PROJECT SUMMARY Excessive alcohol drinking Initiated during adolescence is known to disturb typical neurodevelopmental patterns, increase the risk of developing alcohol use disorder (AUD), and accelerate involutional processes in adulthood. In response to RFA-AA-21-008, the Administrative Resource (AR) proposes to coordinate activities of the National Consortium on Alcohol and Neurodevelopment in Adolescence - Adulthood (NCANDA-A) to follow for the next 5 years a diverse community sample of male and female participants recruited in three age bands (12- 14, 15-17, 18-21 years old) as mostly no-to-low drinkers, tracked over the last 8 years across 5 sites (N=831; 93% retention rate). This consortium reflects seven applications: NCANDA - Administrative Resource (UCSD) and NCANDA - Data Analysis Resource (SRI), and five cross-national Research Project Sites, located at Duke University (Duke), Oregon Health Science University (OHSU), University of Pittsburgh (Pitt), SRI International (SRI), and UC San Diego (UCSD). Monitoring has involved annually multimodal neuroimaging (MRI, DTI, resting state fMRI, task fMRI), cognitive, clinical, behavioral, and biological data, collected in person or remotely by computer and our mobile app. These measures will now be complemented with new advanced neuroimaging and sleep and physical activity tracking. Our accelerated longitudinal design uniquely positions NCANDA-A (ages 18-34) to quantify transient or enduring alcohol-related disturbances in adolescent and early adult neural system growth trajectories and functional concomitants. NCANDA-A proposes four consortium-wide specific aims and two specialty project aims. In Aim 1, we investigate the impact of excessive alcohol drinking during adolescence and emerging adulthood on subsequent developmental trajectories of cognitive performance, brain structure and function, and psychopathology. Aim 2 identifies the extent to which alcohol’s effects on brain structure and function resolve or persist during desistance of binge drinking. Aim 3 identifies adolescent biological, environmental, and behavioral factors that forecast excessive drinking during early adulthood. Aim 4 quantifies COVID-19 pandemic impact on alcohol use, stress, and wellbeing. Aim 5 (SRI and Pittsburgh sites) identifies interactions among alcohol use, sleep, and cardiac function. Aim 6 (UCSD, Duke and OHSU sites) determines the extent to which short-term (i.e., 4 weeks) alcohol use discontinuation results in acute improvement in cognition, affect, sleep and resting heart rate, and reversal of structural and functional brain effects of binge alcohol use. For each aim, sex differences will be tested. With longitudinal data collected into early adulthood during this renewal, NCANDA-A will provide novel information on the enduring and transient effects of adolescent drinking on adult functioning by discovering elements and mechanisms linking these dynamic processes and identifying modifiable risk factors.