The experimental effects of psilocybin on symptoms of anxiety and depression : A meta-analysis

Simon B. Goldberg, Brian T. Pace, Christopher R. Nicholas, Charles L. Raison, Paul R. Hutson

Psychiatry Research, 2020, 284,  112749

Doi : 10.1016/j.psychres.2020.112749

 

A B S T R A C T

The current meta-analysis examined the effects of psilocybin in combination with behavioral interventions on anxiety and depression in samples with elevated symptoms. Across four studies (one uncontrolled; three randomized, placebo-controlled; N = 117), within-group pre-post and pre-follow-up effects on anxiety and depression were large (Hedges’ gs=1.16 to 1.47) and statistically significant. Across three placebo-controlled studies, pre-post placebo-controlled effects were also large (gs = 0.82 to 0.83) and statistically significant. No serious adverse events were reported. Limitations include the small number of studies and risk for bias within studies. Results tentatively support future research on psilocybin for the treatment of anxiety and depression.

Keywords : Anxiety, Depression, Psilocybin

 

1. Introduction

There has been remarkable progress developing pharmacological and behavioral treatments for anxiety and depressive disorders in the past century (Baldwin et al., 2005; Butler et al., 2006; Cipriani et al., 2018). While many benefit from existing therapies, others remain symptomatic, do not comply with treatment, or experience withdrawal or adverse side effects (Davies and Read, 2019; Gartlehner et al., 2016; Rossom et al., 2016; Simon et al., 2001; Westen and Morrison, 2001). Thus, there is a need for new treatment approaches. Researchers have recently resumed investigating psychedelic compounds as a novel treatment approach. One such substance is psilocybin (4-phosphoroyloxy-N,N dimethyltryptamine), a plant alkaloid and 5- HT2A receptor agonist. Research on the potential therapeutic benefits of psilocybin have focused on treating anxiety (Griffiths et al., 2016; Grob et al., 2011), depression (Carhart-Harris et al., 2016, 2018; Ross et al., 2016), and substance use (Bogenschutz et al., 2015; Johnson et al., 2017). Although thorough narrative reviews of this literature exist (dos Santos et al., 2018; Reiche et al., 2018), no metaanalysis has been conducted. A quantitative synthesis can support planning future trials and allows formal assessment of publication bias and heterogeneity. The current study meta-analyzed clinical trials testing psilocybin for anxiety and depression.

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Goldberg et al-2020-The experimental effects of psilocybin on symptoms of anxiety and depression-A meta-analysis