Summary of findings 1. Ketamine compared to placebo for adults with unipolar major depressive disorder.
| Ketamine compared to Placebo for adults with unipolar major depressive disorder | ||||||
| Patient or population: adults (aged 18 years+) with unipolar major depressive disorder Setting: any setting (outpatient, inpatient, or both) Intervention: ketamine Comparison: placebo | ||||||
| Outcomes | Relative effect (95% CI) | Anticipated absolute effects* (95% CI) | Certainty of the evidence (GRADE) | What happens | ||
| Without ketamine | With ketamine | Difference | ||||
| Efficacy: number of participants who respond to treatment ‐ at 24 hours (Response) assessed with: HDRS, HDRS‐17, MADRS № of participants: 185 (7 RCTs) | OR 3.94 (1.54 to 10.10) | Study population | ⊕⊝⊝⊝ VERY LOW 1 2 | |||
| 8.8% | 27.4% (12.9 to 49.2) | 18.7% more (4.1 more to 40.4 more) | ||||
| Efficacy: number of participants who achieve remission ‐ at 24 hours (Remission) assessed with: MADRS, HDRS № of participants: 75 (3 RCTs) | OR 5.60 (1.07 to 29.46) | Study population | ⊕⊝⊝⊝ VERY LOW 3 4 | |||
| 2.4% | 12.0% (2.5 to 41.8) | 9.6% more (0.2 more to 39.4 more) | ||||
| Depression rating scale score ‐ at 24 hours assessed with: HDRS, HDRS‐17, MADRS № of participants: 231 (8 RCTs) | ‐ | ‐ | ‐ | SMD 0.87 lower (1.26 lower to 0.48 lower) | ⊕⊝⊝⊝ VERY LOW 1 2 5 | |
| Acceptability: total dropouts № of participants: 201 (6 RCTs) | OR 1.25 (0.19 to 8.28) | Study population | ⊕⊝⊝⊝ VERY LOW 1 2 6 | |||
| 34.0% | 39.1% (8.9 to 81) | 5.2% more (25.1 fewer to 47 more) | ||||
| Acceptability: dropouts due to adverse effects ‐ not reported | ‐ | ‐ | ‐ | ‐ | ||
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; HDRS: Hamilton Depression Rating Scale; MADRS: Montgomery‐Asberg Depression Rating Scale; OR: Odds ratio;RCT: randomised controlled trial;SMD: standardised mean difference. | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect. | ||||||
1 Downgraded by one point due to the low number of participants available for this outcome and the associated width of the confidence intervals.
2 Downgraded by two points due to the majority of trials being unclear or high risk regarding the blinding of outcome assessments.
3 Downgraded by two points due to the very low number of participants available for this outcome and the associated width of the confidence intervals.
4 Downgraded by one point due to the majority of trials being unclear regarding blinding of outcome assessments.
5 Downgraded by one point due to moderately large heterogeneity (I2 value = 30% to 60%).
6 Downgraded by two points due to substantially large heterogeneity (I2 value = 50% to 90%).