SynthesisPharmacological reports : PR2020
Efficacy of single and repeated administration of ketamine in unipolar and bipolar depression: a meta-analysis of randomized clinical trials.
Synthesis in Pharmacological reports : PR, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06620276 (Acceptance and Commitment Therapy in Patients With Alcohol Use Disorder and Comorbid Treatment-Resistant Depression Who Are Undergoing Ketamine Intervention), which is not on this map. Cited by 72 papers, 3 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.
Acceptance and Commitment Therapy in Patients With Alcohol Use Disorder and Comorbid Treatment-Resistant Depression Who Are Undergoing Ketamine Intervention: A Feasibility Study
Who cites it
72 citing papers in PubMed, 3 syntheses or guidelines pooled it, 149 citations in OpenAlex.
- 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
- The antidepressant effect and safety of non-intranasal esketamine: A systematic review.Journal of psychopharmacology (Oxford, England) · 2022Pooled it
- Ketamine and other glutamate receptor modulators for depression in adults with bipolar disorder.The Cochrane database of systematic reviews · 2021Pooled it
- The role of cytochrome P450 polymorphisms in the pharmacokinetics of oral esketamine.The pharmacogenomics journal · 2026Trial
- Brain functional network correlates and predictors of the perioperative antidepressant effect of esketamine in breast cancer patients: a double-blind randomized controlled trial using resting-state fMRI and graph theory.Translational psychiatry · 2026Trial
- A short-acting psychedelic intervention for major depressive disorder: a phase IIa randomized placebo-controlled trial.Nature medicine · 2026Trial
- Functional connectivity subtypes during a positive mood induction: Predicting clinical response in a randomized controlled trial of ketamine for treatment-resistant depression.Journal of psychopathology and clinical science · 2025Trial
- A randomized controlled pilot study of daily intravenous ketamine over three days for treatment-resistant depression.BMC psychiatry · 2024Trial
- The effect of ketamine on affective modulation of the startle reflex and its resting-state brain correlates.Scientific reports · 2023Trial
- From depression to bone health: examining the skeletal effects of classical and rapid-acting antidepressants.The international journal of neuropsychopharmacology · 2026Review
- Next-Generation Pharmacotherapies for Unipolar Mood Disorders: A Leading Article on Phase II/III Drug Development Across Diverse Mechanisms.CNS drugs · 2026Review
- Detecting neuroplastic effects induced by ketamine in healthy human subjects: A multimodal approach.Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism · 2026Article
- Psychoactive and Neurobiological Effects of Ketamine in Humans: A Scoping Review of Clinical Evidence.Journal of clinical medicine · 2026Review
- NADPH oxidase-1 suppression prolongs the antidepressant-like effect of ketamine.Molecular psychiatry · 2026Article
- Enhancing plasticity to treat depression and other central nervous system diseases using event-driven pharmacology.Journal of psychopharmacology (Oxford, England) · 2026Review
- Intermittent Ketamine and Neuromodulation Treatment Evoke Synergistic Antidepressant-Relevant Action.Biological psychiatry · 2026Article
- Synaptic Plasticity-Intrinsic Excitability and Antidepressant Discovery.Biomedicines · 2026Review
- Transforming treatment-resistant depression (TRD) care in the Gulf Cooperation Council (GCC) countries: a narrative review of emerging therapies, advancements, and implementation barriers.Annals of general psychiatry · 2026Review
- Neural signaling mechanisms in depression: bridging classical monoamine hypotheses, animal models, and emerging antidepressant strategies.Frontiers in cell and developmental biology · 2026Review
- Ketamine for treatment resistant depression in individuals with eating disorders: a comparison study.Journal of eating disorders · 2025Article
12 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundDue to unmet clinical needs for efficient drugs with a rapid onset of antidepressant effects, we aimed to evaluate the efficacy of single-dose ketamine in different subgroups of patients with major depression and establish whether repeated ketamine administration could be a viable strategy to maintain treatment gains.
methodsElectronic databases (Medline via PubMed, Embase, Cochrane Library, Trip Database) were systematically searched until February 22, 2019, for published peer-reviewed randomized controlled trials (RCTs) concerning a single and repeated administration of ketamine in patients with major depression. All relevant RCTs were selected and critically appraised, and a meta-analysis of eligible studies was performed.
resultsA total of 20 studies were included in the meta-analysis. The largest effect of ketamine vs. controls in reducing depressive symptoms was observed at 24 h (SMD = - 0.89; 95% CI - 1.24; - 0.53; p < 0.00001); however, a significant difference was shown for up to 7 days after a single dose. Significant differences compared with controls were observed for up to 7 days in treatment-resistant patients and when ketamine was added to ongoing antidepressant treatment, while there were no significant differences at 7 days when ketamine was used as monotherapy. In patients with major depression, initial antidepressant effects of ketamine were maintained during repeated dosing. At 2-3 weeks of repeated ketamine treatment, significant reduction of depression severity scores was observed: SMD = - 0.70; 95% CI - 1.15; - 0.25 or SMD = - 0.81; 95% CI - 1.41; - 0.20 (depending on the dosing regimen used); p ≤ 0.009 vs placebo.
conclusionsOur meta-analysis revealed rapid and robust antidepressant effects of single-dose ketamine in patients with treatment-resistant depression (TRD). By pooling data from RCTs, we showed for the first time that repeated ketamine administration is effective in sustaining initial antidepressant effects observed after single dosing.
Indexed as
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.