Chronic insomnia may do more than leave you tired—it could speed up brain aging.A new study in Neurology finds people with chronic insomnia are 40% more likely to develop mild cognitive impairment (MCI) or dementia compared to those without the disorder.Chronic insomnia is defined as trouble sleeping at least three days a week for three months or more.Researchers tracked nearly 2,800 healthy, older adults for over five years. The participants reported on their sleep quantity, took yearly cognitive tests, and some underwent brain scans.The results showed people suffering chronic insomnia had faster declines in memory and thinking skills.Those with insomnia and short sleep experienced declines equivalent to 4 years of additional brain aging. Their scans also revealed changes associated with Alzheimer’s disease, including more amyloid plaques and white matter damage.One study author says these findings “suggest chronic insomnia could be an early warning sign or even a contributor to future cognitive problems.”More research is needed to determine whether improving sleep—through therapy, medication, or healthy habits—might help protect the brain and slow cognitive decline.Source: Neurology®Author Affiliations: Mayo Clinic, Icahn School of Medicine at Mount Sinai.Sign up for our weekly HealthDay newsletter