The age-period design yielded convergent results (Figure S4). More 11-year-olds reported past-30-day nicotine use (1.8 vs. 0.1%; p < .001) or misuse of prescription drugs (0.9% vs. 0%, p = .005) during May/June 2020 than in 2018/2019. Fewer 12-year-olds reported past-30-day alcohol use in May/June 2020 versus 2019 (1.2% vs. 2.2%, p = .01), but more reported nicotine use (1.2% vs. 0%, p < .001), misuse of prescription drugs (0.6% vs. 0%, p = .006), and inhalant use (0.5% vs. 0%, p = .03).
