The Role of Impulsivity in the Association Between Posttraumatic Stress Disorder Symptom Severity and Substance Use in Male Military Veterans.

High rates of posttraumatic stress disorder (PTSD) and comorbid substance use disorder (SUD) are prevalent in military veterans. However, few studies have investigated impulsivity as a risk factor for engaging in substance use behavior for individuals who are experiencing PTSD symptoms. The present study evaluated impulsivity as a moderator of the association between PTSD symptoms and alcohol/drug use. Male military veterans (N = 106) completed self-report measures of alcohol use behavior, drug use behavior, and impulsivity. Participants also completed a structured diagnostic interview to assess for PTSD. The findings indicated that impulsivity moderated the relation between total PTSD symptoms and alcohol use, B = 0.01, p = .035, along with associations between alcohol use and two of the symptom clusters: PTSD reexperiencing symptoms, B = 0.01, p = .016; and PTSD avoidance/numbing symptoms, B = 0.01, p = .029. Veterans with high levels of impulsivity were at significantly higher risk of engaging in alcohol use than veterans with low-to-average levels. Impulsivity did not potentiate the relation between PTSD hyperarousal symptoms and alcohol use nor did it moderate the association between any of the PTSD variables and drug use. Impulsivity appears to serve as a significant risk factor for alcohol use, but not drug use, for male veterans experiencing PTSD symptoms. Future studies are necessary to replicate and expand upon these findings, particularly to facilitate the development of integrated evidence-based treatments that target both alcohol use and impulsivity within the context of PTSD.