Abstract
Our objective was to examine the influence of COVID-19 vaccination on recent (i.e., past month) moderate or severe symptoms of anxiety (GAD-7 ≥ 10) or depression (PHQ-8 ≥ 10) before and after the COVID-19 vaccine became universally available for adults in the U.S. Participants belonged to the Communities, Households, and SARS-CoV-2 Epidemiology Cohort (CHASING COVID), a national longitudinal study. Our analytic population included 4,832 participants who reported vaccination status from December 2020 to December 2021 with follow-up outcomes assessed through March 2022. We emulated a hypothetical randomized experiment, a target trial, to estimate the effect of COVID-19 vaccination on symptoms of anxiety or depression. Before vaccines were universally available, participants who were vaccinated versus not had significantly lower adjusted odds of symptoms of moderate or severe anxiety (aOR: 0.79; 95% CI: 0.70-0.89). In the universal vaccine era, vaccination was associated with marginally higher adjusted odds of symptoms of moderate or severe anxiety (aOR: 1.23; 95% CI: 1.00-1.50). Vaccination did not influence subsequent moderate or severe depressive symptoms in the preuniversal vaccine era (aOR: 0.92; 95% CI: 0.82-1.03) or universal vaccine era (aOR: 1.11; 95% CI: 0.91-1.36). Research into the longitudinal relationship between COVID-19 vaccination and symptoms of depression and anxiety is warranted, with a focus on advancing understanding of potential mediators on the pathway between vaccination and mental health as well as modifiable factors, such as vaccine hesitancy or vaccine beliefs, that may help identify populations for whom vaccination may be particularly beneficial to their mental health.