PhD student Ilan Wald of Tel Aviv University’s School of Psychological Sciences were able to identify factors that mitigate against PTSD.

Through psychological and DNA studies, they discovered that excessive threat vigilance, a behavior typically associated with elevated anxiety in everyday life, is a normal response in soldiers during combat deployment. In combat, those soldiers who avoided threats were more likely to develop PTSD as a result of traumatic experiences.

Through attention bias modification training — which trains participants to direct their attention either towards or away from threatening stimuli — soldiers could learn to increase their vigilance towards threats before they’re deployed, possibly reducing their risk for PTSD, Bar-Haim says. He also notes that this discovery could prove valuable in PTSD prevention for populations that are more likely to be exposed to traumatic situations.

Identifying this protective factor is a first step towards preventative treatment, Prof. Bar-Haim says. Teaching soldiers to be more sensitive to threats prior to deployment could reduce the overall risk of developing PTSD. The researchers are currently developing a study that will test different preventative treatment options, and hope to have results in the next few years.

This study, which was done in collaboration with the IDF, the National Institutes of Mental Health, and Mount Sinai School of Medicine in New York, was recently published in JAMA Psychiatry.