PROJECT SUMMARY/ABSTRACT (PROJECT LEADER GORMLEY) Young adults with attention-deficit/hyperactivity disorder (ADHD) are less likely to enroll in college, earn signifi- cantly lower GPAs if they do enroll, and are susceptible to a range of adverse outcomes. These include increased risk-taking, higher rates of criminality, and higher prevalence of comorbid disabilities. One of the most common comorbid conditions of adult ADHD is substance use disorder (SUD), with nearly 30% of those with ADHD diag- nosed with a non-alcohol related SUD during their lifetime and 42.7% with an alcohol use disorder. Costs asso- ciated with ADHD are estimated to total up to $141 billion annually from both direct costs (e.g., legal fees, injury, property damage) and indirect costs such as lost income due to missing work or being fired. The addition of a SUD confers an additional economic burden of $193 billion. However, substance use alone use does not explain the relationship between ADHD and poorer academic outcomes. Instead, ADHD and substance use confer unique and substantial risks for academic functioning, placing college students with ADHD who use substances at a compounded risk for adverse outcomes. Students with ADHD make up 6% of first-year college students and are more likely to enroll in 2-year colleges. Current published research on substance use among college students with ADHD has been primarily drawn from studies based in 4-year colleges using cross-sectional designs. The long-term goal of this work is to limit substance use related harms and facilitate academic, social, and vocational success for college students with ADHD. The objective of this developmental project is to determine the rela- tionship between substance use and educational outcomes among college students with rigorously defined ADHD enrolled in 2- and 4-year institutions. A total of 100 first-time first-year college students (50 from 2-year and 50 from 4-year institutions) will be recruited. The 2 Specific Aims are to: 1) determine the relationship between frequency of substance use and academic functioning for first-year college students with ADHD enrolled at 2-year and 4-year institutions and identify potential differences based on the type of institution and 2) identify factors associated with substance use initiation, persistence, and cessation. Results will provide rich preliminary data using both traditional assessment (e.g., interviews, rating scales) and responsive ecological momentary assessment via the Open Dynamic Interaction Network (ODIN), a cell phone-based platform developed by the Rural Drug Addiction Research (RDAR) Center. The study will be the first to provide longitudinal detail about substance use among college students with ADHD across their first year and the first to include 2-year institu- tions. Identifying differences in patterns across the 2 institution types will yield vital information for understanding the needs of these students in settings within which they...