Insomnia Tied to 26% Higher Stroke Risk in New Review

A new review in Sleep Medicine Reviews links insomnia to a 26% higher stroke risk plus elevated odds of dementia, depression and hospitalization.

A study published Sunday in the journal *Sleep Medicine Reviews* pooled evidence from about 20 comprehensive review studies involving millions of participants across multiple countries, according to ABC News. Researchers from Austria, Germany, Italy and Switzerland found insomnia was linked to a 26% increased risk of stroke. AOL reports that its analysis drew on 1.3 million participants from six prior studies examining stroke risk factors, occupational injuries, and hospitalizations. People with insomnia also had nearly 30% higher odds of being hospitalized for any reason, per ABC News, which AOL puts at a 28% higher hospitalization risk. Lead author Luca Vignatelli of the IRCCS Institute of Neurological Sciences in Bologna told ABC News that "insomnia deserves attention as a warning sign of the status of brain and mental health."

Neurologists say the connection is biologically plausible. "Sleep disruption contributes to inflammation, increased blood clots, and other factors that can bring on a stroke," Beth Malow, a neurologist and chief of the Division of Sleep Disorders at Vanderbilt Health, told AOL. Dr. Christopher Yi, a vascular surgeon at MemorialCare Orange Coast Medical Center, explained to AOL that poor sleep raises cortisol, which over time can contribute to higher blood pressure, elevated heart rate and plaque build-up in the arteries. He added that insomnia can also impair metabolism, raising the odds of weight gain, diabetes and high cholesterol — all stroke risk factors. Sleep specialist Dr. W. Christopher Winter cautioned to AOL that the link likely runs both ways, since people predisposed to stroke are also predisposed to poor sleep.

The review also connected insomnia to dementia, particularly Alzheimer's disease, and to higher rates of depression and attempted suicide, according to ABC News. ABC News notes that sleep plays a key role in clearing waste products tied to impaired brain function and Alzheimer's from the brain — "when you sleep, that's when your brain takes out the trash," sleep physician Dr. Thanuja Hamilton told the outlet. Experts told ABC News that sleep problems are often overlooked in mental health care, with poor sleep and anxiety or depression feeding each other in a cycle. Still, study author Dr. Stefan Seidel of the Medical University of Vienna told ABC News that people should not be frightened: population-level risk increases do not mean any individual with insomnia will develop dementia or have a stroke.

The authors emphasized that the findings show associations only and do not prove insomnia directly causes stroke, dementia or mental illness, ABC News reports. That caution echoes earlier research: AOL cites a 2023 *Neurology* data analysis of 31,126 adults in which people reporting insomnia symptoms were more likely to have a stroke over nine years of follow-up, with the link strongest in adults under 50. The new review also did not test whether treating insomnia reduces stroke risk, AOL notes, so doctors frame better sleep as a way to lower the underlying risk factors rather than a proven stroke-prevention strategy. Experts told ABC News that sleep should become a routine part of health conversations at any age.

Cognitive behavioral therapy for insomnia (CBT-I) is considered the gold-standard treatment, though experts told ABC News it takes effort and is worth it. Practical habits include a consistent sleep schedule — "our circadian rhythm likes consistency," Hamilton told ABC News — plus keeping the bedroom cool, turning off screens 30 to 60 minutes before bed, and avoiding late coffee or alcohol. Doctors told AOL that anyone whose sleep trouble persists despite hygiene changes should see a primary care provider or sleep specialist to rule out causes like sleep apnea, and that acting early is better. Separately, Reuters' Health Rounds newsletter reports that Kyverna's experimental CAR T-cell therapy significantly improved walking ability in stiff-person syndrome patients, with benefits persisting one year after treatment.