Prospective associations between meth/amphetamine (speed) and MDMA (ecstasy) use and depressive symptoms in secondary school students

Background Research has raised significant concern regarding the affective consequences of synthetic drug use. However, little evidence from well-controlled longitudinal studies exists on these consequences. The aim of this study was to determine whether use of meth/amphetamine (speed) and 63,4- methylenedioxymethamphetamine (MDMA, ecstasy) is independently predictive of subsequent depressive symptoms in adolescents. Methods A sample of 3880 adolescents from secondary schools in disadvantaged areas of Quebec, Canada, were followed over time (2003e2008). Logistic regression was used to test the association between meth/ amphetamine and MDMA use in grade 10 (ages 15e16 years) and elevated depressive symptoms on an abridged Center for Epidemiologic Studies-Depression scale in grade 11, controlling for pre-existing individual and contextual characteristics. Results After adjustment, both MDMA use (OR 1.7, 95% CI 1.1 to 2.6) and meth/amphetamine use (OR 1.6, 95% CI 1.1 to 2.3) in grade 10 significantly increased the odds of elevated depressive symptoms in grade 11. These relationships did not vary by gender or pre-existing depressive symptoms. Increased risk was particularly observed in concurrent usage (OR 1.9, 95% CI 1.2 to 2.9). Conclusions Adolescent use of meth/amphetamine and MDMA (particularly concurrent use) is independently associated with subsequent depressive symptoms. Further enquiry must determine whether these associations reflect drug-induced neurotoxicity and whether adolescence is a period of increased vulnerability to the hazards of synthetic drug exposure.

Adolescent Illicit Drug Use and Subsequent Academic and Psychosocial Adjustment : an Examination of Socially-Mediated Pathways

Background: Questions remain regarding the consequences of illicit drug use on adolescent adjustment and the nature of mechanisms that may explain these consequences. In this study, we examined whether early-onset illicit drug use predicts subsequent academic and psychosocial adjustment and whether associations are socially-mediated by decreased school engagement and increased peer deviancy. Method: 4885 adolescents were followed throughout secondary school. We used regressions to determine whether illicit drug use in grade 7 predicted academic achievement, school dropout, depressive symptoms, and conduct problems in grades 10–11, adjusting for potential confounders. We used path analysis to test whether significant associations were mediated by school engagement and peer deviancy in grade 8. Results: Illicit drug use predicted conduct problems and school dropout, but not academic achievement and depressive symptoms. The association between illicit drug use and conduct problems was fully mediated by increased peer deviancy. The association between illicit drug use and school dropout was partially mediated by increased peer deviancy, but remained mostly direct. No indirect association via decreased school engagement was found. Examination of reverse pathways revealed that conduct problems and academic achievement in grade 7 predicted drug use in grades 10–11. These associations were mediated by peer deviancy and school engagement (conduct problems only). Conclusion: Adolescent illicit drug use influences the risk of school dropout and conduct problems in part by contributing to deviant peer affiliation. Reciprocal social mediation characterizes the association between drug use and conduct problems. A reverse mechanism best explains the association with academic achievement.