Common and differential factors associated with abstinence and poly drug use among Australian adolescents

Background: Social norms relating to youth substance use are changing. In Australia, alcohol use among adolescents has fallen dramatically and tobacco and cannabis use have also reduced, albeit more moderately. The aim of the present study was to identify (i) factors associated with compliance with recommendations for zero intake of alcohol, tobacco, and cannabis and (ii) factors associated with poly drug use (intake of all three substances).

Methods: As part of the Young Minds Matter Study, a self-report survey was administered to 1661 Australian adolescents aged 15-17 years. The survey included items relating to: substance use; psychological, social, and protective factors; and demographic characteristics. Probit regression analyses were conducted to generate a model of factors associated with abstinence from all three substances and a model of factors associated with the use of all three substances.

Results: While there were substantial differences between the two models indicating that different factors may influence the initiation of substance use versus poly drug use, there were also several common factors that operated in opposite directions. These were child age, degree of parental supervision and monitoring, the experience of externalising problems, and a diagnosis of major depression.

Conclusion: The results highlight the potential utility of targeting high-risk youth by identifying (i) parents' supervision and monitoring behaviours and (ii) children's externalising problems and symptoms of depression. Directly addressing these factors in substance-use interventions may delay or prevent initiation while also reducing the likelihood of adolescents engaging in poly drug use.