Emerging scientific evidence suggests that where you live might significantly influence whether you receive a diagnosis of dementia, including Alzheimer’s disease. Although this neurodegenerative condition is often associated with aging, new research reveals that environmental and systemic factors tied to geographic location could be just as impactful as individual health behaviors or genetics.
Currently, it is estimated that nearly 7 million Americans are living with Alzheimer’s disease, including approximately 200,000 individuals under the age of 65 who are affected by early-onset Alzheimer’s. Projections indicate a troubling trajectory: the number of cases is expected to double every five years after age 65, potentially reaching 14 million by the year 2060. While the aging population is a well-known contributor to this increase, researchers have recently uncovered that local health systems and even regional norms may also be playing a critical role.
A groundbreaking study conducted by researchers at the University of Michigan has brought to light the startling revelation that your odds of being diagnosed with dementia may be heavily influenced by your zip code. This means that someone living in one part of a state could face twice the risk of a dementia diagnosis compared to someone residing just a few towns away.
A Deeper Look Into Geographic Disparities
The study, led by Dr. Julie Bynum, a geriatrician and health care researcher, mapped out dementia diagnoses across 306 regions in the United States and identified a clear pattern of geographical variation. Even after accounting for variables such as age, race, and socioeconomic status, distinct differences in diagnosis rates persisted. These disparities were especially apparent within the same state, indicating that localized factors—rather than broader demographic trends—are likely at play.
According to Dr. Bynum, “These findings go beyond demographic and population-level differences in risk, and indicate that there are health system-level differences that could be targeted and remediated.“
In simple terms, the differences are not just due to who lives in a particular area, but how the health system functions there. Everything from the standard practices followed by local health care providers to how informed or proactive individuals are about seeking medical care may be influencing whether or not a dementia diagnosis is made.
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The Role of Healthcare Access and Awareness
The variation in diagnosis intensity—how often dementia is diagnosed compared to what is expected—was dramatic in some cases. For example, in Portland, Oregon, the diagnosis intensity was recorded at 1.2, indicating more cases than anticipated. Meanwhile, just a few hours away in Bend, Oregon, the figure dropped to 0.8, pointing to fewer-than-expected diagnoses.
Similar patterns were observed in other states. In Florida, Gainesville had a diagnosis intensity of 1.1, while the neighboring rural community of Ocala recorded a lower score of 0.9. These localized differences underscore the potential influence of healthcare access, quality of medical facilities, community education, and even cultural attitudes toward aging and cognitive health.
Researchers emphasized that such variations might not necessarily indicate actual differences in how prevalent Alzheimer’s disease is from one location to another. Instead, they could be reflective of how well or poorly communities are detecting and diagnosing the condition.
The Stroke Belt: A Region of Elevated Risk
The study highlighted a particularly high concentration of dementia diagnoses in the southern United States, especially in a region often referred to as the “Stroke Belt.” This area, encompassing states such as Alabama, Georgia, Mississippi, Louisiana, and others, is already known for elevated rates of cardiovascular disease, which is itself a recognized risk factor for cognitive decline.
The Stroke Belt also includes Arkansas, Indiana, Kentucky, North Carolina, South Carolina, Tennessee, and Virginia. Populations in these states tend to exhibit higher rates of hypertension, diabetes, obesity, and smoking—all factors that increase the risk of both stroke and dementia. The overlap between cardiovascular and cognitive health means that residents in these regions may be especially vulnerable.
Interestingly, researchers found unexpected results even within the Stroke Belt. Some parts of Mississippi, for instance, showed fewer diagnoses than expected, while certain areas of central Texas were marked by higher-than-anticipated diagnosis rates. This suggests that even within high-risk regions, local healthcare infrastructure, public health policies, and individual behaviors can create significant variability.
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Environmental and Systemic Factors at Play
The research team emphasized that environmental risks—such as exposure to pollution or lack of access to nutritious food—alongside systemic issues in healthcare delivery, may be contributing to the observed disparities. In addition to tangible factors like transportation or proximity to medical facilities, less visible influences such as provider bias, differences in diagnostic training, or regional variations in medical screening protocols could be affecting who gets diagnosed and when.
Dr. Bynum noted, “The message is clear: from place to place, the likelihood of getting your dementia diagnosed varies, and that may happen because of everything from practice norms for health care providers to individual patients’ knowledge and care-seeking behavior.”
In areas with fewer diagnoses than expected, it is possible that dementia is being underdiagnosed or recognized too late. On the other hand, regions with higher-than-expected rates might be more proactive in early detection—or they might even be overdiagnosing in certain cases. The study stops short of confirming which of these is more common but suggests that both scenarios could be occurring simultaneously in different parts of the country.
Implications for Policy and Public Health
The findings, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, carry significant implications for public health policy, especially for those aged 66 to 74 and among racial and ethnic minority groups. The researchers argue that efforts to detect and treat Alzheimer’s must consider these local variations in diagnosis intensity and work to ensure more equitable access to cognitive health services across all regions.
“For communities and health systems, this should be a call to action for spreading knowledge and increasing efforts to make services available to people,” said Bynum. “And for individuals, the message is that you may need to advocate for yourself to get what you need, including cognitive checks.”
In practice, this might mean encouraging physicians to adopt uniform screening guidelines, improving community outreach to raise awareness of early symptoms, or even addressing broader social determinants of health that affect diagnosis rates—such as education, income, and insurance coverage.
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The Path Forward
While the study does not provide a definitive answer as to whether certain regions are truly experiencing higher rates of Alzheimer’s or whether differences stem from how diligently it is diagnosed, it lays the groundwork for future investigations. With the number of Alzheimer’s cases expected to rise sharply in the coming decades, understanding and addressing these geographical disparities is essential.
The authors of the study encourage further exploration into the factors behind both overdiagnosis and underdiagnosis. They suggest that future research could examine how physician training, access to diagnostic tools such as neuroimaging, and patient advocacy play into these patterns. Additionally, integrating this geographic data with environmental metrics may uncover further correlations that could aid in early prevention efforts.
What Individuals Can Do
For those concerned about cognitive health, especially if living in a region with historically low diagnosis rates, it becomes important to take a proactive role. Scheduling regular checkups, talking openly with healthcare providers about memory concerns, and staying informed about the early warning signs of dementia can make a substantial difference.
Likewise, participating in community education initiatives and advocating for improved healthcare resources in underdiagnosed areas could help bridge the gap in access to timely and accurate diagnosis.
