Organization interventions as a mediator of change in grades in the Challenging Horizons Program.

This study evaluated whether an organization intervention was a mediator of change for grade point average (GPA) in a randomized clinical trial of a school-based treatment program for adolescents with attention deficit hyperactivity disorder (ADHD). A demographically diverse sample of 148 participants (105 males) with a diagnosis of ADHD were recruited from nine middle schools. Comprehensive diagnostic evaluations were completed and participants were randomized into one of three conditions (two active treatment conditions, one control condition) for a randomized clinical trial that lasted an entire school year. The results of the trial are reported elsewhere (Evans et al., 2016; Schultz et al., 2017); in this study we evaluated four of the criteria for determining mediation as reported by Kazdin (2007) to determine whether response to the organization intervention in this school-based treatment program mediated the relationship between dosage and GPA beyond previous GPA. The results provided evidence that response to the organization intervention mediated the relationship between intervention dosage and change in GPA.