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

• Published in: Human psychopharmacology 2016-09, Vol.31 (5), p.356-372
• Main Authors: Bouso, José Carlos, Pedrero-Pérez, Eduardo José, Gandy, Sam, Alcázar-Córcoles, Miguel Ángel
• Format: Article
• Language: English
• Subjects: Addiction Research Center Inventory (ARCI); Adult; ayahuasca; Banisteriopsis - chemistry; Factor Analysis, Statistical; Female; Hallucinogen Rating Scale (HRS); Hallucinogens - administration & dosage; Hallucinogens - pharmacology; Humans; Male; Middle Aged; Mystical Experience Questionnaire (MEQ); N,N-Dimethyltryptamine - administration & dosage; N,N-Dimethyltryptamine - pharmacology; Plant Preparations - administration & dosage; Plant Preparations - pharmacology; psychedelics; Psychometrics; Surveys and Questionnaires; Young Adult
• ISSN: 0885-6222; 1099-1077
• DOI: 10.1002/hup.2545

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.