Abstract
BACKGROUND: Sexual minority women and gender diverse individuals (SMWGD) are at heightened risk for alcohol and cannabis use disorders compared to heterosexual and cisgender individuals, and their heightened risk has been attributed to minority stress. However, few longitudinal studies have examined mechanisms through which minority stress may impact substance use, and none have done so at the event-level. METHODS: We utilized data from a 30-day ecological momentary assessment study of 429 SMWGD who used alcohol or cannabis regularly to test a mechanistic process in which minority stress predicts alcohol and cannabis use via coping motives for use at the event-level. RESULTS: When individuals experienced more enacted stigma (e.g., microaggressions) than usual during one assessment, they were more likely to use cannabis to cope during the next. In turn, occasions when cannabis was used to cope were marked by more sessions of cannabis use, longer intoxication, higher subjective intoxication, and more cannabis consequences. Indirect effects of enacted stigma on cannabis use via coping motives were significant. However, only one of internalized stigma's indirect effects was significant, with internalized stigma predicting cannabis consequences via daily coping motives. No indirect effects predicting alcohol use were significant. CONCLUSIONS: Findings provide robust evidence that using to cope is a mechanism through which enacted stigma predicts cannabis use and internalized stigma predicts cannabis consequences. Results did not provide evidence for similar associations for alcohol. Our findings suggest that interventions designed to reduce cannabis use among SMWGD should attend to their minority stress experiences and cannabis use motives and teach alternative coping strategies.