PROJECT SUMMARY This supplement requests funds to make the longitudinal data acquired in the first eight years by the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study publicly available via the National Institute of Mental Health Data Archive Repository (NDA). From 2013 to 2015, the 5 sites of NCANDA recruited a diverse community sample of mostly no-to-low drinkers (12 to 21 years old, N=831) and tracked them since then (93% retention rate). Monitoring has involved annually acquired multimodal neuroimaging (MRI, DTI, resting state fMRI) and cognitive, clinical, and behavioral data. While data acquired by the current funding cycle (a.k.a. NCANDA-A), i.e., from 9 years onwards, are uploaded to NDA, no funds are budgeted for archiving the longitudinal data of the first 8 years to NDA. The supplement would provide those funds and thus give complete public access to this unique and valuable longitudinal data set using a single data structure, a critical step in easing analysis of the impact of heavy alcohol drinking on the NCANDA cohort. NCANDA-A has 4 main aims. With respect to Aim 1, the consortium has been investigating the impact of excessive alcohol drinking during adolescence and emerging adulthood on subsequent developmental trajectories of cognitive performance, brain structure and function, and psychopathology. For Aim 2, NCANDA has been identifying neurodevelopment patterns describing the extent to which alcohol's effects on brain structure and function resolve or persist during desistance after binge drinking. Aim 3 focuses on data-driven analysis to identify adolescent biological, environmental, and behavioral factors (e.g., age of drinking onset) that forecast excessive drinking during early adulthood. Regarding Aim 4, NCANDA-A has been quantifying the impact of the COVID pandemic on life stress and social, emotional, and economic wellbeing and their relations with alcohol use patterns. For each aim, sex differences in development, alcohol use patterns and history, impact of alcohol use on the brain, and sex-differentiating psychosocial factors are tested. Since the initiation of the study, the NCANDA sites have been uploading their data onto servers of the NCANDA Data Analysis Resource (DAR), whose administrative PI is Dr. Pohl. With respect to NCANDA-A, the DAR manages the data in line with five aims. Aim D1 ensures that procedures for collection and quality control of neuroimaging, neuropsychological, and clinical assessment data are standardized. For Aim D2, the DAR has been advancing the existing informatics infrastructure for integrating data collected across all sites. With respect to Aim D3, they are enhancing macrostructural, microstructural, and functional neuroimage processing and analysis. Regarding Aim D4, the DAR creates machine (deep) learning frameworks identifying predictive markers of early adulthood drinking. Finally, for Aim D5, they maintain data sharing and distribution systems for co...