Neural Rewiring of Resilience: The Effects of Combat Deployment on Functional Network Architecture

Background: Although combat-deployed soldiers are at high risk for developing trauma-related psychopathology, most will remain resilient for the duration and aftermath of their deployment tour. The neural basis of this type of resilience is largely unknown, and few longitudinal studies exist on neural adaptation to combat in resilient individuals for whom a pre-exposure measurement was collected. Here, we delineate changes in the architecture of functional brain networks from pre- to postcombat in psychopathology-free, resilient participants. Methods: Tier 1 infantry recruits (n = 50) participated in this longitudinal, functional magnetic resonance imaging study together with a comparison group of university students (n = 50). Changes in within- and between-network functional connectivity were analyzed as a function of exposure group. Results: Significant group × time interactions manifested in the default mode, cognitive control, and ventral attention networks; significant increases from baseline in both within- and between-network connectivity were noted postdeployment in soldiers only. Conclusions: These results indicate global changes in brain functional architecture in resilient combat-deployed participants relative to age-matched students, suggesting that neural adaptation may support resilience to combat exposure.