Impact of phased COVID-19 vaccine rollout on anxiety and depression among US adult population, January 2019–February 2023: a population-based interrupted time series analysis

Background: Existing research lacks information on the potential impacts of multi-phased coronavirus disease 2019 (COVID-19) vaccine rollouts on population mental health. This study aims to evaluate the impact of various COVID-19 vaccine rollout phases on trends and prevalence of anxiety and depression among US adults at a population level. Methods: We performed a US population-based multi-intervention interrupted time series analysis through Deep Learning and autoregressive integrated moving average (ARIMA) approaches, analyzing 4 waves of US CDC's Behavioral Risk Factor Surveillance System (BRFSS) data (January 2019–February 2023) to assess changes in the weekly prevalence of anxiety and depression following interruptions, including all major COVID-19 vaccine rollout phases from 2020 to early 2023 while considering pandemic-related events. Findings: Among 1,615,643 US adults (1,011,300 [76.4%] aged 18–64 years, 867,826 [51.2%] female, 126,594 [16.9%] Hispanic, 120,380 [11.9%] non-Hispanic Black, 1,191,668 [61.7%] non-Hispanic White, and 113,461 [9.5%] other non-Hispanic people of color), we found that three COVID-19 vaccine rollout phases (ie, prioritization for educational/childcare workers, boosters for all US adults, authorization for young children) were associated with a 0.93 percentage-point (95% CI −1.81 to −0.04, p = 0.041), 1.28 percentage-point (95% CI −2.32 to −0.24, p = 0.017), and 0.89 percentage-point (95% CI −1.56 to −0.22, p = 0.010) reduction, respectively, in anxiety and depression prevalence among the general US adult population despite an upward trend in the prevalence of anxiety and depression from 2019 to early 2023. Among different population groups, Phase 1 was associated with increases in anxiety and depression prevalence among Black/African Americans (2.26 percentage-point, 95% CI 0.24–4.28, p = 0.029), other non-Hispanic people of color (2.68 percentage-point, 95% CI 0.36–5.00, p = 0.024), and lower-income individuals (3.95 percentage-point, 95% CI 2.20–5.71, p < 0.0001). Interpretation: Our findings suggest disparate effects of phased COVID-19 vaccine rollout on mental health across US populations, underlining the need for careful planning in future strategies for phased disease prevention and interventions. Funding: None.