Project Summary/Abstract The long-term objective of the proposed study is to identify a putative intervention mechanism of change for altering the developmental trajectory of alcohol use problems among an at-risk population. To attain this goal, the applicant will receive advanced training in risk factors of alcohol use, multi-method data design and collection, and quantitative skills via coursework, lab rotations, workshops, and consultation. This is an important area of research as adolescents with ADHD are at-risk for experiencing alcohol-related problems 5,6 and developing alcohol use disorders as emerging adults 3, 4. The applicant’s team previously implemented a training intervention for adolescents with ADHD, and preliminary investigations revealed this intervention was the first intervention for youth with ADHD to be associated with positive treatment-related gains in alcohol use problems 7. The magnitude of these differences grew over time, consistent with findings of other outcomes from this intervention 14. Thus, this intervention may alter the developmental trajectory of alcohol use problems for adolescents with ADHD. A leading developmental biopsychosocial model of the link between ADHD and alcohol use problems 10 highlights the critical role of emotion dysregulation (ED) in catalyzing risk for alcohol use problems among individuals with ADHD. Thus, the goals of the current study are to examine the durability of improvements in alcohol-related problems as the youth transition into emerging adulthood, a time when alcohol use peaks 2, and to examine ED as a putative mechanism of change in the pathway to problematic alcohol use. Efforts will be made to retain the original sample of adolescents with ADHD (n = 171) who previously participated in a randomized controlled trial of a training intervention while in high school. Participants provided self-report of alcohol use behaviors and ED at 3 points over the previous 3 to 5 years. In the proposed study, participants will report their current patterns of alcohol use and associated problems. To enhance our understanding of the complex construct of ED, ED will be measured via multiple units of analysis (i.e., self-report, physiological, behavior). Structural equation modeling will be employed to address the following aims: (1) examine intervention effects on alcohol use problems; (2) examine intervention effects on ED; and (3) examine the association between ED and alcohol use problems, and, in an exploratory aim, examine whether intervention has an effect on alcohol use problems via ED. Sex will be explored as a moderator across these aims given evidence of potential sex-specific pathways to use among individuals with ADHD 55-58. The proposed study has the potential to identify an intervention mechanism of change to be targeted in future interventions that may reduce the detrimental outcomes experienced by youth at-risk of alcohol use problems. Further, the training afforded to the applica...