The Psychological Costs of War: Military Combat and Mental Health

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In The Psychological Costs of War: Military Combat and Mental Health (NBER Working Paper No. 16927), authors Resul Cesur, Joseph Sabia, and Erdal Tekin report that the mere length of deployment or breaks between deployments are far less significant for veterans experiencing post-traumatic stress disorder (PTSD) than the frequency of actual exposure to firefights. These researchers exploit the variation in overseas assignments that control for mental health prior to deployment in order to study the relationship between military combat and young adults' mental health. They find that U.S. soldiers who serve in combat zones are at greater risk of PTSD and are more likely to receive psychological or emotional counseling than their counterparts serving outside the United States in non-combat zones.

The authors estimate that just the combat-induced PTSD imposes two-year costs of $1.5 to $2.7 billion on the U.S. health care system. They determine that the psychological costs of combat are largest for soldiers who kill someone (or believe they have killed someone), are injured in combat, or witness the death or wounding of a civilian or a coalition member. These troops are at substantially increased risk of suicide or thoughts of suicide, depression, and PTSD. Interestingly, the authors find that observing the killing, death, or wounding of the enemy has no independent adverse psychological consequences. These findings are consistent with the hypothesis that strong feelings of guilt may accompany the death of non-combatants or fellow soldiers.

The data used in this study come from the National Longitudinal Study of Adolescent Health (Add Health), conducted by the Carolina Population Center at the University of North Carolina at Chapel Hill. The Add Health is a nationally representative, school-based longitudinal study that began surveying U.S. adolescents in seventh to twelfth grades in the mid-1990s. Follow-up studies contain a relatively large sample of military servicemen and women and provide information on whether active-duty servicemen and women were deployed to a combat zone, assigned to a non-combat zone outside of the United States, or served on active-duty in the United States exclusively. Violent combat events are self-reported, and because the survey reaches back to adolescence, the authors of this paper have information on the respondent's mental health prior to any military deployment.

The measure of depressive symptoms used here comes from a version of the Center for Epidemiological Studies-Depression (CES-D) Scale; additional measures of mental health are generated by respondents' answers to a question about whether they had "received psychological or emotional counseling in the past 12 months" and whether "a doctor, nurse or other health care provider ever told you that you have or had post-traumatic stress disorder?"

This analysis provides credible estimates of the causal effect of combat service on young adults' psychological well-being. However, the authors caution that their estimates of the cost of PTSD include only the short-run costs for younger soldiers. Future research that follows soldiers as they transition back into civilian life will be able to provide further information on the longer-run effects of combat service.

--Matt Nesvisky