Alcohol Use Disorder as a Moderator in the Relationship Between PTSD and Suicidality Among Military Personnel

Abstract

Background: Alcohol use disorder (AUD), posttraumatic stress disorder (PTSD), and suicide are substantial public health concerns among military service members, yet the nature of their relationships is not well understood. The present study tests the hypothesis that AUD moderates the relationship between PTSD symptom severity and suicidality. Methods: This secondary analysis uses data collected at baseline for a randomized clinical trial. The sample consists of 161 active-duty service members from three service branches (Army, Air Force, and Navy). All participants met diagnostic criteria for PTSD and were not engaged in evidence-based PTSD treatment at the time of enrollment. Zero-inflated Poisson generalized linear regression models were used to test the associations of PTSD and AUD symptom severity with likelihood and severity of suicidal ideation. Results: Findings suggest that AUD symptom severity moderates (i.e., amplifies) the relationship between PTSD symptoms and severity of suicidal ideation among military personnel with untreated PTSD. Among service members with low or absent AUD, no significant association was found between PTSD symptoms and severity of suicidal ideation. However, when AUD severity was average (i.e., sample mean) or high, PTSD symptoms had a significant positive association with severity of suicidal ideation. Conclusions: This study highlights the importance of including assessment of AUD and PTSD in suicide risk evaluations. Further, results provide strong support for the maintenance and further development of treatment programs that simultaneously address AUD and PTSD comorbidity in the military health system.