Abstract:
The aim of this study was to establish whether children with Attention-Deficit/Hyperactivity show deficits in cognitive impulsiveness and motor functions, caused by a hypofunctioning dopamine system. A group of 84 primary school children, 42 classified as ADHD and 42 controls, matched for age, gender and SES, with children without ADHD symptomatology, were compared on their performance on neuropsychological tests which test the functions of the cortical areas supplied by two dopamine branches, the meso-cortical and nigrostriatal branches. The battery consisted of the Wisconsin Card Sorting Test, the Grooved Pegboard, and the Maze Coordination Task. The results of the tests were analysed as a function of gender and ADHD-subtypes. In the majority of tests the clinical groups performed worse than the control groups. This was the case for both genders. The Hyperactive/Impulsive and Combined subtypes consistently performed poorer than the other groups. The results indicate that children with ADHD are more impulsive (deficient executive functions) and have poorer motor control than their control counterparts, which may be an indication of dopamine dysfunction.
