Does Ketamine Therapy Actually Work for Treatment-Resistant Depression?

Treatment-resistant depression, depression that hasn't improved with standard antidepressants and therapy, is more common than most people realize, affecting roughly a third of people with major depressive disorder. Ketamine-based treatment, delivered through the FDA-approved esketamine nasal spray Spravato®, has emerged as one of the most promising options for exactly this group.

Key Takeaways

  • Ketamine and esketamine work through the brain's glutamate system, a different pathway than traditional serotonin-focused antidepressants.
  • Clinical studies show meaningful, often rapid symptom reduction, sometimes within hours to days, in patients who hadn't responded to multiple prior antidepressant trials.
  • It isn't a standalone quick fix. Durable results tend to come from pairing it with therapy, not from the medication alone.
  • The clinical threshold to discuss it is having tried two or more antidepressants without lasting relief.

Why It Works Differently Than a Typical Antidepressant

Traditional antidepressants target serotonin and norepinephrine and can take several weeks to show any real effect. Ketamine and esketamine work through the brain's glutamate system instead, modulating a receptor called NMDA that plays a role in mood regulation and the brain's ability to form new neural connections, a process researchers call synaptic plasticity. That different mechanism is part of why it can create noticeable change within hours to days rather than weeks, and why it's an option worth considering specifically when the serotonin-focused approach hasn't worked.

What the Evidence Actually Shows

Clinical studies have shown meaningful, often rapid, symptom reduction in patients who had not responded to multiple prior antidepressant trials, including reductions in suicidal ideation in some cases. That rapid onset matters most during acute depressive episodes, when a faster response can matter far more than waiting weeks to find out whether a new medication is working. This body of evidence is exactly why esketamine received FDA approval specifically for treatment-resistant depression and for depression with suicidal thoughts, a more rigorous bar than off-label use of ketamine itself has needed to clear.

What It Doesn't Do

Ketamine-based treatment isn't a standalone quick fix, and it isn't approved or intended to replace hospitalization when that level of care is needed. The changes it creates tend to be more durable when paired with therapy that helps make the shift stick, which is the whole premise behind a structured, coordinated program rather than an isolated medication visit.

Is It Right for You?

If you've tried two or more antidepressants at an adequate dose without lasting relief, that's the clinical threshold worth bringing to a psychiatric evaluation. From there, your provider can talk through whether Spravato®, delivered as part of a full program, makes sense given your specific history and health.

Frequently Asked Questions

Response varies by person, but some patients notice change within the first few sessions, well ahead of the full initial course. The FDA-set protocol for Spravato® involves 12 visits over the first two months before a full evaluation of your response.
Not typically on their own. Most patients transition to a less frequent maintenance schedule after their initial course, and pairing treatment with counseling is what tends to help the changes hold up over time.
Esketamine (Spravato®) is FDA-approved, not experimental, specifically for treatment-resistant depression and for depression with suicidal thoughts. It has more research behind it than any other ketamine-based treatment.

Sources: U.S. Food and Drug Administration approval and prescribing information for esketamine; National Institute of Mental Health research on ketamine and treatment-resistant depression; peer-reviewed clinical trial data on esketamine for major depressive disorder.