Cannabis is amongst the most commonly used illicit psychoactive substances in developed nations (1;2). Ten percent of individuals who ever use cannabis meet criteria for lifetime cannabis dependence, which is associated with significant comorbid adverse mental health outcomes (3–5). A recent survey of U.S. adults showed that the past year prevalence of cannabis use disorders has increased from 1.5% to 2.9% in the decade spanning 2002–2012, an increase apparently attributable to a corresponding increase in use during that period of time (6).
