Real-world effectiveness of ketamine in treatment-resistant depression: A systematic review & meta-analysis
Alnefeesi, Y., Cao, B., Ceban, F., Chen-Li, D., Di Vincenzo, J. D., Gill, H., Ho, R., Jawad, M. Y., Lee, Y., McIntyre, R. S., Meshkat, S., Rosenblat, J. D., Teopiz, K. M.
This meta-analysis (2022) assessed the effectiveness of ketamine for treatment-resistant depression (TRD) using real-world data. While the mean antidepressant effect of ketamine was found to be significant, there are high levels of variability between patients. Treatment effects were found to be similar following repeated treatments.
Abstract
Ketamine is a promising therapeutic option in treatment-resistant depression (TRD). The acute efficacy of ketamine in TRD has been demonstrated in replicated randomised-controlled trials (RCTs), but the generalizability of RCT data to real-world practice is limited. To this end, we conducted a systematic review (Search date: 25/12/2021; 1482 records identified) and meta-analysis of studies evaluating the real-world clinical effectiveness of ketamine in TRD patients. Four overlapping syntheses (Total n = 2665 patients; k = 79 studies) and 32 meta-regressions (Total n = 2050; k = 37) were conducted. All results suggest that the mean antidepressant effect is substantial (mean ± 95% CI, % responded = 45 ± 10%; p < 0.0001, % remitted = 30 ± 5.9%; p < 0.0001, Hedges g of symptomatological improvement = 1.44 ± 0.609; p < 0.0001), but the effect varies considerably among patients. The more treatment-resistant cases were found to remit less often (p < 0.01), but no such effect on response was evident (p > 0.05). Meta-regressions also confirmed that the therapeutic effect does not significantly decline with repeated treatments (p > 0.05). These results demonstrate that even the most treatment-resistant patients may benefit from ketamine, and that mid-to-long term treatment is effective in many patients.