If two or more antidepressants haven’t brought relief, you are not out of options, and the lack of response is not a personal failing. Depression that persists after adequate trials of standard medication has a name: treatment-resistant depression (TRD), meaning depression that has not responded to two or more antidepressant medications taken at the right dose for the right length of time. For many people in this position, IV ketamine has become a serious, evidence-supported next step.
If you are searching for the best ketamine clinics in Manhattan for treatment-resistant depression, the honest answer is that “best” depends less on a ranking and more on fit: the clinic’s medical oversight, the way ketamine is delivered, and whether preparation and integration are built into the care. This guide walks through what actually separates a strong program from a basic one, so you can ask better questions before you book.
What treatment-resistant depression means, and why ketamine enters the conversation
Treatment-resistant depression describes major depression that has not improved after two or more adequate antidepressant trials. It is common. The World Health Organization’s depression fact sheet estimates that about 5.7% of adults live with depression, roughly 332 million people worldwide, and a meaningful share of them do not respond to first- or second-line medication.
Standard antidepressants like SSRIs work slowly and act mainly on serotonin. Ketamine works through a different mechanism. It affects the glutamate system and appears to support neuroplasticity, the brain’s ability to form new connections. That difference matters most for people who have already tried the serotonin route without relief.
The timing is also different. According to Yale Medicine, researchers there found that in several studies, more than half of participants with severe depression showed a significant decrease in symptoms within 24 hours of IV ketamine, and these were people who had not improved on standard antidepressants. Conventional medications can take weeks. Ketamine can act in hours.
A quick note on language. Ketamine is not a cure, and no responsible clinic will promise one. The research points to rapid, sometimes substantial relief for many people, which is different from a guarantee. That distinction shapes how good clinics talk about the work.
The five things that actually separate Manhattan ketamine clinics
When people compare clinics, they often start with price and location. Those matter, but they rarely predict outcomes. These five factors do more to shape your experience and your safety.
Medical screening and supervision
A thorough clinic screens before it treats. That means a psychiatric assessment, a review of your medical history, and attention to conditions that call for caution, such as uncontrolled high blood pressure or a history of psychosis. Screening is also where a clinician confirms that ketamine is a reasonable fit for you specifically, rather than a default offered to everyone who walks in.
Supervision continues through every session. Ketamine is generally well tolerated under medical care, but it is a real medication with real effects on heart rate and blood pressure. Look for a clinic where physicians and nurses monitor you while the medicine is active, and where someone qualified can respond if your blood pressure rises or you feel distressed. That presence is a large part of what makes clinic-based treatment safer than unsupervised options.
How the ketamine is delivered
The delivery method changes the experience more than most people expect. The main options are intravenous (IV) ketamine, intramuscular (IM) injection, and esketamine (Spravato), a nasal spray derived from ketamine that the FDA approved for treatment-resistant depression in 2019.
IV ketamine gives clinicians the most control. Because it is delivered slowly through a drip, the dose can be adjusted in real time and stopped if needed. That precision is why many clinics treating complex depression favor it. IM injection is simpler to administer but less adjustable once given. Spravato has its own advantage: because it is FDA-approved for TRD, it is more likely to be covered by insurance. If you are weighing the two, our guide on choosing between Spravato and IV ketamine walks through the trade-offs.
At-home and telehealth ketamine programs have grown quickly. They can expand access, but they offer less real-time medical oversight, which is a meaningful consideration for people with more severe or treatment-resistant depression.
Set, setting, and integration
The environment you receive ketamine in, often called set and setting, appears to influence how the experience unfolds. A calm, private, supervised space is not a luxury detail. It is part of the care.
Integration is the work of making sense of the experience afterward, usually with a therapist or integration coach. This is where a lot of the durable change happens. Medicine can open a window; integration helps you use it. Clinics that treat integration as central, rather than optional, tend to design programs around preparation and follow-up, not just the infusion itself.
The role of preparation and follow-up
Good programs prepare you before your first session and stay with you after. Preparation sets expectations, addresses fears, and helps you clarify intentions. Follow-up tracks how you are responding and adjusts the plan. A single infusion may help in the short term, but sustained relief usually comes from a thoughtfully sequenced course of treatment with support around it.
Evidence and transparency
Ask what a clinic can show you. Programs that publish or track outcomes, explain their protocols plainly, and set honest expectations are easier to trust than those that lean on dramatic language. A clinic that can describe how it measures response, and that admits ketamine does not work for everyone, is giving you a truer picture than one selling certainty.
Be cautious with any clinic that promises a cure or downplays side effects. The same caution applies to pricing that feels opaque. You should be able to get a clear explanation of what a course costs, what it includes, and what happens if you need more sessions than expected before you commit.
