Inhibitory Control Deficits in Children with Oppositional Defiant Disorder and Conduct Disorder Compared to Attention Deficit/Hyperactivity Disorder: A Systematic Review and Meta-analysis

Inhibitory control deficits are known to be characteristic of Oppositional Defiant Disorder (ODD), Conduct Disorder (CD), and Attention-Deficit/Hyperactivity Disorder (ADHD); but it is unclear whether children with ODD/CD have inhibitory control problems independent of ADHD comorbidity. Previous reviews of inhibitory control and ODD/CD have only focused on one type of measure of inhibitory control or used non-clinical samples. The current meta-analysis explored inhibitory control problems of children with ODD/CD by systematically reviewing studies where children have a diagnosis of ODD and/or CD. Comparisons were made across 25 studies between children with ODD/CD, ODD/CD + ADHD, ADHD, and healthy controls (HC) on various measures of inhibitory control and ADHD symptomatology to explore impacts of ADHD comorbidity. A small significant effect (g = -0.58, p < .001) suggested children with ODD/CD are likely to have more difficulties with inhibitory control than healthy children. However, comparisons between clinical groups suggested this effect may be due to ADHD symptomatology present in each group. As difficulties with inhibitory control are similar, across clinical groups, a dimensional approach to understanding ODD/CD and ADHD may be more useful to consider in future diagnostic criteria. Similarities across clinical groups highlight that therapeutic approaches that assist children with disruptive behaviours could benefit from teaching children and their families how to cope with inhibitory control deficits.