J Child Psychol Psychiatry 2010 Aug 12;51(8):895-904. Epub 2010 Apr 12.
Department of Psychology, University of Aarhus, Aarhus, Denmark.
Objective: The study investigates behavioural, academic, cognitive, and motivational aspects of functioning in school-age children with attention-deficit/hyperactivity disorder (ADHD) with and without an executive function deficit (EFD).
Method: Children with ADHD--EFD (n = 22) and children with ADHD + EFD (n = 26) were compared on aspects of ADHD behaviour, school functioning, general cognitive ability, intra-individual response variability, affective decision-making, and delay aversion.
Results: Children with ADHD--EFD and children with ADHD + EFD were comparable in terms of ADHD symptomatology and school functioning. However, children with ADHD + EFD had significantly lower IQ and more intra-individual response variability than no EFD counterparts. Children with ADHD alone appeared more delay averse on the C-DT task than children with ADHD + EFD.
Conclusions: Some children with ADHD were primarily characterised by problems with executive functions and variability others by problems with delay aversion supporting multiple pathway models of ADHD. Given the exploratory nature of the study, results are in need of replication.