Attention to Threats and Combat-Related Posttraumatic Stress Symptoms Prospective Associations and Moderation by the Serotonin Transporter Gene Combat-Related Posttraumatic Stress

Wald I, Degnan KA, Gorodetsky E, et al. — Mon, 01 Apr 2013 00:00:00 GMT

Importance

Combat places soldiers at risk for posttraumatic stress disorder (PTSD). 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.

Objective

To investigate the interplay among attention to threat, combat exposure, and other risk factors for PTSD symptoms in soldiers deployed to combat.

Design and Setting

Longitudinal prospective study of Israeli Defense Force infantry soldiers carried out in 2008 through 2010. Repeated measurements during a 1-year period included baseline and predeployment data collected in training camps and deployment data collected in the combat theater.

Participants

Infantry soldiers (1085 men; mean age, 18.8 years).

Main Outcome Measures

Postcombat PTSD symptoms.

Results

Soldiers developed threat vigilance during combat deployment, particularly when they were exposed to high-intensity combat, as indicated by faster response times to targets appearing at the location of threat relative to neutral stimuli (P < .001). Threat-related attention bias also interacted with combat exposure to predict risk for PTSD (P < .05). Bias toward threat at recruitment (P < .001) and bias away from threat just before deployment (P < .05) predicted postcombat PTSD symptoms. Moreover, these threat-related attention associations with PTSD were moderated by genetic and environmental factors, including serotonin transporter (5-HTTLPR) genotype.

Conclusions and Relevance

Combat exposure interacts with threat-related attention to place soldiers at risk for PTSD, and interactions with other risk factors account for considerable variance in PTSD vulnerability. Understanding these associations informs research on novel attention bias modification techniques and prevention of PTSD.

Neural Network Modulation by Trauma as a Marker of Resilience Differences Between Veterans With Posttraumatic Stress Disorder and Resilient Controls Neural Network Modulation and Resilience

James LM, Engdahl BE, Leuthold AC, et al. — Mon, 01 Apr 2013 00:00:00 GMT

Importance

Posttraumatic stress disorder (PTSD) and resilience reflect 2 distinct outcomes after exposure to potentially traumatic events. The neural mechanisms underlying these different outcomes are not well understood.

Objective

To examine the effect of trauma on synchronous neural interactions for veterans with PTSD and resilient controls using magnetoencephalography.

Design

Participants underwent diagnostic interviews, a measure of exposure to potentially traumatic events, and magnetoencephalography.

Setting

US Department of Veterans Affairs medical center.

Participants

Eighty-six veterans with PTSD and 113 resilient control veterans recruited from a large Midwestern medical center.

Main Outcome Measures

Multiple regression analyses were performed to examine the effect of lifetime trauma on global and local synchronous neural interactions. In analyses examining the local synchronous neural interactions, the partial regression coefficient indicates the strength and direction of the effect of trauma on the synchronous interactions between the 2 neural signals recorded by a pair of sensors. The partial regression coefficient, or slope, is the primary outcome measure for these analyses.

Results

Global synchronous neural interactions were significantly modulated downward with increasing lifetime trauma scores in resilient control veterans (P = .003) but not in veterans with PTSD (P = .91). This effect, which was primarily characterized by negative slopes (ie, decorrelations) in small neural networks, was strongest in the right superior temporal gyrus. Significant negative slopes were more common, stronger, and observed between sensors at shorter distances than positive slopes in both hemispheres (P < .001 for all) for controls but not for veterans with PTSD.

Conclusions

Neural modulation involving decorrelation of neural networks in the right superior temporal gyrus and, to a lesser extent, other areas distinguishes resilient veterans from those with PTSD and is postulated to have an important role in healthy response to trauma.

JAMA Psychiatry: Military/Veterans Medicine Topic Collection

Attention to Threats and Combat-Related Posttraumatic Stress Symptoms Prospective Associations and Moderation by the Serotonin Transporter Gene Combat-Related Posttraumatic Stress

Neural Network Modulation by Trauma as a Marker of Resilience Differences Between Veterans With Posttraumatic Stress Disorder and Resilient Controls Neural Network Modulation and Resilience