Previous GBD studies (GBD 1990 and its subsequent updates) significantly enhanced the global awareness of the burden of mental and substance use disorders[11-13] but did not include cannabis dependence. In 1990 the drug use disorder estimate was defined as ‘dysfunctional and harmful drug use’[11] and in 2002 ‘opioid dependence and harmful use and cocaine dependence’ were included as one group[12].
