When people think about the side effects of vaccines, they probably think about fever, pain, being tired,… But a new study looked at other secondary effects of vaccination: what is the effect of vaccination on anxiety and depression, the other pandemic happening because of the coronavirus:

In this paper, we use data from a national survey collected to estimate how COVID-19 vaccination impacts anxiety and depression symptoms. After instrumenting for COVID-19 vaccination using variation in state eligibility rules, we estimate that becoming vaccinated leads to an approximately 30% reduction in mental health symptoms. Importantly, nearly all of the benefits appear to be private benefits, and we find little evidence of external mental health benefits from COVID-19 vaccination. We also find substantial heterogeneity in the impact of COVID-19 vaccination on mental health. We find larger reductions in anxiety and depression symptoms among lower-income populations, workers who lack the ability to telework, and households that rent their housing. The heterogeneity in the benefits of COVID-19 vaccinations reflects the heterogeneity in the health and economic impacts of the pandemic.

Abstract of the working paper:

The COVID-19 pandemic has led to a “second pandemic” of anxiety and depression. While vaccines are primarily aimed at reducing COVID-19 transmission and mortality risks, they may have important secondary benefits. We use data from U.S. Census Bureau’s Household Pulse Survey merged to state-level COVID-19 vaccination eligibility data to estimate the secondary benefits of COVID-19 vaccination on mental health outcomes. To address endogenous COVID-19 vaccination, we leverage state-level variation in the timing of when age groups are eligible for vaccination. We estimate that COVID-19 vaccination reduces anxiety and depression symptoms by nearly 30%. Nearly all the benefits are private benefits, and we find little evidence of spillover effects, that is, increases in community vaccination rates are not associated with improved anxiety or depression symptoms among the unvaccinated. We find that COVID-19 vaccination is associated with larger reductions in anxiety or depression symptoms among individuals with lower education levels, who rent their housing, who are not able to telework, and who have children in their household. The economic benefit of reductions in anxiety and depression are approximately $350 billion. Our results highlight an important, but understudied, secondary benefit of COVID-19 vaccinations.