Individuals diagnosed with either depression or diabetes, or both, are at a higher risk of dementia compared with people who have neither of the conditions, said a new study.
While Type-2 diabetes is associated with a 20 percent greater risk of dementia and depression alone was associated with an 83 percent greater risk, having both depression and Type-2 diabetes was associated with a 117 percent greater risk, the study indicated.
The risk for dementia appeared to be even greater among those study participants younger than 65.
Dimitry Davydow from the University of Washington School of Medicine, Seattle, and co-authors examined the risk of dementia among individuals with depression, Type-2 diabetes or both.
They compared risk 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.
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 percent 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 percent) had depression alone and 6,466 (10.8 percent) had Type-2 diabetes alone, while 4,022 (6.7 percent) had both conditions.
The study was published online in the journal JAMA Psychiatry.