Insomnia Raises Dementia Risk in Older Adults
New research links chronic insomnia to faster brain aging and cognitive decline.
A Mayo Clinic study following over 2,700 cognitively healthy older adults found that chronic insomnia increased the risk of mild cognitive impairment or dementia by 40% and was tied to accelerated brain aging, equivalent to 3.5 additional years.
Study Details
Researchers analyzed data from the Mayo Clinic Study of Aging, including 2,750 older adults with an average age of 70. None had dementia at the start. Annual cognitive assessments tracked changes over nearly six years, alongside imaging markers of brain health such as amyloid deposits and white matter hyperintensities.
Chronic insomnia was defined as trouble sleeping at least three nights a week for three months or longer. About 16% of participants fell into this category.
Methodology
Participants underwent comprehensive yearly neuropsychological testing across memory, executive function, language, and visual-spatial domains. Sleep history was assessed through clinical records. Statistical models adjusted for multiple confounders, including APOE4 genetic risk, comorbidities, mood disorders, and sleep apnea.
Key Findings
Higher dementia risk: Chronic insomnia increased the likelihood of developing mild cognitive impairment or dementia by 40%.
Accelerated brain aging: Insomnia was linked to an additional 3.5 years of brain aging.
Cognitive decline: Faster decreases in global cognitive scores were observed, especially in APOE4 carriers.
Brain changes: Insomnia correlated with higher amyloid burden and white matter hyperintensities, though it did not accelerate their accumulation over time.
Medication not protective: Hypnotic drugs did not reduce risk of cognitive decline in participants with insomnia.
Implications for Practice
For patients, these findings underscore that chronic insomnia is more than a nuisance it may directly influence long-term brain health. Seeking early evaluation and evidence-based treatment for persistent sleep problems could be a protective step against dementia.
For clinicians, the results highlight the importance of screening for insomnia during routine care of older adults, particularly those with other dementia risk factors. Addressing sleep quality may serve as a low-cost, non-pharmacological approach to preserving cognition and delaying neurodegeneration.