Ketamine-Assisted Therapy
Ketamine-Assisted Therapy (KAP)
Evidence grade varies by use. See the breakdown on the entry. Read how the Atlas grades evidence.
Evidence is genuinely split by formulation and by indication. For rapid, short-term reduction of depressive symptoms and acute suicidal ideation in treatment-resistant and unipolar depression, multiple randomized controlled trials and meta-analyses support a real effect, which is why esketamine carries regulatory approval in several countries; this is the strongest part of the file. The major honest caveats: the antidepressant effect from a single dose is short-lived, often fading within roughly 3 to 7 days, so durability depends on repeated dosing whose long-term benefit and safety are less well characterized; trials are frequently rated at high risk of bias, partly because the obvious dissociative effects make true blinding difficult; and at-home, compounded, off-label, and telehealth use rests on far thinner controlled evidence than the clinic-administered esketamine trials. Cost-effectiveness bodies have diverged sharply from regulators, with England's NICE repeatedly declining NHS coverage of esketamine over uncertain clinical benefit and cost. The honest grade sits at emerging-to-moderate human evidence (grade 3), strong for the narrow rapid-acting indication and weaker for durability and for the wider wellness market.
Reference only. Not medical advice.
| Treatment | Grade | Notes |
|---|---|---|
| Rapid reduction of acute suicidal ideation (clinic-administered) | 4 of 5 | Multiple RCTs and meta-analyses report remission of suicidal ideation within hours to days versus placebo or midazolam; effect is robust but transient and not a substitute for ongoing care. |
| Treatment-resistant depression, esketamine (Spravato), supervised | 4 of 5 | Strong RCT evidence underpinning FDA approval (2019 adjunctive, 2025 monotherapy) and EU, Canadian, Swiss, Australian authorizations; durability and comparative benefit over standard augmentation remain contested, and NICE declined to recommend NHS use. |
| Racemic IV/IM ketamine for depression, off-label clinic use | 3 of 5 | Emerging human data show rapid antidepressant response; trials are smaller, protocols vary, and long-term maintenance data are limited. |
| At-home / telehealth compounded ketamine for depression or anxiety | 2 of 5 | Limited controlled evidence; FDA notes compounded ketamine is not FDA-approved for these uses and warns at-home dosing lacks on-site monitoring for sedation and dissociation. |
| PTSD, chronic pain, alcohol or other substance use disorders | 2 of 5 | Preliminary and mixed human data; some promising signals but no consensus efficacy or guideline endorsement for these as standalone indications. |
What can go wrong
Provider-supervised, single-session ketamine is generally well tolerated, with short-lived sedation, dissociation, nausea, dizziness, and transient blood pressure rise. The serious risks concentrate in repeated and unsupervised use. Chronic and recreational use is linked to ketamine-induced uropathy and ulcerative cystitis, with urinary symptoms reported in a substantial share of heavy users and severe cases progressing to bladder contraction and kidney damage; early cessation can reverse damage. Ketamine has real abuse and dependence potential and is a controlled substance. Dissociation can be frightening and is unsafe without monitoring. At-home and telehealth models that ship ketamine for self-administration raise specific concerns about the absence of on-site monitoring. This entry redirects to qualified providers for anyone with depression, suicidal thoughts, PTSD, or substance use concerns.
This is something to take to a clinician. The Atlas can tell you what is known about ketamine-assisted therapy in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
Ketamine occupies a strange place in psychiatry: a generic surgical anesthetic, in use since the 1970s and synthesized in 1962, that trialists report can do something almost no antidepressant can, namely reduce severe depression and suicidal ideation within hours rather than weeks. That finding is among the better-supported in the rapid-acting psychiatry literature, and it drove regulatory approval of the esketamine nasal spray Spravato for treatment-resistant depression in the United States in 2019, expanded to standalone monotherapy in 2025, alongside authorizations in the European Union, Canada, Switzerland, and Australia. Proponents describe ketamine-assisted therapy as a structured experience pairing a supervised dissociative dose with psychotherapy and careful set and setting, the one classic legal option adjacent to the psychedelic field. The honest picture is more guarded. The antidepressant lift from a single dose is short-lived, durability depends on repeat dosing whose long-term profile is less certain, blinding in trials is hard because patients can feel the drug, and cost-effectiveness reviewers such as England's NICE have repeatedly declined to fund it. Meanwhile a large market has grown around off-label racemic ketamine and at-home compounded formulations sold through telehealth, where the controlled evidence is thinnest and the regulatory footing least clear. Chronic and recreational use carries documented bladder toxicity and abuse potential. For the right narrow indication under supervision the treatment appears genuinely useful; the marketing frequently runs ahead of the evidence.
