The first speaker was Dr. Mark Geyer (University of California, San Diego, United States), who highlighted the shift of psychedelic research from “Psychotogens to Psychotomimetics to Psychotherapeutics.” He gave an overview of the field’s history with a focus on the psychotomimetic (the potential of psychedelics to mimic psychosis) properties of these substances.

Psychotomimetic properties were an area of substantial interest in the neuropsychiatry field in the mid-twentieth century. Geyer and his colleagues were specifically interested in cross-species research and translational paradigms such as startle response and prepulse inhibition, which are largely altered in people with schizophrenia and related disorders.

As research interests in psychedelics grew, more support was needed. Geyer went on to describe the creation of the Heffter Research Institute and the new area of therapeutic research. He ended by describing the various ongoing studies and the evidence of clinical efficacy for a variety of indications. When asked if he would do anything differently if he had a chance to do things over again, Geyer responded, “I don’t know.”

Next up, Dr. David Yaden (Johns Hopkins University, United States) discussed the importance of instrumentation and methodological advancement to push the field forward. He pointed out that many of the measures used in psychedelic research are a product of W.E.I.R.D. (Western, Educated, Industrialised, Rich, and Democratic). Yaden compared the psychedelic field to where “personality psychology was before the Big 5 was developed,” suggesting that there is room for new, and better, measures.

Engaging the audience, Yaden asked which commonly used scales and their specific measures would predict positive outcomes in psychedelic studies. He shared items from the mystical and challenging experiences questionnaires, the 5- or 11-item altered states of consciousness scale, and the ego dissolution inventory. He then shared data from the Many Analysts Project and ended by sharing The Psychedelic Archives Project, which is focused on gathering relevant accounts from all major population centres worldwide to expand our understanding of psychedelic experiences.

The seminar shifted to Dr. Harriet de Wit (University of Chicago, United States), who discussed research into low doses of psychedelics and the methodological challenges associated with testing mini and microdoses. She began by highlighting the various claims and headlines around these practices, stating: “[It’s] our job to bring this to a lab and see if there is a scientific basis for it.”

Some of the methodological challenges she described included mirroring doses that people are taking in the real world, measuring something that is supposed to be subperceptual, managing expectancies, and deciding how to choose subject samples. de Wit went on to discuss the findings of her laboratory’s studies on low doses of LSD versus placebo. She also described published data where low doses produced no consistent effects on mood or on tasks measuring psychomotor activity or on emotional tasks.

de Wit’s final comments were focused on individual differences between participants and how they may or may not respond to psychedelics. She spoke to issues with some exclusion criteria and how they make studies less generalisable. She completed her talk with a quote from Huston Smith, who referred to Stan Grof’s theory of psychedelics bringing buried patient material to the forefront of consciousness.

Going deeper into human research, Dr. Franz Vollenweider (University of Zürich, Switzerland), shared a variety of studies focused on neuroimaging to understand sense of self and emotional regulation following psychedelic administration or non-drug altered states of consciousness.

A large majority of his work aims to understand what influences the antidepressant effects of psychedelics. Dosing appears to have a large influence, with higher doses producing loss of self and lower doses producing a slightly altered perception of self. There seems to be a sweet spot in the mid-dose range, he said, allowing for increased arousal, emotional activation and uncontrolled thinking that may lead to insights.

Published work by Vollenweider and colleagues has demonstrated receptor occupancy at the serotonin 2A receptor following psychedelic administration in regions relevant for self-processing. He described the dynamic processes of connectivity across regions and how asking questions at different time points could yield greater insights. Their recent work has been aimed at understanding other non-ordinary states of consciousness and the synergies between mindfulness meditation and the psychedelic experience in Zen experts.

The last two presentations of the seminar were on opposite sides of the spectrum, with the first being a highly molecular pharmacology focused discussion with Dr. Bryan Roth (University of North Carolina, Chapel Hill, United States). Roth began by sharing the amount of reagents and tools his lab has shared, including close to 150,000 plasmids through the nonprofit repository Addgene.

To lay the groundwork for his talk, he shared the importance of understanding drug interactions with G protein-coupled receptors (GPCRs), the most common receptors targeted in drug discovery. At one point, he shared an image of a neuron, stating, “This is what a neuron looks like folks, it’s not a little pyramid,” which is how crude images of neurons are typically drawn. The rest of his talk included some unpublished data focused on Gq-signalling related to psychedelic compounds. (Roth recently began a blog to share his thoughts, research and insights into the field.)

The last seminar was by Dr. Scott Thompson (University of Colorado School of Medicine, United States), which focused on the real-world implications of research and the intersection of public health policy. He opened by encouraging the audience to open their minds and think about “how we’re in the mess we’re in” due to the circular distribution of scientific publications. Scientists write for scientists, often leaving the public and ultimately, the policymakers, uninformed, he argued.

Colorado’s Natural Medicine Healing Act passed in 2022, he noted, establishing an advisory board to formulate rules over a two-year period. The first version of the board had no scientific or medical expertise, which led Thompson to create the Psychedelic Public Policy Partnership. The partnership helped to push for the screening of family history of psychosis in potential natural medicine clients, qualification and education requirements for practitioners and other safety considerations.

Thompson shares that this science-policy influence is bidirectional, with public health concerns informing his own lab’s research, as well as others. Some examples include assessing the cardiovascular risk of microdosing, psilocybin and driving risks, and the Open Psychedelic Evaluation Nexus (OPEN), which, among other things, assesses real-world data associated with legal psychedelic use.