Trial reportThe American journal of psychiatry2013
Antidepressant efficacy of ketamine in treatment-resistant major depression: a two-site randomized controlled trial.
Trial report in The American journal of psychiatry, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 14 registered trials, which are not on this map. Cited by 539 papers, 15 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
A Safe Ketamine-Based Therapy for Treatment Resistant Depression
Spreading Depolarization and Ketamine Suppression
Effects of Low-dose Ketamine as an Adjunct to Propofol-based Anesthesia for Electroconvulsive Therapy
Clinical Trial of the Use of Ketamine in Treatment Resistant Depression
Evaluation of the Initial Prescription of Ketamine and Milnacipran Forin Depression in Patients With a Progressive Disease
Evaluation of Schemes of Administration of Intravenous Ketamine in Treatment-resistant Depression: Clinical-neuroimaging Correlation
Ketamine for Severe Adolescent Depression: Intermediate-term Safety and Efficacy
Intramuscular Ketamine Versus Escitalopram and Aripiprazole in Acute and Maintenance Treatment of Patients With Treatment-resistant Depression
A Pilot Study to Assess the Efficacy of Subanesthetic Doses of IV Ketamine in the Treatment Drug Resistant Epilepsy
Effects Of Different Anesthesia Applications On Mood, Depression, And Anxiety Levels In Burn Patients
Nebulized Ketamine for the Treatment of Major Depressive Disorder in an Inpatient Setting: A Midazolam-controlled Randomized Controlled Trial
Effect of Subanesthetic Dose of Esketamine on Sleep Quality in Patients With Breast Cancer After Chemotherapy
Esketamine Versus Crisis Response Planning Versus Enhanced Treatment as Usual for Suicide Prevention: A Pragmatic Randomized Trial in a Brazilian Municipality (SAVE)
Intra-Sessional Autonomic Arc Detection Using Continuous HRV and EDA Monitoring in Adults Undergoing Ketamine-Assisted Therapy for PTSD: A Prospective Observational Signal Characterisation Pilot Study
Who cites it
539 citing papers in PubMed, 15 syntheses or guidelines pooled it, 1,186 citations in OpenAlex.
- Cognitive effects of intravenous Ketamine in treatment-resistant depression: A systematic review.Psychological medicine · 2026Pooled it
- Comparative Efficacy and Safety of Ketamine Versus Midazolam for Suicidality: A GRADE-Assessed Systematic Review and Meta-Analysis of Randomized Controlled Trials.Brain and behavior · 2026Pooled it
- Intranasal esketamine plus oral antidepressant for treatment-resistant depression: acute induction and maintenance relapse-prevention outcomes in a systematic review and meta-analysis.Frontiers in psychiatry · 2026Pooled it
- Depressive disorders: systematic review of approved psychiatric medications (2009-April 2025) and pipeline phase 3 medications.BMC psychiatry · 2025Pooled it
- Ketamine-induced altered states of consciousness: a systematic review of implications for therapeutic outcomes in psychiatric practices.European archives of psychiatry and clinical neuroscience · 2025Pooled it
- Efficacy and safety of ketamine and esketamine in reducing the incidence of postpartum depression: an updated systematic review and meta-analysis.BMC pregnancy and childbirth · 2025Pooled it
- Comparative safety and tolerability of ketamine and esketamine for major depressive disorder: a systematic review and meta-analysis.Frontiers in pharmacology · 2025Pooled it
- Efficacy and safety of ketamine and esketamine for unipolar and bipolar depression: an overview of systematic reviews with meta-analysis.Frontiers in psychiatry · 2024Pooled it
- So how special is special K? A systematic review and meta-analysis of ketamine for PTSD RCTs.European journal of psychotraumatology · 2024Pooled it
- Brain-based correlates of antidepressant response to ketamine: a comprehensive systematic review of neuroimaging studies.The lancet. Psychiatry · 2023Pooled it
- International pooled patient-level meta-analysis of ketamine infusion for depression: In search of clinical moderators.Molecular psychiatry · 2022Pooled it
- Efficacy and Safety of Ketamine vs Electroconvulsive Therapy Among Patients With Major Depressive Episode: A Systematic Review and Meta-analysis.JAMA psychiatry · 2022Pooled it
- Blood-based biomarkers of antidepressant response to ketamine and esketamine: A systematic review and meta-analysis.Molecular psychiatry · 2022Pooled it
- A Systematic Review of Neurocognitive Effects of Subanesthetic Doses of Intravenous Ketamine in Major Depressive Disorder, Post-Traumatic Stress Disorder, and Healthy Population.Clinical drug investigation · 2022Pooled it
- Efficacy and safety of racemic ketamine and esketamine for depression: a systematic review and meta-analysis.Expert opinion on drug safety · 2022Pooled it
- Sustained pharmacodynamic effects of S-ketamine on cortical excitability and resting-state brain activity: A randomized, placebo-controlled trial.British journal of clinical pharmacology · 2026Trial
- Subacute effects of ketamine on neural correlates of reward processing.Translational psychiatry · 2026Trial
- A preliminary proof-of-concept trial on the effects of ketamine on fatigue: a randomized crossover trial.Pharmacological reports : PR · 2026Trial
- Investigation of Esketamine Administration During Surgical Procedures for the Alleviation of Postoperative Anxiety and Depression in Adolescent Patients: A Randomized Controlled Trial.Drug design, development and therapy · 2026Trial
- Antidepressant efficacy of ketamine plus naltrexone for major depression comorbid with alcohol use disorder: a randomized controlled trial.The international journal of neuropsychopharmacology · 2025Trial
479 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
12 authors at 2 institutions in 1 country.
Funding
Abstract
objectiveKetamine, a glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, has shown rapid antidepressant effects, but small study groups and inadequate control conditions in prior studies have precluded a definitive conclusion. The authors evaluated the rapid antidepressant efficacy of ketamine in a large group of patients with treatment-resistant major depression.
methodThis was a two-site, parallel-arm, randomized controlled trial of a single infusion of ketamine compared to an active placebo control condition, the anesthetic midazolam. Patients with treatment-resistant major depression experiencing a major depressive episode were randomly assigned under double-blind conditions to receive a single intravenous infusion of ketamine or midazolam in a 2:1 ratio (N=73). The primary outcome was change in depression severity 24 hours after drug administration, as assessed by the Montgomery-Åsberg Depression Rating Scale (MADRS).
resultsThe ketamine group had greater improvement in the MADRS score than the midazolam group 24 hours after treatment. After adjustment for baseline scores and site, the MADRS score was lower in the ketamine group than in the midazolam group by 7.95 points (95% confidence interval [CI], 3.20 to 12.71). The likelihood of response at 24 hours was greater with ketamine than with midazolam (odds ratio, 2.18; 95% CI, 1.21 to 4.14), with response rates of 64% and 28%, respectively.
conclusionsKetamine demonstrated rapid antidepressant effects in an optimized study design, further supporting NMDA receptor modulation as a novel mechanism for accelerated improvement in severe and chronic forms of depression. More information on response durability and safety is required before implementation in clinical practice.
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Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.