An overlooked link between marriage and dementia deserves a closer look
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We know that social connection is beneficial for cognitive health, [but this study] challenges the long-held notion that marriage is a protective factor in the risk of developing dementia.
—Hayley B. Kristinsson, PsyD, ABPP-CN
Research has highlighted how marriage may have a favorable impact on cognitive health.[] But there's evidence to suggest a big perk to staying single: It may actually decrease a person's risk of dementia.[]
Specifically, researchers found that unmarried individuals—including never-married, divorced, or widowed older adults—had a lower dementia risk than married individuals.
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The analysis, published in the Alzheimer’s & Dementia journal in 2025, used study data from the National Alzheimer's Coordinating Center (NACC) that included annual clinical dementia evaluations for 24,000 adults over up to 18 years of follow-up.
The researchers note that their findings are “contrary to most previous longitudinal studies, which have reported that married individuals have a lower risk of cognitive impairment and dementia than unmarried groups.”[]
This is what matters most
The researchers discuss evidence that being single or divorced may increase an individual’s social engagement and well-being, which may “potentially serve as protective factors against dementia over time.” Additionally, they note how married individuals tend to have less social integration, which could work against cognitive health.
They also address how the quality of a person’s marriage may influence whether marriage benefits or harms their cognitive future.
“There is substantial evidence that the health benefits of marriage appear to be only in high-quality marriages,” the researchers state. “In contrast, individuals who are unhappy in their marriage, an indicator of marital quality, are more likely to have equal or worse health and mortality risk compared to those who are widowed, divorced, or never-married counterparts.”
Hayley B. Kristinsson, PsyD, ABPP-CN, a board-certified neuropsychologist with UCI Health and an assistant clinical professor at the University of California, Irvine, Department of Neurology, says the new study “challenges the long-held notion that marriage is a protective factor in the risk of developing dementia.”
“The health benefits of marriage may only be in high-quality, happy marriages,” Kristinsson says. “[Other] studies have shown that individuals in unhappy marriages are more likely to be at risk of poor health outcomes, suggesting that marriage quality plays a role in the association between marriage and risk of dementia.”
Still, she adds, research on marriage and dementia risks is mixed. It may be too soon—and too broad a statement—to say for sure that one’s marriage status increases or decreases their dementia risk.
The bigger takeaway? “We know that social connection is beneficial for cognitive health,” Kristinsson says. “Whether that occurs within the context of marriage or being single is likely less important than the social connection itself.”
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