Adolescent treatment outcomes for comorbid depression and substance misuse: A systematic review and synthesis of the literature

•CBT, MET, FCT and SSRIs treat adolescents with depression and substance misuse•Treatments gains are inconsistent across measures of depression•Treatment gains are equivocal for substance misuse•Sequencing treatment to address substance misuse first might improve outcomes•Improvements in reward processing and self-efficacy are two potential mediators

The quantitative literature on the treatment of comorbid depression and substance misuse among adolescents was reviewed, including: (1) a synthesis of the empirical evidence of the multiple models of integrated treatment for depression and substance use, (2) an examination of proposed mechanisms underlying symptom change in these integrated treatment models targeting depression and substance use, and (3) a methodological critique and suggestions for future research. We reviewed 15 studies reporting on treatment outcomes among adolescents with comorbid depression and non-tobacco related substance use disorders (SUD) and general misuse. Although there is empirical evidence linking Cognitive-Behavioral Therapy (CBT), Motivational Enhancement Therapy (MET), and Family-Focused Therapy (FFT) to depression and SUD symptom reduction in adolescents, few studies have provided data on mechanisms that may account for this effect. Potential mechanisms include improvements in dysfunctional reward processing and self-efficacy. Although this review highlights promising findings for the treatment of comorbid depression and substance misuse in adolescents, further work is warranted; as such results could have important implications for intervention development.