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Combat exposure, threat attention created risk for PTSD in soldiers

When combat exposure interacted with threat-related attention bias, soldiers were at risk for posttraumatic stress disorder, according to researchers who studied combat veterans who served in the Israeli Defense Forces. The findings may have implications for more effective interventions for returning service members.

“The excessive rates of PTSD and other adjustment disorders in soldiers returning home make it imperative to identify risk and resilience factors that could be targeted by novel therapeutic treatments,” the researchers wrote.

Ilan Wald, MA, of Tel Aviv University, and colleagues investigated the relationship between combat exposure, threat vigilance and additional PTSD risk factors among 1,085 male soldiers aged 18 to 24 years. Data were collected at baseline within 2 weeks of recruitment, before deployment (during training) and again after deployment. Assessments post-deployment took place in combat theaters.

The researchers evaluated threat-related attention bias using a dot-probe task, which measured how quickly the soldiers could react to a threatening target compared with a neutral one. PTSD severity was measured using the PTSD Checklist, and trauma was assessed using a questionnaire. The soldiers’ assignments, obtained from military records, determined the extent and intensity of their combat exposure. Soldiers also reported on their individual combat experiences.

Wald and colleagues also examined genetic risk factors for PTSD by performing genotyping.

Results indicated that soldiers exposed to more intense combat experiences developed faster response times to threatening targets vs. soldiers with low exposure (P<.001). Combat exposure interacted with threat-related attention bias to predict risk for PTSD in soldiers (P<.05). Bias toward threats at the time of recruitment (P<.001) and bias toward neutral targets just prior to deployment (P<.05) predicted PTSD symptoms after combat. The researchers also found that the associations between threat vigilance and PTSD symptoms were governed by genetic and environmental factors, including the 5-HTTLPR genotype, which helps regulate serotonin.

“Ample evidence indicates that attention is deployed in a biased, maladaptive pattern in PTSD and anxiety disorders, that such threat-related attention biases are plastic, shifting after exposures to danger, and that such bases predict PTSD symptoms in soldiers exposed to war-zone stress,” the researchers wrote.

Disclosure: The researchers report no relevant financial disclosures.