Abstract

Cannabis is the third most used substance after tobacco and alcohol, with approximately 220 million people reporting its use within the past year globally. Over the last two decades, the prevalence of cannabis consumption has been steadily increasing, in the context of a changing landscape in regulation worldwide.Cannabis legalization for medical and recreational purposes has been implemented in countries like Uruguay, Canada, and the United States, but several others are considering reforms. The effects of these regulatory shifts on cannabis use and health outcomes vary, depending on the population and indicator used. In this chapter we present a brief overview of cannabis history, the distribution of use and related harm across different societies, a description of different regulatory schemes, and their known effect on population use and health, followed by a discussion of emerging themes in cannabis research, including ways of administration, type of products, and measurement challenges. These sections cover relevant aspects of cannabis epidemiology for continued research and policy adaptation.