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Post-acute psychological effects of classical serotonergic psychedelics: a systematic review and meta-analysis

Published online by Cambridge University Press:  04 November 2020

Simon B. Goldberg Open the ORCID record for Simon B. Goldberg [Opens in a new window] ,
Benjamin Shechet ,
Christopher R. Nicholas ,
Chi Wing Ng ,
Geetanjali Deole ,
Zhuofan Chen  and
Charles L. Raison
Simon B. Goldberg*
Affiliation:
Department of Counseling Psychology, University of Wisconsin – Madison, Madison, WI, USA
Benjamin Shechet
Affiliation:
Department of Counseling Psychology, University of Wisconsin – Madison, Madison, WI, USA
Christopher R. Nicholas
Affiliation:
Department of Family Medicine and Community Health, University of Wisconsin – Madison, Madison, WI, USA
Chi Wing Ng
Affiliation:
Department of Counseling Psychology, University of Wisconsin – Madison, Madison, WI, USA
Geetanjali Deole
Affiliation:
Department of Counseling Psychology, University of Wisconsin – Madison, Madison, WI, USA
Zhuofan Chen
Affiliation:
Department of Counseling Psychology, University of Wisconsin – Madison, Madison, WI, USA
Charles L. Raison
Affiliation:
School of Human Ecology, University of Wisconsin – Madison, Madison, WI, USA Usona Institute, Fitchberg, WI, USA
*
Author for correspondence: Simon B. Goldberg, E-mail: [email protected]
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Abstract

Background

Scientific interest in the therapeutic effects of classical psychedelics has increased in the past two decades. The psychological effects of these substances outside the period of acute intoxication have not been fully characterized. This study aimed to: (1) quantify the effects of psilocybin, ayahuasca, and lysergic acid diethylamide (LSD) on psychological outcomes in the post-acute period; (2) test moderators of these effects; and (3) evaluate adverse effects and risk of bias.

Methods

We conducted a systematic review and meta-analysis of experimental studies (single-group pre-post or randomized controlled trials) that involved administration of psilocybin, ayahuasca, or LSD to clinical or non-clinical samples and assessed psychological outcomes ⩾24 h post-administration. Effects were summarized by study design, timepoint, and outcome domain.

Results

A total of 34 studies (24 unique samples, n = 549, mean longest follow-up = 55.34 weeks) were included. Classical psychedelics showed significant within-group pre-post and between-group placebo-controlled effects on a range of outcomes including targeted symptoms within psychiatric samples, negative and positive affect-related measures, social outcomes, and existential/spiritual outcomes, with large between-group effect in these domains (Hedges' gs = 0.84 to 1.08). Moderator tests suggest some effects may be larger in clinical samples. Evidence of effects on big five personality traits and mindfulness was weak. There was no evidence of post-acute adverse effects.

Conclusions

High risk of bias in several domains, heterogeneity across studies, and indications of publication bias for some models highlight the need for careful, large-scale, placebo-controlled randomized trials.

Keywords

AnxietyayahuascadepressionLSDmeta-analysispsilocybinpsychedelicspsychological effects
Type
Review Article
Information
Psychological Medicine , Volume 50 , Issue 16 , December 2020 , pp. 2655 - 2666
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Copyright
Copyright © The Author(s), 2020. Published by Cambridge University Press

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