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Assessment of the acute subjective psychedelic experience: A review of patient-reported outcome measures in clinical research on classical psychedelics

Oliver Rumle Hovmand, Emil Deleuran Poulsen, Sidse Arnfred

Journal of Psychopharmacology November 16, 2023 DOI: 10.1177/02698811231200019 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Review Peer reviewed
Sample size 93
Population Clinical trials on classical psychedelics
Topics Ayahuasca LSD Psilocybin
Keywords Hallucinogen Clinical psychology Parapsychology Population Rating scale Level of consciousness Psychotherapist
Citations 31
Key findings Seventeen different rating scales were used across 93 trials of classical psychedelics, with the five most utilized being the Five-Dimensional Altered States of Consciousness Questionnaire, visual analog or Likert scales, the Hallucinogen Rating Scale, the States of Consciousness Questionnaire, and the Abnormer Psychischer Zustand.

Abstract

Background: The classical psychedelics psilocybin, peyote, ayahuasca/ N, N-dimethyltryptamine, and lysergic acid diethylamide can temporarily produce altered states of consciousness, characterized by changes in sensory perception, thought, mood, and the sense of self-reality and meaning. It is important to have reliable instruments for quantifying these altered states in trials, due to a plausible link between the acute subjective experience and treatment outcome.

Methods: We conducted a review of outcome measures applied in research on classical psychedelics to assess one or more dimensions of the acute subjective psychedelic experience. Three relevant databases were searched electronically. Two reviewers independently conducted article selection and data extraction regarding the instruments, dimensions, geography, population, and psychedelic substance investigated in the included studies. We identified the five most utilized instruments for the most recent 6 years, as well as the five most utilized instruments for each psychedelic.

Results: We included 93 papers, which reported on 93 unique trials and utilized 17 different rating scales. Of these, the most utilized were the Five-Dimensional Altered States of Consciousness Questionnaire, visual analog or Likert scales specially developed for the trials, the Hallucinogen Rating Scale, the States of Consciousness Questionnaire, and the Abnormer Psychischer Zustand.

Discussion: Considerable variability was found in the instruments utilized in clinical trials on classical psychedelics. We advise and encourage the development of a core outcome set for psychedelic research to enable altered state comparisons across compounds, participants, and settings. We further advise that instruments be designed to assess the “setting” of a psychedelic experience.

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