Study Summary

Thirty participants with a range of experience using ayahuasca were randomized to receive 14.1-20.1mg of ayahuasca or placebo in this naturalistic, placebo-controlled, observational study exploring the the role of set and setting on the psychological effects of ayahuasca after participation in a non-clinical ayahuasca ceremony. Empathy, subjective drug effects and symptoms of depression stress and anxiety were assessed using the Multifaceted Empathy Test (MET), the Ego Dissolution Inventory (EDI), the 5-Dimensional Altered States of Consciousness Rating Scale (5D-ASC), the Depression, Anxiety, and Stress Scale 21 (DASS-21), the Brief Symptom Inventory 18 (BSI-18), and the Five Facets Mindfulness Questionnaire (FFMQ-39). Study findings indicate that ayahuasca increased emotional empathy to negative stimuli compared to placebo. Subjective ratings of the psychedelic experience were relatively low in both treatment groups and no significant between-group differences were found. Ratings of stress, depression, and anxiety were lower after the ceremony as compared to base-line, independent of treatment group.