In addition, the use of the term lifetime to describe the prevalence of substance use disorders in adolescence does not necessarily indicate the persistence of these disorders in the long term, in particular because individuals may “mature out” of harmful substance use as they progress into adulthood or begin to assume adult responsibilities.37,38 A final limitation of the present investigation is that it cannot account for societal factors that vary over time and that affect prevalence rates, such as the degree of tolerance for specific illicit substances or their availability. It is important to consider that psychoactive substances are implicated in more than 12% of mortality worldwide and their use constitutes the leading cause of preventable death.39,40 Because the early onset of substance use is a significant predictor of substance use behavior and disorders in a life-span,1–9 the public health implications of the current findings are far reaching. The prevention of both alcohol and illicit drug abuse requires strategies that target early adolescence and take into account the highly differential influence that population-based factors may exert by stage of substance
