An international team led by Luca Vignatelli of the Institute of Neurological Sciences in Bologna, published in the journal Sleep Medicine Reviews, analyzed roughly 20 comprehensive review studies covering millions of participants across multiple countries. The umbrella review examined seven outcomes: dementia, stroke, depression, suicidal behavior, death, hospitalization and occupational injury. It found insomnia linked to a 26% increased risk of stroke, associations with dementia and Alzheimer's disease, higher rates of depression and suicidal ideation, attempts and deaths, and nearly 30% higher odds of being hospitalized for any reason. No clear association was found with death, and evidence on occupational injury was too limited to draw conclusions.

According to Seoul Economic Daily, the team used an umbrella systematic review pooling previously published meta-analyses, examining 16 existing meta-analyses and conducting new reviews for stroke, occupational injury and hospitalization. The clearest figure came from stroke: nine studies covered a combined 1,343,164 people, and a meta-analysis of six put the hazard ratio at 1.26, with a 95% confidence interval of 1.05 to 1.53 — a wide range showing variation in association strength. Five hospitalization studies covering 517,620 people found a 28% higher odds ratio. For dementia, most reviews observed an association, with the link to Alzheimer's disease relatively consistent. Limitations included varying definitions of insomnia and few studies accounting for sleeping-pill use.

'Insomnia deserves attention as a warning sign of the status of brain and mental health,' Vignatelli told ABC News. Researchers suggest sleep plays a role in clearing waste products linked to impaired brain function: 'When you sleep, that's when your brain takes out the trash,' sleep medicine physician Dr. Thanuja Hamilton told ABC News. Experts note a two-way loop between poor sleep and mental health — anxiety and depression disrupt sleep, and sleeplessness raises vulnerability to both. The authors cautioned the findings show associations only and do not prove insomnia causes these conditions. 'An increased risk at the population level does not mean that an individual with insomnia will develop dementia, depression or have a stroke,' co-author Dr. Stefan Seidel of the Medical University of Vienna told ABC News.

Insomnia is the most common sleep disorder in the United States, and the pressure is global: Seoul Economic Daily reports that data from Korea's Health Insurance Review and Assessment Service show insomnia patients climbed about 16% to roughly 760,000 in 2024 from about 650,000 in 2020. Experts argue sleep should become routine in health conversations. 'Sleep should be a topic to discuss with your doctor when talking about health, at any age,' Vignatelli told ABC News, while Seidel said sleep should be included in brain health care and reflected in health promotion programs in communities, schools and workplaces. Nightly habits may compound the concern: Hindustan Times reports a European Heart Journal study of 11,071 UK Biobank participants found nighttime light exposure above 3 lux was associated with measurable cardiac changes, with shorter sleep duration statistically mediating around 24% to 49% of the association.

Cognitive behavioral therapy for insomnia is often the first treatment option for long-term insomnia, focusing on changing thoughts and behaviors that interfere with sleep. 'The gold standard of treatment for insomnia is CBT, but it's difficult and it's time-consuming... But it is worth it,' Hamilton told ABC News. Experts recommend maintaining a consistent sleep schedule because the circadian rhythm 'likes consistency,' turning off phones and TVs 30 to 60 minutes before bed, and avoiding late coffee or alcohol. On the light front, Hindustan Times reports practical steps from Dr. Anil Dhall: use a sleep timer if a TV helps you drift off, keep unnecessary lights off, and block outdoor light with curtains. If sleep problems persist, researchers say it is a reason to identify underlying causes and seek evidence-based treatment rather than to be frightened.