Scoping Review of Experiential Measures from Psychedelic Research and Clinical Trials

This review (2022) investigates the subjective (experiential) measures that are being used in psychedelic trials and finds good correlations between mystical experiences (MEQ) and oceanic boundlessness and therapeutic/mood outcomes. Similar results (with fewer participants studied) are also found for challenging experiences, psychological insight, and emotional breakthroughs. Alas, not much comment is made about the construct validity of the measures.


“Subjective responses to psychoactive drugs have served as intriguing windows into consciousness as well as useful predictors. Subjective reactions to psychedelic molecules are particularly interesting given how they covary with subsequent improvements associated with psychedelic-assisted treatments. Although links between subjective reactions and decreases in treatment-resistant clinical depression, end-of-life anxiety, and maladaptive consumption of alcohol and nicotine appear in the empirical literature, the measurement of these subjective responses has proven difficult. Several scales developed over many decades show reasonable internal consistency. Studies suggest that many have a replicable factor structure and other good psychometric properties, but samples are often small and self-selected. We review the psychometric properties of some of the most widely used scales and detail their links to improvement in response to psychedelic-assisted treatments. Generally, assessments of mystical experiences or oceanic boundlessness correlate with improvements. Challenging subjective experiences, psychological insight, and emotional breakthroughs also show considerable promise, though replication would strengthen conclusions. We suggest a collaborative approach where investigators can focus on key responses to ensure that the field will eventually have data from many participants who report their subjective reactions to psychedelic molecules in a therapeutic setting. This may aid in predicting improvement amongst targeted conditions and wellbeing.”

Authors: Zachery Herrmann, Mitch Earleywine, Joseph De Leo, Sarah Slabaugh, Timothy Kenny & A. John Rush