Alcohol-Related Problems As Moderators of PTSD Symptom Change During Use of a Web-Based Intervention for Hazardous Drinking and PTSD.

OBJECTIVE:Alcohol-related problems (e.g., physical, interpersonal, intrapersonal, impulse control, social responsibility) can have an impact on posttraumatic stress disorder (PTSD) symptoms during treatment. Evidence-based online self-help tools exist to target alcohol use and related problems and co-occurring PTSD symptoms. It is unknown to what degree individuals with varying alcohol-related problems respond differently to web-based interventions for hazardous alcohol use and PTSD. The current study evaluated specific alcohol-related problems as potential moderators of PTSD symptom changes during the VetChange online intervention while controlling for average daily alcohol use, gender, race, and age. METHOD:We conducted a secondary analysis of a randomized controlled trial that included 600 post-9/11 veterans (518 men and 82 women). Mixed-effects regression models of alcohol-related problems on PTSD severity scores over time were performed separately in an initial intervention group (IIG; n = 404) and a delayed intervention group (DIG; n = 196) that was used as a comparison condition. RESULTS:Interpersonal problems emerged as a moderator of PTSD symptom changes in IIG such that veterans endorsing greater interpersonal problems demonstrated larger reductions in PTSD symptoms throughout VetChange. There were no significant moderation effects in DIG. Non-White veterans reported significantly higher PTSD symptoms during VetChange. Post hoc analyses indicated that veterans with higher interpersonal problems were more likely to engage in online intervention content focused on identifying high-risk drinking situations and coping with symptoms. CONCLUSIONS:Findings imply that veterans reporting alcohol-related interpersonal problems may benefit the most from, and be more motivated to use, online interventions for hazardous alcohol use and PTSD symptoms.