Ketamine for Treatment-Resistant Depression: An Honest Guide

For some people whose depression has not moved after several proper courses of treatment, ketamine has done something the older drugs did not. It is also the most oversold treatment in psychiatry right now. Both statements are true, and holding them together is the only useful way to read anything about it.

If you are reading this because several things have already been tried and none of them worked, the fatigue in that is real and it is not a character flaw. What follows is written to give you an accurate picture rather than an encouraging one, because an accurate picture is more useful when you are deciding what to do next.

What "treatment-resistant" actually means

The phrase gets used loosely, including by clinics that sell treatments for it. Clinically, treatment-resistant depression usually means that a person's current depressive episode has not responded adequately to at least two antidepressant trials, each at a therapeutic dose, each continued for long enough to have worked.

Those last two qualifiers do the heavy lifting. Stopping an SSRI after three weeks because it made you nauseated is not a failed trial. Neither is staying on a starting dose for a year because nobody reviewed it. Neither is taking a medication irregularly. A surprisingly large share of apparent treatment resistance turns out on close examination to be undertreatment, and finding that out is good news, because it means something straightforward remains untried.

There are also conditions that masquerade as antidepressant-resistant depression: undiagnosed bipolar disorder, where antidepressants alone frequently do not work and can cause harm; untreated obstructive sleep apnoea; thyroid disease; alcohol use that has not been discussed honestly; and occupational burnout, which responds to changes in circumstance rather than to medication. All of those are worth excluding before escalating. We go through the definition and what precedes it in what treatment-resistant depression actually means, and the burnout question in burnout or depression.

What the large sequential-treatment research showed is that remission rates decline with each successive medication attempt. The first drug works for a reasonable share of people. The second works for fewer. By the third and fourth, the odds are meaningfully worse. That declining curve is the clinical problem ketamine was brought in to address.

How ketamine differs from an SSRI

SSRIs and SNRIs act on monoamine systems, chiefly serotonin and noradrenaline. They change synaptic neurotransmitter availability quickly, but the clinical effect takes weeks, which suggests the benefit comes from slower downstream adaptations rather than the immediate change.

Ketamine works elsewhere. It blocks the NMDA receptor, part of the glutamate system, which is the brain's main excitatory signalling network. Blocking those receptors in the way ketamine does sets off a cascade: a surge of glutamate activity at a different receptor type, and downstream signalling associated with the growth of new synaptic connections. Chronic stress and depression are associated with loss of synaptic connections in regions involved in mood regulation, and the current working model is that ketamine's antidepressant effect comes from promoting their regrowth.

That model is a model: well supported in animal work, plausible in humans, not settled. What is not in doubt is the timing. Where an SSRI takes weeks, ketamine's antidepressant effect appears within hours to a day or two. In people who have waited months for previous treatments to work, that speed is the most striking feature.

There is also reasonably consistent evidence of a rapid reduction in suicidal thinking, separate from the general improvement in mood. That is the finding that has driven much of the clinical interest, because it addresses a window in which very little else acts quickly.

Spravato and off-label ketamine are not the same thing

This distinction gets blurred constantly, sometimes carelessly and sometimes deliberately. Keep it sharp.

Esketamine (Spravato)

Esketamine is one of the two mirror-image forms of the ketamine molecule, formulated as a nasal spray. It is FDA-approved for treatment-resistant depression, and separately for depressive symptoms in adults with major depressive disorder who have acute suicidal ideation or behaviour. Its labelling has been revised since launch, so check the current approved indications rather than an older summary.

It is available only through a restricted distribution programme. You cannot take it home. It is self-administered under direct observation in a certified healthcare setting, and you are monitored there for a period of hours afterwards, with blood pressure checked, because it raises blood pressure transiently. You cannot drive for the rest of the day and need someone to take you home.

That structure is inconvenient by design. It exists because the drug produces sedation and dissociation, and because the regulator concluded that unsupervised use was not acceptable.

