Ayahuasca is a plant concoction containing N,N-dimethyltryptamine (DMT) and certain β-carboline alkaloids from South America. Previous research in naturalistic settings has suggested that ingestion of ayahuasca can improve mental health and well-being; however, these studies were not placebo controlled and did not control for the possibility of expectation bias. This naturalistic observational study was designed to assess whether mental health changes were produced by ayahuasca or by set and setting. Assessments were made pre- and post-ayahuasca sessions in 30 experienced participants of ayahuasca retreats hosted in the Netherlands, Spain, and Germany. Participants consumed ayahuasca (N = 14) or placebo (N = 16). Analysis revealed a main effect of time on symptoms of depression, anxiety, and stress. Compared to baseline, symptoms reduced in both groups after the ceremony, independent of treatment. There was a main treatment × time interaction on implicit emotional empathy, indicating that ayahuasca increased emotional empathy to negative stimuli. The current findings suggest that improvements in mental health of participants of ayahuasca ceremonies can be driven by non-pharmacological factors that constitute a placebo response but also by pharmacological factors that are related to the use of ayahuasca. These findings stress the importance of placebo-controlled designs in psychedelic research and the need to further explore the contribution of non-pharmacological factors to the psychedelic experience.

Ayahuasca是一种植物混合物，含有N，N-二甲基色胺（DMT）和某些来自南美的β-咔啉生物碱。以前在自然主义环境中的研究表明，摄入树花可以改善心理健康和幸福感。但是，这些研究不受安慰剂控制，也没有控制预期偏差的可能性。这项自然主义的观察性研究旨在评估心理健康的改变是由阿育吠陀还是由环境和习俗引起的。评估是在荷兰，西班牙和德国举办的ayahuasca静修会的30名经验丰富的参与者进行的ayahuasca之前和之后的会议中进行的。参与者食用ayahuasca（N = 14）或安慰剂（N= 16）。分析显示时间对抑郁，焦虑和压力症状有主要影响。与基线相比，仪式后两组患者的症状均减轻，与治疗无关。对内隐情绪移情有一种主要的治疗方式×时间交互作用，表明ayahuasca增加了对负面刺激的情绪移情。目前的发现表明，阿育吠陀仪式参加者心理健康的改善可以由构成安慰剂反应的非药理学因素驱动，也可以由与使用阿育吠陀有关的药理学因素驱动。这些发现强调了迷幻药研究中安慰剂对照设计的重要性，以及需要进一步探索非药理学因素对迷幻药体验的贡献。