What sampling was use in this study? We analyzed data from the ABCD Study, a demographically diverse study of development across adolescence including 11,875 children at 21 sites in the United States. The study sample, recruitment, procedures, and measures are described elsewhere (Garavan et al., 2018). Centralized institutional review board (IRB) approval was obtained from the University of California, San Diego (protocol number: 160091AW). Study sites obtained approval from local IRBs. Parent/guardian and the child provided written informed consent and assent, respectively. Starting in May 2020, participants in the ongoing ABCD Study were invited to participate in a substudy comprising online surveys, which were distributed electronically at six time points across 2020-2021, to assess the effect of the pandemic on youth and families. Starting dates for distribution of the COVID surveys were: May 16, 2020 (Survey 1), June 24, 2020 (Survey 2), August 4, 2020 (Survey 3), October 8, 2020 (Survey 4), December 13, 2020 (Survey 5), and March 12, 2021 (Survey 6). Data included here are from 5,027 adolescents (2,424 girls and 2,603 boys), who completed the 2-year annual follow-up visit (pre-pandemic period; age range: 10-13 years, M = 11.94 years; 3.0 release: 2018-2020) and at least one COVID-19 Rapid Response Research Survey (COVID-19 assessments; age range: 11-14 years; ABCD COVID-19 Survey releases: DOI: https://nda.nih.gov/study.html?id=1041 and https://nda.nih.gov/study.html