Episode 312B
Robin Carhart-Harris, Ph.D.
In this episode of The Psychedelic Podcast, Paul F. Austin is joined by renowned neuroscientist Dr. Robin Carhart-Harris and microdosing policy advocate John Downs for a replay of a live event originally held on June 10th, Microdosing vs. SSRIs: What’s Happening in the Brain and Why It Matters. Together, they explore the scientific distinctions between SSRIs and psychedelics, focusing on neuroimaging, brain entropy, emotional processing, and the REBUS model. Dr. Carhart-Harris shares key insights from landmark studies on psilocybin therapy and discusses the evidence (and limitations) around microdosing. John Downs closes the conversation with an update on the Microdosing Collective’s efforts to shift policy and expand access.
Robin Carhart-Harris, PhD is a neuropharmacologist, psychologist, and Ralph Metzner Distinguished Professor in Neurology and Psychiatry at the University of California, San Francisco. He leads the Psychedelics Division at UCSF’s Neuroscape and formerly founded and led the Centre for Psychedelic Research at Imperial College London.
John Downs is Executive Director of the Microdosing Collective, advocating for responsible policy reform and legal access to microdosing. With 25 years’ experience in sales, business development, and emerging markets, John helps individuals optimize mindset, performance, and purpose.
Podcast Highlights
- Why SSRIs blunt, while psychedelics reset emotional processing
- How psilocybin compares to antidepressants in clinical trials
- Brain entropy, plasticity, and the REBUS model explained
- The role of the default mode network in mental health
- Why microdosing research is still so limited
- Ketamine vs. psilocybin: differences in brain mechanisms
- Is serotonin syndrome a real microdosing risk?
- Can psychedelics reverse long-term SSRI effects?
- The Microdosing Collective’s mission for policy reform
- What Robin Carhart-Harris’ upcoming book will explore
Show Links
Join Paul F. Austin and Dr. Dave Rabin live on September 1st to map where your role begins and ends when a client on antidepressants asks for support: what you can hold, what belongs to the prescriber, and how the two of you keep the client safe.
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A 3-month live online training led by board-certified psychiatrist Dr. Dave Rabin for therapists, clinicians, coaches, and facilitators working with medicated clients. Learn practical frameworks for tapering, withdrawal vs. relapse, prescriber collaboration, psychedelic readiness, and supporting clients within your scope.
Next cohort begins September 16, 2026.