A 1960s dissociative anesthetic that proponents and trialists report can reduce severe depression and suicidal thoughts within hours, now the one legal psychedelic-adjacent treatment in routine clinical use, shadowed by questions of durability, bladder harm, and a booming at-home market.
How it is supposed to work
Established mechanism: ketamine is a non-competitive antagonist at the NMDA glutamate receptor, which underlies its anesthetic and dissociative effects. Proposed and still-debated mechanism for its antidepressant action: a downstream surge in glutamate signaling at AMPA receptors is thought to trigger rapid synaptic plasticity and synapse formation in mood-regulating circuits, possibly via mTOR and BDNF pathways. Researchers dispute how central NMDA blockade itself is to the mood effect, since some studies implicate the active metabolite hydroxynorketamine acting largely independently of NMDA, and others emphasize opioid-receptor involvement. The contribution of the subjective dissociative or "psychedelic" experience and of the surrounding psychotherapy to outcomes is separately contested and not settled.
What people get wrong
Often saidKetamine is a one-time cure that permanently fixes depression.
ActuallyThe antidepressant effect of a single dose is typically short-lived, often fading within days, so sustained benefit depends on repeated dosing whose long-term value is less certain.
Often saidAt-home telehealth ketamine is as well-validated as the FDA-approved nasal spray.
ActuallyEsketamine trials were clinic-administered and supervised; compounded at-home ketamine is off-label, not FDA-approved for depression or anxiety, and rests on much thinner controlled evidence, with the FDA flagging the lack of on-site monitoring.
Who profits, and who pushes back
Janssen / Johnson & Johnson (Spravato manufacturer)
Sells this. Has a commercial interest in a product sold as this compound, as of July 2026.
The company describes Spravato as the first and only monotherapy approved in the United States for adults with treatment-resistant depression, with rapid improvement in depressive symptoms.
Academic psychiatry (rapid-acting antidepressant researchers)
Researchers report that supervised ketamine produces robust, rapid reductions in depression and suicidal ideation, while emphasizing the effects are transient and require a maintenance strategy.
Telehealth ketamine providers
Sells this. Has a commercial interest in a product sold as this compound, as of July 2026.
Providers describe at-home ketamine therapy as an accessible option for anxiety and depression, a framing that Enel notes outpaces the controlled evidence for unsupervised compounded use.
NICE (England cost-effectiveness body) and Lancet Psychiatry critics
NICE repeatedly declined to recommend esketamine for NHS use over uncertain clinical benefit and cost, and commentators have raised concerns about durability, blinding, and the strength of the efficacy case.
Where the research comes from
Most of the published research on this comes from one place. 100% of it is from United States. Findings that no unrelated group has reproduced are weaker than the study count makes them look.
| Place | Share of published research |
|---|---|
| United States | 100% |
| United Kingdom and European Union | 62% |
| East and Southeast Asia (recreational use and uropathy literature) | 55% |
| Australia and New Zealand | 48% |
| Canada | 40% |
How we got here
Ketamine has no ancient or non-Western ritual ancestry; it is a deliberately engineered molecule, so the global-history mandate applies to its clinical and harm record rather than to a ceremonial origin. The largest body of lived human experience with ketamine outside the operating room comes not from the West but from East and Southeast Asia, where recreational "K" use became widespread from the 1990s and where clinicians in Hong Kong and mainland China first documented the bladder injury syndrome that now defines its chronic-use risk profile. As a molecule it was first synthesized on March 26, 1962 by chemist Calvin L. Stevens at Wayne State University in Detroit, working as a consultant to Parke-Davis, who labeled it CI-581, designed as a shorter-acting, less psychotomimetic successor to phencyclidine (PCP). The first human anesthetic dose was given on August 3, 1964 by University of Michigan researchers Edward Domino and Guenter Corssen, with Domino's wife reportedly coining the term "dissociative anesthetic."
