A transdiagnostic systematic review and meta-analysis of ketamine’s anxiolytic effects
Hannah Hartland, Kimia Mahdavi, Luke A. Jelen, R. Strawbridge, A. Young, Laith Alexander
medRxiv December 11, 2022 preprint DOI: 10.1177/02698811231161627 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review and meta-analysis Randomized |
|---|---|
| Sample size | 14 |
| Population | Participants in randomized controlled trials measuring anxiolytic effects of ketamine in mood disorders, anxiety disorders, and chronic pain |
| Topics | Esketamine Ketamine |
| Citations | 22 |
| Key findings | 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.