If psychedelic drugs are introduced in clinical practice, there is a risk that their use will get ahead of the evidence on their safety and efficacy, in much the same way that “medical cannabis” has done, Emeritus Professor Wayne Hall from UQ’s Centre for Youth Substance Abuse Research has cautioned. 
A psychedelic drug is one that “produces thought, mood and perceptual changes otherwise rarely experienced except in dreams, contemplative and religious exaltation, flashes of vivid involuntary memory, and acute psychosis”. It does so “without causing physical addiction, craving, major physiological disturbances, delirium, disorientation or amnesia”.
The “classic psychedelics” include mescaline, psilocybin, lysergic acid diethylamide (LSD), dimethyltryptamine (DMT), and plant-based substances such as ibogaine and ayahuasca. Their chemical structures differ, but they all act on the 5-HT2A serotonin receptor. 3,4-methylenedioxymethamphetamine (MDMA) is also included, although it does not produce the perceptual effects of the classic psychedelics.
Over the past two decades, there has been a revival of clinical research on the therapeutic use of psilocybin and MDMA. This research has been encouraged by the US Food and Drug Administration (FDA) because in phase 2 trials these drugs have produced substantial benefits, respectively, in patients with treatment-resistant depression and post-traumatic stress disorder (PTSD). Funding for psychedelic research has largely been philanthropic, because the pharmaceutical industry is not interested in drugs that are off patent.
Media: Professor Wayne Hall, w.hall@uq.edu.au; Kirsten O’Leary, UQ Communications, k.oleary@uq.edu.au, +61 7 3365 7436, @UQhealth.
