Neurology

Chronic insomnia linked to cognitive decline in older adults

September 15, 2025

Study details: This longitudinal analysis from the Mayo Clinic Study of Aging included 2,750 cognitively unimpaired older adults (mean age, 70.3 years) with or without chronic insomnia (defined as difficulty sleeping ≥3 days a week for ≥3 months). Participants underwent annual neuropsychological testing and serial imaging (amyloid-PET and MRI for white matter hyperintensities [WMH]). Mixed-effects and Cox models assessed associations between insomnia, sleep duration changes, cognitive outcomes, and brain health over a median follow-up of 5.6 years.

Results: Chronic insomnia was associated with a significantly faster decline in global cognitive scores (0.011/year; 95% confidence interval [CI], -0.020 to -0.001, p-interaction = 0.028)) and a 40% increased risk of incident cognitive impairment (hazard ratio, 1.4; 95% CI 1.07-1.85, p = 0.015). Insomnia with reduced sleep correlated with worse baseline cognition (β=-0.211), higher WMH burden (β=0.147), and elevated amyloid-PET levels (β=10.5). Conversely, insomnia with increased sleep was associated with lower WMH burden (β=-0.142). No associations were found between insomnia and longitudinal changes in WMH or amyloid accumulation. Hypnotic use did not impact cognitive outcomes.

Clinical impact: Chronic insomnia, especially when accompanied by reduced sleep, may be an early marker of neurodegeneration. Sleep patterns could inform risk stratification and preventive strategies for cognitive decline and Alzheimer’s disease in aging populations.

Source:

Carvalho DZ, et al. (2025, October 7). Neurology. Associations of Chronic Insomnia, Longitudinal Cognitive Outcomes, Amyloid-PET, and White Matter Changes in Cognitively Normal Older Adults. https://pubmed.ncbi.nlm.nih.gov/40929630/