Alzheimer's Disease Prevalence in U.S. Regions

Alzheimer’s disease affects millions of Americans and its prevalence varies significantly across different regions of the United States1 . Recent research reveals that the highest rates of Alzheimer’s dementia are concentrated in the eastern and southeastern parts of the country, where demographic factors such as age and race play a major role2 . Understanding these regional differences is essential for effective public health planning and resource allocation3 .

Risk Factors for Higher Alzheimer's Rates

Alzheimer’s disease dementia prevalence is strongly influenced by demographic and health-related risk factors. Age remains the most significant risk factor, with prevalence increasing sharply among older adults, especially those aged 85 and above1 . In addition to age, race and ethnicity contribute to disparities in Alzheimer’s rates. African Americans aged 65 and older have about twice the prevalence of Alzheimer’s disease and related dementias compared to non-Hispanic whites, while Hispanics have about 1.5 times the prevalence4 5.

Counties with higher Alzheimer’s prevalence typically have larger populations of older adults and higher proportions of Black and Hispanic residents5 . For example, Bronx County, New York, has a notably high percentage of residents aged 85 and older (14%) and substantial African American (30.1%) and Hispanic (46.9%) populations, all of which correlate with its elevated Alzheimer’s prevalence5 6.

“Alzheimer’s dementia is a multifactorial disease involving several risk characteristics that interact with demographic risk factors and ultimately contribute to the prevalence.”

— Kumar B. Rajan, PhD, Rush University Medical Center6

Other contributing factors include lifestyle, chronic diseases such as diabetes and hypertension, and socioeconomic determinants, although these are less well characterized at the county level due to data limitations5 . Alzheimer’s dementia is multifactorial, with risk factors interacting to influence disease prevalence in communities6 .

Key risk factors for higher Alzheimer’s prevalence include:

• Advanced age, particularly 85 years and older1
• African American race, with roughly double the prevalence compared to non-Hispanic whites5
• Hispanic ethnicity, with approximately 1.5 times the prevalence compared to non-Hispanic whites5
• Presence of chronic conditions like diabetes and hypertension5
• Lifestyle factors and socioeconomic status, which require further study at local levels5

💡 Did You Know? The top 3 states with the highest number of people with Alzheimer's dementia are California, Florida, and Texas7 .

Regional Alzheimer's Disease Statistics

The first-ever county-level estimates of Alzheimer’s disease dementia prevalence across all 3,142 U.S. counties reveal striking geographic variation2 . The eastern and southeastern regions of the U.S. exhibit the highest prevalence rates, driven largely by demographic factors such as older populations and higher percentages of Black and Hispanic residents2 3.

Among counties with populations of 10,000 or more adults aged 65 and older, the highest Alzheimer’s prevalence rates are found in:

Other counties with elevated prevalence include Orleans Parish, Louisiana (15.4%), Dougherty County, Georgia (15.3%), Orangeburg County, South Carolina (15.2%), Imperial County, California (15.0%), and El Paso County, Texas (15.0%) 26.

States with the highest estimated number of older adults living with Alzheimer’s disease are California (719,700), Florida (579,900), and Texas (459,300), reflecting both population size and prevalence rates7 3.

The geographic pattern of Alzheimer’s prevalence aligns with demographic distributions:

“Some regions had higher percentages of minority residents living with Alzheimer’s. Having this information can help guide decision-making and the allocation of resources and health programs aimed at helping those with dementia in the areas where they’re needed most.”

— Kumar B. Rajan, PhD, Rush University Medical Center6

• The East and Southeast have higher percentages of older adults and minority populations, contributing to increased prevalence2 3.
• The West and Southwest are projected to experience the largest percentage increase in Alzheimer’s cases between 2020 and 2025, indicating emerging regional needs6 .
• Mortality data adjusted for age show variability by state, but differences may also reflect other population characteristics and reporting practices8 .

Public health officials rely on these granular county-level data to identify areas with high risk and high need for culturally sensitive health support and caregiver training services5 . This information is critical for allocating resources effectively and planning for the growing demand for dementia care.

The growing prevalence of Alzheimer’s disease also highlights the urgent need for a larger, well-trained workforce. The Alzheimer’s Association projects a need for 1.2 million additional direct care workers by 2030 to meet the increasing demand for dementia care9 5.

“These new estimates add more granular data to our understanding of Alzheimer’s prevalence across the country. This information, in addition to raising awareness of the Alzheimer’s crisis in specific communities, may help public health programs better allocate funding, staffing and other resources for caring for people with Alzheimer’s and all other dementia.”

— Kumar B. Rajan, PhD, Rush Medical College2

Key regional findings:

• Highest prevalence counties are concentrated in the East and Southeast U.S. 2
• Older age and higher minority populations explain much of the regional variation5 6
• California, Florida, and Texas have the largest numbers of people living with Alzheimer’s due to population size7
• West and Southwest regions will see the fastest growth in cases in coming years6
• County-level data enable targeted public health interventions and resource planning5