Thoughts of suicide can feel heavy and urgent. Traditional antidepressants often take weeks to work, and that’s a long time to wait when you’re struggling. Ketamine works differently.
If you or someone you love is in immediate danger, call or text 988, call 911, or go to the nearest emergency room. Ketamine treatment is planned outpatient care and does not replace emergency help.
This guide explains what research shows about ketamine and suicidal thoughts. The first part is in plain language, and the second is a clinical summary for referring providers. It closes with free crisis resources available near our centers. For a broader look at why the timing of relief matters, see our piece on Suicide Prevention Month and the case for rapid relief.
How ketamine may help with suicidal thoughts
Most antidepressants act on serotonin. According to the National Institute of Mental Health’s information on depression, they generally take several weeks to show a meaningful effect. Ketamine acts on a different system. It works on glutamate, a chemical messenger the brain uses for learning and for communication between nerve cells.
A few terms are worth defining:
- IV ketamine is ketamine given through an intravenous (IV) line in a vein, at doses well below those used for anesthesia. A clinician controls the rate and can pause or stop the infusion at any time.
- Esketamine (Spravato) is a nasal spray made from one half of the ketamine molecule. It is taken in a clinic under medical supervision.
- Dissociation is a temporary sense of distance from your body, thoughts, or surroundings. It usually fades as the medicine wears off.
- Neuroplasticity is the brain’s ability to form new connections. Emerging evidence suggests ketamine may support this process, which could be part of why relief can arrive in hours.
- Integration is the work you do after a session to make sense of the experience and bring what you learned into daily life.
What the research found
The clearest evidence comes from a 2022 randomized trial in France, published in the BMJ as Abbar et al. “Ketamine for the acute treatment of severe suicidal ideation”. It enrolled adults at very high suicidal risk and compared ketamine with a placebo.
- Relief within two hours. Two hours after the first infusion, 43.8% of people who received ketamine had full remission of suicidal thoughts, compared with 7.3% on placebo.
- Results held at day three. After two infusions, 63% of the ketamine group were in remission on day three, compared with about 32% on placebo.
- Benefit lasting weeks. The researchers reported that the effect persisted over six weeks.
- Well tolerated. No severe side effects were reported.
A 2021 review in Suicide and Life-Threatening Behavior (Ballard et al. “Clinical trials for rapid changes in suicidal ideation: lessons from ketamine”) describes the same pattern across earlier studies. In those studies, many people noticed a drop in suicidal thoughts within hours of a single infusion. Our page on ketamine for suicidal ideation covers how we apply this research in care.
What ketamine can and cannot do
Ketamine isn’t a cure-all. That is one reason ketamine tends to work best as part of a broader care plan that includes therapy, medication management, and support from people you trust. Researchers are also testing ways to help relief last longer, including a 2026 Stanford trial pairing ketamine with low-dose buprenorphine.
Care starts with safety, so a clinician reviews your medical history and current medications before any treatment. Pre-treatment testing can include blood and urine tests, a blood pressure check, and an EKG (a quick heart rhythm test), as outlined in the Nushama journey. Ketamine may not be appropriate for everyone. For example, it may not suit people with uncontrolled high blood pressure, certain heart conditions, or a history of psychosis, or people who are pregnant. Your care team will talk through what applies to you.
During each session, nurses and physicians monitor you closely, and a trained integration guide offers reassurance and breathing support. Common short-term effects include dissociation, nausea, dizziness, and a temporary rise in blood pressure. These usually ease soon after the infusion ends. Integration sessions afterward help you sort through what came up and decide on next steps.
For clinicians: a research summary
For psychiatrists, therapists, and primary care clinicians considering a referral, these points from the literature may be useful. SI refers to suicidal ideation throughout.
- Onset and peak. A single subanesthetic infusion reduces depressive symptoms within hours. The largest effect sizes appear about 24 hours post-infusion (Ballard et al. 2021). Early trials assessed participants at 40, 80, 120, and 230 minutes, with many primary outcomes at 24 hours. Most infusions ran over about 40 minutes.
- SI beyond mood. A 2018 meta-analysis by Wilkinson and colleagues, as cited in Ballard, found that ketamine reduced SI for up to one week. This effect appeared to occur independently of its antidepressant effect.
