Measuring the subjective: revisiting the psychometric properties of three rating scales that assess the acute effects of hallucinogens.
José Carlos Bouso, Eduardo José Pedrero-pérez, Sam Gandy, Miguel Ángel Alcázar-córcoles
Human psychopharmacology September 1, 2016 Peer reviewed DOI: 10.1002/hup.2545 via PubMed
Summary
The study assessed the psychometric properties of three questionnaires used to evaluate the effects of hallucinogens in 158 subjects (100 men) who took ayahuasca. The findings revealed that the results did not consistently align with existing theoretical proposals, suggesting that previous studies may have used inappropriate psychometric methods. The authors emphasize the need for larger samples and precise measurement tools to better understand the subjective effects of psychedelics.
Study at a glance
| Design | observational cohort |
|---|---|
| Sample size | 158 |
| Population | subjects who took ayahuasca |
| Key finding | The results did not consistently match theoretical proposals regarding the psychometric properties of the questionnaires used. |
Abstract
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). 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. 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. 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.