Meta-analysis · 2026
Review of 21 studies: ketamine linked to large short-term drops in suicidal thinking
- Original title
- Ketamine treatment alleviates suicide ideation in high-risk populations: a systematic review and meta-analysis.
- Authors
- Tang W, Jiang WW, Que WQ, et al.
- Journal
- Epidemiology and psychiatric sciences, 2026
- Molecules
- Ketamine
- Conditions
- Suicidal ideation, Depression
- Participants
- 927
- Evidence grade
- Moderate
- Source
- Read the original paper
The question
Does ketamine reduce suicidal thinking in people considered at high risk of suicide, and what side effects are reported?
What they did
The researchers searched for double-blind randomized controlled trials and open-label (unblinded) studies published up to October 2025 that tested ketamine for suicidal ideation. They followed standard systematic review reporting guidelines and combined the results statistically. Twenty-one studies with a total of 927 participants met their criteria. They also looked at which participant characteristics were linked to bigger effects.
What they found
Pooled across studies, ketamine was associated with a large reduction in suicidal thinking (standardized mean difference -1.40, 95% confidence interval -2.15 to -0.66, P < 0.001), though the authors graded this as low-quality evidence. Side effects were common: dissociation, a feeling of detachment from oneself or surroundings, was reported by 38.8% of participants, nausea by 31.6%, dizziness by 24.7%, headache by 22.0% and anxiety by 15.8%. The effect appeared stronger in younger people and in those with more severe suicidal thinking.
The fine print
The included studies were a mix of blinded randomized trials and uncontrolled open-label studies, so some of the improvement may reflect expectation or natural recovery rather than the drug. The wide confidence interval suggests results varied a lot between studies, and the authors rated the overall evidence as low quality. The review does not report how long the benefit lasted, and optimal dosing remains unclear. This summary is based on the abstract only.
What it means
Pooled research suggests ketamine is associated with short-term reductions in suicidal thinking among high-risk people, but the underlying evidence is uneven, side effects are frequent, and long-term effects are still unknown.
Evidence grade: Moderate. A meta-analysis that pools both blinded randomized trials and uncontrolled open-label studies, and the authors themselves rated the pooled evidence as low quality.
This summary is based on the study’s published abstract.