Overview

• Following 2,750 adults aged 50 and older for about 5.5 years, Mayo Clinic researchers found chronic insomnia was linked to a 40% higher likelihood of developing mild cognitive impairment or dementia.
• Participants were classified using medical-record diagnoses of insomnia at least twice a month apart, a definition that identified 16% of the cohort.
• Insomnia coupled with shorter-than-usual sleep corresponded to worse cognitive performance equivalent to roughly four extra years of aging and to higher amyloid plaques plus more white-matter hyperintensities on brain scans.
• The measured effect of chronic insomnia on decline was comparable in size to the risk from carrying the ApoE4 genetic variant, which itself remained a strong predictor of faster deterioration.
• The study found no clear benefit or harm from commonly used sleep medications, evidence for newer orexin blockers remains small and short-term, and CBT for insomnia improves sleep yet has not been proven to prevent dementia.