For many older adults, the occasional restless night is nothing new. But when sleep troubles become chronic, the effects may go far beyond feeling tired the next day. New research suggests that long-term insomnia could accelerate memory decline and increase the risk of dementia.
Published in Neurology, the research shows that people living with chronic insomnia—defined as difficulty sleeping at least three nights a week for three months or longer—faced a 40 per cent higher risk of mild cognitive impairment or dementia compared with those who slept more soundly.
The study’s authors say that the difference is similar to adding an extra 3.5 years of ageing to the brain.
“Insomnia doesn’t just affect how you feel the next day—it may also impact your brain health over time,” said study author Diego Z. Carvalho, MD, of the Mayo Clinic in Rochester, Minnesota, and a member of the American Academy of Neurology.
“We saw faster decline in thinking skills and changes in the brain that suggest chronic insomnia could be an early warning sign or even a contributor to future cognitive problems.”
Researchers followed 2,750 older adults, average age 70, for nearly six years. Of these, 16 per cent had chronic insomnia. Each year, participants completed memory and thinking tests, and some also had brain scans.
By the end of the study, 14 per cent of people with insomnia had developed mild cognitive impairment or dementia, compared with 10 per cent of those without sleep problems. The risk remained even after adjusting for age, blood pressure, sleep medication use, and sleep apnea.
“Our results suggest that insomnia may affect the brain in different ways, involving not only amyloid plaques, but also small vessels supplying blood to the brain,” Carvalho said.
“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.”
If you’re struggling to get a good night’s rest, you’re not alone. While there are plenty of so-called quick fixes, Sleep Expert Carmel Harrington, PhD, recommends focusing on enjoyable, “mentally stimulating” habits that can genuinely improve sleep quality.
Wake up at the same time every day — consistency helps set your body clock.
Move your body daily — even a 20-minute lunchtime walk can make a difference.
Clear your mind before bed — in the early evening, spend up to 20 minutes writing down worries and possible solutions. Close the notebook and put it away so the issues don’t follow you to bed.
Sleep in too long on weekends — try not to go more than an hour past your usual wake-up time.
Have caffeine after midday — it can linger in your system longer than you think.
Rely on alcohol for sleep — more than one drink can reduce sleep quality.
Nap for long stretches — keep daytime naps to 20 minutes or less.
IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.