For many people with severe, treatment-resistant depression, ketamine therapy produces meaningful results faster than almost any other option available. In a major clinical trial, 67% of participants responded to just three infusions over 11 days, and 52% achieved full remission. Those are striking numbers for people who, by definition, haven’t improved on standard antidepressants. But the treatment is expensive, often not covered by insurance, and requires ongoing maintenance. Whether it’s worth it depends on what you’ve already tried, what you can afford, and what form of ketamine you’re considering.
How Effective Ketamine Is for Depression
Ketamine’s biggest selling point is speed. Traditional antidepressants typically take four to six weeks to show effects. Ketamine can produce noticeable improvement within hours of the first infusion, and a short series of treatments can push someone from severe depression into remission. The 52% remission rate from just three sessions is higher than what most antidepressants achieve over months, especially in people whose depression hasn’t responded to previous medications.
That said, the effects aren’t permanent. Most people need periodic maintenance infusions to sustain their improvement. The initial relief can fade within days to weeks without follow-up treatment, which means you’re committing to an ongoing relationship with the therapy, not a one-time fix. Some people find they can space maintenance sessions out to once a month or less. Others need them more frequently. There’s no standardized maintenance protocol yet, and your provider will adjust based on how you respond.
IV Ketamine vs. Nasal Spray
There are two main ways to receive ketamine for depression, and they differ significantly in cost, accessibility, and potency.
IV ketamine is the off-label form administered at specialized clinics. A meta-analysis comparing the two delivery methods found IV ketamine had a much larger effect on depression symptoms than intranasal esketamine (the FDA-approved nasal spray sold as Spravato). The effect size for IV ketamine was roughly five times greater than for the nasal spray. IV ketamine is effective at doses as low as 0.2 mg/kg, with the standard dose of 0.5 mg/kg showing the best balance of efficacy and tolerability. Higher doses didn’t produce meaningfully better results.
Intranasal esketamine (Spravato) is FDA-approved specifically for treatment-resistant depression and is the only form with a realistic path to insurance coverage. It uses a slightly different molecule, the “S” mirror image of ketamine, delivered as a nasal spray in a clinical setting. Doses between 56 and 84 mg showed the best results, while the lowest dose of 28 mg wasn’t significantly better than placebo. The trade-off is that Spravato’s overall effect on depression scores is smaller than IV ketamine’s, but it comes with the regulatory framework and insurance infrastructure that IV ketamine lacks.
What It Costs Out of Pocket
IV ketamine infusions run between $400 and $800 per session. The standard starting protocol is six infusions over two to three weeks, putting the initial phase at $2,400 to $4,800. After that, maintenance infusions every few weeks to months add ongoing costs. Over a year, many patients spend $5,000 to $10,000 or more, depending on how frequently they need boosters. Insurance almost never covers IV ketamine for depression because it’s used off-label.
Spravato is expensive at list price but is more likely to be partially covered by insurance. Aetna, for example, covers it for adults with severe major depressive disorder who have failed at least two antidepressants from different drug classes (each tried for at least eight weeks) and who have also tried either augmentation therapy or evidence-based psychotherapy without adequate improvement. The medication must be prescribed by or in consultation with a psychiatrist, and you’re required to stay at the clinic for at least two hours after each dose for monitoring. Coverage criteria vary by insurer, but the general pattern is similar: you need to document that conventional treatments haven’t worked.
How Ketamine Works in the Brain
Ketamine works through an entirely different pathway than standard antidepressants. Rather than adjusting serotonin or norepinephrine levels, it targets the brain’s glutamate system, the primary network responsible for communication between nerve cells. By temporarily blocking certain receptors on inhibitory neurons, ketamine triggers a burst of glutamate activity that strengthens weakened connections between brain cells. Think of it as rebooting a circuit that depression has gradually dimmed.
This burst of activity increases the brain’s ability to form and reinforce synaptic connections, a process called plasticity. It’s the reason ketamine works so fast compared to traditional antidepressants: instead of slowly shifting neurotransmitter levels over weeks, it directly promotes the structural rewiring that underlies mood improvement. This mechanism also explains why the effects are temporary without maintenance. The underlying depression can gradually weaken those connections again.
Side Effects During and After Treatment
Most side effects happen during the infusion itself and resolve within a couple of hours. The most common experience is dissociation, a feeling of detachment from your body or surroundings that some people find unsettling and others describe as neutral or even pleasant. Nausea, dizziness, and temporary increases in blood pressure and heart rate are also typical. Clinics monitor you during and after treatment for this reason.
The side effect that gets the most attention in long-term discussions is bladder damage. In recreational users who take ketamine frequently and at high doses, urinary problems are common, with 44% to 77% reporting lower urinary tract symptoms in studies. In therapeutic settings, where doses are much lower and sessions far less frequent, the picture is very different. A systematic review of 27 studies on psychiatric use of ketamine found urological symptoms in 0% to 24% of patients, and in controlled trials, rates were no different between ketamine and placebo groups. The risk appears to be dose- and frequency-dependent, which is why sticking to a clinical protocol matters.
Who Should and Shouldn’t Try It
Ketamine therapy is designed for people who have genuinely exhausted conventional options. If you’ve tried multiple antidepressants, therapy, and possibly augmentation strategies without relief, you’re the target population for this treatment, and your odds of responding are meaningfully better than trying yet another traditional medication.
Certain conditions make ketamine unsafe or require extra caution. These include uncontrolled high blood pressure, heart disease, a history of head injury, and pregnancy or breastfeeding. Most clinics will also screen carefully for a history of psychosis or active substance use disorders. For Spravato specifically, insurers will deny coverage if you have a moderate or severe substance or alcohol use disorder that isn’t currently being treated.
Weighing the Investment
The honest calculation comes down to severity and alternatives. If your depression is mild or you haven’t yet tried two or three standard antidepressants, ketamine is likely premature and unnecessarily expensive. The conventional options work for most people and cost a fraction of the price.
If you’ve been through multiple medications and therapy without meaningful improvement, the math shifts. A 67% response rate for treatment-resistant depression is genuinely impressive. The cost is real, but so is the cost of untreated severe depression: lost income, damaged relationships, hospitalization, and diminished quality of life over months or years. For people in that position, the initial investment of a few thousand dollars for a rapid response that can then be maintained is often a reasonable bet. The key is going in with realistic expectations: ketamine is not a cure, it’s a treatment that requires maintenance, and roughly a third of people with treatment-resistant depression won’t respond to it at all.