A new study published in the May Journal of the American Geriatrics Society has found that husbands or wives who care for spouses with dementia are more likely to develop the memory-impairing condition than those whose spouses don’t have it.

The 12-year study was conducted by researchers at Johns Hopkins, Utah State University, and Duke University. Scientists examined 1,221 married couples ages 65 or older. They found that individuals whose spouses had already been diagnosed with dementia were six times as likely to develop the condition themselves compared to those without an affected spouse.

The researchers report that the increased risk of the condition the caregivers were found to have is comparable to the risk of developing Alzheimer’s disease associated with a well-studied gene variant.

"Caregiving has positive aspects, as well as negative ones," said researcher Peter Rabins, M.D. "If we can boost the positive aspects and reduce the negative ones, we may be able to reduce a caregiver’s risk of developing dementia."

Scientists speculate that the stress of caregiving might be responsible for the increased dementia risk for spouses, although more research is need to identify what that mechanism might be.