Transdiagnostic Processes Linking Posttraumatic Stress Disorder Symptoms to Alcohol Use Severity

Objective: The high comorbidity between posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) is well-established and complex. However, there is a need to explore transdiagnostic constructs that may underlie this association to better understand what accounts for this comorbidity and to inform treatment development. Method: Thus, the present study utilized a large, cross-sectional dataset (N = 513; M_e = 38.25 years, SD = 10.07; 49.9% female), based on national recruitment, to (1) examine whether the associations between PTSD symptom severity (PCL-5) and alcohol use severity (AUDIT) were statistically mediated by (a) anxiety sensitivity (SSASI); and (b) difficulties with emotion regulation (DERS-16); and (2) examine whether coping motives for drinking moderate this indirect effect. Sex assigned at birth was included as a covariate. Results: When examining the hypothesized mediators (SSASI and DERS-16) in separate models, there was a statistically significant indirect effect of PCL-5 on AUDIT through both SSASI and DERS. However, when both SSASI and DERS were entered into a model simultaneously, only SSASI served as a statistically significant mediator. Coping motives for drinking did not moderate the observed indirect effect. Conclusions: The current findings highlight anxiety sensitivity and emotion regulation as transdiagnostic processes that may explain, at least partially, the relationship between PTSD symptom severity and alcohol use; however, stronger evidence was evident for anxiety sensitivity. These findings may help inform the development of refined, streamlined interventions for PTSD and alcohol use that directly target these processes.