Late-life depression appears to be associated with mild cognitive impairment and an increased risk of dementia, according to new research.

Researchers note that symptoms of depression occur in 3 percent to 63 percent of patients with mild cognitive impairment (MCI) and some studies have shown an increased dementia risk in individuals with a history of depression.

While different mechanisms have been proposed, the link between depression and cognitive decline are not clear, the researchers noted.

This led Edo Richard, M.D., Ph.D., of the University of Amsterdam in the Netherlands, and his colleagues to evaluate the association of late-life depression with MCI and dementia in a group of 2,160 Medicare recipients.

“We found that depression was related to a higher risk of prevalent MCI and dementia, incident dementia, and progression from prevalent MCI to dementia, but not to incident MCI,” the researchers note in their study, which was published in Online First by Archives of Neurology.

Baseline depression was associated with prevalent mild cognitive impairment (odds ratio [OR] 1.4) and dementia (OR .2), as well as an increased risk of incident dementia (hazard ratio [HR], 1.7).

Patients with MCI and coexisting depression at baseline also had a higher risk of progression to dementia (HR, 2.0), especially vascular dementia (HR, 4.3) — but not Alzheimer’s disease.

“Our finding that depression was associated… with both MCI and dementia and longitudinally only with dementia suggests that depression develops with the transition from normal cognition to dementia,” the researchers conclude.

Source: JAMA and Archives Journals