Alzheimer's Disease Is Most Common in These Areas of the U.S.

Certain regions of the United States may be more likely to experience Alzheimer's disease (AD), a new study finds.

An estimated 6.7 million Americans, age 65 and older, are currently living with Alzheimer's disease (AD). Cases of AD can vary in severity, but experts agree that an Alzheimer's diagnosis is not something to be taken lightly.

To understand the prevalence of Alzheimer's across the US, researchers conducted a first-of-its-kind study. They presented the results at the Alzheimer’s Association International Conference (AAIC) in Amsterdam earlier this month.

The research team found that certain regions of the United States (primarily the East and Southeast) had a higher prevalence of the disease.

The data can be broken down into the highest overall prevalence at the state level, the highest overall prevalence level at the county level, and the highest overall number at the state level.

Maryland, New York, and Mississippi were the states with the highest prevalence of AD. Miami-Dade County in Florida, Baltimore City in Maryland, and Bronx County in New York had the highest prevalence of AD among larger U.S. counties. California, Florida, and Texas had the highest overall number of people with AD.

“Our study suggests that Alzheimer's dementia is differently distributed across the United States,” Klodian Dhana, MD, PhD, assistant professor in the division of geriatrics and palliative medicine at Rush University Medical Center, told Health. “These data may help public health programs to screen older adults for Alzheimer's and other dementias and provide resources for caring for people with Alzheimer’s,” Dhana said.  

Factors That Contribute to a Higher Prevalence of Alzheimer's Disease

Dhana and colleagues analyzed data from the Chicago Health and Aging Project (CHAP) and the National Center for Health Statistics (NHCS) to make their conclusions. The estimates were based on the distribution of established risk factors, such as age, sex, and race.

“Therefore, counties/states with more people aged >85y and minorities will have a higher estimate for the prevalence of Alzheimer's dementia,” he said. 

The research team noted a combination of two specific demographic characteristics that may explain the higher prevalence in these counties: an older average age of populations and higher percentages of Black and Hispanic residents.

For example, among residents aged 65 years and older of the Bronx County in New York, 14% were 85 and older (compared to a national average of 12% of people 65 and older), 30.1% were African Americans and 46.9% were Hispanic Americans (compared to national averages of 9.4% and 8.8%, respectively).

According to the Alzheimer’s Association, older Black people are about twice as likely to have Alzheimer’s or other dementias as older white people, and older Hispanics are about one and one-half times as likely to have Alzheimer’s or other dementias as older white people.

“However, Alzheimer's dementia is a multifactorial disease with more risk factors (e.g., lifestyle, diabetes, hypertension) contributing to disease risk, incidence, and prevalence," Dhana said, "future studies shall consider the distribution of these risk factors in the community."

What Regional Statistics Tell Us About Alzheimer's Disease

Alzheimer’s prevalence estimates can help federal and state public health officials determine the burden on the healthcare system; county-level estimates help to understand and pinpoint areas of high risk and high need “where, for example, culturally-sensitive health support and caregiver training services are needed,” said Matthew Baumgart, vice president of health policy at the Alzheimer’s Impact Movement. 

As the prevalence of Alzheimer’s disease increases, so does the need for a larger workforce that is trained in diagnosing, treating, and caring for those living with the disease, he added.

By 2030, 1.2 million additional direct care workers will be needed to care for the growing number of people living with dementia, according to the Alzheimer’s Association.

For healthcare workers treating people with AD, Percy Griffin, PhD, director of scientific engagement for the Alzheimer’s Association, said this research can give them a better understanding of the resources needed to effectively do their work, as well as the intensity and type(s) of outreach to reach the local people who need their services and care.

Griffin emphasized the importance of specific data and the impact it can have on a community's care and resources.

“For those people living with the disease, this kind of granular local prevalence data may help them learn more about the community of individuals and families affected by Alzheimer’s in their local area, and help them feel less alone."