Objective: We evaluated the effects of treatment compliance with the Challenging Horizons Program (CHP) for high school aged adolescents with attention-deficit hyperactivity disorder (ADHD).
Method: Participants were 185 high school aged adolescents (65% non-Hispanic White; 79% male) with a diagnosis of ADHD who were randomly assigned to either CHP or community control. Outcomes included parent-rated academic functioning, parent- and self-rated social-emotional functioning, and GPA. The complier average causal effect (CACE) was estimated using propensity-weighted models for youth engaging in ≥ 30 CHP individual sessions (15-20 min) across the academic year.
Results: Most (78%) CHP participants engaged in≥30 CHP sessions. CACE analyses using latent growth curve modeling revealed significant treatment effects among treatment compliers across ratings of academic and social outcomes relative to similar control participants. For most outcomes, CACE estimates were larger than those found in intent-to-treat analyses, especially at 6-months follow-up.
Conclusions: Compliance with 30 or more individual CHP sessions appeared to be an attainable threshold associated with incremental gains across several academic and social outcomes. Effects of compliance were amplified at 6-months follow-up, supporting the hypothesized theory of change of training interventions. Future work should focus on facilitators of treatment engagement and feasibility of the CHP as delivered by high school personnel.