(PS10-41) The Impact of PTSD Symptom Change on Alcohol Use: A Closer Look at Negative Affect and Avoidance

Alcohol misuse and alcohol use disorder (AUD) following a traumatic event are extremely common (Guinle, 2020; Keyes et al., 2011). Posttraumatic stress disorder (PTSD) and AUD often present together, with comorbidity rates as high as 42%, and AUD has also been found to be a strong predictor of more severe PTSD (Blanco et al., 2013; Debell et al., 2014). After trauma, alcohol use primarily functions as a coping mechanism related to high levels of negative affect and avoidance, two core subclusters of PTSD symptoms (Boness et al., 2021; Khantzian, 1986, 1997). Surprisingly, there have been few studies investigating whether alcohol use is predictive of higher avoidance and negative affect symptoms in individuals with PTSD. Furthermore, it remains unclear whether change in these PTSD subclusters during treatment is predictive of associated changes in alcohol use. Individuals with PTSD (N = 149) were part of a doubly randomized control trial, receiving either prolonged exposure (PE) or PE + sertraline for 10 weeks. Individuals with current substance abuse disorder were excluded, though individuals with lifetime substance abuse were included. Alcohol use and related problems were measured using the Addiction Severity Index- Self Report (ASI-SR; McGahan et al., 1986). Avoidance and negative affect scores were calculated from the Post Traumatic Symptom Scale- Self Report (PSS-SR; Foa et al., 1993). Majority of the sample (64.1%) reported drinking in the past month and 31.7% of the sample endorsed drinking past intoxication at least once in the past month. Preliminary analyses revealed that higher baseline alcohol use and alcohol related problems were weakly associated with higher baseline self-report PTSD (r = .17, p = .045) and depression (r = .18, p = .034) symptoms; however, did not approach significance for avoidance and negative affect. ASI scores did not significantly change from pre to post treatment (t=.97, p = 0.34). Logistic regression analyses were conducted to predict past-month alcohol use and related problems post-treatment. Analyses revealed that PSS-SR avoidance scores throughout treatment were not a significant predictor of alcohol use and related problems post-treatment (β = -.03; p = .43). Reduction in PSS-SR negative affect scores approached significance in predicting ASI scores indicating alcohol use and related problems post-treatment (β = .03; p = .06). Alcohol use and related problems may be associated with more severe presentations of PTSD, though alcohol’s role as a potential coping mechanism for specific symptoms of PTSD remains unclear. Negative affect may serve as a promising potential mediator of alcohol use post treatment, though further investigation is necessary, specifically with a sample that exhibits higher levels of problematic drinking.