Chronic insomnia linked to faster brain aging and dementia risk

A new study of older adults suggests that chronic insomnia may be linked to faster brain ageing and a higher risk of mild cognitive impairment and dementia. Researchers tracking 2,750 cognitively healthy Americans with an average age of 70 for about 5.6 years found that people diagnosed with chronic insomnia were 40 percent more likely to develop mild cognitive impairment or dementia than those without the disorder, the study published in Neurology reported.

At the start of the study 16 percent of participants had chronic insomnia, defined as difficulty falling or staying asleep at least three nights per week for three months or longer. Over the follow-up period 14 percent of people with insomnia developed mild cognitive impairment or dementia, compared with 10 percent of those without. After adjusting for age, high blood pressure, sleep apnea, use of sleep medications and other potential confounders, the researchers said the excess risk associated with insomnia corresponded to roughly 3.5 additional years of brain ageing and was accompanied by faster declines on tests of memory, attention and spatial reasoning.

The team, led in part by Diego Z. Carvalho, a neurologist at the...