Dementia is a term used to describe a decline in cognitive function, including memory, language, and problem-solving abilities. It is often associated with old age, but it can occur at any age. There are many different types of dementia, including Alzheimer’s disease, which is the most common cause of dementia.
The study also found a decrease in disparities based on race and sex.
A recent study conducted by the RAND Corporation found that the prevalence of dementia among people over age 65 in the United States decreased by 3.7 percentage points from 2000 to 2016.
The age-adjusted prevalence of dementia fell from 12.2% of people over age 65 in 2000 to 8.5% of people over age 65 in 2016, representing a nearly one-third reduction from the 2000 level. The prevalence of dementia decreased consistently over the entire study period, with a particularly rapid decline observed between 2000 and 2004.
Differences in the prevalence of dementia between Black men and white men narrowed, with the prevalence of dementia dropping by 7.3 percentage points among Black men as compared to 2.7 percentage points among white men.
The findings were recently published in the journal Proceedings of the National Academy of Sciences.
“The reasons for the decline in the prevalence of dementia are not certain, but this trend is good news for older Americans and the systems that support them,” said Péter Hudomiet, the study’s lead author and an economist at RAND, a nonprofit research organization. “This decline may help reduce the expected strain on families, nursing homes, and other support systems as the American population ages.”
Michael D. Hurd and Susann Rohwedder of RAND are co-authors of the study.
The prevalence of dementia was higher among women than men over the entire period, but the difference shrank between 2000 and 2016. Among men, the prevalence of dementia decreased by 3.2 percentage points from 10.2% to 7.0%. The decrease was larger among women — 3.9 percentage points from 13.6% to 9.7%.
In 2021, about 6.2 million U.S. adults aged 65 or older lived with dementia. Because age is the strongest risk factor for dementia, it has been predicted that increasing life expectancies will substantially increase the prevalence of DOI: 10.1073/pnas.2212205119
The study was funded by the National Institute on Aging.
