PLoS ONE
October 24, 2023
Jules Evans, Oliver Robinson, Eirini K. Argyri et al.
166 citations
Long-term adverse experiences after psychedelic use can last weeks, months, or even years and are understudied. A mixed-method study of 608 participants who reported extended difficulties found the most common challenges were anxiety and fear, existential struggle, social disconnection, depersonalization, and derealization. For about one-third of participants, problems persisted over a year; for one-sixth, they lasted more than three years. Shorter difficulties were predicted by knowing the dose and drug type and by lower difficulty during the experience; a narrower range of difficulties was predicted by taking the drug in a guided setting. Implications for harm reduction are discussed.
Frontiers in Psychiatry
June 12, 2023
Rayyan Zafar, Maxim Siegel, Rebecca Harding et al.
95 citations
Psychedelic therapy is regaining scientific and medical interest, with growing evidence for its safety and efficacy in treating psychiatric disorders, including addiction. This review charts research on these interventions for addiction, starting with the socioeconomic impact of addiction and current treatment options. It examines historical studies from the mid-late 1900s, real-world evidence from naturalistic and survey-based studies, and modern clinical trials from first-in-human to phase II. The review also covers translational neuropsychopharmacology techniques like fMRI and PET that help explain therapeutic mechanisms. A better understanding of these treatment effects can optimize psychedelic therapy development and improve patient outcomes.
PloS one
January 1, 2025
Eirini K Argyri, Jules Evans, David Luke et al.
27 citations
Psychedelic experiences can sometimes trigger long-lasting existential distress, marked by confusion about existence and purpose, alongside cognitive, emotional, social, and bodily difficulties. Interviews with 26 people who experienced such distress revealed that ontological challenges—struggles with understanding reality—were common. Participants alleviated distress primarily through 'grounding' practices: embodiment, social connection, and cognitive normalization of their experience. The findings suggest psychedelic experiences act as pivotal mental states that can facilitate transformative learning, challenging and expanding meaning-making. This work contributes to understanding how people reestablish coherence and grow after ontologically challenging psychedelic experiences.
Neuroscience and biobehavioral reviews
July 1, 2026
Marcus J Glennon, Catherine I V Bird, Prateek Yadav et al.
2 citations
Setting up a psychedelic research study involves a long, arduous, and Kafkaesque process with many unstandardised challenges. These complexities challenge existing assumptions about psychiatric prescribing, the placebo effect, and definitions of selfhood. This review brings together major UK psychedelic research teams to formalise these unique considerations, addressing sociocultural, political, legal, pharmacological, safety, study design, and experiential facets. It identifies continuing areas of debate and provides a practical, experience-based guide with recommendations for policymakers and future researchers intending to set up a psychedelic study or clinical trial.
arXiv Preprint Archive
March 28, 2025
Marcus J. Glennon, Catherine I. V. Bird, Prateek Yadav et al.
Setting up a psychedelic study is a long and complex process that presents unique challenges not yet standardized. This review brings together major UK research teams to formalize these considerations, identify ongoing debates, and provide a practical guide for researchers and policymakers. It addresses challenges to existing assumptions about psychiatric prescribing, the placebo effect, and definitions of selfhood. The paper can be read end-to-end or used as a manual with sections for specific needs.