Substance Use Disorders (SUD)Ayahuasca

Measuring the subjective: revisiting the psychometric properties of three rating scales that assess the acute effects of hallucinogens

This study (n=158) examined the psychometric properties of three commonly used rating scales (MEQ, HRS, ARCI). The authors found only sparing agreement of their psychometric analyses with the theoretically proposed models of the scales.

Authors

  • Sam Gandy
  • José Carlos Bouso

Published

Human Psychopharmacology
individual Study

Abstract

Objective

In the present study we explored the psychometric properties of three widely used questionnaires to assess the subjective effects of hallucinogens: the Hallucinogen Rating Scale (HRS), the Mystical Experience Questionnaire (MEQ), and the Addiction Research Center Inventory (ARCI).

Methods

These three questionnaires were administered to a sample of 158 subjects (100 men) after taking ayahuasca, a hallucinogen whose main active component is N,N-dimethyltryptamine (DMT). A confirmatory factorial study was conducted to check the adjustment of previous data obtained via theoretical proposals. When this was not possible, we used an exploratory factor analysis without restrictions, based on tetrachoric and polychoric matrices and correlations.

Results

Our results sparsely match the theoretical proposals of the authors, perhaps because previous studies have not always employed psychometric methods appropriate to the data obtained. However, these data should be considered preliminary, pending larger samples to confirm or reject the proposed structures obtained.

Conclusions

It is crucial that instruments of sufficiently precise measurement are utilized to make sense of the information obtained in the study of the subjective effects of psychedelic drugs. Copyright © 2016 John Wiley $ Sons, Ltd.

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Research Summary of 'Measuring the subjective: revisiting the psychometric properties of three rating scales that assess the acute effects of hallucinogens'

Introduction

Bouso and colleagues frame the problem by noting that classic hallucinogens produce dramatic alterations in consciousness but that measuring those subjective effects remains challenging. The introduction reviews commonly used instruments in contemporary psychedelic research — including the Hallucinogen Rating Scale (HRS), the Mystical Experience Questionnaire (MEQ), and the Addiction Research Center Inventory (ARCI) — and argues that, while neurobiological and pharmacological methods have advanced, many psychometric tools have not been revisited with modern statistical techniques. The authors highlight that only a few instruments (notably some versions of the OAV/5D-ASC and the MEQ in limited contexts) have undergone rigorous confirmatory psychometric evaluation, whereas factorial structure, item loadings and reliability of HRS and ARCI have been incompletely assessed or analysed with outdated methods. This study therefore set out to re-examine the factor structure and internal consistency of the MEQ, HRS and the 49-item ARCI using data gathered after naturalistic ayahuasca ceremonies in Spain. The investigators aimed to apply confirmatory and exploratory factor-analytic methods appropriate to ordinal and dichotomous data (polychoric and tetrachoric correlations) and to propose tentative alternative structures or reduced versions when the original theoretical models did not fit the empirical data. The authors also translated the MEQ into Spanish and treated the work as a first transcultural psychometric effort in a sample of ayahuasca users.

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Study Details

  • Study Type
    individual
  • Journal
  • Compound
  • Topic
  • Authors
  • APA Citation

    Bouso, J. C., Pedrero-Pérez, E. J., Gandy, S., & Alcázar-Córcoles, M. Á. (2016). Measuring the subjective: revisiting the psychometric properties of three rating scales that assess the acute effects of hallucinogens. Human Psychopharmacology: Clinical and Experimental, 31(5), 356-372. https://doi.org/10.1002/hup.2545

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