Spouses of individuals who have dementia face an increased risk of developing the condition themselves, according to a study from Taiwan.
Over a median follow-up of 5.5 years for men and 7 years for women, all-cause dementia occurred more frequently among men and women whose spouses had dementia (exposed group) than among those whose spouses had no dementia (unexposed group) (men: 19.91 percent vs 12.15 percent; women: 14.21 percent vs 8.48 percent). [JAMA Netw Open 2026;9:e2624175]
Having a spouse with dementia was associated with around a 70-percent higher risk of all-cause dementia among men (hazard ratio [HR], 1.69, 95 percent confidence interval [CI], 1.64–1.73) and women (HR, 1.74, 95 percent CI, 1.70–1.78).
On the absolute scale, the 5-year cumulative incidence was 6.47 percent among exposed women vs 3.72 percent among unexposed women, corresponding to an adjusted risk difference (ARD) of 2.75 percentage points. Among men, the 5-year cumulative incidence was 9.24 percent vs 5.75 percent in the exposed and unexposed groups, respectively, with an ARD of 3.49 percentage points (95 percent CI, 3.30–3.69).
Similar associations were observed when looking at dementia subtypes, including Alzheimer’s disease (men: HR, 1.74, 95 percent CI, 1.68–1.81; women: HR, 1.74, 95 percent CI, 1.69–1.79) and vascular dementia (men: HR, 1.72, 95 percent CI, 1.52–1.94; women: HR, 1.77, 95 percent CI, 1.60–1.95).
In subgroup analyses, the risk of all-cause dementia associated with spousal dementia exposure was attenuated among individuals with higher income or more children. Associations were broadly similar across sex and urbanicity.
A clinical risk marker
Chi-Shin Wu, MD, PhD
Investigator/Attending Physician at National Center for Geriatrics and Welfare Research, National Health Research Institutes, Yunlin, Taiwan“The association remained after adjustment for measured health conditions, but residual confounding remains possible. Similar premarital characteristics, decades of shared lifestyle, and caregiving burden may all contribute,” Wu added.
In their paper, Wu and colleagues explained that the elevated dementia risk observed among spouses of individuals with dementia may reflect initial “assortative mating,” with individuals frequently selecting partners with similar levels of education, socioeconomic status, cognitive reserve, and health behaviours—factors that directly affect dementia risk.
“Couples may also share dietary habits, physical activity patterns, and other socioeconomic conditions that influence cardiometabolic health and cognitive ageing,” the investigators noted.
Other possible pathways linking spousal dementia exposure to cognitive decline include caregiver distress, depression, sleep disturbance, social isolation, metabolic dysregulation, inflammation, and adverse health behaviours, they added. [J Geriatr Psychiatry Neurol 2011;24:191-198; Int Psychogeriatr 2018;30:1131-1138]
To screen or not to screen
Wu emphasized that their observational data alone do not justify universal cognitive screening or a specific screening schedule for all spouses.
“However, clinicians should remain attentive to cognitive concerns, changes in daily functioning, depression, sleep disturbance, and caregiver strain. Cognitive assessment is particularly appropriate when the spouse or family reports changes [in cognitive function] or when caregiving demands are substantial,” he said.
To mitigate dementia risk in exposed spouses, Wu recommended that clinicians assess caregiver burden, mood, sleep, social isolation, and cardiovascular risk factors; encourage physical activity and social engagement; and connect families with respite care and community support.
“Dementia care should consider the household as the unit of care. When one spouse is diagnosed, the health and support needs of the other spouse should not be overlooked—particularly when financial resources or people available to share caregiving are limited,” Wu concluded.
Study details
Wu and colleagues used Taiwan’s National Health Insurance Research Database to identify dementia cases between 1998 and 2022 among married individuals, with follow-up through 2022. Spouses of individuals with dementia were matched to unexposed spoused according to birth year, sex, income, and urbanicity.
A total of 955,105 individuals were included in the analysis. Of these, 118,904 women and 72,117 men were in the exposed group, and 475,616 women and 288,468 men were in the unexposed group.
Overall, most men (39.5 percent) and women (39.6 percent) were in the 65–74-year age group at cohort entry. Most individuals resided in urban areas (47.9 percent of men and 51.1 percent of women), and nearly half were in the lowest income category.