The ABCD Study® (Adolescent Brain Cognitive Development Study) is a U.S. research initiative focused on understanding brain development and child health over time. Described as the largest long-term study of its kind in the United States, it includes 11,880 participants and operates through 21 research sites nationwide. Its website serves participants, families, educators, and scientists, offering information about the study’s history, design, procedures, and participating institutions.

The initiative supports scientific research through resources such as study data, imaging protocols, fMRI tasks and tools, publications, workgroups, and funding announcements. Its commitment to open science includes data-sharing resources and guidance on responsible, ethical use of research findings. The site also provides educational materials, participant resources on substance use and prevention, resume and career resources, and information about genetic testing and results. Participants aged 18 or older may choose to receive their personal genetic results. ABCD also publishes news, infographics, webinars, and youth health data briefs, helping make study information accessible to research communities and the public.