Dr David Erritzøe, the clinical director of the Psychedelic Research Centre at Imperial College, London, joins us for a far-reaching discussion of research into the use of psychedelic drugs to treat mental health disorders, in particular depression. We touch upon our current understanding of how such drugs may work; challenges in designing clinical trials to test their efficacy such as challenges designing an appropriate placebo arm and using drugs illegal in the UK; the political background to such trials; microdosing; safety and more!