A Systematic Review of the Self-Medication Hypothesis in the Context of Posttraumatic Stress Disorder and Comorbid Problematic Alcohol Use.

Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) commonly co-occur and are associated with many negative public health outcomes. There are several etiological models that explain the overlap between PTSD and AUD, including shared genetic risk and phenotypic causality, but the predominant model of etiologic association is the drinking-to-cope self-medication model. Although the self-medication model is conceptually appealing and has been widely accepted within the literature examining alcohol use and anxiety (e.g., PTSD) phenotypes, the findings are inconsistent and there is a lack of rigorous empirical evidence in support of this model. This review, which was, to our knowledge, the first systematic review of the self-medication model in relation to PTSD to date, aimed to synthesize the current literature on the association between PTSD and problematic alcohol use within the context of the self-medication model. In total, 24 studies met the inclusion criteria for the review and assessed the self-medication hypothesis using a variety of measurement instruments and data analytic approaches, such as mediation, moderation, and regression. Overall, the included studies provide evidence for the self-medication hypothesis but are limited in rigor due to methodological limitations. These limitations, which include issues with the operationalization (or lack thereof) of trauma-related drinking to cope, are discussed, and directions for future research are presented.