History repeating: guidelines to address common problems in psychedelic science
The paper identifies ten key methodological and inferential challenges in contemporary psychedelic research that undermine internal, external, construct and statistical validity and often co‑occur, casting doubt on claims about efficacy and safety. It groups these problems by ease of resolution and provides a roadmap and practical checklist for researchers, journalists, funders and policymakers to improve rigour and better assess whether current optimism about therapeutic potential is warranted.
Authors
- Michiel Van Elk
Published
Abstract
Research in the last decade has expressed considerable optimism about the clinical potential of psychedelics for the treatment of mental disorders. This optimism is reflected in an increase in research papers, investments by pharmaceutical companies, patents, media coverage, as well as political and legislative changes. However, psychedelic science is facing serious challenges that threaten the validity of core findings and raise doubt regarding clinical efficacy and safety. In this paper, we introduce the 10 most pressing challenges, grouped into easy, moderate, and hard problems. We show how these problems threaten internal validity (treatment effects are due to factors unrelated to the treatment), external validity (lack of generalizability), construct validity (unclear working mechanism), or statistical conclusion validity (conclusions do not follow from the data and methods). These problems tend to co-occur in psychedelic studies, limiting conclusions that can be drawn about the safety and efficacy of psychedelic therapy. We provide a roadmap for tackling these challenges and share a checklist that researchers, journalists, funders, policymakers, and other stakeholders can use to assess the quality of psychedelic science. Addressing today’s problems is necessary to find out whether the optimism regarding the therapeutic potential of psychedelics has been warranted and to avoid history repeating itself.
Research Summary of 'History repeating: guidelines to address common problems in psychedelic science'
Introduction
Psychedelics—including serotonergic hallucinogens (for example, psilocybin and LSD), MDMA, DMT, and dissociatives such as ketamine—have attracted strong clinical and public interest over the past decade. Preliminary clinical trials and experimental research report therapeutic signals across conditions including major depressive disorder, post‑traumatic stress disorder, end‑of‑life anxiety and addiction, and many participants describe psychedelic experiences as highly meaningful with downstream effects on wellbeing, creativity and connectedness. These developments have been accompanied by rapid commercial investment, patenting activity, legal changes in some jurisdictions and the emergence of specialised clinics. Van Elk and colleagues set out to examine whether the current optimism is supported by a robust evidence base. Rather than presenting a single new trial or a formal systematic review, they identify and discuss ten recurring problems in contemporary psychedelic research. These problems are grouped by the authors into three difficulty categories (easy, moderate, hard) and mapped onto four types of validity (internal, external, construct, and statistical conclusion validity). The paper aims to show how these recurring threats co‑occur, to provide mitigation strategies and to offer a checklist to help researchers, funders, reviewers, journalists and policymakers assess the quality of psychedelic studies.
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van Elk, M., & Fried, E. I. (2023). History repeating: guidelines to address common problems in psychedelic science. Therapeutic Advances in Psychopharmacology, 13. https://doi.org/10.1177/20451253231198466
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