Number needed to treat (NNT) for ketamine and esketamine in adults with treatment-resistant depression: A systematic review and meta-analysis.
Journal of affective disorders July 1, 2024 Cameron N Calder, Angela T H Kwan, Kayla M Teopiz et al. 31 citations
Ketamine is effective for adults with treatment-resistant depression. A systematic review of 21 placebo-controlled randomized trials with 2042 participants calculated the number needed to treat (NNT) for racemic ketamine: 7 at 4 hours, 3 from one day to one week, and 9 at four weeks. Esketamine had an NNT of 2 at one day and 11 at four weeks. Numbers needed to harm indicated low risk. The NNTs under 10 across observation intervals are considered highly clinically meaningful for this difficult-to-treat disorder. Limitations include potential functional unblinding and selective reporting bias.