There is increasing interest in the potential for psychedelic drugs such as psilocybin, LSD and ketamine to treat several mental health disorders, with a growing number of randomised controlled trials (RCTs) being conducted to investigate the therapeutic effectiveness of psychedelics. In order for an RCT to give an unbiased estimate of treatment effect size, participants and persons involved in the conduct of the trial should remain blinded to the intervention – a requirement difficult to achieve given the strong subjective effects of psychedelics. While psychedelic RCTs have generally shown promising results, with large effect sizes reported, these are likely over-estimated due to de-blinding of participants and high levels of response expectancy. The implications of medical regulators potentially  approving psychedelic drugs as medicines despite these confounds existing in trial data will be discussed.


Dr Suresh Muthukumarasway is currently an Associate Professor in psychopharmacology at The University of Auckland.

Suresh started studying psychedelic drugs in 2011, collaborating with Professor David Nutt and Dr Robin Carhart-Harris, investigating the electrophysiology of psilocybin. Since then he has been involved in neuroscience studies of LSD, ketamine, DMT and ayahuasca. His research group is soon to start the first placebo controlled study of LSD microdosing, where participants will be allowed to take LSD at home on prescription.

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