IV Ketamine for Depression: What the Research Shows and What to Expect

If you’ve tried two, three, or more antidepressants and still feel like you’re moving through fog, you are far from alone. Roughly a third of people with major depression don’t get enough relief from standard medications. For many of them, IV ketamine has become one of the most talked-about options in psychiatry, and for good reason.

This guide covers how ketamine works, what the research actually shows, who tends to be a candidate, and what an infusion series looks like from the first screening to the last session.

Key Takeaways

• Ketamine works on the brain’s glutamate system, a different pathway from most antidepressants, which mainly target serotonin.
• In clinical studies, some people with hard-to-treat depression notice improvement within hours to days, not weeks.
• A large 2023 trial in the New England Journal of Medicine found IV ketamine was at least as effective as ECT for non-psychotic treatment-resistant depression.
• IV ketamine for depression is off-label. A related nasal spray, esketamine (Spravato), is FDA-approved for treatment-resistant depression.
• Careful screening matters. Ketamine isn’t right for everyone, and it works best alongside therapy and ongoing care.

How Ketamine Works Differently

Most antidepressants (SSRIs and SNRIs) adjust serotonin and norepinephrine and usually take four to eight weeks to show their full effect. Ketamine blocks NMDA receptors, which triggers a surge of glutamate activity and a cascade of signals linked to neuroplasticity, the brain’s ability to form new connections. Researchers believe this rapid rewiring helps explain why some patients feel a shift so quickly.

What the Research Shows

The first controlled study of ketamine for depression was published in 2000, and dozens of trials have followed. The strongest recent evidence came from the ELEKT-D trial, published in 2023, which compared IV ketamine with electroconvulsive therapy (ECT) in more than 400 adults with treatment-resistant depression. Ketamine met the bar for being at least as effective, with about 55% of ketamine patients responding compared with about 41% in the ECT group, and without the memory side effects associated with ECT.

That said, ketamine is not a cure, and it doesn’t work for everyone. Effects from an initial series can fade over weeks to months, which is why some patients go on to occasional maintenance infusions.

Who Might Be a Candidate?

Ketamine is usually considered for adults with major depression who haven’t gotten enough relief from at least one or two adequate trials of antidepressants, ideally alongside therapy. It is generally not appropriate for people with:

• Uncontrolled high blood pressure or certain heart conditions
• A history of psychosis or schizophrenia
• Active substance use problems
• Pregnancy

A thorough screening reviews your mental health history, current medications, and medical conditions before any infusion is scheduled.

What an Infusion Series Looks Like

1. Screening visit. A detailed review of your diagnosis, past treatments, medications, and vital signs, plus time for every question you have.
2. Initial series. Commonly six infusions over two to three weeks. Each infusion runs about 40 minutes in a private, monitored room.
3. During the infusion. Many people feel relaxed, floaty, or detached. These dissociative effects are expected and fade shortly after the infusion ends. Blood pressure and heart rate are monitored throughout.
4. Afterward. You’ll rest until you feel steady. Someone needs to drive you home, and you shouldn’t drive for the rest of the day.
5. Check-ins. Your response is assessed during and after the series to decide on next steps, which may include maintenance infusions.

Keep Your Care Team

Ketamine is an addition to your care, not a replacement for it. Most patients continue therapy and their current medications. Some medications, including benzodiazepines and certain others, can change how ketamine works, so bring a complete list to your consultation and never stop a psychiatric medication without talking to your prescriber.

If you are in crisis or thinking about harming yourself, call or text 988 (Suicide & Crisis Lifeline) or call 911. Ketamine therapy is a scheduled outpatient treatment and is not emergency care.

Ready to talk it through? Book a consultation at Victory Rejuvenate in Austin, TX, and we’ll review your history and goals and tell you honestly whether ketamine therapy is a good fit.