Can Anti-Inflammatory Drugs Treat Depression?

Scientists are investigating whether anti-inflammatory medications can treat a specific subset of depression, as approximately 25% of patients exhibit elevated inflammatory proteins in their blood. According to researchers, these proteins may impair the brain’s emotional regulation and reduce the effectiveness of standard antidepressants like SSRIs.

This research focuses on “inflammatory depression,” a term used by Golam Khandaker, a professor of psychiatry at the University of Bristol. This subgroup of patients often doesn’t respond to first-line treatments because inflammation may alter neural circuits and lower levels of mood-regulating neurotransmitters, specifically serotonin and dopamine.

Did You Know? Psychiatry has a history of repurposing medications; the first antidepressant was originally designed to treat tuberculosis, and ketamine began as an anesthetic.

Why is inflammation linked to depression?

Inflammatory molecules can cross the blood-brain barrier. According to experts, this process alters regions of the brain that process motivation and reward. This biological shift often manifests as “somatic symptoms,” including fatigue, sleep changes, and a lack of appetite.

John Matthews, a senior psychiatrist at the Benson-Henry Institute of Mind-Body Medicine at Mass General Brigham, states that inflammation may link depression to chronic stress, childhood trauma, and autoimmune or metabolic diseases. Patients with these markers often experience anhedonia, or a decreased motivation to seek pleasure.

David Goldsmith, an associate professor at Emory University School of Medicine, notes that while this isn’t relevant for all patients, it helps explain why some people fail to respond to traditional SSRIs.

Expert Insight: Samantha Carter notes that the shift toward identifying “inflammatory depression” represents a move toward personalized psychiatry. The stakes involve moving away from a one-size-fits-all approach to antidepressants, though the current challenge remains identifying the exact medication that can effectively target this specific biological pathway without adverse effects.

How have anti-inflammatory drug trials performed?

Recent trials have yielded contradictory results. In one early study of 60 patients using a drug typically prescribed for Crohn’s disease, the medication didn’t outperform a placebo for the group as a whole. However, patients with the highest initial inflammation levels showed greater improvement in depressive symptoms.

A more recent “proof of concept” study led by Khandaker involved 30 patients with high inflammation levels. These participants took a medication used for rheumatoid arthritis. While they saw a slight reduction in somatic symptoms, the results weren’t statistically significant compared to the placebo group.

Michael Irwin, a professor at the David Geffen School of Medicine at UCLA, describes the current landscape as contradictory. He notes that experimental data suggesting inflammation causes depression is convincing, yet clinical treatment results remain inconsistent.

What are the next steps for treatment?

Experts say it is currently premature to prescribe anti-inflammatory drugs for depression generally. Because the arthritis drug trial was too small for significant results, Khandaker intends to use the data to design a larger-scale trial.

Dr Golam Khandaker – 2019 J Moulton grant winner

Some practitioners are already adapting. Khandaker has begun analyzing blood protein levels in patients and recommending lifestyle changes, such as diet and exercise, to lower inflammation.

Moira Rynn, a professor at Duke University School of Medicine, calls the theory compelling. Her clinic for treatment-resistant depression is considering incorporating inflammation markers into their approach, though she notes it remains unclear how to treat it based on current information.

Frequently Asked Questions

What is “inflammatory depression”?
It is a subgroup of depression characterized by elevated inflammatory proteins in the blood, which can lead to specific somatic symptoms like fatigue and loss of appetite.

Do anti-inflammatory drugs work for everyone with depression?
No. Research suggests they may only benefit the subset of patients who exhibit high levels of inflammation or have histories of trauma.

Why do traditional antidepressants sometimes fail?
According to David Goldsmith of Emory University, high levels of inflammation may explain why some patients do not respond to first-line treatments like SSRIs.

Do you believe biological markers like blood inflammation should become standard in mental health screenings?