Depression & Dementia

1 min

Researchers found that people over age 50 who suffered from depression were up to 15 times more likely to develop dementia than their peers with normal moods. The investigators reported that 5.7 percent of patients diagnosed with depression eventually developed dementia compared to only 2.6 percent of people of the same age who had not been depressed, over a follow-up of more than 10 years. Lead researcher Peter Nordstrom of Sweden’s Umea University said that because the study was observational in nature, it didn’t prove that depression causes dementia or that people diagnosed with depression are bound to develop dementia. However, the link between the two diseases was seen even when depression occurred more than 20 years before dementia. The investigators also reported that among more than 25,000 siblings over age 50 when one was diagnosed with depression and the other wasn’t, the depressed sibling was 20 times more likely to be diagnosed with dementia within six months than his or her brother or sister without depression. Although the risk of dementia declined over time, the study found that it persisted for more than 20 years.

Source:
Peter Nordstrom et al, “The association of depression with subsequent dementia diagnosis: A Swedish nationwide cohort study from 1964 to 2016.” PLOS, January 9, 2020, doi.or/10.1371/joural.pmed.1003016

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