Overview
- The umbrella systematic review published Monday, Sept. 28, 2026 pooled more than 1.3 million participants and reported a 26% higher risk of stroke and 28% higher odds of hospital admission for people with insomnia.
- Beyond stroke and hospitalisations, the review found consistent associations between insomnia and depression and suicidal behaviour, and suggestive evidence linking insomnia to dementia, particularly Alzheimer’s disease.
- The authors stress the results show associations rather than proof of cause because included studies used different insomnia definitions, showed large variation in effect sizes, and rarely separated the effects of sleep medications.
- Researchers and quoted experts recommend that clinicians recognise chronic insomnia as a warning sign, include sleep in routine brain-health discussions, and offer evidence-based treatment where appropriate.
- The team urges future studies to use harmonised diagnostic criteria, include more diverse populations and collect detailed data on medication and biological mechanisms; the project was funded by the European Academy of Neurology with disclosed industry grants.