Insight Conference
Dr. Chris Letheby
11:00am - 11:30am
Room 4


The causal relevance of psychedelic experiences to therapeutic benefits

Increasing evidence suggests that psychedelic-assisted psychotherapy can durably reduce symptoms of anxiety, depression, and addiction. Despite increasing enthusiasm about this treatment modality, including “Breakthrough Therapy” designations and talk of a “new paradigm” in psychiatry, fundamental questions remain unresolved. First, it is unclear whether psychedelic administration has a genuine causal effect on symptomatology, given problems concerning blinding and placebo control. Second, if there is a real causal effect, it is unclear whether it is caused partly by psychedelic experiences themselves, or wholly by non-experiential neurobiological processes. So far, both questions have eluded decisive empirical resolution. Building on recent discussions of these issues, I formulate novel, or at least under-appreciated, arguments that psychedelic treatments do have a genuine causal effect on psychiatric symptoms, and that psychedelic experiences themselves are part of the causal mechanism underlying this effect. These arguments involve interpreting existing empirical evidence through the lens of philosophical frameworks for thinking about mechanistic explanation, levels of explanation, and mechanistic evidence. I also consider possible experimental avenues for making further progress on these issues.


Lecturer in Philosophy & Postdoctoral Researcher

Dr. Chris Letheby

University of Western Australia & University of Adelaide
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