After the pandemic began in March, the number of excess deaths in the United States rose for all American adults. During the summer, as the pandemic eased, the rate of excess mortality declined among older Americans but remained unusually high among young adults. When statisticians at the Centers for Disease Control totaled the excess deaths for age groups through the end of September, they reported that the sharpest change – an increase of 26.5% – occurred among Americans aged 25 to 44. That trend persisted through fall, and most of the excess deaths among younger people were not linked to the coronavirus, as researchers from the University of Illinois found by analyzing excess deaths from March through the end of November. Among Americans aged 15 to 54, there were roughly 56,000 excess deaths, of which about 22,000 involved COVID-19, leaving 34,000 from other causes. The Canadian government also reported especially high mortality among Canadians under 45: nearly 1,700 excess deaths from May through November, with only 50 of those deaths attributed to COVID-19. “We don’t know exactly why, but a lot of adults were dying last year who would not have ordinarily died, and it wasn’t just because of COVID,” says Sheldon H. Jacobson, one of the Illinois researchers. “It’s possible that some of the COVID-19 deaths were undercounted, but there were many deaths due to other causes. Shutdowns certainly caused mental health issues, and a lot of preventive medical treatments were delayed.”