Using Classification and Regression Tree Modeling to Investigate the Effects of Subanesthetic Ketamine Infusion on Remission of Suicidal Symptoms.
Ping-Chung Wu, Wei-Chen Lin, Tung-Ping Su, Cheng-Ta Li, Hui-Ju Wu, Shih-Jen Tsai, Ya-Mei Bai, Pei-Chi Tu, Wei-Chung Mao, Mu-Hong Chen
Pharmacopsychiatry February 26, 2026 DOI: 10.1055/a-2807-8161 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Post hoc analysis of randomized placebo-controlled and open-label trials Peer reviewed |
|---|---|
| Sample size | 67 |
| Population | Patients with treatment-resistant depression and prominent suicidal ideation |
| Intervention | Ketamine |
| Dose | 0.5 mg/kg |
| Duration | Single infusion |
| Topics | Esketamine Ketamine |
| Key findings | Combinations of baseline clinical markers—mild or moderate depression severity, shorter current episode, no more than four antidepressant failures, low or moderate current suicide risk, and a history of suicide attempts—predict rapid and sustained antisuicidal response to a single sub-anesthetic ketamine infusion. |
Abstract
As accumulating evidence suggests the antisuicidal properties of ketamine, elucidating its underlying mechanisms and predictors of treatment response has become crucial. Whether a combination of clinical markers can enhance the prediction of the antisuicidal response to ketamine remains unclear.Using data from our previous randomized placebo-controlled and open-label trials, this post hoc analysis evaluated 67 patients with treatment-resistant depression and prominent suicidal ideation who received a single ketamine infusion of 0.5 mg/kg. A classification and regression tree model was used to identify the combinations of clinical and demographic characteristics at baseline that can predict the antisuicidal response to ketamine infusion.Combinations of clinical predictors, including mild or moderate depression severity, a shorter duration of the current episode, no more than four trials of antidepressant failures, low or moderate current suicide risks, and a history of suicide attempts, offered superior predictive power for the rapid and sustained antisuicidal effects of sub-anesthetic ketamine infusion, outperforming the predictive power of any individual predictor.Clinicians can use our findings to identify individuals who are most likely to benefit from the antisuicidal effects of ketamine. Further research is required to corroborate these findings.CART found combined baseline markers, including mild/moderate depression, shorter episode, ≤4 failed antidepressants, low/moderate suicide risk, and prior attempts, predict rapid/sustained antisuicidal response of sub-anesthetic ketamine in TRD.
Comparable studies
Other randomized controlled trials on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Subanesthetic Effects of the Noncompetitive NMDA Antagonist, Ketamine, in Humans Healthy human subjects recruited from the community | 1994 | Randomized controlled trial | n = 19 |
| Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial Patients with treatment-resistant major depression experiencing a major depressive episode | 2013 | Randomized controlled trial | n = 73 |
| Remifentanil-induced Postoperative Hyperalgesia and Its Prevention with Small-dose Ketamine Patients undergoing major abdominal surgery | 2005 | Randomized controlled trial | n = 75 |
| Efficacy of Intravenous Ketamine for Treatment of Chronic Posttraumatic Stress Disorder Patients with chronic PTSD related to a range of trauma exposures | 2014 | Randomized controlled trial | n = 41 |
| Ketamine-Induced Deficits in Auditory and Visual Context-Dependent Processing in Healthy Volunteers Healthy volunteers | 2000 | Single-blind placebo-controlled study | n = 20 |
Citations in the library
Cites 11
- 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 October 3, 2017
- Ketamine for rapid reduction of suicidal thoughts in major depression: a midazolam-controlled randomized clinical trial American Journal of Psychiatry December 5, 2017
- Ketamine for suicidal ideation in adults with psychiatric disorders: A systematic review and meta-analysis of treatment trials Australian & New Zealand Journal of Psychiatry November 15, 2019
- Ketamine for the acute treatment of severe suicidal ideation: double blind, randomised placebo controlled trial British medical journal February 2, 2022
- A Randomized, Double-Blind, Midazolam-Controlled Trial of Low-Dose Ketamine Infusion in Patients With Treatment-Resistant Depression and Prominent Suicidal Ideation The International Journal of Neuropsychopharmacology March 26, 2023
and 6 more in the library