Management of substance abuse

The health and social effects of nonmedical cannabis use

New WHO publication on cannabis


The report was prepared by the Management of Substance Abuse (MSB) unit in the Department of Mental Health and Substance Abuse (MSD) of the World Health Organization (WHO), Geneva, Switzerland.

Executive editors: Wayne Hall, Maria Renström and Vladimir Poznyak

The WHO staff involved in production of this document, developed under the overall guidance of Shekhar Saxena, Director, Department of Mental Health and Substance Abuse, were: Vladimir Poznyak, Maria Renström, Elise Gehring, Dag Rekve and Nicolas Clark. The report benefited from technical inputs to all chapters by Lauren Chidsey in her capacity as a consultant, Dr Meleckidzedeck Khayesi, Department of Management NCDs, Disability, Violence & Injury Prevention (NVI), Dr Eda Lopato, Department of Essential Medicines and Health Products (EMP) and Dr Lars Moller, WHO Regional Office for Europe..

WHO wishes to acknowledge the particular contribution of Wayne Hall, Centre for Youth Substance Abuse Research, Australia, as the main writer and editor of this document. Furthermore, special thanks are due to the members of the drafting group, namely: Louisa Degenhardt, National Drug and Alcohol Research Centre (NDARC), Australia; Jurgen Rehm, Centre for Addiction and Mental Health (CAMH), Canada; and Amy Porath-Waller, Canadian Centre on Substance Abuse (CCSA), Canada.

WHO would like to acknowledge the contributions made by the following individuals to the development of this document: Peter Allebeck, Karolinska Institute, Sweden; Courtney L Bagge, University of Mississippi Medical Center, USA; Ruben Baler, National Institute on Drug Abuse (NIDA), USA; Vivek Benegal, National Institute of Mental Health and Neurosciences, India; Guilherme Borges, Institute of Psychiatry, Mexico; Bruna Brands, University of Toronto, Canada; Paul Dargan, Guy’s and St. Thomas’ NHS Foundation Trust, United Kingdom; Marica Ferri, European Monitoring Centre for Drugs and Drug Addiction (EMCDDA); Valerie Wolff Galani, University Hospital of Strasbourg, France; Gilberto Gerra, United Nations Office on Drugs and Crime (UNODC); Paul Griffiths, European Monitoring Centre for Drugs and Drug Addiction (EMCDDA); Hongxing Hu, Xinjiang Medical University, China; Carlos Ibanez Pina, University of Chile, Chile; Emilie Jouanjus, University of Toulouse, France; Bertha K Madras, Harvard Medical School, USA; David Ndetei, Africa Mental Health Foundation, Kenya; Rajat Ray, Himalayan Institute of Medical Sciences, India; Jallal Toufiq, Ar-razi University Psychiatric Hospital and the National Center on Drug Abuse Prevention, Treatment and Research, Morocco; Roy Robertson, University of Edinburgh, United Kingdom; Camila Silveira, Institute of Psychiatry, University of São Paulo Medical School, Brazil; Kurt Straif, International Agency for Research on Cancer (IARC); Donald Tashkin, David Geffen School of Medicine at UCLA, USA; Nora Volkow, National Institute on Drug Abuse (NIDA), USA.

David Bramley edited the report with the help of Lauren Chidsey, and Irène R. Lengui was responsible for the graphic design and layout.

Administrative support was provided by Divina Maramba.

WHO interns who contributed to the report include: Enying Gong, Cesar Leos-Toro, Sharon Lee and Sergio Scro.

WHO gratefully acknowledges the financial and organizational support provided to this project by the Ministry of Health and Social Affairs, Sweden.

This publication contains the collective views of an international group of experts, and does not necessarily represent the decisions or the stated policy of the World Health Organization.