If your spouse develops dementia, your own risk rises—but not because dementia is contagious. A new study of almost 1 million married couples in Taiwan reveals that partners of people with dementia are about 70% more likely to receive a diagnosis themselves, even after accounting for shared health habits and medical conditions.
The Research
Published by researchers analyzing Taiwan's national health insurance database from 1998 to 2022, the study included over 190,000 people whose spouse was newly diagnosed with dementia, matched to over 760,000 people without a demented partner. After adjusting for age, sex, income, location, medical conditions, and healthcare use, the elevated risk persisted: women had a 74% higher relative risk, men 69%.
In absolute terms, over five years, about 6.5% of women with a demented spouse developed dementia themselves (vs. 3.7% without), and 9.2% of men (vs. 5.8%). That translates to roughly three extra cases per 100 people over five years.
Lead researcher Joyce Siette and colleagues stress that the study does not show dementia is passed between partners. Instead, it points to shared lifestyle, assortative mating (people choosing similar partners), and the chronic stress of caregiving—which can disrupt sleep, social activity, and health behaviors—all linked to cognitive decline.
Why It Matters
This large-scale finding reinforces that brain health is not just individual. Couples age together, and their environments, habits, and stressors converge. For anyone, it highlights that supporting a partner's brain health may also protect your own.
What You Can Do
Focus on modifiable factors you share: exercise together, maintain social connections, prioritize sleep, and manage stress. If you're a caregiver, seek respite and support—studies show that caregiver burnout itself is a risk factor for cognitive decline.
Source: Nautilus
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