Declining adolescent cannabis use occurred across all demographic groups and was accompanied by declining use of other psychoactive drugs, New Zealand, 2001–2012

AIM: Cannabis use declined in New Zealand adolescents between 2001 and 2012. We investigated i) whether changes in adolescent cannabis use occurred across all demographic groups, and ii) whether declining cannabis use was accompanied by increasing use of other psychoactive drugs. METHOD: We conducted secondary analysis of repeat cross-sectional data from nationally representative surveys of secondary school students (2001, 2007, 2012) to determine trends in never-use of cannabis and other psychoactive drugs by age, sex, ethnicity, deprivation, school decile and urban/rural locale. Logistic regression was used to test whether changes in cannabis non-use over time varied between demographic groups. RESULTS: Never-use of cannabis and of other psychoactive substances increased between 2001 and 2012 in all included age, ethnic, sex and socioeconomic groups. Māori, younger students and those in low decile schools demonstrated the greatest reductions in cannabis use over the study period. CONCLUSION: The decline in adolescent cannabis use between 2001 and 2012 occurred across all main demographic groups and was not accompanied by a rise in the use of other psychoactive drugs. Ethnic and socioeconomic inequities in adolescent cannabis use decreased over the study period.