The harm caused by alcohol, tobacco and cannabis use in adolescents is substantial. In addition to increased risk of addiction, adolescent substance use can lead to accidents and injuries, medical conditions such as asthma, anxiety, depression, psychosis and impaired brain function, poor academic performance, unintended pregnancies, criminal involvement and even death. These negative consequences are more pronounced with the use of two or more substances by adolescents (comorbid substance use). Understanding patterns and predictors of comorbid substance use among adolescents is important to minimise the resulting harm.
This report explores the patterns of individual and comorbid use of substances (alcohol, tobacco or cannabis) among a nationally representative sample of 14 and 15-year-olds (using data from the 2018 Youth Insights Survey, YIS) in New Zealand. The study also examined trends in the prevalence of individual and comorbid substance use over time (2012-2018 YIS).