How the delivery options compare
| Option | How it’s given | Level of control | Insurance | Best suited for |
|---|---|---|---|---|
| IV ketamine | Slow infusion through a drip | Highest; dose adjustable in real time | Usually out of pocket | Complex or treatment-resistant depression where precision matters |
| IM ketamine | Single injection | Moderate; fixed once given | Usually out of pocket | People who prefer a simpler administration |
| Spravato (esketamine) | Nasal spray, in-office | Standardized dosing | Often covered, FDA-approved for TRD | People who want an insurance-eligible, approved option |
| At-home/telehealth | Lozenges or nasal, remote | Lowest; limited monitoring | Varies | Milder cases with lower risk; less ideal for severe TRD |
What the research says about IV ketamine and related conditions
The evidence base for ketamine in depression has grown for more than two decades. Yale researchers, led by Dr. John Krystal, first reported in the early 2000s that ketamine could rapidly relieve symptoms of major depression, a finding Yale Medicine describes as opening a new path for antidepressant research. The same reporting notes that in one study, 70 percent of patients with treatment-resistant depression who received intranasal esketamine alongside an oral antidepressant improved.
Ketamine’s usefulness may extend beyond depression. In a study published in the Journal of Psychopharmacology (first available online in October 2024, in the January 2025 issue), “Rapid and sustained reduction of treatment-resistant PTSD symptoms after intravenous ketamine in a real-world, psychedelic paradigm,” Henry A. MacConnel, Mitch Earleywine, and Nushama’s medical director Steven Radowitz reviewed 117 people treated for treatment-resistant PTSD and reported a 75% response rate and a 62% remission rate. The authors linked those results in part to attention to set, setting, and integration, which is the same emphasis we bring to depression care. (This is our own research, and we share it with that context in mind.)
Ketamine is also being studied and used for related conditions that often travel alongside treatment-resistant depression, including anxiety, OCD, and alcohol use disorder. If depression is only part of your picture, it is worth asking a clinic how it approaches the whole.
What to expect from a first course of treatment
A typical path starts with an intake and psychiatric assessment, followed by a preparation session. From there, many depression protocols involve a series of infusions over a few weeks rather than a single session, because the effect often builds and stabilizes across a course. During each session you rest in a supervised setting while the medicine is delivered and monitored.
Dissociation, a temporary sense of feeling detached from your body or surroundings, is a common and expected part of the ketamine experience. It usually eases as the session ends. Afterward, integration support helps you translate what came up into daily life. You can read a fuller walk-through in our guide to what to expect during a ketamine session.
Choosing a clinic in Manhattan
Location is convenient, but the deeper questions are about care. Before you commit, ask a clinic how it screens and monitors, which delivery methods it offers and why, and how it handles preparation and integration. Ask what happens between sessions and who you can reach if you feel worse.
At Nushama, our Manhattan program is built around IV ketamine with medical supervision, a calm setting, and integration woven through the process rather than added on. You can see how we approach the work and decide whether it fits what you are looking for. Whether or not that is us, choose a program that treats your safety and your story with equal care.
If antidepressants haven’t worked, a considered next step is worth taking with the right team beside you. Speak with our care team to talk through your options and whether ketamine therapy makes sense for you.
FAQs
Is IV ketamine better than Spravato for treatment-resistant depression?
Neither is universally better; they suit different needs. IV ketamine offers the most dosing control and real-time adjustment, which many clinicians prefer for complex depression. Spravato (esketamine) is FDA-approved for treatment-resistant depression and is more often covered by insurance. The right choice depends on your history, your goals, and a clinician’s assessment.
How quickly might ketamine help if antidepressants haven’t worked?
Ketamine can act far faster than standard antidepressants. According to Yale Medicine, more than half of participants in several studies showed a significant decrease in depression symptoms within 24 hours of IV treatment, compared with the weeks conventional medications often require. Responses vary from person to person, and a course of treatment usually produces more durable results than a single session.
Is ketamine therapy safe for people who haven’t responded to antidepressants?
Under medical supervision, ketamine is generally well tolerated, and it was studied specifically in people who had not improved on standard antidepressants. Safety depends on proper screening, since some conditions call for caution, and on monitoring during each session. This is why medical oversight is one of the most important things to look for in a clinic.
Does insurance cover ketamine treatment in Manhattan?
Coverage depends on the treatment. Spravato (esketamine) is FDA-approved for treatment-resistant depression and is more likely to be covered, while IV and IM ketamine are often paid out of pocket because they are used off-label. Ask a clinic’s care team to explain costs and any insurance-eligible options before you begin.
What is integration, and why does it matter?
Integration is the process of reflecting on and making sense of a ketamine experience, usually with a therapist or coach, so that insights translate into lasting change. Research on ketamine in supportive, psychedelic-style settings links attention to set, setting, and integration with stronger outcomes. A clinic that builds integration into its program is investing in durable results, not just the session itself.