It is no surprise that covid-19 has made people sad. Research in the Lancet, a medical journal, suggests that the pandemic caused almost 130m new cases of depression and anxiety worldwide in the year to January 2021. Yet one effective solution is already being rolled out: the covid vaccine.

In America, access to the jabs varied by age and state. This allowed researchers at the University of Southern California and the RAND Corporation to assess the effect of vaccination on self-reported mental health in the Census Bureau’s Household Pulse Survey. Throughout the pandemic, separate cross-sectional waves of the survey have been conducted every one-to-two weeks. The researchers found that covid vaccination reduced symptoms of depression by 27% and anxiety by 28%.

The benefits were not spread equally. African-Americans, renters and people earning less than $35,000 a year reported some of the biggest improvements. Government workers benefited more than private-sector employees and households with children reported a larger drop in anxiety than those without. People who could work from home had no significant reduction in mental-health problems, perhaps because they did not face a trade-off between work and virus exposure.

The rollout of vaccines has benefited all Americans, whether they have received a dose or not. Restrictions have been relaxed, allowing people to see more of their friends and family, in-person mental-health appointments to resume and children to go back to school. Yet the researchers found that high vaccination rates in respondents’ home states did not ease their mental-health woes. Instead, people only reported less anxiety and depression when they themselves had been jabbed.

A shortage of mental-health workers in America makes therapy, psychiatry and rehabilitation expensive. Few providers are covered by insurance. People seeking mental-health services are five times more likely to pay to be seen outside their insurance network than those in need of physical care. Thus the researchers argue that the reduction in mental illness caused by vaccination is saving hundreds of billions of dollars. Vaccine hesitancy might carry two risks. The physical one of becoming seriously ill—and an underappreciated psychological one, too. ■

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