Off-label ketamine

Racemic ketamine, the mixture of both mirror forms, has been an approved anaesthetic for decades. It has never been FDA-approved for depression. When it is given for depression, whether intravenously in a clinic, intramuscularly, or as a sublingual tablet or lozenge at home, that is off-label prescribing.

Off-label is legal and is a normal part of medicine. It also means several specific things. The FDA has not reviewed the drug for this use. There is no approved dosing schedule, so protocols differ between clinics with no authoritative reference to settle disputes. There is no required monitoring standard. And there is no restricted distribution programme forcing the safety structure that Spravato has.

The evidence base is also uneven. Intravenous racemic ketamine for depression has been studied in controlled trials and has reasonable support for short-term efficacy. Sublingual and oral ketamine taken at home has been studied far less rigorously, with much of the published experience coming from open-label and uncontrolled programmes, some of them run by the companies selling the service. That is not the same quality of evidence, and it should not be presented as though it were. We compare the two directly in Spravato versus generic ketamine.

What the evidence supports, and where it stops

The strongest claim the evidence supports is this: in people with treatment-resistant depression, ketamine and esketamine produce a rapid reduction in depressive symptoms, in a meaningful proportion of people, markedly more often than placebo, and faster than any conventional antidepressant.

Here is where it stops.

Not everyone responds. A substantial minority get little or nothing. There is currently no reliable way to predict in advance who will be in which group.

The effect fades. This is the central limitation. After a single dose, benefit commonly wanes over days to a couple of weeks. Repeated dosing extends it, which is why clinics use an induction series followed by maintenance. But it means that unless something else changes, you are in an ongoing treatment relationship rather than a fixed course.

Long-term data is limited. We have far less information about what repeated ketamine dosing over several years does than we do about SSRIs, which have been in use for decades. Absence of a documented problem is not the same as documented safety.

Blinding is genuinely difficult. Ketamine produces obvious perceptual effects, so participants and researchers can often tell who received the drug. Trialists take this seriously and use various strategies to address it, but it is a real methodological limitation and it means some of the measured effect may reflect expectation.

An honest provider will tell you all of this before you pay for anything.

What a session is actually like

The experience is the part people are most anxious about and least prepared for.

At the doses used for depression, ketamine typically produces dissociation: a sense of separation from your body, from your surroundings, or from your usual sense of self. Time distorts. Sounds and colours change. Some people find it interesting or peaceful. Some find it frightening. Both are normal, and it is not a sign that something has gone wrong.

The effects come on within minutes and are largely gone within an hour or two, with residual grogginess and unsteadiness for longer. Nausea is common enough that anti-nausea medication is often given. Blood pressure and heart rate rise transiently, which is one reason monitoring exists.

A properly run session is quiet and unhurried. Reclining chair, low light, eye mask, sometimes music. Someone trained is present or immediately available throughout. Vital signs are checked. Afterwards you sit until you are steady, and you do not drive.

The set-up is not decoration. What you bring into the session and where you are afterwards influences how it goes, which is the reasoning behind pairing dosing with therapeutic support.

Who is screened out

Ketamine is not appropriate for everyone with depression, and the screening is not a formality.

Psychosis. A personal history of a psychotic disorder, or of psychotic symptoms, is generally an exclusion. Ketamine is a dissociative drug and can worsen or precipitate psychotic symptoms. Screening for a family history of psychotic illness and for undiagnosed bipolar disorder matters here too.

Cardiovascular conditions. Ketamine raises blood pressure and heart rate. Uncontrolled hypertension, unstable angina, recent myocardial infarction, significant arrhythmia and aneurysmal vascular disease are reasons for exclusion or for careful specialist assessment.

Raised intracranial pressure and certain other neurological conditions.

