ABCD Study

The ABCD (Adolescent Brain Cognitive Development) Study is an ongoing longitudinal research study being undertaken by a consortium of 21 data collection sites across the United States as well as a Coordinating Center and a Data Analysis Informatics & resource Center. It is the largest long-term study of brain development and child health in the U.S. The study collects data on behavior and brain development of nearly 12,000 youth beginning at ages 9-10 and continuing through young adulthood in six domains: physical health, mental health, neurocognition, substance use, novel technology (e.g., Fitbit, app usage), and family, friends & community, as well as neuroimaging (structural and functional MRI and diffusion MRI), and biospecimens collection to measure environmental exposures and substance use. Data derived from linked external datasets using geocoded residential and school histories enrich the study’s data collection by providing information about the contexts and environments in which youth live, work, and play.

The ABCD Study(R) is primarily motivated by the need to develop a "baseline" for adolescent development. A goal of the study is to characterize the development of youth before onset of mental health symptoms, or initiation of substance use, as well as characterize the impact of substance exposure on adolescent neurocognitive development. Data are also collected on sleep habits, screen use, demographics, clinical measures, neuroimaging, and biological samples to allow a holistic picture of adolescent development.

The ABCD Consortium was established in 2015 and data collection began in 2016.  Baseline data collection spanned 2016-2018. Each year, participants return for data collection, but the neuroimaging protocol is administered every other year. In addition to the annual comprehensive data collection, youth participate in brief mid-year virtual interviews. The first data release was shared in 2019. Data Release 6.0 was released via the NIH Brain Development Cohorts Data Hub in June 2025 and contains cumulative data from baseline through the six-year follow-up visit (age 15-16 years) with data from about 60% of participants at that timepoint.

The study includes administration of a range of behavioral assessments, including mental health, language, and working memory.

Several different biospecimen samples are collected for the analysis of hormones, DNA, and environmental exposures. These biospecimens include hair, blood, saliva, and deciduous (baby) teeth. Deciduous teeth can be tested for environmental neurotoxins that were encountered at specific ages (as early as prenatally) by analyzing the chemical content of successive tooth layers.

Researchers can obtain information about how to access banked biospecimens at https://nida.nih.gov/funding/nida-funding-opportunities/nih-brain-development-cohorts-biospecimen-access-program and https://grants.nih.gov/grants/guide/pa-files/PAR-23-229.html.

The ABCD brain imaging protocol includes 3D T1 and 3D T2-weighted scans, as well as diffusion-weighted images, resting state scans, and three functional magnetic resonance imaging (fMRI) tasks. The fMRI tasks include: Monetary Incentive Delay task, Stop Signal task, and the EN-back task (for emotional regulation). Order and version are randomized across participants, and when taken together the tasks are meant to measure reward processing, motivation, impulsivity, impulse control, working memory, and emotion regulation.

Assessments of participants’ parents  include questions about family, friends & community, family history of mental and physical health, and current and past substance use. Biospecimens, brain imaging, and neurocognitive data are not collected from parents.

In response to physical distancing guidelines during the COVID-19 pandemic, the study implemented virtual assessments and included COVID-19 relevant survey questions.

• ABCD Home. The official web site for the project, including a searchable publications page
• Data sharing. The NIH Brain Development Cohorts Data Hub