Objective: The aim was to explore mediators of change in parent training (PT) for 3- to 8-year-old children with ADHD difficulties. Method: Parents of 64 children received PT with Incredible Years® and assessed child ADHD symptoms and conduct problems and their parenting strategies, parental self-efficacy, and therapeutic alliance before, during, and after PT. Product-of-coefficients mediation analyses in multilevel models were applied, and causal relations between mediators and outcome were investigated in time-lagged analyses. Results: Increased parental self-efficacy and reduced negative parenting statistically mediated reductions in ADHD and conduct problems in the product-of-coefficient analyses. However, time-lagged analyses were unable to detect a causal relation between prior change in mediators and subsequent child symptom reduction. There was limited evidence of therapeutic alliance as mediator of child symptom reduction or change in parenting variables. Conclusion: Parental self-efficacy and reductions in negative parenting may mediate change in PT, but more fine-grained time-lagged analyses are needed to establish causality.
Keywords: ADHD; conduct problems; incredible years; mediation; parent training; treatment.