Dose effect of psilocybin on primary and secondary depression: a preliminary systematic review and meta-analysis.
Nannan Li, Yi-Ru Hu, Wang-ni Chen, Bin Zhang
Journal of Affective Disorders September 17, 2021 DOI: 10.1016/j.jad.2021.09.041 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review and meta-analysis Peer reviewed |
|---|---|
| Sample size | 136 |
| Population | Patients with primary major depression and secondary depression in cancer patients |
| Intervention | Psilocybin |
| Dose | 30-35 mg/70 kg |
| Duration | Follow-up longer than 1 month |
| Measures | Beck Depression Inventory (BDI) |
| Topics | Depression Psilocybin |
| Key findings | Across 7 studies, psilocybin was associated with a large reduction in depressive symptoms (pooled Hedges' g = 1.289), with the strongest effects at 30-35 mg/70 kg (g = 3.059), in primary depression (g = 2.190), and beyond one month of follow-up (g = 1.123). The authors conclude that the optimal dose may be 30-35 mg/70 kg or higher, but describe these findings as preliminary given the small number and variable quality of included studies. |
Abstract
Background: Previous studies have shown that psilocybin has antidepressant effects. In the current study, we aim to explore the dose effects of psilocybin on primary (major depression patients) and secondary depression (depressed cancer patients).
Methods: Published studies concerning psilocybin for depression were retrieved. In accordance with PRISMA guidelines, 6 databases (PubMed, Embase, Web of Science, Cochrane Library, Clinicaltrials.gov 2.3 and WanFang database) were searched for research studies published or still in progress from inception to 30 November, 2020, with language restricted to English and Chinese. Hedges' g of Beck Depression Inventory (BDI) score changes was calculated as the primary outcome.
Results: 7 articles were finally included, with a total of 136 participants. In terms of efficacy, Hedges' g was 1.289 (95%CI=[1.020, 1.558], heterogeneity I2=50.995%, p<0.001). As psilocybin dose increases within a certain range, the antidepressive effect declines and then increases, with 30-35 mg/70 kg achieving the optimal therapeutic effect. Subgroup analysis suggested that the antidepressive effect of psilocybin was extremely significant at a relatively high dose (30-35mg/70kg: Hedges' g=3.059, 95%CI=[2.269, 3.849], p<0.001), long-term (>1month: Hedges' g=1.123, 95%CI=[0.861, 1.385], p<0.001) and when used in primary depression patients (Hedges' g=2.190, 95%CI=[1.423, 2.957], p<0.001).
Limitations: Only a small number of studies can be identified of variable quality, thus our conclusions remain preliminary.
Conclusions: Our preliminary results have shown that psilocybin exerts a rapid effect in reducing depressive symptom on primary and secondary depression. The optimal dose of psilocybin may be 30-35mg/70kg or higher; future clinical trials are warranted for further evaluation on its effect.