One in ten older Americans has dementia

Researchers at Columbia University found that nearly 10 percent of U.
S.
adults age 65 and older have dementia and another 22 percent have mild cognitive impairment, the first nationally representative study
of the prevalence of cognitive impairment in more than 20 years.
People with dementia and mild cognitive impairment are more likely to be older, less educated, and racially black or Hispanic
.
Men and women have similar
rates of dementia and mild cognitive impairment.

While dementia and mild cognitive impairment are well known to be common in the United States, there are few
accurate, up-to-date national prevalence measures.

"These data are critical to understanding the causes, costs, and consequences of dementia and mild cognitive impairment in the United States, as well as informing policies aimed at reducing their impact on patients, families, and public programs," said Jennifer J.
Manly, Ph.
D.
, lead author of the study and professor
of neuropsychology at Columbia University's Gertrude H.
Sergievsky Center and Taub Institute for Alzheimer's Disease and Brain Aging.

35% of people in their 90s have dementia

The study is based on data
from 3,500 individuals who participated in the nationally representative Health and Retirement Study.
Between 2016 and 2017, each participant completed a comprehensive set of neuropsychological tests and in-depth interviews that were used to develop algorithms
for diagnosing dementia or mild cognitive impairment.

Dementia and mild cognitive impairment

Dementia is characterized by cognitive impairment that begins in adulthood, affecting a person's ability to
independently complete daily activities.
Mild cognitive impairment is a classification of people who are thought to transition between normal aging and dementia, but not all people with mild cognitive impairment will develop dementia
.

The incidence of dementia and mild cognitive impairment rises dramatically with age: 3% of people aged 65 to 69 have dementia, and 35% of people aged 90 and over have dementia
.

"As baby boomers live longer and age, cognitive impairment is expected to increase significantly in the coming decades, impacting individuals, families and programs
that provide care and services for people with dementia," Manley said.

The impact of dementia, including unpaid home care, is estimated at $257 billion per year on the U.
S.
economy and $800 billion
worldwide.

Disparities in cognitive impairment are caused by structural and social inequalities

Unlike previous large dementia studies in the United States, participants in this new study are representatives of older adults, allowing researchers to examine differences
in the national prevalence of dementia and mild cognitive impairment based on age, race and ethnicity, sex, and education.

The data show that older adults who identify as black or African American have a disproportionate burden of dementia, older adults who identify as Hispanic have a disproportionate burden of mild cognitive impairment, and those who have less access to education have a disproportionate burden of both types of cognitive impairment
.

"Overall, dementia research has focused on college-educated white people," Manly said
.
"This study is representative of older people who have historically been excluded from dementia research, but who are at higher
risk of developing cognitive impairment due to structural racism and income inequality.
If we're interested in improving equity in brain health later in life, we need to know where we stand now and where
our resources should be directed.
”

Journal Reference:

1. Jennifer J.
   Manly, Richard N.
   Jones, Kenneth M.
   Langa, Lindsay H.
   Ryan, Deborah A.
   Levine, Ryan McCammon, Steven G.
   Heeringa, David Weir.
   Estimating the Prevalence of Dementia and Mild Cognitive Impairment in the US.
   JAMA Neurology, 2022; DOI: 10.
   1001/jamaneurol.
   2022.
   3543

Columbia University Irving Medical Center.
"One in 10 older Americans has dementia.
" ScienceDaily.
ScienceDaily, 24 October 2022.
<www.
sciencedaily.
com/releases/2022/10/221024131046.
htm>.

Columbia University Irving Medical Center.
(2022, October 24).
One in 10 older Americans has dementia.
ScienceDaily.
Retrieved October 24, 2022 from www.
sciencedaily.
com/releases/2022/10/221024131046.
htm

Columbia University Irving Medical Center.
"One in 10 older Americans has dementia.
" ScienceDaily.
www.
sciencedaily.
com/releases/2022/10/221024131046.
htm (accessed October 24, 2022).