Colloquium Meetings 2025-2026
Robin Carhart-Harris
How Psychedelics Work: Illuminating the Hidden Mind.
Dr Carhart-Harris obtained a PhD in Psychopharmacology from the University of Bristol in 2009 before moving to Imperial College London. There, Prof CH and colleagues completed multimodal human functional neuroimaging studies with LSD, psilocybin, MDMA and DMT, and clinical trials of psilocybin therapy for various disorders, including trials in depression, anorexia and fibromyalgia syndrome. Dr CH founded the Centre for Psychedelic Research at Imperial College London in April 2019 and set up the Carhart-Harris Lab at University of California San Francisco in 2023, where he moved in 2021, becoming the Ralph Metzner Distinguished Professorship in Neurology and Psychiatry at University of California. He spoke at the World Economic Forum (WEF) in Davos in 2019, was listed among the top 31 medical scientists by The Times newspaper in 2020, TIME magazine’s ‘100 Next’ in 2021 and Vox Magazine’s ‘Future 50’ in 2023. His research program at UCSF focuses on the action of psychedelics and psychedelic-therapy. He has published widely, including in top-tier scientific and medical journals and will soon release his first book, entitled: How Psychedelics Work.
Abstract
This talk addresses first principles of psychedelic action, beginning with a compound (psychological and pharmacological) definition of what they are. It also defines plasticity and describes how psychedelics enhance a very basic form of plasticity, thereby making people more context sensitive. By definition, psychedelic therapy is a context sensitive combination treatment (CSCT). I offer a candidate biomarker of what I call 'mediational plastity' (M-plasticity), the entropy of spontaneous brain activity (ESBA). I raise the hypothesis that context sensitivity increases (under psychedelics) as a function of increased ESBA. I also introduce recalibrative plasticity (R-plasticity) and suggest some candidates for it. I discuss the relevance of allostatic recalibration and explain what this is and why its relevant to the action of psychedelic therapy. Altogether, this talk will demystify psychedelic medicine, showing that it is neither snake oil nor a traditional pharmacotherapy, rather it is a paradigm challenging CSCT that demands to be understood as such.