Contrary to long-standing assumptions in aging and public health research, a new study has found that older adults who are divorced or never married may actually have a lower risk of developing dementia compared to those who are married.
This surprising result, published in Alzheimer’s & Dementia, challenges the widely held belief that marriage offers protective health benefits against cognitive decline.
The study was led by researchers at Florida State University College of Medicine and the University of Montpellier, using data from more than 24,000 participants enrolled in the National Alzheimer’s Coordinating Center (NACC). All participants were free of dementia at the beginning of the study and underwent yearly clinical evaluations over a follow-up period of up to 18 years.
Over the 18-year span, researchers analyzed how marital status at the start of the study—categorized as married, divorced, widowed, or never married—related to later risk of being diagnosed with dementia. Participants were assessed annually by trained professionals, and diagnoses were made using standardized clinical procedures.
- Overall dementia incidence was 20.1%.
- Among married participants, 21.9% developed dementia—the highest rate of all groups.
- The rate was identical (21.9%) for widowed participants.
- In contrast, only 12.8% of divorced and 12.4% of never-married participants developed dementia.
Even after accounting for age, sex, physical and mental health, lifestyle behaviors, genetic factors, and differences in how participants were referred to clinics, the divorced and never-married groups maintained significantly lower risks.
Specifically:
- Divorced individuals had a 34% lower risk of developing dementia (HR = 0.66).
- Never-married individuals had a 40% lower risk (HR = 0.60).
- Widowed individuals showed a 27% lower risk in early models, but this was not significant after full adjustment.
The research team also explored how marital status related to different types of dementia:
- Alzheimer’s disease and Lewy body dementia were more common in married individuals.
- No consistent links were found between marital status and vascular dementia or frontotemporal lobar degeneration.
- Divorced and never-married individuals were also less likely to progress from mild cognitive impairment (MCI) to full dementia.
These results run counter to many earlier studies that suggested unmarried individuals may be more vulnerable to cognitive decline. Historically, marriage has been associated with benefits like better mental health, more social support, and healthier lifestyles—all of which are thought to protect brain health.
However, this new study provides a more nuanced view, made possible by its large sample size, long follow-up period, and use of consistent, professional clinical evaluations.
Importantly, the researchers controlled for many potential confounding factors, including depression, chronic illness, alcohol use, smoking history, and genetics. The findings still held, suggesting that marital status may influence cognitive health in ways not previously understood.
Interestingly, the study also found that the pattern of lower dementia risk among unmarried individuals was seen across both sexes and among participants of different ages, educational backgrounds, and genetic risk levels.
The effects were slightly stronger in men and in people who were referred by healthcare professionals, but overall, the patterns were broadly consistent.
This study opens the door to reevaluating assumptions about the social and health benefits of marriage in older age—especially when it comes to cognitive health. It’s not clear why being divorced or never married might protect against dementia, but researchers suggest a few possibilities:
- Married individuals may experience more chronic stress related to caregiving, marital conflict, or emotional burden, especially in later years.
- Unmarried individuals may have developed stronger self-reliance or broader social networks that provide cognitive stimulation.
- Selection factors may play a role—some people who remain unmarried may possess traits that also help preserve cognitive health.
It’s also possible that diagnosis patterns differ. Married individuals might be more likely to seek medical help or have their cognitive changes noticed sooner by spouses, leading to higher diagnosis rates. However, this study minimized that bias by using structured clinical evaluations across all groups.
This large and carefully controlled study shows that being unmarried in older age—specifically being divorced or never married—does not increase the risk of dementia and may even reduce it. The findings challenge previous beliefs and suggest that being unmarried should not automatically be considered a risk factor for cognitive decline.
Instead, more research is needed to understand the social, psychological, and biological mechanisms that might explain why unmarried people fared better in terms of brain health.
As the number of older adults who are unmarried continues to rise, these findings provide a more optimistic view of aging outside traditional marital structures and could influence future approaches to dementia prevention and care.
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The research findings can be found in Alzheimer’s & Dementia.
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