Insomnia Isn't Just Fatiguing-It Could Be Aging Your Brain Faster: Study Shows - Video

Chronic insomnia may accelerate brain aging and significantly increase the risk of developing cognitive impairments, including dementia. The findings, published in journal Neurology, suggest that sleep problems in older adults are not just disruptive but could have long-term consequences for brain health.

Chronic insomnia, defined as difficulty sleeping at least three days a week for three months or more was associated with a 40% higher risk of developing mild cognitive impairment or dementia.

The study followed 2,750 cognitively healthy adults, with an average age of 70, for an average of 5.6 years. Of the participants, 16% had chronic insomnia. Each participant completed yearly thinking and memory assessments, and a subset underwent brain imaging to examine signs of small vessel disease and amyloid plaque buildup—both markers associated with Alzheimer’s disease. At the start of the study, participants were also asked whether they had been sleeping more or less than usual over the prior two weeks.

By the end of the study, 14% of participants with chronic insomnia had developed cognitive impairments, compared to 10% of those without insomnia. Notably, participants who reported getting less sleep than usual showed lower cognitive scores and more brain changes, including increased amyloid plaques, similar to changes seen in people with the APOE ε4 gene, a known genetic risk factor for Alzheimer’s. In contrast, those who reported more sleep than usual showed fewer white matter changes.

"This reinforces the importance of treating chronic insomnia -- not just to improve sleep quality but potentially to protect brain health as we age. Our results also add to a growing body of evidence that sleep isn't just about rest -- it's also about brain resilience," said study author Diego Z. Carvalho, MD, of the Mayo Clinic in Rochester, Minnesota, and a member of the American Academy of Neurology.

While further research is needed, the findings emphasize the importance of diagnosing and treating chronic insomnia, not only for better sleep but also to potentially safeguard cognitive health.

Reference: Diego Z. Carvalho, Bhanu Prakash Kolla, Stuart J. McCarter, Erik K. St. Louis, Mary M. Machulda, Scott A. Przybelski, Angela J. Fought, Val J. Lowe, Virend K. Somers, Bradley F. Boeve, Ronald C. Petersen, Clifford R. Jack, Jonathan Graff-Radford, Andrew William Varga, Prashanthi Vemuri. Associations of Chronic Insomnia, Longitudinal Cognitive Outcomes, Amyloid-PET, and White Matter Changes in Cognitively Normal Older Adults. Neurology, 2025; 105 (7) DOI: 10.1212/WNL.0000000000214155