Abstract
This narrative review summarises the latest evidence on the causes and consequences of substance use in adolescence and describes long-term trends in adolescent alcohol, tobacco and cannabis use in Aotearoa. Adolescence is a time of rapid brain development when young people are uniquely vulnerable to the risks of substance use. It is a major cause of health and social harm in this age group and can affect adult outcomes and the health of the next generation. Therefore, substance use trends are central to understanding the current and future state of child and youth wellbeing in Aotearoa. Adolescent use of alcohol, tobacco and cannabis peaked in the late 1990s/early 2000s, then declined rapidly, and prevalence is now much lower than 20 years ago. However, levels of adolescent binge drinking remain high by international standards and disparities in tobacco and cannabis use by ethnicity and socioeconomic status are wide. Evidence suggests we may again be at a turning point, with-long term declines stalling or reversing in the past 2-5 years, and vaping emerging as a new risk. Greater investment in primary prevention is indicated, including restrictions on alcohol marketing and availability, and alleviation of poverty, racism and marginalisation.