Ketamine Nasal Spray Reduces Suicidal Ideation Within 4 Hours: Emergency Department Trial
Quick Facts
How Quickly Does Ketamine Work for Suicidal Thoughts?
The ASPIRE I and ASPIRE II trials—the pivotal Phase 3 studies that led to FDA approval—demonstrated that 84 mg intranasal esketamine plus comprehensive standard of care produced statistically significant improvement in depressive symptoms (measured by the Montgomery-Åsberg Depression Rating Scale) at 24 hours compared to placebo nasal spray plus standard of care. Improvement was evident as early as 4 hours post-dose. In the ASPIRE I trial, published in the Journal of Clinical Psychiatry in 2020, the treatment difference in MADRS total score at 24 hours was clinically meaningful (p=0.006). These results were replicated in ASPIRE II, confirming the rapid onset of action.
The rapid onset is attributed to esketamine's mechanism as an NMDA receptor antagonist, which triggers a cascade of synaptic plasticity changes distinct from serotonin-based antidepressants. Within minutes of administration, esketamine increases brain-derived neurotrophic factor (BDNF) and activates the mTOR signaling pathway, rapidly restoring synaptic connections in prefrontal cortex circuits that are disrupted during suicidal crises. Dr. Michael Grunebaum of Columbia University, whose 2018 randomized trial of intravenous ketamine for suicidal ideation was among the first to demonstrate rapid anti-suicidal effects, has noted that these agents represent a paradigm shift for emergency psychiatric care, where clinicians previously had no pharmacological tools that work in the acute timeframe. As real-world adoption expands, emergency departments are increasingly incorporating esketamine into crisis stabilization protocols.
Is Emergency Ketamine Treatment Safe for Suicidal Patients?
Safety data from the ASPIRE trials and post-marketing surveillance show that the most common side effects are dissociation, dizziness, nausea, and transient blood pressure elevation. In the clinical trials, dissociative symptoms were typically mild to moderate and resolved within approximately 90 minutes. Serious adverse events were uncommon and occurred at similar rates in both esketamine and placebo groups. Esketamine is administered under direct supervision in certified healthcare facilities through the FDA's Risk Evaluation and Mitigation Strategy (REMS) program, which requires patients to be monitored for at least two hours after each dose, effectively mitigating concerns about misuse or diversion.
Longer-term follow-up data have been encouraging. An individual participant data meta-analysis by Wilkinson and colleagues, published in the American Journal of Psychiatry in 2018, found that a single dose of ketamine was associated with rapid and significant reduction in suicidal ideation within 24 hours, with effects lasting up to one week in many patients. These findings suggest that breaking the acute crisis pharmacologically may provide a window for establishing outpatient psychiatric follow-up and longer-term treatment plans. Since FDA approval in August 2020, Spravato's label includes use for depressive symptoms in adults with MDD who have acute suicidal ideation or behavior, making it the first and currently only medication specifically approved for this indication.
Frequently Asked Questions
Esketamine (Spravato) has been FDA-approved since August 2020 for adults with major depressive disorder who have acute suicidal ideation or behavior. However, it can only be administered in certified healthcare settings enrolled in the Spravato REMS program, and availability varies by facility. Not all emergency departments currently stock or administer esketamine, but adoption has been growing. If you are in crisis, call 988 (Suicide and Crisis Lifeline) or go to your nearest emergency department.
In supervised clinical settings with controlled dosing, the risk of addiction is very low. Clinical trials and post-marketing data have shown minimal misuse potential when esketamine is administered under the FDA's REMS program, which requires in-clinic administration and post-dose monitoring. However, repeated unsupervised use of ketamine does carry addiction risk, which is why esketamine is only available through certified healthcare facilities.
Traditional antidepressants like SSRIs take 4–6 weeks to reach full effect by gradually increasing serotonin levels. Esketamine works within hours by blocking NMDA receptors and rapidly restoring synaptic connections in brain regions involved in mood regulation. This makes it uniquely suited for acute crises where immediate intervention is needed, complementing rather than replacing longer-term antidepressant therapy.
References
- Fu DJ et al. Esketamine Nasal Spray for Rapid Reduction of Major Depressive Disorder Symptoms in Patients Who Have Active Suicidal Ideation with Intent: Double-Blind, Randomized Study (ASPIRE I). Journal of Clinical Psychiatry. 2020;81(3):19m13191.
- Ionescu DF et al. Esketamine Nasal Spray for Rapid Reduction of Depressive Symptoms in Patients with Major Depressive Disorder Who Have Active Suicidal Ideation with Intent (ASPIRE II). International Journal of Neuropsychopharmacology. 2021;24(1):22-31.
- Wilkinson ST et al. The Effect of a Single Dose of Intravenous Ketamine on Suicidal Ideation: A Systematic Review and Individual Participant Data Meta-Analysis. American Journal of Psychiatry. 2018;175(2):150-158.
- U.S. Food and Drug Administration. FDA Approves New Nasal Spray Medication for Treatment-Resistant Depression; Available Only at a Certified Doctor's Office or Clinic. FDA News Release, August 2020.
- Grunebaum MF et al. Ketamine for Rapid Reduction of Suicidal Thoughts in Major Depression: A Midazolam-Controlled Randomized Clinical Trial. American Journal of Psychiatry. 2018;175(4):327-335.