Research library / Review

Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function

Johnson MW, Hendricks PS, Barrett FS, et al. Pharmacology & Therapeutics 2019;197:83-102

This review pulls together several strands of research on classic psychedelics such as LSD, mescaline and psilocybin. It traces their history from religious use through 1950s-60s psychiatry to the research shutdown of the early 1970s. It then covers population studies, which mostly link non-medical use with neutral or positive mental health, while noting that some people are harmed when use is unsupervised. It reviews early clinical trials in end-of-life distress, depression and smoking and alcohol addiction, the evidence that these drugs reliably trigger mystical-type experiences, and brain imaging studies. As a narrative review, it does not systematically weigh evidence or pool results, and many of the trials it describes were small. It is useful as an overview of the field as of 2019.