Objective: To systematically examine the effectiveness and tolerability of psilocybin for treating end-of-life anxiety symptoms.
Methods: The Medline, Embase, CENTRAL, and PsycINFO databases were searched up to November 25, 2020. We enrolled clinical trials investigating psilocybin for treating end-of-life anxiety symptoms. Meta-analysis was conducted using random-effects model.
Results: Overall, five studies were included, revealing that psilocybin was superior to the placebo in treating state anxiety at 1 day (Hedges' g, -0.70; 95% confidence interval, -1.01 to -0.39) and 2 weeks (-1.03; -1.47 to -0.60) after treatment. Psilocybin was more effective than placebo in treating trait anxiety at 1 day (-0.71; -1.15 to -0.26), 2 weeks (-1.08; -1.80 to -0.36), and 6 months (-0.84; -1.37 to -0.30) after treatment. Psilocybin was associated with transient elevation in systolic (19.00; 13.58-24.41 mm Hg) and diastolic (8.66; 5.18-12.15 mm Hg) blood pressure compared with placebo. The differences between psilocybin and placebo groups with regard to allcause discontinuation, serious adverse events, and heart rates were nonsignificant.
Conclusion: Psilocybin-assisted therapy could ameliorate end-of-life anxiety symptoms without serious adverse events. Because of the small sample sizes of the included studies and high heterogeneity on long-term outcomes, future randomized controlled trials with large sample sizes are needed.
Keywords: Cancer; End-of-life anxiety; Life-threatening disease; Meta-analysis; Psilocybin.