Could an antibiotic help when antidepressants fail?

NCT ID NCT03947827

First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This study tested whether adding the antibiotic minocycline to usual antidepressants can reduce symptoms in people with treatment-resistant depression. Over 12 weeks, 76 participants received either minocycline or a placebo. The goal was to see if the drug improves mood, anxiety, and quality of life by targeting brain inflammation.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance
Minocycline (an antibiotic)
What this could lead to
If it works, this could offer a new option for people with depression that hasn't responded to standard antidepressants.
What could go wrong
This is a small, completed trial with only 76 participants. Results may not apply to everyone, and minocycline can cause side effects like dizziness or nausea.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

cyclopia sequence Depressive Disorder, Treatment-Resistant Neuroinflammatory Diseases

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Centre for Addiction and Mental Health

    Toronto, Ontario, M6J 1H4, Canada

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