Cannabis is globally the most commonly used psychoactive substance under international control. In 2013, an estimated 181.8 million people aged 15-64 years used cannabis for nonmedical purposes globally (uncertainty estimates 128.5–232.1 million) (UNODC, 2015). There is an increasing demand of treatment for cannabis use disorders and associated health conditions in high- and middle-income countries, and there has been increased attention to the public health aspects of cannabis use and related disorders in international drug policy dialogues.

This publication builds on contributions from a broad range of experts and researchers from different parts of the world. It aims to present the current knowledge on the impact of nonmedical cannabis use on health.