Dimethyltryptamine (DMT): Prevalence, user characteristics and abuse liability in a large global sample

Introduction

DMT (N,N-dimethyltryptamine) is a naturally occurring tryptamine found in mammals and plants worldwide and produces rapid, short-lived but profound alterations of perception and consciousness. Earlier clinical work from the mid-20th century and renewed investigations since the 1990s characterised its subjective effects using structured scales and described pharmacology implicating serotonergic (especially 5-HT2a) mechanisms, some activity at sigma-1 receptors, and marked first-pass metabolism by monoamine oxidase (necessitating MAO inhibitors for oral activity, as in ayahuasca). Smoking emerged ethnographically and pharmacologically as a route that avoids first-pass metabolism, producing an onset within minutes and a brief peak and overall duration much shorter than most other classic psychedelics. Winstock and colleagues note that, despite prior characterisations of subjective experiences, large-scale contemporary data on the prevalence of DMT use and how its effect and risk profile compare with other commonly used psychedelics are lacking. The study therefore set out to estimate the prevalence of DMT use in a large global sample, describe user characteristics, and compare the subjective effect profile and perceived harms of DMT with those of LSD, psilocybin (magic mushrooms) and ketamine, with particular attention to the implications of the smoking route of administration.