Feasibility and Effectiveness of Gamified Digital Intervention to Prevent Alcohol and Mental Health Risks - Project Abstract Sexual minority women consume alcohol, experience alcohol-related problems, and suffer from mental health problems at higher rates than do their heterosexual peers. Although several clinical programs are being developed for sexual minority women (SMW) seeking treatment for these problems, only a small proportion of SMW needing it ever seek treatment. Meanwhile, preventive interventions able to avoid these problems by reducing drinking and improving psychological well-being among non-treatment seeking SMW have been slow to emerge. The proposed research builds on R21AA025767, which established the preliminary feasibility and effectiveness of delivering personalized normative feedback on drinking and coping behaviors to SMW within a broader app-based social competition designed to challenge harmful stereotypes about this population and foster a supportive virtual community. In our pilot trial, sexual minority women enthusiastically engaged with the app in the absence of participation incentives for doing so. Further, relative to a sub-sample that received PNF on control topics within the competition, those who received PNF on drinking and coping substantially reduced their consumption and negative consequences over a 4-month period. Moreover, qualitative feedback suggested that negative stereotype disconfirming PNF and social media inspired community features (present across conditions) may have also provided psychological benefits beyond the alcohol and coping PNF evaluated. To build on these promising findings and remedy limitations, this research proposes to first optimize the app based on feedback from participants in the pilot trial (AIM1) and then conduct a large, sophisticated, Type I implementation-effectiveness trial to simultaneously examine the effects of the fully featured app on drinking, alcohol-related problems, and psychological well-being relative to a limited feature psychoeducational control version of the app (AIM2), identify explanatory psychological mechanisms associated with the fully featured app’s effectiveness (AIM3), elucidate demographic and sexual minority stigma-related moderators (AIM4), and examine engagement, acceptability, and sustainability of use under real world conditions among a sub-sample of unincentivized, fully featured app users (AIM 5).