Department of Research & Evaluation News

In a study of more than 10,000 Kaiser Permanente members diagnosed with both prostate cancer and depression, those who used antidepressants had a lower risk of cancer recurrence. These findings appeared September 9, 2022, in Cancer Causes & Control.

“Our research highlights how important it is for patients with prostate cancer to be screened and treated for depression,” said Reina Haque, PhD, a researcher with the Kaiser Permanente Southern California Department of Research & Evaluation, and lead author of the study.

“We hope our study can boost awareness of the potential benefits of antidepressants for both depression outcomes and, indirectly, possibly lowering the risk of cancer recurrence,” Dr. Haque said.

It is unknown exactly how antidepressants might influence prostate cancer recurrence. The underlying links could be behavioral, biochemical, or both.

“It may be that being treated for depression — whether it’s with antidepressants, talk therapy, or another non-pharmaceutical approach — influences people’s lifestyle habits in ways that also help prevent recurrence,” Dr. Haque said. “For instance, they may be more physically active or less likely to smoke.”

More research will be needed to investigate these possibilities. Regardless, Dr. Haque said, “Our findings suggest that a person’s mental health status should be evaluated as a routine part of the prostate cancer diagnosis process.”

Insights from 2 decades of data

Prostate cancer survivors are 3 times more likely to be diagnosed with depression than the general population of men. A growing body of research suggests a link between depression and risk of worse outcomes for multiple kinds of cancer.

However, less is known about whether antidepressants could help ease this risk. A study of women with metastatic breast cancer suggested potential benefits, but until now, no large-scale analysis had explored this topic among prostate cancer patients.

In the new study, Haque and colleagues analyzed electronic health record data of 10,017 men who had been diagnosed with both depression and stage I or II prostate cancer. These records spanned multiple years—more than 2 decades for some patients. The researchers applied statistical tools to investigate an association between prostate cancer recurrence and antidepressant use, while accounting for demographics, tumor characteristics, and other potentially complicating factors.

The analysis showed that prostate cancer survivors with depression who did not use antidepressants were 34% more likely to experience recurrence of their cancer.

“When we broke down the data by type of prostate cancer treatment, antidepressants were still linked to lower risk of recurrence, regardless of whether patients received surgery, radiation, hormonal therapy, or watchful waiting,” Dr. Haque said.

The researchers also took a closer look at the 5,931 men in the study who had received antidepressants. They found that, the longer cumulative amount of time a patient had used antidepressants, the lower their risk of prostate recurrence.

“This clear trend lends a lot of confidence to our findings,” Dr. Haque said. “Again, the underlying mechanisms remain to be identified, but you could imagine that, for instance, a person taking antidepressants might be coming in for doctor’s visits more often for prescriptions, and so little problems could be identified before they become big problems — like cancer recurrence.”

Mental and physical health go hand in hand

Looking ahead, the researchers hope to follow up on underlying factors that could be involved in the relationship between antidepressants and prostate cancer recurrence. For example, in their analysis, Black men and Hispanic men were less likely to use antidepressants than non-Hispanic white men.

“We would like to better understand why men of color might have lower use of antidepressants,” Dr. Haque said. “How much are they being screened for depression, and how does that relate to their cancer recurrence risk compared to other men?”

Such insights could help further refine understanding of the relationship between depression, depression treatment, and cancer outcomes.

“Our new study reinforces what I and other researchers increasingly see: that mental health and physical health go hand in hand, and addressing both issues is important in bettering cancer outcomes,” Dr. Haque said.

In addition to Dr. Haque, other authors on the study were Stephanie Reading, PhD; Lie Hong Chen, DrPH; and Jeff Slezak, MS, of Kaiser Permanente Southern California Department of Research & Evaluation; and Michael R. Irwin, MD, PhD, of the University of California at Los Angeles, Geffen School of Medicine.