Do Children with Co-Occurring ADHD and DCD Differ in Motor Performance?

Attention Deficit Hyperactivity Disorder (ADHD) is characterized by inappropriate levels of activity, impulsivity, and inattention. Developmental Coordination Disorder (DCD) is a condition involving challenges in acquiring and executing motor skills. This cross-sectional study aimed to distinguish motor symptoms between ADHD and ADHD/DCD. A total of 283 children from two elementary schools underwent screening, leading to the identification of 27 children with ADHD. The assessment encompassed the Swanson, Nolan, and Pelham-IV Questionnaire (SNAP-IV), the Movement Assessment Battery for Children (MABC-2), and the Motor Development Scale (MDS). The groups consisted of ADHD (14) and ADHD/DCD (13). Statistical analysis revealed significant differences in general motor age means between groups (p = 0.016), indicating inferior performance in the ADHD/DCD group. The coexistence of DCD significantly influenced the motor performance of children with ADHD, particularly in fine motor skills (p = 0.018) and balance (p = 0.033). Both groups exhibited mild to moderate risk of motor development delay. It is suggested that ADHD is associated with motor problems, even when DCD is not co-occurring. Specific domain-based analysis could demonstrate how the co-occurrence with DCD affects the motor performance of children with ADHD, with statistically significant differences observed in fine motor skills and balance.