Method: This study utilized a large statewide youth risk surveillance dataset of youth self-report of substance use and related risk and protective factors as measured by the CTC Youth Survey (Glaser et al, 2005). A total of 217, 276 adolescents in grades 6, 8, 10, and 12 were assessed. Structural Equation Models utilizing FIML followed by tests of moderation of implied pathways were used to test hypotheses. Latent variables representing youth attitudes, subjective norms, and perceived behavioral control regarding marijuana use were regressed on intentions to use and lifetime incidence.
Results: The overall model fit of the Theory of Planned behavior predicting adolescent marijuana use provided good fit to the data (c2(51) = 52848, p < 0.001, CFI = 0.96, TLI = 0.92, RMSEA = 0.06, NFI = 0.96). After controlling for core features of the TPB model, several features of the school environment continued to moderated the relationship between intention and use including academic performance (β = .013, p <.001), school commitment (β = -.02, p<.001), positive home-school communication (β = .09, p<.05), teacher praise (β =.02, p<.001), and rewards for prosocial involvement (β = .09, p<.001). The availability of organized prosocial activities (e.g., sports, clubs) did not significantly influence substance use decisions.
Conclusion: These findings replicate and extend the Theory of Planned Behavior as applied to adolescent marijuana use, and provide additional evidence of how features of the school context directly influence adolescent marijuana use decision-making. Greater attention to these organizational variables may help potentiate the effect of universal school-based drug prevention programming.