July 21, 2026, 3:02 pm | Read time: 5 minutes
When a person develops dementia, it often changes the daily life of the entire family. A large study now suggests that spouses of those affected also have an increased risk of developing dementia later. FITBOOK also inquired with study author Chi-Shin Wu from the National Health Research Institutes in Taiwan.
Increased Risk for Both Genders
People whose spouses were newly diagnosed with dementia were significantly more likely to develop dementia themselves compared to similar individuals without a partner with dementia. The risk was 74 percent higher for women and 69 percent higher for men.
The absolute numbers also show the difference. Of 100 women whose partners developed dementia, about six to seven developed dementia themselves within five years. In the comparison group without a partner with dementia, it was only about four out of 100 women. Among men, around nine out of 100 affected individuals developed dementia within five years, compared to just under six out of 100 in the comparison group.
However, study author Chi-Shin Wu says: “Dementia affects the entire household, not just the person diagnosed. Spouses should be aware of their increased risk but not be alarmed–the increased risk does not mean they will inevitably develop dementia.”
How the Study Was Conducted
For the study, published in the journal “JAMA Network Open,” researchers analyzed health data from more than 955,000 married people in Taiwan. The basis was the national health insurance database, which covers nearly the entire population of the country. They observed married individuals whose spouses were first diagnosed with dementia between 1998 and 2022. These were compared with up to four similar individuals of the same age, gender, income, and place of residence whose spouses did not have dementia.1
The aim of the study was to determine whether living with a spouse with dementia is associated with a higher personal risk of dementia. The background is that spouses often share similar lifestyle habits, environmental conditions, and health risks over many years. Additionally, caring for a partner with dementia is often associated with psychological stress, lack of sleep, and changes in daily life.
Younger Spouses More Affected
The connection was evident not only for dementia overall but also for the two most common forms of dementia: Alzheimer’s and vascular dementia, which is caused by vascular damage in the brain. In both cases, the risk of developing the disease was similarly significantly increased for people with a spouse with dementia.
It was also interesting that the relative risk increases were more pronounced in younger spouses. With increasing age, however, the absolute differences became larger. This means that overall, more people developed dementia at an older age, so the difference between the groups also grew.
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What This Specifically Means
The increased risk could be due to shared lifestyle habits, environmental factors, or the physical and psychological burden of caregiving. Chi-Shin Wu considers a single cause unlikely: “Similar characteristics before marriage and decades of shared lifestyle habits likely create a common baseline risk, while the stress of caregiving can additionally contribute.” The results therefore suggest that the family environment should be more involved in the prevention and care of dementia.
For practical purposes, the absolute differences are particularly relevant. Although the relative risk was significantly increased, this corresponded to an additional dementia risk of 2.75 percentage points for women and 3.49 percentage points for men within five years. The results therefore suggest that spouses of people with dementia should be supported medically, psychologically, and socially at an early stage.
According to the study, part of the risk could be explained by selective partner choice. People tend to choose partners with similar educational backgrounds, social status, and lifestyles. Since these characteristics influence the risk of dementia, both partners often bring comparable health conditions into the marriage from the start.
Additionally, the absolute risk differences were greater among people with lower incomes and fewer children. However, the researchers point out that the number of children is only a rough indication of possible family support and does not provide information about actual help in everyday life.
From the perspective of Wu and his team, this should also be reflected in care. “Dementia care should consider the entire household as a care unit. When one spouse is diagnosed with dementia, care offerings should also address the health needs and support requirements of the other spouse, especially in families with limited financial resources or few people to share caregiving responsibilities.”
Assessment of the Study and Possible Limitations
The strengths of the study include the large number of participants, nearly one million people. This allowed the researchers to reliably examine differences between various age, income, and population groups.
However, the study also has limitations. The dementia diagnoses come from health and billing data and were not confirmed by specific examinations such as biomarkers. Additionally, information on important influencing factors such as education, diet, exercise, smoking behavior, social activity, or the actual burden of caring for a partner with dementia was missing.
Moreover, the study cannot prove a cause-and-effect relationship. The increased risk could also be due to shared lifestyle habits, similar social and health conditions, or the burdens of caregiving. According to the authors, the study’s sponsors had no influence on its conduct or publication.