Meta-Analysis: High-Dose Psilocybin Shows Small Advantage Over Escitalopram for Depression – The BMJ

Study Design and Population: This systematic review and Bayesian network meta-analysis evaluated the effectiveness of oral monotherapy with psychedelics (psilocybin, LSD, MDMA, ayahuasca) compared to escitalopram in adults with depressive symptoms. The analysis included 15 trials with psychedelics and 5 trials with escitalopram, covering a total of 811 participants in psychedelic trials and 1968 in escitalopram trials.

Main Findings: The analysis revealed that only high-dose psilocybin demonstrated a significant improvement in depressive symptoms compared to placebo when considered in the context of antidepressant trials, but the effect size was small (standardized mean difference of 0.31). High-dose psilocybin also outperformed escitalopram (10 mg and 20 mg), with a mean difference exceeding the minimal important difference. However, the placebo response was generally lower in psychedelic trials compared to antidepressant trials, suggesting potential overestimation of effect sizes in psychedelic studies.

Implications for Practice: The findings suggest that while high-dose psilocybin may offer a small advantage over escitalopram for treating depression, the overall effect size is comparable to traditional antidepressants. The results highlight the importance of considering the impact of blinding and placebo response in psychedelic trials, and suggest that improved blinding and standardized psychotherapies could help better assess the true efficacy of these treatments.

Reference: Hsu, T.-W., Tsai, C.-K., Kao, Y.-C., Thompson, T., Carvalho, A. F., Yang, F.-C., Tseng, P.-T., Hsu, C.-W., Yu, C.-L., Tu, Y.-K., & Liang, C.-S. (2024). Comparative oral monotherapy of psilocybin, lysergic acid diethylamide, 3,4-methylenedioxymethamphetamine, ayahuasca, and escitalopram for depressive symptoms: systematic review and Bayesian network meta-analysis. BMJ, 386, e078607. DOI: https://doi.org/10.1136/bmj-2023-078607