Childhood adversity and combat as predictors of depression and post-traumatic stress in deployed troops

Background: Previous studies have shown a relationship between childhood adversity and health outcomes in adulthood. The military represents a segment of the young working population that faces unique hazards that may be worsened by previous adverse life experiences. To date, no comprehensive studies of childhood adversity have been conducted with military samples that have included combat troops before and after a combat deployment. Methods: Surveys were administered in 2003 to 4529 male soldiers who had not deployed to Iraq, and in 2004 to a separate group of 2392 male soldiers 3 months after returning from Iraq. The main predictor was adverse childhood experiences, an aggregated construct representing incremental exposure to six types of traumatic childhood experiences. This construct correlated with depression and post-traumatic stress disorder rates, as well as symptom scores. For the post-Iraq sample, analyses were conducted to assess whether individuals with childhood trauma were affected differently by exposure to combat. Results: The likelihood of screening positive for depression and post-traumatic stress disorder was significantly higher for individuals reporting exposure to two or more categories of childhood adversity. Core analyses showed that adverse childhood experiences were a significant predictor of mental health symptoms, beyond the expected contribution of combat. Conclusions: This study confirms the high prevalence of adverse childhood experiences and the association of these experiences with key mental health outcomes. In addition, the results highlight the importance of considering pre-enlistment childhood traumatic experiences as well as the level of combat exposure in the treatment of military personnel returning from combat operations.