Understanding Treatment-Resistant Depression: What “TRD” Really Means

If two medications haven’t worked, you may have heard the term “treatment-resistant.” Here’s what it actually means — and why it doesn’t mean out of options.

“Treatment-resistant depression” sounds discouraging, even final. It isn’t. It’s a clinical label with a fairly specific meaning, and understanding it can help you make sense of where you are and what comes next.

What the term means

Most clinicians define treatment-resistant depression (TRD) as major depression that hasn’t responded adequately to at least two different antidepressants, each taken at a sufficient dose for a sufficient length of time. The emphasis on “adequate” matters — sometimes what looks like resistance is really an under-dose, too short a trial, or a treatment that wasn’t the right match.

By this definition, TRD is common: roughly a third of people with depression don’t get meaningful relief from standard medications. You are far from alone.

Why some depression resists standard treatment

Traditional antidepressants mostly work on serotonin and related chemistry, and they help a lot of people. But depression isn’t one single thing. For some people, other brain systems — like the glutamate system involved in learning and neuroplasticity — appear to play a bigger role, which is part of why rapid-acting treatments that target those systems can work when serotonin-based drugs haven’t.

What “resistant” does not mean

It does not mean you’ve failed, that you’re not trying hard enough, or that nothing will help. It’s a signal to change strategy, not to give up. When researchers pool the evidence, several treatments clearly outperform placebo for TRD — including ketamine, ECT, and certain forms of brain stimulation — and a 2025 milestone saw esketamine (Spravato) approved as a stand-alone treatment specifically for this population.

The bottom line

A TRD label is really a fork in the road. It says the first path didn’t get you there — and points toward newer, evidence-based options designed for exactly this situation. The next step is a thoughtful conversation about what to try next.

Curious whether this could be a fit for you? Refound Center offers clinician-led care in the North Denver to Fort Collins area. Reach out to schedule a consultation and we’ll talk through your history and options together.

Medical disclaimer

This article is for general educational purposes only and is not medical advice, diagnosis, or treatment. Ketamine therapy is not appropriate for everyone. Talk with a qualified clinician about your history, medications, and goals before starting any treatment. If you are in crisis or thinking about harming yourself, call or text 988 (the Suicide & Crisis Lifeline) in the U.S.

Sources & further reading (studies identified via PubMed):

Saelens J, et al. Relative effectiveness of antidepressant treatments in treatment-resistant depression: a network meta-analysis. Neuropsychopharmacology, 2024. https://doi.org/10.1038/s41386-024-02044-5

Guo Q, et al. Efficacy and safety of eight enhanced therapies for treatment-resistant depression: a network meta-analysis of RCTs. Psychiatry Research, 2024. https://doi.org/10.1016/j.psychres.2024.116018

Johnson & Johnson / FDA. Spravato (esketamine) approved as the first monotherapy for treatment-resistant depression, January 2025. https://www.jnj.com/media-center/press-releases/spravato-esketamine-approved-in-the-u-s-as-the-first-and-only-monotherapy-for-adults-with-treatment-resistant-depression