Comorbid Developmental Coordination Disorder and ADHD: The Effects on Emotional and Behavioural Problems in Young Children.

Both DCD and ADHD are recognised neurodevelopmental conditions, however, their co-occurrence and subsequent effects remain insufficiently explored. This paper aims to address this gap by examining the relationship between motor proficiency and ADHD symptoms in young children, and elucidating the combined impact on internalising and externalising symptoms. Data from the Coordination and Activity Tracking in CHildren (CATCH) study (n = 532) were analysed. Children aged 6-9years were classified into typically motor developing (TMD; Movement Assessment Battery for Children-2nd Edition [MABC-2] > 16th percentile), at risk for DCD (DCDr; MABC-2 6th ≤ 16th percentile), or with probable DCD (pDCD; MABC-2 < 6th percentile). ADHD symptoms were assessed using the Conners Parent Rating Scale, 3rd Edition, and mental health symptoms assessed with the Child Behaviour Checklist for school-aged children (CBCL). 28% of children with pDCD and 19% of children with DCDr had clinically significant ADHD symptoms. Those with comorbid pDCD and clinically significant ADHD symptoms exhibited significantly elevated CBCL scores compared to those without clinically significant ADHD symptoms. The increased experience of mental health challenges in children with comorbid pDCD and clinically significant ADHD symptoms underscores the importance of universal screening for ADHD and mental health concerns in children with DCD.