Predicting cannabis use among adolescents in four European Countries: combining personal values and the theory of planned behaviour

Abstract

Aims: The onset and maintenance of cannabis use have been explained with reference to the Theory of Planned Behaviour (TPB). At the same time, personal values play an important role in determining appropriate behaviour during social interactions, and cannabis use is no exception. Combining Schwartz’s Theory of Human Values and the TPB offers a framework for identifying the relationship between adolescents’ personal values structure and cannabis use. The two main aims of this study are to: (1) test a predictive model that combines these two theories to explore the interaction of cultural and personal variables that influence cannabis use during adolescence; and (2) analyse the moderation effect of four European countries on the proposed model. Methods: A total of 3768 secondary school students from Spain, Italy, Romania and Portugal completed a questionnaire on personal values and the TPB applied to cannabis use intention. Direct and indirect effects were assessed using path analysis and moderation effects using multi-group analysis.Results: Collectivistic values (i.e. conformity and tradition) were associated with low cannabis intention and use, individualistic values (i.e. hedonism and power) with higher cannabis intention and use. Regarding the moderation effect of countries, the effects of attitudes on intention and cannabis use were higher among Italian participants, who also showed a high prevalence of cannabis use. Meanwhile the effect of abstinence self-efficacy was lower among Romanian and Portuguese participants, both of whom reported lower cannabis use.Conclusion: The results support the notion that personal values are background variables that affect cannabis use through the TPB variables.