on substance use behaviors and depression among this population. A similar recommendation was made by Brook et al. (2014), who advised that treatment for depression should particularly emphasize tobacco prevention and cessation. The chronicity of the associations between depressive symptoms and daily smoking and marijuana use, particularly among females, highlight that prevention and treatment efforts during adolescence could markedly disrupt this comorbidity. With regard to alcohol, the crucial window for intervention appears to be early adolescence, when the comorbidity association is the strongest. While treatment modalities that jointly address depression and substance use have not been well-developed, particularly for adolescents, one promising approach is integrated CBT that focuses on both substance use and depression (Curry et al., 2003). Additionally, a recent study comparing sequential and simultaneous substance use and depression treatment found both to be efficacious (Rohde et al., 2014). Overall, our results highlight notable variation in the association between depressive symptoms and substance use by age, and potentially by gender, suggest that tailoring of prevention and treatment efforts to particular age-gender combinations may produce the greatest public health benefit.
