In This Article

• Is marriage truly protective against dementia?
• What does an 18-year study of 24,000+ people reveal?
• Why are divorced and never-married adults at lower risk?
• Does this challenge our assumptions about relationships and aging?
• What are the implications for cognitive health screening?

Why Unmarried People May Have Lower Dementia Risk

For decades, marriage has been touted as a cornerstone of health and longevity. Advocates of the “marital resource model” argue that being married offers emotional support, economic stability, and social accountability—benefits that allegedly help protect against chronic diseases and cognitive decline. But what happens when data tells a different story?

A new 2025 study published in Alzheimer’s & Dementia followed over 24,000 older adults for up to 18 years through the National Alzheimer’s Coordinating Center (NACC). What the researchers discovered turns the conventional narrative upside down: married individuals were more likely to develop dementia compared to their unmarried counterparts. Not only was the risk lower among the divorced and never married, but even widowed individuals—long thought to be at heightened risk—showed reduced likelihood of dementia in some models.

The Numbers Don't Lie

In this massive cohort study, 20.1% of participants developed dementia during the follow-up period. Yet when broken down by marital status, divorced and never-married individuals had a significantly lower hazard ratio for developing all-cause dementia than those who were married. Even after adjusting for key variables—like age, sex, education, depression, genetic risk, and physical health—the divorced and never-married groups still came out ahead. And this wasn’t just about generic dementia. These findings held true even for Alzheimer’s disease and Lewy body dementia.

This wasn’t a one-off result either. Sensitivity analyses, controlling for cognitive impairment at baseline and stratifying by years of follow-up, confirmed the trend. Widowed individuals also fared better than expected, especially when their diagnosis occurred later in life. The robustness of these findings demands attention—and explanation.

Explanations and Implications

So why would unmarried individuals be less likely to be diagnosed with dementia? One possible answer: diagnosis bias. Married individuals are more likely to have a spouse notice changes in memory or behavior and encourage medical evaluation. Unmarried individuals may simply fly under the diagnostic radar for longer, delaying their diagnosis or avoiding it altogether. This could make it appear that married individuals are at greater risk, when in fact they are simply being diagnosed more frequently and earlier.

But the delayed-diagnosis theory can’t explain it all. The study found that, even accounting for referral source—whether participants came to clinics via professional referral or on their own—the protective effect of being unmarried still held. And in some cases, those who had recently become widowed showed even lower risk than their still-married peers, raising the question: could the institution of marriage, especially when strained or stressful, actually contribute to cognitive decline?

Not All Marriages Are Created Equal

Here’s where the discussion gets more nuanced. Prior studies have shown that marital quality is a crucial factor. High-conflict or emotionally distant marriages may offer fewer of the protective benefits commonly associated with matrimony. In fact, research suggests that poor marital quality can have equal or worse health outcomes than divorce. For many, being single may mean more control over social interactions, freedom from caregiving burdens, and less chronic stress—factors that might reduce long-term risk of dementia.

Additionally, unmarried people—especially those who are never married—often cultivate broader social networks beyond the spouse-centric model. They may maintain regular contact with friends, neighbors, or community groups. Some evidence even suggests that single adults are more likely to engage in volunteering, hobbies, and physical activity—activities long associated with reduced cognitive decline.

Policy and Public Health Ramifications

These findings hold important implications for public health messaging and medical screening. If being unmarried doesn't increase risk—and may even be protective—it challenges programs that prioritize married individuals as lower-risk. It also underscores the importance of monitoring unmarried adults more carefully for underdiagnosed cases, given that they may delay seeking medical attention for early symptoms.

Moreover, we need to rethink caregiving assumptions. Much of dementia care policy is built around the idea that a spouse will notice changes and take responsibility for care decisions. But if spouses are also at increased risk, and if unmarried individuals are slipping through the cracks, our system is woefully unprepared for the future. These findings invite a shift toward more inclusive models of dementia screening and care—ones that account for diverse relationship statuses and social structures.

Rethinking What “Healthy Aging” Looks Like

Let’s be clear: this study doesn’t suggest that being married causes dementia, or that being single is some magic shield. Rather, it tells us that the simplistic belief in marriage as a universal good for health may be outdated. The real protective factors might lie in psychological resilience, social engagement, stress reduction, and access to quality healthcare—regardless of marital status.

In other words, we need to stop using marital status as a shortcut for assessing risk. It’s not whether you wear a ring on your finger; it’s how you live your life. Do you maintain social connections? Do you find meaning in your daily routine? Do you manage stress effectively and seek timely medical care? These are the questions that matter more than relationship labels.

Sometimes science doesn’t just refine our assumptions—it shatters them. This study does exactly that, challenging long-standing beliefs about love, commitment, and cognitive health. In the end, it reminds us that human relationships are complex, and their impact on our brains is just as nuanced.

So, next time someone says you need to marry to age well, point them to the data. Because the path to a healthy mind may not be down the aisle—it might just be through self-awareness, connection, and living life on your own terms.

About the Author

Alex Jordan is a staff writer for InnerSelf.com

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Article Recap

An 18-year study of over 24,000 older adults challenges the belief that marriage protects against dementia. The data shows that unmarried individuals—whether divorced, widowed, or never married—have a lower risk of dementia, including Alzheimer's and Lewy body dementia. The study urges a rethinking of dementia screening, caregiving assumptions, and the role of social structures in aging well.

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