The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. [...] DR SHEKHAR SAXENA DIRECTOR DEPARTMENT OF MENTAL HEALTH AND SUBSTANCE ABUSE v The health and social effects of nonmedical cannabis use ACKNOWLEDGEMENTS 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. [...] The purpose of the meeting was to review the latest evidence of the impact of nonmedical cannabis use on health, which is defined by WHO as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.1 The meeting also addressed health system responses to cannabis- use disorders and other health conditions caused by or associated with nonmedical ca [...] The discussion of the health and social consequences of cannabis use is limited to the nonmedical use of the cannabis plant. [...] Even with a fixed dose of THC in a cannabis cigarette, THC pharmacokinetics and effects vary as a function of the weight of the cannabis cigarette, the THC potency in the cigarette, its preparation, the concentration of other cannabinoids, the rate of inhalation, the depth and duration of puffs, the volume inhaled, the extent of breath-holding, the vital capacity and the escaped smoke and dose tit