The Antidepressants That Are Anticancer Too

We’ve written about antidepressant side effects before: How Serious Are Antidepressant Side Effects?

…including the more specific: How Much Weight Gain Do Antidepressants Cause?

However, you might not have heard about this antidepressant side effect—not least of all because the research in question was published a few days ago (at time of writing).

The New News about Selective Serotonin Reuptake Inhibitors

Selective serotonin reuptake inhibitors (SSRIs), which are by far the most widely-used antidepressant type (including sertraline, commonly-known by brand names like Prozac and Zoloft, amongst many others) increase serotonin levels by blocking the serotonin transporter (SERT), whence the name “sertraline”.

Importantly, it also boosts T-cell activity in tumors (that’s a good thing).

How this research came about: researchers found that tumors contain immune cells with high levels of serotonin-regulating molecules, prompting investigation into serotonin’s role in cancer.

Previously, the same team of researchers found that MAO-A, an enzyme that breaks down serotonin, weakens T-cells in tumors. Although monoamine oxidase inhibitors (MAOIs), another common kind of antidepressant, improved T-cell function, their safety profile isn’t nearly as good, and those risks prompted researchers to explore SSRIs instead.

The good news: SSRIs target only SERT and are already widely used with minimal side effects, making them a safer and more practical option for this kind of repurposing.

How effective is it? In mouse and human tumor models (melanoma, breast, prostate, colon, and bladder cancers), SSRIs improved T-cell effectiveness and reduced tumor size by over 50%.

Even better news: combining SSRIs with immune checkpoint blockade (ICB) therapies like anti-PD-1 antibodies produced significantly better results, including complete remission in some models.

You can read the paper itself here in full: Serotonin transporter inhibits antitumor immunity through regulating the intratumoral serotonin axis

Want to learn more?

You can learn more about the beneficial effects of healthy serotonin levels, here: Serotonin For More Than Just Happiness

And if you’re on antidepressants, but not SSRIs or MAOIs? We might just have you covered:

Norepinephrine vs Alzheimer’s Disease ← because selective noradrenaline* reuptake inhibitors (SNRIs) are another kind of antidepressant; mirtazapine is a common example of this

*noradrenaline is the international name for what is called norepinephrine in the US

And finally, if this seems like a lot of options and you’re not sure what kind of antidepressant (if any!) is right for you, then check out:

Antidepressants: Personalization Is Key!

Take care!