Depression and diabetes linked to increased dementia risk

Depression and diabetes linked to increased dementia risk

Published online by JAMA Psychiatry the study* shows the risk is even greater among individuals diagnosed with both depression and diabetes. As many as 20% of people with type 2 diabetes mellitus also have depression, state the authors. 

Dimitry Davydow, of the University of Washington School of Medicine, Seattle, and co-authors examined the risk for dementia among individuals with depression, type 2 diabetes, or both, compared with individuals with neither condition in a group of more than 2.4 million Danish citizens, who were 50 and older and free from dementia from 2007 through 2013.

Overall, 19.4% of individuals in the group had a diagnosis of depression (477,133 individuals), 9.1% had type 2 diabetes (223,174 individuals), and 3.9% (95,691 individuals) had diagnoses of both diabetes and depression. The average age at initial diagnosis of type 2 diabetes was 63.1 years old and the average age at initial diagnosis of depression was 58.5 years old.

The authors found that during the study period, 2.4% of individuals (59,663 people) developed dementia and the average age at diagnosis was nearly 81 years. Of those individuals who developed dementia, 15,729 people (26.4%) had depression alone and 6,466 (10.8%) had type 2 diabetes alone, while 4,022 (6.7%) had both conditions.

The results of the study indicate that type 2 diabetes alone was associated with a 20% greater risk for dementia, and depression alone was associated with an 83% greater risk, while having both depression and type 2 diabetes was associated with a 117% greater risk. The risk for dementia appeared to be even greater among those study participants younger than 65.

"In light of the increasing societal burden of chronic diseases, further research is needed to elucidate the pathophysiologic mechanisms linking depression, DM [type 2 diabetes mellitus] and adverse outcomes such as dementia and to develop interventions aimed at preventing these dreaded complications," the study concludes.


* Wayne Katon, et al. Effect of Depression and Diabetes Mellitus on the Risk for Dementia: A National Population-Based Cohort Study. JAMA Psychiatry. Published online April 15, 2015. doi:10.1001/jamapsychiatry.2015.0082

By Jo Carlowe,

OnMedica, Thursday 16 April 2015

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