Cannabis is globally the most commonly used psychoactive substance under international control. There is an increasing attention to health and social consequences of nonmedical cannabis use, including cannabis use disorders. The purpose of this brief is to provide concise up-to-date information on the global epidemiology of nonmedical use of cannabis, the short-term adverse health effects of cannabis use, and the long-term adverse effects of regular cannabis use on mental and physical health and social outcomes.

Scope – effects of nonmedical cannabis use - This brief presents an update of the evidence on the negative health and social effects of nonmedical cannabis use since 2016, and especially its impacts on adolescents and young adults. The subjective positive effects experienced by some people using cannabis and the therapeutic benefits from medical preparations of cannabis are outside the scope of this brief, as are prevention and treatment policies which are discussed elsewhere. This document is not normative in nature and does not intend to make recommendations.