Can You Decrease Your Dementia Risk by Treating Depression?

Early Life and Late Life Depression Are Risk Factors for Dementia

Depression: A Risk for Dementia
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Depression--those feelings of pervasive sadness, apathy, and pointlessness--can deeply impact the quality of life a person experiences. But, research also suggests that depression may trigger a higher risk of developing dementia as well.

A Summary of Five Studies

1. Researchers reviewed the results of 23 studies that have been conducted about depression and dementia. They found that depression significantly increases the chances of dementia- both as a group of all of the kinds of dementia, as well as specifically for Alzheimer's disease and for vascular dementia.

Interestingly, the highest risk following depression was for vascular dementia.

2. A second study involved 1,764 participants who were monitored and tested for approximately 8 years to evaluate depression symptoms and dementia symptoms. The researchers found that there was a significant correlation between late-life depression and the risk of dementia.

3. Researchers conducted a comprehensive review of 16 studies about late-life depression and five studies about earlier life depression (depression was considered "earlier-life" if it was present before the age of 60). After their review, they concluded that individuals with either late-life or earlier-life depression were both two to four times more likely to later develop dementia than those without depression.

4. A fourth study found that both depression and type 2 diabetes pose a significantly higher risk of developing dementia, and that when participants had both depression and types 2 diabetes, the risk of dementia was even greater than expected.

(The expected risk would have been the addition of the risks from both depression and diabetes, but the risk from the combination of those conditions was even higher.)

5. Another study measured total brain volume, hippocampal volume, and white matter lesions of older adults without dementia. These participants had symptoms of depression and some of them were taking an antidepressant medication.

Antidepressant use and symptoms of depression were both separately associated with a decrease in total brain volume, decreased hippocampus size and an increase in white matter lesions in the brain- all of which are commonly seen in dementia.

Why Is Depression a Risk for Dementia?

The short answer: We're not completely sure. However, we do know that depression has been associated with changes in the brain that could make it more likely for dementia to develop. This idea is supported by research demonstrating that earlier-life depression is a risk factor for late-life dementia that develops many years later.

It's also possible that depression which develops shortly before dementia is diagnosed could be one of the early symptoms of dementia, or it could be a response to an awareness that it's becoming more difficult to remember and process information. In other words, depression could be a symptom of, or a response to, early dementia.

    Next Steps

    • Seek to detect symptoms of depression in yourself and your loved ones.
    • Talk to your physician about treating your depression.
    • Consider both medications and non-drug approaches to treat depression.
    • Remember that depression is most often very treatable, so don't wait. Getting help may be the best solution both for your current mood and feelings, as well as for your long-term cognitive abilities.


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