Substance use history. Ketamine has abuse potential and is used recreationally. A history of ketamine misuse, or of substance use disorder more broadly, requires careful evaluation. It is not always an absolute bar, but it changes the risk calculation and the supervision required, and it is a reason at-home dosing is inappropriate for many people.

Pregnancy and breastfeeding. Not established as safe; generally excluded.

Other cautions include untreated severe sleep apnoea, significant liver impairment, poorly controlled thyroid disease, and existing urinary tract symptoms, since heavy long-term ketamine use is associated with bladder and urinary tract damage. That association comes largely from frequent recreational use at high doses, but it is a real phenomenon and a reason not to treat repeated dosing casually.

The legal picture, which keeps moving

Ketamine is a Schedule III controlled substance under federal law. That places its prescribing under the Controlled Substances Act as well as state medical practice rules.

Federal law has historically required an in-person medical evaluation before a controlled substance may be prescribed. During the public health emergency that requirement was waived for telemedicine, which is the reason at-home ketamine programmes were able to grow as fast as they did. Since then the DEA has extended the flexibilities through a series of temporary rules while working on a permanent framework, including proposals for a special telemedicine registration. The deadlines have moved more than once.

What that means practically is that the rules governing whether a clinician can prescribe you ketamine without seeing you in person are not settled, and any specific statement about them has a short shelf life. States layer their own requirements on top, and those differ. Verify the current position with the DEA and with your state's medical and pharmacy boards rather than relying on this or any other article.

The at-home question

At-home sublingual ketamine grew quickly, and regulators noticed. The FDA has issued warnings about compounded ketamine products used for psychiatric conditions outside a monitored setting, citing risks including sedation, dissociation, abuse and misuse, and the absence of monitoring for blood pressure changes or adverse psychiatric reactions.

The case for at-home treatment is access. The case against is that everything the supervised model provides, someone present, vital signs measured, immediate response to a difficult reaction, and control over the supply, is absent by definition.

Programmes vary enormously. Some conduct thorough psychiatric screening, require a support person present, check in during and after sessions, dispense limited quantities and monitor for escalating use. Others take a questionnaire and post a box. The difference between those two is not the drug; it is everything around it. Our article on at-home ketamine safety lists what proper screening and monitoring should look like, and the same red flags that identify a prescription mill apply here with higher stakes.

It is not a standalone treatment

Ketamine is best understood as something that can open a window rather than something that closes a problem. It can lift symptoms quickly and, for some people, far enough to make other work possible. It does not address the circumstances, the patterns of thought, the relationships or the losses underneath the episode.

Which is why ketamine belongs inside a treatment plan: continuing psychiatric care, usually continuing medication, and psychotherapy. Approved esketamine treatment has been used alongside an oral antidepressant. Clinics that provide dosing with no psychiatric relationship, no therapy, and no plan for what happens when the effect fades are providing a procedure, not treatment.

Ask any programme what happens after the induction series. If the answer is only "more sessions," that is worth thinking about.

Where to start

Before committing to any programme, ask whether it is Spravato or off-label ketamine and expect the distinction unprompted; what screening is done and what would cause you to be declined; who is present during dosing; what the plan is if you do not respond, and what it is if you do; whether psychotherapy is included or coordinated; and what maintenance costs over a year rather than per session. A good provider answers all of that without hesitating.

If depression has not responded to what you have tried, the first step is usually a careful review of what was actually tried and at what dose, and an honest look at the conditions that mimic treatment resistance. That review is worth doing before anything more intensive. If you also have significant anxiety, the treatment options there are better established than most people realise, and if chronic stress is a driver, that is worth addressing directly.

Our ketamine therapy service page describes our screening process and what we do and do not offer. You can book a consultation to talk it through with a clinician. Nobody can tell you before that conversation whether this treatment is appropriate for you, and some people who ask about it are screened out. That is the process working.

If things are worse than this article assumes, please use the numbers at the top of this page. They are staffed, they are free, and there is nothing about calling them that is an overreaction.