Emotion Regulation in the Association Between Posttraumatic Stress Disorder and Substance Use: A Systematic Review With Narrative Synthesis.

Posttraumatic stress disorder (PTSD) and substance use commonly co-occur and represent a unique clinical challenge. Current interventions show modest effect sizes and high rates of dropout highlighting the need to better understand the mechanisms underlying the PTSD-substance use association. Evidence suggests emotion regulation may be an important factor underlying this association. This systematic review aims to examine the role of emotion regulation in the association between PTSD and substance use and to provide an understanding of differences in emotion regulation based on gender, trauma type, and social factors. Systematic searches of Medline, Embase, PsycInfo, ASSIA, CINAHL, and Web of Science identified 33 studies that met the review inclusion criteria. While findings were mixed, the results largely suggest difficulties regulating negative and positive emotions are important in the PTSD-substance use association. Emotion regulation was elevated in individuals with PTSD-substance use disorder (SUD) compared to SUD only and among individuals with more severe PTSD and substance use symptoms. A small number of studies highlighted the role of emotion regulation difficulties over time and in relation to treatment outcomes. Preliminary findings suggested there may be differences in emotion regulation in PTSD-substance use based on gender, trauma type, and social factors, though this requires further examination. Limitations of the included studies include small sample sizes, cross-sectional designs, and a predominant focus on alcohol use. The findings largely support self-medication and negative reinforcement models of substance use and highlight the possible utility of integrated interventions focusing on emotion regulation for PTSD-substance use. Recommendations for further research are discussed.