Parenting Practices as Mediators of Treatment Effects in an Early-Intervention Trial of Multidimensional Family Therapy

Abstract

Background: Contemporary intervention models use research about the determinants of adolescent problems and their course of symptom development to design targeted interventions. Because developmental detours begin frequently during early-mid adolescence, specialized interventions that target known risk and protective factors in this period are needed. Methods: This study (n = 83) examined parenting practices as mediators of treatment effects in an early-intervention trial comparing Multidimensional Family Therapy (MDFT), and a peer group intervention. Participants were clinically referred, low-income, predominantly ethnic minority adolescents (average age 14). Assessments were conducted at intake, and six weeks after intake, discharge, and at 6 and 12 months following intake. Results: Previous studies demonstrated that MDFT was more effective than active treatments as well as services as usual in decreasing substance use and improving abstinence rates. The current study demonstrated that MDFT improves parental monitoring—a fundamental treatment target—to a greater extent than group therapy, and these improvements occur during the period of active intervention, satisfying state-of-the-science criteria for assessing mediation in randomized clinical trials. Conclusions and Scientific Significance: Findings indicate that change in MDFT occurs through improvements in parenting practices. These results set the foundation for examining family factors as mediators in other samples.

Keywords:

• Adolescent substance abuse
• mediation
• multidimensional family therapy
• young adolescents

Notes

¹The negative valence items were not further analyzed due to extreme parameter estimates, indicating that the items did not provide a good match to the samples' severity of these negative interactions (i.e., item threshold values exceeded values of 6).

²We were unable to estimate bootstrapped mediation test statistics using the asymmetric confidence interval method ([26]) because the procedures are not available when using the numerical integration techniques that are necessary to estimate two-part models.