- Acute randomized controlled trial (RCT) data. In the double-blind, placebo-controlled BMJ trial (Abbar et al. 2022), adults with severe SI received two infusions 24 hours apart. Remission at day 3 was 63.0% vs 31.6%. Remission 2 hours after the first infusion was 43.8% vs 7.3%. Subgroup analyses found the largest effect in participants with bipolar disorder, which is worth weighing in patient selection.
- Goals shape the protocol. In an emergency setting, the aim may be near-zero SI over the first hours to days, possibly diverting psychiatric hospitalization. In outpatient care for longstanding SI, the aim is more often a gradual reduction sustained over weeks to months. Repeated dosing of ketamine and esketamine is being actively studied.
- Mechanism. The pathway is still under investigation. Findings from Zanos et al. (2016), as cited in Ballard, suggest antidepressant effects depend more on enhanced AMPA receptor throughput than on NMDA receptor antagonism alone. AMPA and NMDA receptors are two types of glutamate receptors.
At Nushama, an acute IV ketamine series is typically six infusions over two to three weeks, with maintenance offered as needed every one to six months. Spravato follows the dosing schedule set out in its FDA-approved labeling, with more frequent sessions during an initial induction phase and less frequent sessions during maintenance. See our page for referring providers for details.
Spravato is FDA-approved for treatment-resistant depression and for depressive symptoms in adults with major depressive disorder with acute suicidal ideation or behavior. Spravato’s FDA prescribing information states that it has not been shown to prevent suicide or reduce suicidal ideation or behavior. It also states that use does not preclude the need for hospitalization when clinically warranted. Check the current label for full indications and warnings.
IV ketamine is private pay. Spravato is covered by most major insurers when eligibility criteria are met. Patients who already work with a therapist or psychiatrist should ask how care will be coordinated with them. The same provider page details screening, follow-up measures, and how referrals work.
Suicide prevention resources near our centers
If you or someone you love is struggling, help is available right now. Each resource below is free and confidential.
National: available everywhere
- 988 Suicide & Crisis Lifeline. Call or text 988, 24/7, or chat through 988lifeline.org. Dialing 988 also works in Canada, where it connects to Canada’s own national suicide crisis helpline.
- NAMI (National Alliance on Mental Illness). NAMI offers education, free support groups for people living with mental health conditions and their families, and Suicide Prevention Month resources each September.
New York City
NYC 988 offers support by phone, text, or chat, 24/7/365, in more than 200 languages. Counselors can also connect you to ongoing mental health and substance use services. Learn more at NYC 988.
Nushama’s Manhattan center is at 515 Madison Avenue, 21st Floor, in Midtown, with the entrance on East 53rd Street. It offers IV ketamine, Spravato, and TMS (transcranial magnetic stimulation). Visit our New York page for the care team and directions.
Rockland County, NY
The Behavioral Health Helpline & Mobile Response Team is available at 845-517-0400, 24/7. It provides outreach, information, referrals, and phone support. Help is available in person or by phone for children and adults in Rockland County. The Rockland County Department of Mental Health lists this line along with other local and national resources.
Nushama has a Rockland center; see the Rockland County page for the address and directions. The phone number is (845) 682-7200. It offers IV ketamine and Spravato. The same page lists the clinical team.
Aventura and Miami-Dade County, FL
211 Miami is available by dialing 211, 24/7, or by calling (305) 631-4211. It offers crisis counseling by phone and referrals to community resources for suicide and mental health concerns. More information is at 211 Miami.
Nushama serves the Aventura area and lists suicidal ideation among the conditions we treat. For urgent situations that are not emergencies, reaching out directly is the best way to learn how soon an appointment may be available. Our crisis support protocol for Aventura explains how that works. Our plain-English guide to Spravato eligibility in Aventura covers who qualifies, the REMS safety program rules, and insurance basics.
Taking a next step
Standard treatment may not have brought you enough relief from thoughts of suicide, or you may be supporting someone in that situation. A consultation can be a calm place to start. We’ll review your history, talk through whether IV ketamine or Spravato may be a fit, and work alongside the clinicians you already trust. Book a consultation with our care team whenever you’re ready.