References: (1) Rootman I.Trends in self-reported use of marijuana among Canadian teenagers . Chron Dis Can1984;5: 8-9. (2) Hollander M., Davis BLTrends in adolescent alcohol and drug use in Vancouver. Vancouver: Alcohol and Drug Programs, British Columbia Ministry of Health, January 1983. (3) Smart RG, Goodstadt MS, Adlaf EM, Sheppard MA, Chan CGPreliminary report of alcohol and other drug use among Ontario students in 1983, and trends since 1977, Toronto: Addiction Research Foundation, 1983. (4) Mitic W., Neumann B.Drug use among Halifax adolescents—1983 . Halifax : Nova Scotia Commission on Drug Dependency, November 1983 .