If you’re a chronic insomniac, you could be experiencing faster decline in memory and thinking skills than your best sleep partners. In other words, your brain could be aging faster.
In a study published Wednesday in the journal Neurology, researchers found that people with chronic insomnia, characterized by having trouble sleeping at least three days a week for three months or more, were significantly more likely to develop mild cognitive impairment or dementia than their healthy counterparts.
“Insomnia doesn’t just affect how you feel the next day—it can also affect your brain health over time,” Diego Carvalho, a neurologist at the Mayo Clinic and co-author of the study, told the American Academy of Neurology in a statement in the Journal. “We saw a more rapid decline in thinking skills and brain changes, suggesting that chronic insomnia could be an early warning sign or even a contributor to future cognitive problems.”
3.5 years older
To be clear, the researchers don’t know whether insomnia causes brain aging; they’re simply highlighting an association. In the study, the team followed more than 2,500 cognitively healthy people with an average age of 70 for an average of 5.6 years. 16% of the participants had chronic insomnia.
14% of people with chronic insomnia developed mild cognitive impairment or dementia during the study, while only 10% of participants without insomnia developed the same symptoms. After the researchers took into account differences such as high blood pressure, use of sleeping pills, age and a diagnosis of sleep apnea, they found that the insomniac participants had a 40% higher risk of developing mild cognitive impairment or dementia than those without insomnia. That’s the equivalent of 3.5 extra years of aging. Their performance on thinking tests also declined more quickly.
Among the insomniacs, those who reported sleeping less than usual in the past two weeks were more likely to have lower cognitive test scores at the start of the study, the equivalent of looking four years older. They also had more white matter hyperintensities (potentially damaged brain tissue from small vessel disease) and amyloid plaques (a protein linked to Alzheimer’s disease). The latter accumulation was similar to that seen in people with known genetic risk factors.
Maintaining brain strength
“Our results suggest that insomnia may affect the brain in multiple ways, involving not only amyloid plaques but also the small vessels that supply blood to the brain,” said Carvalho. “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 the growing body of evidence that sleep is not just about rest – it’s also about brain resilience.”
Participants who reported getting more sleep than usual in the past two weeks were more likely to have less white matter hyperintensities at the start of the study.
The researchers acknowledge that their results are limited by the fact that insomnia diagnoses came from medical records, which don’t indicate the severity of symptoms or include undiagnosed cases. Nevertheless, the point of the study seems clear enough to me: get enough sleep. And if you can’t, get help.
