Depression and anxiety mediate the relationship between COVID-19 stay-at-home orders and tobacco and marijuana use

Persons under SAH orders had 2.18 (95% CI: 1.27, 3.73) times the odds of moderate-to-severe depression across the first seven waves, relative to those living in states without SAH orders. Those with moderate-to-severe depression and anxiety had lower odds of both marijuana (OR = 0.37, 95% CI: 0.17, 0.84) and cigarette use (OR = 0.29, 95% CI: 0.13, 0.65) compared to those with normal-mild PHQ-4 scores. Worsened mental health within a person resulted in 0.22 (95% CI: 0.12, 0.40) times the odds of marijuana use and 0.26 (95% CI: 0.15, 0.47) times the odds of cigarette use. Tests of the joint effects suggest evidence of multiple mediated pathways.