Effects of cannabis use on community-based alcohol treatment outcomes in adolescents - PROJECT SUMMARY/ABSTRACT Most (60-90%) adolescents in treatment for alcohol use disorder (AUD) also have a co-occurring psychiatric disorder (COD) other than substance use, and adolescents with AUD+CODs have worse treatment outcomes compared to those with only AUD. Among adolescents seeking treatment for AUD+CODs, over 80% also use cannabis. The adult AUD treatment literature demonstrates worse alcohol-related treatment outcomes for individuals who used cannabis during AUD treatment, but similar information is missing regarding how cannabis use might influence AUD+COD treatment processes. Consistent with NIAAA’s strategic plan to improve treatment for AUD+CODs, this K23 proposal aims to fill a critical gap in understanding how cannabis use affects AUD+COD treatment outcomes among adolescents in community-based treatment. Understanding whether, for whom, in what contexts, and how cannabis use relates to treatment processes and AUD+COD outcomes in real-world community-based treatment will inform viable and meaningful cannabis-related intervention targets for adolescent AUD+COD treatment. This K23 will use mixed methods to inform how cannabis use relates to AUD+COD treatment processes and outcomes. Participants will be recruited from community-based intensive outpatient programs for AUD+CODs who also use cannabis. Aim 1a will use qualitative interviews (N=25) to explore adolescents’ perspectives on their cannabis use in the context of AUD+COD treatment. Aim 1b will use an open pilot ecological momentary assessment (EMA) study (N=5) to solicit feedback and refine the Aim 2 protocol. Aim 2 will use 21 days of EMA during treatment plus longitudinal follow-up surveys at 0-, 1-, 2-, and 3-months post-intensive outpatient treatment (N=90) to understand the dynamics of how AUD+COD processes unfold when adolescents are using cannabis in their natural environments. Results will shed light on how cannabis use affects AUD+COD treatment among adolescents with AUD+CODs and identify productive treatment targets that prioritize adolescents’ lived experiences and are relevant in community-based care. Results will also inform models of addressing polysubstance use in treatment more broadly, which is prevalent in community-based care but largely neglected in clinical trials. This K23 leverages the candidate’s expertise using EMA and multilevel modeling to study alcohol-cannabis co-use while providing needed training in qualitative and mixed methods research, developmentally informed research on adolescents in the context of community-based treatment, advanced structural equation modeling, and professional development, to launch a successful NIAAA-funded clinical research career advancing adolescent addiction science and community-based treatment. A mentorship team with unique and complementary areas of expertise are committed to the candidate’s research and training.