Adolescent alcohol and cannabis transitions: Associations with multidimensional SES and cannabis policy - PROJECT SUMMARY/ABSTRACT Adolescents currently engaged in substance use often co-use (e.g., both alcohol and cannabis; AC co-use), yet few have systematically examined how youth AC co-use patterns change over time (e.g., additive or substitution effects) in differing recreational cannabis policy contexts. Particularly as it relates to environmental opportunity and social inequality, factors like socioeconomic status (SES) and may play a critical role. This project will inform prevention intervention strategies, specifically for young people engaged in alcohol use, by examining the intersection of comprehensive socioenvironmental opportunity and state- level cannabis policy, and their associations with adolescent AC co-use transitions. The aims are to identify latent profiles and longitudinal transition patterns of AC co-use, and to examine how AC profiles and transition probabilities are associated with multidimensional SES (mSES) and state-level recreational cannabis law (RCL) in two different policy environments. Disaggregating patterns of AC co-use in young people is essential to informing public health and clinical practice, as each year more states enact RCLs, and on-the-ground providers largely operate without information about how to navigate changes in use patterns among this age group. An exploratory aim will evaluate sociodemographic characteristics in these highly diverse samples (Mage=16.8; 55% Hispanic/Latino; 10.6% sexual and gender minority status). Here, the applicant will maximize data from two of her primary mentor's NIAAA-funded longitudinal R01s of underage youth engaged in alcohol use (N=710) collected across two regions with differing RCLs. The training plan is designed to provide a rich program of training in advanced longitudinal modeling, adolescent development, contemporary issues in addiction, and an initial exploration into how patterns may differ for underrepresented and underserved youth. The proposed project is a natural extension of the applicant’s current program of research, and critically, would provide essential protected research and training time to develop requisite skills and hone expertise to launch a career as an independent NIH-funded scientist. Without the F31 support, the applicant will need to take on teaching obligations in her department, rendering it far more difficult to achieve this same degree of crucial breadth and depth in training, particularly around writing and dissemination efforts. The applicant will be mentored by Dr. Feldstein Ewing (Sponsor, University of Rhode Island; URI), an expert in adolescent addiction and its prevention and treatment. Drs. Manshu Yang (URI) and Tammy Chung (Rutgers University) will also provide training in AC co-use, latent variable modeling, and longitudinal methods. Drs. Feldstein Ewing, Yang, and Chung have an over decade of work successfully collaborating, even while housed at different institutions, supporting a synergistic training environment that will work closely with the applicant to ensure that she meets and achieves all proposed research and training aims.