Moderators of the relationship between combat experiences and alcohol use in active-duty U.S. military personnel 2001-2021

Combat experiences (CE) are a signature occupational hazard for U.S. Military personnel. Those who have served in combat consume more alcohol than non-combat service members and their civilian counterparts. Alcohol use and its outcomes cost the Department of Defense (DoD) billions of dollars annually, exacting a steep toll on individuals, families, and communities. Despite tremendous effort, alcohol problems persist in the military. This study explored the factors that may moderate the relationship between CE and alcohol use in recent service members. A longitudinal sample from the 2011 Walter Reed Army Institute of Research (WRAIR) Land Combat Study (n=500) containing U.S. Army Soldiers returning from the Global War on Terror was subjected to analyses. Confirmatory factor analyses tested distinct categories of CE. Linear modeling was used to verify the relationship between CE and alcohol use. Mediation analysis tested the plausible causal pathway of behavioral health symptoms between CE and alcohol use. Moderation analysis was conducted to search for interaction effects of marital/relational satisfaction, education, sleep duration, organizational factors, and appraisals of the meaning regarding the CE on the relationship between CE and alcohol use. The CFA revealed a three-factor solution containing the categories of “fighting,” “threats to oneself,” and “death of others” (CMIN/DF = 2.88, RMSEA = .06, CFI = .96, TLI = .95). All categories except “death of others” were related to total alcohol use scores at 16-months post-deployment. Combined, total CE at three months post-deployment was associated with alcohol use at 16 months post-deployment (β = .10, SE = .02, 95% C.I. (.00, .08), n = 399]. Symptoms of post-traumatic stress (PTS) showed total mediation of the relationship between CE and alcohol use while controlling for age [β = .05; bootstrapped SE = .05, t = 1.02, 95% C.I. (.00, .10)]. Education level, sleep duration, relational satisfaction, organizational support, and appraisal of combat did not moderate the CE and alcohol use relationship while controlling for age. Organizational support did moderate the mediated relationship of PTS symptoms to alcohol use while controlling for age [B = .03, SE = .01, 95% C.I. (.01, .05)]. There were distinct categories of CE and they had differing relationships with subsequent alcohol outcomes. Those outcomes were totally mediated by PTS symptoms which were, in turn, moderated by organizational support. As organizational support increased, the strength of the relationship between PTS and alcohol use increased. Moderate and high organizational support were related to a greater relationship between PTS and alcohol use. Findings have implications for leaders who can distinguish between supportive climates versus settings that tolerate alcohol use. This has practice implications for screening, prevention, and treatment of PTS rather than CE as a risk factor for increased, subsequent alcohol use. Recruitment efforts should target resilient candidates and delay combat service for service members at risk of developing PTS. Future research might focus on which aspects of organizational support specifically moderate PTS and alcohol use. Disclaimer: Materials for this study have been reviewed by the Walter Reed Army Institute of Research. There is no objection to its presentation and/or publication. The opinions or assertions contained herein are the private views of the author and are not to be construed as official, or as reflecting true views of the Department of the Army or the Department of Defense. The investigators have adhered to the policies for the protection of human subjects as prescribed in AR 70–25.