Summary: Yes, recent research shows a newly discovered benefit of antidepressants has the potential to improve treatment for several forms of cancer.
Key Points:
- Antidepressants are a first-line medication for major depressive disorder (MDD)
- Antidepressants are also effective for several addition mental health disorders
- A new study shows antidepressants in the SSRI class can improve the action of a specific type of immune cell
- That immune cell is a key player in how our body fights cancer
What are SSRIs?
SSRIs are selective serotonin reuptake inhibitors. They work by preventing the hormone neurotransmitter serotonin from being absorbed – the reuptake part of the name – by neurons in the human brain. Serotonin is associated with positive mood, and increased levels of serotonin in the brain are associated with improved mood.
- 1974: Fluoxetine, the first SSRI, developed by pharmaceutical company
- 1987: Food and Drug Administration (FDA) approves fluoxetine for treatment of major depressive disorder (MDD)
- Fluoxetine is better known by its brand name, Prozac
- 1987 – present:
- FDA approves several more SSRIs, including but not limited to Zoloft, Luvox, Paxil, Lexapro, and Celexa.
The benefits of SSRIs include:
- Effective:
- Reduce low mood associated with depression
- Reduce low mood associated with other menta health disorders
- Increase motivation to recover from depression
- Increase ability to engage in psychotherapy
- Safe:
- Some side effects in some patients
- Safe for most patients
- Accessible:
- Getting a prescription for an SSRI is not difficult
- In addition to psychiatrists and psychiatric nurses, family physicians, physician assistants, family nurse practitioners, and some psychiatric pharmacists in some states
Since 1987, the FDA has approved SSRIs for the following mental health and/or behavioral disorders:
- Generalized anxiety disorder (GAD)
- Bulimia nervosa (BN)
- Bipolar depression
- Obsessive-compulsive disorder (OCD)
- Panic disorder (PD)
- Treatment-resistant depression (TRD)
- Post-traumatic stress disorder (PTSD)
- Social anxiety disorder
Before we reveal details about the new benefit of antidepressants, let’s take a look at how many people it may affect.
Prevalence of Antidepressant Medication: Facts and Figures
Data from the National Health and Nutrition Examination Survey (NHNES) shows the following:
Antidepressants: Past-Month Use, 2015 – 2019
Among all adults, 18+:
- 13% percent of adults in the United States used prescription antidepressant medication in the month before taking the survey.
More females than males used antidepressants:
- Females: 18%
- Males: 8%
Older females used antidepressants more than any other demographic group:
- Females 60+: 24%
More college graduates used antidepressants than non-college graduates:
- College graduates: 14%
- High school graduates 12% for
- Didn’t finish high school: 11%
More White people used antidepressants than any other race/ethnicity:
- White: 17%
- Black: 8%
- Hispanic: 7%
- Asian: 3%
Now let’s look at the exciting new discovery about SSRIs: the hidden benefit of antidepressants we’ve been leading up to.
SSRIs and Cancer-Killing T-Cells: The Surprising, Hidden Benefit of Antidepressants
Here’s the big reveal.
A group of researchers recently published a paper called “Serotonin Transporter Inhibits Antitumor Immunity Through Regulating the Intratumoral Serotonin Axis.” Data from the study demonstrates that, in laboratory conditions, treatment with SSRIs can:
- Improve the action – efficiency and effectiveness – of specific cells in the immune system called killer T-cells
- Reduce size of cancerous tumors by 50%
- Reduce tumor size when combined with immune checkpoint blockade (ICB), a relatively new cancer treatment
- Work effectively on tumors associated with skin cancer, breast cancer, colon cancer, and bladder cancer
Dr. Lili Yang, a lead author on the study, describes the impact of SSRIs on killer-T cells in an interview published by Science Daily:
“SSRIs made the killer T cells happier in the otherwise oppressive tumor environment by increasing their access to serotonin signals, reinvigorating them to fight and kill cancer cells.”
There’s another hidden benefit to SSRIs with regards to cancer research: cost. Dr. Yang explains:
“Studies estimate the bench-to-bedside pipeline for new cancer therapies costs an average of $1.5 billion. When you compare this to the estimated $300 million cost to repurpose FDA-approved drugs, it’s clear why this approach has so much potential.”
That logic is hard to argue against and adds more weight to the importance of this new discovery. There are more than 45 million people taking antidepressants in the U.S. today, which means we have access to an enormous amount of information on the action of this drug in the human body, and how it can help people with serious mental illness. Now, that information can help us in a new way: it can help our search for new and novel treatments for several types of cancer.
