Evaluating the differential effects of hazardous drinking on post-traumatic stress disorder outcomes across two prolonged exposure treatment formats

Individuals with post-traumatic stress disorder (PTSD) are at increased risk for hazardous drinking, which often complicates treatment and affects trauma-focused psychotherapy outcomes. The present study is an exploratory, secondary analysis investigating differential effects of prolonged exposure (PE) among those with and without hazardous drinking and whether treatment outcomes varied across these groups as a function of PE format. Data used were from a randomized controlled trial that examined two daily, compressed formats of PE treatment for PTSD (massed and intensive outpatient program) in military personnel and veterans (N = 234). Individuals without hazardous drinking had greater PTSD symptom reductions compared to those with hazardous drinking (d = 0.42, p = 0.001). However, the hazardous drinking group also demonstrated significant reductions in PTSD (d = 1.46, p < 0.001) following treatment, as well as in the number of drinks per week (d = 0.63, p = 0.025) at the 6-month follow-up. There was no significant difference in treatment engagement based on drinking classification and outcomes did not vary based on PE format. The findings suggest that PE is an appropriate treatment for individuals with PTSD and hazardous drinking. However, group differences in PTSD symptom reductions indicate concurrent hazardous drinking reduces treatment benefits of PE.