Meta-analysis · 2026
Oral ketamine for depression: review of 8 randomized trials with 414 people
- Original title
- Short-term effects of oral ketamine for the treatment of depression: A systematic review and meta-analysis of randomized controlled trials.
- Authors
- Shenoy S, Belle VS, Munoli RN, et al.
- Journal
- Asian journal of psychiatry, 2026
- Molecules
- Ketamine
- Conditions
- Depression, Treatment-resistant depression, Bipolar depression
- Participants
- 414
- Evidence grade
- Moderate
- Source
- Read the original paper
The question
Does ketamine taken by mouth reduce depression symptoms in the short term, compared with a placebo or with ketamine given other ways, and is it safe?
What they did
Researchers searched six research databases for randomized controlled trials of oral ketamine in people with unipolar depression, bipolar depression, or treatment-resistant depression (depression that has not responded to standard treatments). They pooled the results of eight trials, involving 414 people in total. The main outcome was change in depression scores on validated rating scales.
What they found
Compared with placebo, oral ketamine was linked to a significant drop in depression scores, with a standardized mean difference of -0.62 (95% confidence interval -0.39 to -0.85), which the authors rated as moderate certainty evidence. People taking oral ketamine were more likely to reach remission, with a pooled risk ratio of 2.38 (95% CI 1.19 to 4.77), and the trials agreed closely on this point (I2 = 0%). Compared with other ways of giving ketamine, oral ketamine showed no significant difference in depression scores (mean difference 0.28, 95% CI -4.58 to 5.14). No serious adverse events were reported.
The fine print
Only eight trials with 414 people in total were available, so the pooled sample is small. The review looked at short-term effects only, so it says nothing about whether benefits last or about longer-term safety. Trials mixed different types of depression, and the abstract does not report doses, treatment length, or blinding quality. This summary is based on the abstract alone.
What it means
Pooled evidence from small randomized trials suggests oral ketamine may reduce depression symptoms in the short term and was tolerated without serious adverse events, but larger and longer trials are needed before firm conclusions can be drawn.
Evidence grade: Moderate. A meta-analysis of randomized trials, but only eight small studies with 414 people in total and short follow-up.
This summary is based on the study’s published abstract.