Investigation of cool and hot executive function in ODD/CD independently of ADHD

Background: Children with oppositional defiant disorder/conduct disorder (ODD/CD) have shown deficits in 'cool' abstract-cognitive, and 'hot' reward-related executive function (EF) tasks. However, it is currently unclear to what extent ODD/CD is associated with neuropsychological deficits, independently of attention deficit hyperactivity disorder (ADHD). Methods: Fifty-nine adolescents with a history of early-onset oppositional problems, 28 with pure ODD/CD symptoms and 31 with ADHD with or without ODD/CD, and 34 healthy controls were administered a task battery measuring motor response inhibition, sustained attention, cognitive flexibility and reward-related decision-making. Findings were analysed using dimensional and group analyses. Results: In group analyses both groups with and without ADHD were impaired in EF measures. Dimensional analyses, however, showed that ODD/CD but not ADHD was related to hot EF based on increased risky decision-making in the Iowa Gambling Task. ODD/CD was also independently related to aspects of cool EF independently of ADHD, namely slower speeds of inhibitory responding and increased intra-subject variability. Conclusions: These findings show EF deficits associated with ODD/CD independently of ADHD, and implicate reward-related abnormalities in theories of antisocial behaviour development.