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 via PubMed
Summary
AI-generated from the abstractA combination of clinical markers better predicts which patients with treatment-resistant depression and suicidal thoughts will respond rapidly and durably to a single low-dose ketamine infusion than any single marker alone. The markers include mild or moderate depression severity, a shorter current episode, no more than four prior antidepressant failures, low or moderate current suicide risk, and a history of suicide attempts. The analysis of 67 patients from previous trials used a decision-tree model to identify these predictors. Clinicians can use these findings to select patients most likely to benefit, though further confirmation is needed.
Study at a glance
| 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 |
| Key finding | 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.