People with comorbid type 2 diabetes and depression are at a higher risk of developing dementia than people with just one of the conditions, according to a recent study published in JAMA Psychiatry.
Researchers performed a national population-based cohort study of more than 2.4 million adults in Denmark, including 477,000 with depression, 223,000 with diabetes and 95,000 with both. The study included Danish citizens 50 years old or older who were free of dementia from January 2007 to December 2013.
All total, 59,663 participants (2.4 percent) developed dementia, of which 6,466 (10.8 percent) had diabetes, 15,729 (26.4 percent) had depression and 4,022 (6.7 percent) had both. When the researchers adjusted the hazard ratio for developing dementia, the risk for those with both conditions was 2.17, higher than the risk ratios from those with just depression (1.2) or diabetes (1.83).
"Persons with comorbid [diabetes mellitus] and depression appeared to have the highest relative risk for dementia, and this association tended to be stronger than additive," wrote the study authors. "From a public health perspective, developing screening and interventions to improve the quality of treatment of depression and DM in this subgroup of patients could be important in reducing the risk for dementia."