Attention Deficit/Hyperactivity Disorder and Motor Planning Difficulties: A Confirmatory Study on the Overlap Between Neurodevelopmental Disorders

Attention deficit/hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) represent two frequent neurodevelopmental disorders, which may be comorbid or have common characteristics with each other. The aim of the present study was to explore the presence of DCD or motor planning difficulties in children with behavioral disorders and/or ADHD, as already stated in the literature. Motor abilities were assessed in a sample of children which underwent a comprehensive neuropsychological evaluation. A total of 43 children were included in the study and were subdivided in three groups: those with ADHD and DCD, those with DCD, and those with ADHD but also presenting motor-praxic difficulties. The first group obtained clinical scores at the considered tests, with worse performances in the balance area; in the second and third groups lower scores were observed in the manual dexterity and balance, with more homogeneous profiles. Overall, 27.3% of ADHD subjects received a diagnosis of DCD as well, whereas 31.8% showed documented motor-praxic difficulties. Our results confirmed an increased prevalence of DCD or general motor difficulties in children with ADHD compared to the general population. Further research should investigate whether a poorer motor performance assessed by standardized tests could be either due to a comorbid neurodevelopmental condition or a direct consequence of the pivotal symptomatology of the disorder.