Participants were enrolled in the ongoing Adolescent Brain Cognitive Development (ABCD) Study, and a sample of 11,880 youth initially enrolled at ages 9–10 years at 22 study sites across the U.S. Recruitment was primarily school-based [23]. At study entry, 48% of youth were female, 20% were Hispanic, 15% were Black, and 2% were Asian. Sixty-eight percent of parents/guardians were married; 53% of families included a parent/guardian who completed BA/graduate degree. All procedures were conducted in accordance with the ethical standards of the 1964 Helsinki Declaration and its later amendments and were approved by an institutional review board.