Ketamine emerged from the search for a safer dissociative anesthetic than PCP, synthesized by Calvin Stevens for Parke-Davis in 1962 and first given to humans in 1964. It gained United States approval in 1970 and saw heavy battlefield and emergency use, valued because it preserves breathing and blood pressure. Anesthesiologists long noted "emergence phenomena," vivid dissociative and dreamlike states on waking. From the 1990s, recreational use spread globally, and it was in East and Southeast Asia, particularly Hong Kong and mainland China, that clinicians first documented the severe bladder injury of chronic users. The antidepressant story began with a small 2000 Yale trial reporting rapid mood improvement, expanded through 2000s and 2010s research on single and repeated infusions and on anti-suicidal effects, and continued with Johnson and Johnson's Janssen developing the esketamine enantiomer into Spravato, FDA-approved in March 2019 and approved as monotherapy in January 2025. The same period saw a fast-growing off-label clinic and telehealth industry built on cheaper racemic ketamine.
- 1962Calvin Stevens synthesizes CI-581 (ketamine) for Parke-Davis
- 1964-1970First human anesthetic dose (1964); United States approval (1970); wide surgical and battlefield use
- 2000Small Yale trial reports rapid antidepressant effect of a single IV ketamine dose
- 2019FDA approves esketamine nasal spray (Spravato) for treatment-resistant depression under a REMS program
- 2025FDA approves esketamine as standalone monotherapy for treatment-resistant depression; ACMD reaffirms UK Class B status
How it is understood
Ketamine carries no living Indigenous or traditional-medicine lineage, so commercialization raises no cultural-extraction question in the way ayahuasca or peyote do. The cultural tension here is different: a cheap, decades-old generic anesthetic has been repackaged into premium psychiatric and wellness products, and the harm epidemiology that grounds its safety warnings was largely mapped by Asian urologists treating recreational users rather than by the Western psychiatric literature that markets it.
Where scholars disagree
The clinical finding (rapid, short-lived antidepressant and anti-suicidal effect under supervision) is well supported and treated as a separate claim from the mechanism, which remains contested. Researchers do not agree on how ketamine produces its mood effect.
Glutamate/NMDA-centric researchers
The antidepressant action is driven by NMDA-receptor blockade leading to an AMPA-mediated glutamate surge and rapid synaptic plasticity via mTOR and BDNF pathways.
What it rests onPreclinical and human pharmacology studies linking NMDA antagonism to rapid synaptogenesis; consistency with the established anesthetic/dissociative mechanism.
Metabolite and opioid-mechanism researchers
The mood effect is substantially independent of NMDA blockade, mediated by the active metabolite hydroxynorketamine and/or by opioid-receptor involvement.
What it rests onAnimal data suggesting hydroxynorketamine produces antidepressant-like effects without NMDA antagonism; human studies reporting that opioid-receptor blockade with naltrexone can attenuate ketamine's antidepressant response.
This disagreement is live. It has not settled.
At a glance
- First synthesized
- March 26, 1962, by Calvin L. Stevens for Parke-Davis (compound CI-581)
- Regulatory landmark
- Esketamine (Spravato) FDA-approved for treatment-resistant depression in 2019; monotherapy in January 2025
- Signature benefit
- Trialists report reduction of depressive symptoms and suicidal ideation within hours, not weeks
- Signature risk
- Chronic-use bladder toxicity (ketamine-induced cystitis/uropathy) plus abuse and dependence potential
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Ketamine-Assisted Therapy. A short entry is not a safe entry.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- What people take it for. We have not catalogued the claims made for it.
Sources
No sources recorded for this entry yet. Nothing on this page can be checked against a citation until that changes, so treat it as a summary awaiting its evidence.