A University of Michigan study reveals that the rate of older adults with dementia declined faster from 2011 to 2021 than it did through 2019, despite a sharp rise in deaths among dementia patients at the start of the COVID-19 pandemic.

Many expected that increased social isolation during the pandemic would lead to higher rates of dementia among older adults. The researchers observed a slight increase in dementia rates in 2020, but by 2021, the overall trend showed an accelerating decline.

Changing risk

“Before the pandemic, dementia rates were falling in the U.S.,” the researchers explain. “At the pandemic’s onset, rates went up slightly, as predicted. However, this increase was overshadowed by a significant rise in deaths among older adults with dementia in 2020-2021, leading to a steeper decline in dementia rates over the decade.”

Dementia rates dropped from 11.9% in 2011 to 9.2% in 2019. After a minor rise to 9.6% in 2020, the rate fell to 8.2% in 2021. On average, the annual decline was 2.8% from 2011 to 2019, increasing to 3.1% from 2011 to 2021.

The researchers used the National Health and Aging Trends Study (NHATS) to track dementia trends over time. They analyzed data from around 48,000 annual interviews with adults aged 72 and older, conducted between 2011 and 2021. Funded by the National Institute on Aging, NHATS examines disability and cognitive function trends in the older U.S. population.

“Robust data like NHATS is crucial for assessing national dementia trends, especially during significant events like the COVID-19 pandemic,” the researchers note. “NHATS tracks social, behavioral, economic, and environmental data over time, helping researchers understand changes and inform policies for the future.”