Here’s Where the Highest Rates of Alzheimer’s Are in the United States

A first-of-its-kind report estimates Alzheimer’s disease prevalence in 3,142 counties across the nation

An elderly woman looks out her window
Researchers estimate the states with the highest rates of Alzheimer's disease are Maryland, New York and Mississippi. shurkin_son via Freepik

Seniors in the eastern and southeastern United States have some of the highest rates of Alzheimer’s disease in the country, according to a first-of-its kind report that estimated disease rates in 3,142 U.S. counties. Across all states, Maryland, New York and Mississippi have the highest proportion of people above 65 years old living with Alzheimer’s disease, per the study.

Researchers at Rush University Medical Center in Chicago presented this data on Monday at the Alzheimer’s Association International Conference and published it in the journal Alzheimer’s and Dementia.

“Having this information is very helpful, because I think it adds to the urgency of the work that we’re doing,” Halima Amjad, a geriatrician at Johns Hopkins Medicine and chair of an Alzheimer’s council in the Maryland state government, who was not involved in the study, tells CNN’s Deidre McPhillips. “For dementia, a lot of the care and support that is offered—through legislation or programs—often occurs at the state and local level, rather than at the national level.”

Alzheimer’s, a degenerative brain disease that destroys memory and cognition, is currently the seventh leading cause of death in the U.S. It is the most common cause of dementia, an umbrella term for a range of symptoms including memory decline, changes in thinking skills, poor judgement and reasoning, and decreased focus and attention. While there is no cure, an early diagnosis of Alzheimer’s can help patients start treatment sooner, participate in clinical trials and make lifestyle changes that may preserve cognitive function.

To estimate Alzheimer’s rates in U.S. counties, the team of researchers combined cognitive data from participants in the Chicago Health and Aging Project with U.S. Census data. Their analysis only included counties with 10,000 or more people over the age of 65.

The team found that the three counties with the highest dementia rates are Miami-Dade County in Florida, Baltimore city in Maryland and Bronx County in New York—at each of these locations, about 16.6 percent of senior residents have the disease. The next highest was Prince George’s County, Maryland, with 16.1 percent.

These counties that lead the country in Alzheimer’s diagnoses have more older residents and a higher percentage of Black and Hispanic people than the national average, the authors note. Black Americans and Latino Americans are about twice as likely and 1.5 times as likely, respectively, to develop Alzheimer’s as non-Hispanic white Americans are, according to the nonprofit Us Against Alzheimer’s.

In Bronx County, for example, the team found 14 percent of seniors were 85 and older, compared to the national average of 12 percent; 30.1 percent were African American, compared to the national average of 9.4 percent; and 46.9 percent were Hispanic Americans, compared to an average of 8.8 percent nationwide, per a statement from the Alzheimer’s Association.

“These populations have historically been underrepresented in clinical trials, so we need to push toward health equity to ensure that they are included,” Percy Griffin, director of scientific engagement for the Alzheimer’s Association, tells Melissa Rudy of Fox News. “Treatments, diagnostic tools and risk reduction strategies should be available for all people, and not just some people from some communities.”

Additionally, the team found the states with the highest total number of Alzheimer’s cases are California, Florida and Texas.

The researchers hope their study will inform better distribution of resources to public health programs that can respond to these disparities in Alzheimer’s rates across the country, per the statement.

Dean Brenner of the Alzheimer’s Association tells Ida Domingo and Kellye Lynn of ABC 7News in Maryland that he hopes this new data will improve resources for Alzheimer’s patients and encourage family members who notice signs of memory loss in their loved ones to seek help quickly.

“It’s crucial, as hard as it is, to speak up and to try to get help for people as early as possible,” he tells the publication.

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