Cannabis supply and demand reduction: Evidence from the ESPAD study of adolescents in 31 European countries

Abstract

Aims: Most national drug policies target both the supply side and the demand side of illicit drug use. Although such policies are intended to affect individual choices, they by definition operate on a national level and cannot be evaluated solely on the basis of individual-level differences. This study aims to evaluate the impact of country-level differences in the availability and perceived risk of cannabis use on individual-level adolescent cannabis use.

Method: The study is based on an analysis of 84,711 students in 31 European countries. Multilevel modelling techniques are used to estimate the effects of country-level differences in the perceptions of availability and risk among non-users on individual-level odds of 30-day cannabis use.

Findings: On the individual level, adolescents who use cannabis find it easier to obtain and less risky if they have used the drug. Controlling for these individual-level associations, adolescents are also found to be less likely to use cannabis in countries where non-users report less availability and more risks associated with cannabis use.

Conclusions: These findings support the notion that both supply reduction and demand reduction may reduce the prevalence of adolescent substance use.

Acknowledgements

The authors would like to thank the Principal Investigators in the participating countries for access to the international ESPAD data. In the United Kingdom the ESPAD project was mainly funded by the Wates Foundation and the University of the West of England. Additional support was provided by the Joseph Rowntree Foundation, the Oakdale Trust, Butcombe Brewery Ltd., Dr. George Carey, the Jack Goldhill Charitable Trust, R & J Lass Charities Ltd., and the North British Distillery Company. For a list of funding agencies and supportive organizations in the other thirty countries see Hibell et al., 2004.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.