HealthDay News — Depression and diabetes both appear to significantly raise the risk of dementia, according to new research. The findings were published online in JAMA Psychiatry.
Dimitry Davydow, MD, MPH, an associate professor of psychiatry and behavioral sciences at the University of Washington School of Medicine in Seattle, and colleagues looked at dementia risk among 2.4 million people in Denmark, age 50 and older, who had depression, type 2 diabetes, or both, and compared them with people who had neither condition. The researchers also took into account medical comorbidities and complications from diabetes.
“Even after taking those into account, diabetes itself raised the risk of dementia by 15%, depression by 83%, and the two together by 107%,” Davydow told HealthDay. The association was especially strong in people younger than 65. In that age group, “a quarter of the cases [of dementia] were attributed to depression and diabetes,” he said.
The research team — led by Davydow and the study’s recently deceased first author, Wayne Katon, MD — followed the study participants from 2007 through 2013. All patients were dementia-free at the start. The researchers said nearly 20% of participants had a diagnosis of depression, about 9% had diabetes, and nearly 4 percent had both.
Over the study period, 59,663 men and women (2.4%) were diagnosed with dementia — at age 81, on average. Of those, 26% had only depression, 11% had only type 2 diabetes, and nearly 7% had both.
Katon W, et al. Effect of Depression and Diabetes Mellitus on the Risk for Dementia. JAMA Psychiatry. 2015; doi:10.1001/jamapsychiatry.2015.0082.