Study Finds Link Between Depression and Dementia

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Introduction

People who suffer from depression are more than twice as likely to develop dementia later in life, a new study from Penn Medicine found. The study was a collaboration between researchers at the Perelman School of Medicine at the University of Pennsylvania and Aarhus University in Denmark. It followed 1.4 million Danish citizens over nearly four decades, according to a press release announcing the findings.

Key Findings

• Those diagnosed with depression were 2.41 times more likely to receive a dementia diagnosis eventually.
• The correlation existed regardless of the age at which the depression was diagnosed.
• Those hospitalized for depression multiple times had a stronger risk of dementia later in life.
• There didn’t seem to be any increased risk among those who were prescribed antidepressants within six months of being diagnosed with depression.

Potential Reasons for the Link

Dr. Rehan Aziz, geriatric psychiatrist at Jersey Shore University Medical Center and associate professor of psychiatry and neurology at the Hackensack Meridian School of Medicine in New Jersey, shared his thoughts on the findings. “The study links depression and dementia — but it does not explain why the risk exists,” he said. He hypothesized that depression and dementia may share similar genetics and cause similar brain changes. Depression can also create a state of inflammation in the brain and impact other brain chemicals, which could trigger later-life memory problems.

Treatment and Risk Reduction

Although the study findings stated that the prescription of antidepressants didn’t seem to impact the risk of dementia, Aziz said more research is needed to make a definitive call. Mental health conditions should “treat depression aggressively” with a combination of medications, psychotherapy, and lifestyle interventions such as diet and exercise. Clinicians should also discuss the possible linkage between depression and dementia and emphasize the importance of adhering to depression treatment.

Conclusion

Further research is needed to understand the link between depression and dementia and to evaluate whether the link may be biological, a result of behaviors associated with depression, or a combination of these mechanisms.

By Melissa Rudy