Systematic Review of Psychometric Instruments Used in Research with Psychedelics.

There has been a revival of research that studies the subjective effects of psychedelic drugs on humans. Areas of health science have been studying their possible therapeutic benefits, and psychological measurement instruments are being developed as the studies progress. However, these instruments currently suffer criticism regarding their number and evidence of psychometric quality. This study aims to review which psychometric instruments are available to assess subjective states induced by psychedelics. We systematically searched five databases (Web of Science, Academic Search Premier, EMBASE, CINAHL and PubMed) using psychometrics and psychedelics related terms identifying studies published from 1990 to 2021. Of 857 articles generated from the systematic-search, fifteen met our criteria and were included in the review, evaluating nine instruments: MEQ, 5D-ASC, HRS, PSI, EDI, CEQ, EBI, EDI and PIQ. Eight dealing with phenomenological aspects of the psychedelic experience and one as a screening tool for psychotic or manic episode. The purpose of each instrument, the number of items in each version, the type of scale and their elaboration process were described. The number of instruments used in psychedelic research is growing steadily, but there are still many other parts of the psychedelic experience that lack measurement.