To study community-dwelling adolescents with AUDs but with no comorbid substance use disorders (SUDs) is important because doing otherwise would make it impossible to disentangle the effects of alcohol on brain structure and function from those of other substances. This goal has been challenging in the United States because the majority of adolescents with AUDs also have substantial histories of other substance use (Substance Abuse and Mental Health Services Administration, 2007). Amongst adolescents in South Africa, however, alcohol (followed by tobacco) remains the most popularly used substance of abuse, despite some recent changes in trends amongst youth seeking treatment (Parry et al., 2004; Pluddemann, 2008). For instance, surveys in Cape Town schools show that untreated adolescents prefer alcohol to cannabis (the most frequently used illicit substance), and demonstrate lower incidence of mixed substance abuse than found in the USA. The reported lifetime prevalence of adolescent substance use indicates that 66% of males and 48% of females consume alcohol, compared to 32% of males and 13% of females who use cannabis. Recent (past month) alcohol use (particularly weekend binge-drinking) is reported
