Data were drawn from the ABCD 3.0 data release (DOI: 10.15154/1519007) and the ABCD COVID-19 Survey First Data Release (DOI: 10.15154/1520584). Figure S1 depicts which participants were used in each analysis. We used inverse probability weighting to ensure that the youth completing each pandemic survey reflected the sociodemographic characteristics of the ABCD Study sample at study entry. For analyses reporting the prevalence of substance use (Analyses 1 and 2), we multiplied the inverse probability weights by preconstructed baseline weights to make the survey completers representative of U.S. children aged 9/10 years in the U.S Census Bureau's American Community Survey (2011–2015) along the following variables: youth sex and race/ethnicity; family income, structure, and employment; census region; and household size (see Supplement for details) [29].
