These researchers examined data from 3 nationally representative New Zealand Youth 2000 surveys (undertaken in 2001, 2007 and 2012), which documented a decline in cannabis use among secondary school students over this period of time. This investigation sought to determine whether changes in adolescent cannabis use occurred across all demographic groups and whether this decline was offset by increasing use of other psychoactive drugs. The decline in adolescent cannabis use was consistent across all main demographic groups (including age, ethnic, sex and socioeconomic groups) and there was no evidence of an accompanying rise in the use of other psychoactive drugs. Ethnic and socioeconomic differences in adolescent cannabis use decreased between 2001 and 2012, with Māori, younger students and students from low decile schools exhibiting the greatest reductions in cannabis use over time.