Insomnia Linked to Increased Risk of Dementia in Older Adults

A recent study suggests that sleep disturbances, specifically insomnia, may significantly contribute to the development of Alzheimer’s disease and other forms of dementia. Approximately one in eight dementia cases among older adults could be connected to the sleeplessness many experience.

Researchers in Boston analyzed medical records from 5,899 individuals aged 65 and older, participants in the National Health and Aging Trends Study. Nearly 30 percent reported symptoms of insomnia, such as difficulties in falling asleep or staying asleep. Of these participants, around 6.6 percent were diagnosed with Alzheimer’s disease or other dementias.

The study also evaluated data from various large-scale studies linking insomnia to dementia risks and found that nearly 13 percent of dementia cases in the study population were attributable to poor sleep. This proportion was notably high among women in their late 60s and men in their early 70s.

The authors noted, "Approximately 13 percent of dementia cases, almost half a million cases, among U.S. older adults may be attributable to insomnia. Addressing insomnia could be a promising target for dementia prevention efforts in aging populations." However, it's important to recognize that these findings demonstrate an association rather than a definitive cause-and-effect relationship.

The research, published in the Journals of Gerontology: Series A, adds to a body of evidence indicating that sleep quality is a crucial factor influencing dementia risk, similar to high blood pressure and hearing loss.

Long-term studies show that both insufficient and excessive sleep—less than or more than the recommended seven to eight hours nightly—may influence the onset of dementia. Deep sleep is believed to assist in clearing the brain of toxins harmful to cells, while inadequate sleep can increase inflammation, which negatively impacts brain health.

Insomnia is prevalent among older adults, and while some may resort to sleeping pills, these do not induce deep sleep and can result in serious long-term side effects. Experts recommend cognitive behavioral therapy (CBT) as the primary treatment for insomnia. CBT focuses on reshaping negative thoughts associated with sleep through relaxation techniques like meditation and visualization.

Additional suggestions for improving sleep quality include avoiding caffeine and alcohol in the hours prior to bedtime and minimizing exposure to electronic screens before sleep. Maintaining a consistent bedtime routine and treating the bed as a restful space can also be beneficial. If sleep is elusive, individuals are advised to get up and engage in calming activities, such as reading or listening to music, for short periods.

While more effective treatments for Alzheimer’s remain to be discovered, enhancing sleep quality might be an important step in mitigating the risk of dementia as people age.

By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University

Source: Yuqian Lin, MS; Fei Wu, MS; Yuhan Wu, MS; et al: “Quantifying the Population-Level Impact of Insomnia on Dementia Among Older Adults in the United States.” The Journals of Gerontology: Series A, December 27, 2025.