Spouses of dementia patients face about a 70% higher risk of developing dementia than people whose spouses do not have the condition, according to a new study.
The research, led by Dr. Wu Chi-shin's team at Taiwan's National Health Research Institutes (NHRI), analyzed the dementia risk of spouses of dementia patients among about 950,000 married people in Taiwan, the medical community said on the 27th. The findings were published in the latest issue of JAMA Network Open, a journal of the American Medical Association.
The researchers identified spouses of people newly diagnosed with dementia between 1998 and 2022, then matched them with a comparison group of the same birth year, sex, income, and residential area at a ratio of 1 to 4. They then statistically adjusted for factors that could affect the results, including number of children, medical use, and the mental, cardiovascular, and metabolic diseases of the individuals and their spouses.
The analysis found that wives of people diagnosed with dementia had a 74% higher risk of developing dementia than women in the comparison group. Husbands also had a 69% higher risk than men in the comparison group. The risk of developing dementia within five years was also higher: for women, the rate among spouses of dementia patients was 6.47%, 2.75 percentage points higher than the control group's 3.72%; for men, it was 9.24%, 3.49 percentage points higher than the control group's 5.75%.
By age group, the rate of increase appeared higher among younger age groups because dementia was originally rare, but the actual number of additional patients was small. In contrast, among older age groups, the number of additional patients was greater even though the rate of increase was relatively smaller.
When Alzheimer's disease and vascular dementia were analyzed separately, the results were similar. The research team interpreted that the absolute increase in risk appeared larger among older age groups because their dementia risk was originally high.
Results Vary by Income and Presence of Children
For those with higher income or more children, the association between a spouse's dementia and one's own dementia risk was somewhat weaker. This was presumed to be because higher income allows relatively greater capacity to use care services or receive economic support, and having more children raises the possibility that family members share the caregiving burden.
The research team noted that the association between a spouse's dementia and increased dementia risk may be the result of a complex interplay of risk factors shared by couples, chronic stress during the caregiving process, depression, sleep disorders, social isolation, increased inflammatory response, and neglect of health management. However, they stressed that a higher dementia risk does not necessarily mean one will develop dementia, and that it has not been proven that caring for a spouse causes dementia.
In Korea, which has entered the era of super-aging, the number of dementia patients is steadily increasing. According to statistics from the Health Insurance Review and Assessment Service, the number of patients, which stood at about 560,000 in 2020, exceeded 700,000 in 2024, an increase of about 25%. The Ministry of Health and Welfare projects that the number of dementia patients in Korea will reach 2 million by 2044.
