Study Finds A Correlation Between Depression & Dementia

Researchers are racing to find a treatment for dementia. In the meantime, any information we can gather about the disease's causes and symptoms is helpful.

A population cohort study published in JAMA Neurology found that over a 41-year period (from 1977 to 2018), the risk of dementia was more than double1 for men and women diagnosed with depression.

The hazard of dementia was greater in men, and one explanation for the heightened risk could be that men are less likely to seek health care than women2, researchers propose. 

The association persisted between dementia and depression that was diagnosed in early and middle life, further suggesting that depression may increase dementia risk. That being said, the reason behind the possible correlation is not yet clear.

The study used data from a nationwide Danish population-based cohort that included 246,499 people with diagnosed depression and 1,190,302 without depression.

While this is a significant observation, it does not confirm that depression is a cause of dementia. However, it does provide another reason to prioritize early depression treatment. The most pressing concern for those with depression is managing current symptoms to improve their quality of life. 

"Effective treatment of [depression] symptoms should be a priority," Raafat Girgis, M.D., a psychiatrist, tells mindbodygreen in response to the study.

Lifestyle changes and talk therapy may be enough to help many people with depression. "Diet and nutrition will be helpful in improving health symptoms, as well as altering and addressing neurotransmitter function," Girgis says. (Here, a few brain foods to consider putting on your grocery list.)

In other cases, medication may be needed. However, older adults with depression may not be good candidates for antidepressants, depending on what other medications they are taking, Girgis explains. For individuals at risk of drug interactions, he notes a new therapy called Problem Adaptation Therapy (PATH)3 may be more helpful.

It's also important to remember that many factors contribute to brain health and cognition—some of which can also simultaneously help ease depression symptoms. "Isolation4 and low activity5 seem to place a person with depression at a higher risk for dementia than anything else," Girgis says. 

Moral of the study: Having depression does not automatically predispose you to dementia. But prioritizing your mental health by making connections with those around you, getting daily movement, and engaging in activities that you enjoy may pay dividends for cognitive health down the line.