Evidence map›Paper›PMID 40051762›Full record

ReviewPsychedelic medicine (New Rochelle, N.Y.)2024

A Systematic Review of Study Design and Placebo Controls in Psychedelic Research.

Alexander Wen, Nikhita Singhal, Brett D M Jones, Richard J Zeifman, Shobha Mehta, Mohammad A Shenasa, Daniel M Blumberger, Zafiris J Daskalakis, Cory R Weissman

Abstract readReview
PubMed Full text at PMC Publisher
In one paragraph

Review in Psychedelic medicine (New Rochelle, N.Y.), 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 20 papers, 6 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
20citing papers in PubMed, 6 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

20 citing papers in PubMed, 6 syntheses or guidelines pooled it.

  1. Pooled it
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  3. Magnitude of response in treatment and control groups within psychedelic trials for psychiatric disorders: A meta-analysis.European psychiatry : the journal of the Association of European Psychiatrists · 2026
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  15. Addressing blinding in classic psychedelic studies with innovative active placebos.The international journal of neuropsychopharmacology · 2025
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Alexander WenDepartment of Psychiatry, University of California San Diego, La Jolla, California, USA.ORCID https://orcid.org/0009-0003-9313-404X
Nikhita SinghalDepartment of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
Brett D M JonesDepartment of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
Richard J ZeifmanNYU Langone Center for Psychedelic Medicine, NYU Grossman School of Medicine, New York, New York, USA.
Shobha MehtaFaculty of Medicine, University College Cork, Cork, Ireland.
Mohammad A ShenasaDepartment of Psychiatry, University of California San Diego, La Jolla, California, USA.
Daniel M BlumbergerDepartment of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
Zafiris J DaskalakisDepartment of Psychiatry, University of California San Diego, La Jolla, California, USA.
Cory R WeissmanDepartment of Psychiatry, University of California San Diego, La Jolla, California, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Introduction: Effective blinding is especially challenging in randomized controlled trials (RCTs) involving psychedelics due to the inherent alterations in consciousness that these compounds induce. In this systematic review and exploratory analysis, we aim at synthesizing the methodologies used in RCTs involving classic psychedelics and identify procedures that can help minimize unblinding and bias. Methods: We completed a literature search that included prospective RCTs published between 1963 and January 2023, in which participants were randomized to receive either a classic psychedelic or placebo. Results: A total of 1402 papers were included in the initial search. After eligibility criteria were applied, 50 papers from 48 clinical trials were included. Most studies were double blinded ( Conclusion: To improve blinding and lower expectancy effects, we suggest incorporating active placebos and utilizing dose response or active comparator study designs.

Indexed as

classic psychedelicsplacebo controlsrandomized control trialsstudy designsystematic review

Identifiers

PMID40051762
PMCPMC11658677

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.