A transdiagnostic systematic review and meta-analysis of ketamine’s anxiolytic effects
Hannah Hartland, Kimia Mahdavi, L. Jelen, R. Strawbridge, A. Young, Laith Alexander
medRxiv December 11, 2022 DOI: 10.1177/02698811231161627 via Semantic Scholar
Summary
Ketamine reduces anxiety symptoms within 12 hours of administration, and the effect lasts for 1 to 2 weeks. A systematic review and meta-analysis of 14 randomized controlled trials found significant reductions in anxiety scores compared to placebo at acute (less than 12 hours), subacute (24 hours), and sustained (7–14 days) time points. Improvements in anxiety and depression symptoms were correlated at 24 hours and at 7–14 days. The relationship between peak dissociation and anxiety improvement was not significant. Most studies had a high risk of bias.
Study at a glance
| Characteristics | Systematic review and meta-analysis Randomized Peer reviewed |
|---|---|
| Sample size | 14 |
| Population | Participants in randomized controlled trials measuring anxiolytic effects of ketamine in mood disorders, anxiety disorders, and chronic pain |
| Keywords | Medicine Psychology |
| Citations | 22 |
| Key finding | Ketamine significantly reduces anxiety scores compared to placebo at acute, subacute, and sustained time points, with effects lasting 1–2 weeks. |
Abstract
Background: Ketamine may be effective in treating symptoms of anxiety, but the time profile of ketamine’s anxiolytic effect is ill-defined. This systematic review and meta-analysis investigated the anxiolytic effect of ketamine at different time points across a range of clinical settings. Methods: Electronic databases were searched to capture randomised control trials measuring the anxiolytic effects of ketamine in contexts including mood disorders, anxiety disorders and chronic pain. Meta-analyses were conducted using a random-effects model. The correlations between (1) improvements in mean anxiety and depression scores, and (2) peak dissociation and improvements in mean anxiety scores were also assessed. Results: In all, 14 studies met inclusion criteria. Risk of bias was high in 11 studies. Ketamine significantly reduced anxiety scores compared to placebo at acute (<12 h; standard mean difference (SMD): −1.17, 95% confidence interval (CI) [−1.89, −0.44], p < 0.01), subacute (24 h; SMD: −0.44, 95% CI [−0.65, −0.22], p < 0.01) and sustained (7–14 days; SMD: −0.40, 95% CI [−0.63, −0.17], p < 0.01) time points. Exploratory analyses revealed improvements in anxiety and depression symptoms correlated at both subacute (R2 = 0.621, p = 0.035) and sustained time points (R2 = 0.773, p = 0.021). The relationship between peak dissociation and improvement in anxiety was not significant. Conclusions: Ketamine appears to offer rapid and sustained anxiety symptom relief across a range of clinical settings, with anxiolytic effects occurring within the first 12 h of administration and remaining effective for 1–2 weeks. Future studies could explore the effects of ketamine maintenance therapy on anxiety symptoms.