Heterogeneity in Pathways Leading to Parenting Intervention Effects for Children with ADHD: An Individual Participant Meta-analysis

Background: Behavioural parenting interventions are evidence-based programs for children with attention-deficit/hyperactivity disorder (ADHD). Gaining insight into individual differences in the pathways leading to intervention effects may contribute to a better understanding of how such interventions work and help personalise interventions. Therefore, we examined whether intervention-related improvements in parenting are related to improvements in child behaviour, and if these relations vary according to parents’ baseline levels of parenting. Methods: We conducted moderated mediation analysis using individual participant data from 19 randomized controlled trials focusing on children with ADHD (n = 1,720). Post-intervention parent reports of child ADHD and oppositional behaviours, and functional impairment, as reported by parents and clinicians, were treated as outcomes. Post-intervention parent reports of constructive parenting (e.g., praise), non-constructive parenting (e.g., physical punishment), and parent-child affection (e.g., warmth) were tested as mediators in the model. Baseline values of each parenting variable were used as moderators of the mediated pathways in the model.Results: Joint intervention improvements (compared to control group) in constructive and non-constructive parenting behaviours and parent-child affection were found to be associated with improvements in children’s behaviour including ADHD severity, oppositional behaviour, and functional impairment. Intervention effects on non-constructive parenting and parent-child affection uniquely accounted for intervention effects on child functional impairment. This link between improvements in non-constructive parenting and functional impairment was strongest for families with higher baseline levels of non-constructive parenting.Conclusions: Joint improvements in parenting behaviours and parent-child affection explained significant variation of parenting intervention effects on children’s behaviour and functional impairment. Unique effects were found for reducing non-constructive parenting on functional impairment, particularly if parents had higher baseline levels of non-constructive parenting. Clinicians should encourage and reinforce improvements in both behavioural and affective components of parenting as these appear to be associated with improvements in child behaviour.