Adolescent Brain Cognitive Development (ABCD) was the largest long-term study of brain development and child health in the United States. ABCD consisted of a Coordinating Center, a Data Analysis and Informatics Resource Center, and 21 research sites across the United States. ABCD had enrolled a diverse sample of 11,878 9-10-year-olds and tracked their biological and behavioral development through adolescence into young adulthood. All participants received repeated state-of-the-art neuroimaging, neuropsychological testing, bioassays, and detailed youth and parent assessments of substance use, mental health, physical health, and culture and environment.

In March 2020, when the participants were ages 11-13, the world became substantially affected by the COVID-19 pandemic, leading to an upheaval in the economy and the lives of almost every family. The majority of U.S. schools closed to reduce viral spread. Many parents incurred changes in work (from home, longer shifts, reduced wages, and/or job loss), some services and support systems were disrupted, and case counts and death tolls surged. The massive multifaceted impact of this unprecedented event had the potential to affect for decades those who were currently children.

The research immediately leveraged the ABCD cohort, infrastructure, and existing protocol to rapidly characterize the impacts of the COVID-19 pandemic on each child in the study. By collecting this situational information as soon as possible, the team was able to use existing ABCD data to examine perturbations in developmental trajectories of brain functioning, cognition, substance use, academic achievement, social functioning, and physical and mental health.

The project queried all ABCD participants and their parents multiple times about the impact of the pandemic on their lives and, in a subset of participants, examined their physical activity and sleep objectively with activity trackers (Fitbits) over the months of school closures, job loss, and disease spread. This allowed the consortium and the scientific community at large to test multiple aims regarding how various facets of the pandemic affected development.