A Longitudinal Investigation of Fine Motor, Executive Functioning, and ADHD in School-Aged Children with Down Syndrome
Authors:   , Maiman Moshe Baruch , Lee Nancy Raitano 
Published: February 2022

Background: Children with Down syndrome (DS) experience higher rates of executive function (EF) difficulties and attention-deficit/hyperactivity disorder (ADHD) than their typically developing peers. Understanding factors that may be related to their high occurrence in this group is important, as such research could help identify children at greater risk for poor outcomes. One potential early marker is fine motor (FM) skills, as concurrent relations among FM skills and both EF difficulties and ADHD symptomatology have been documented in other populations. These relations, however, have yet to be explored longitudinally in individuals with DS. As a first step to establishing longitudinal relations between earlier FM abilities as a precursor for later EF impairments and ADHD symptomology in younger children with DS, the present study examined these relations in a school-age sample of children with DS. Methods: This longitudinal study followed 22 children with DS (male = 41%; Mage= 12.30 years) and 19 children with typical development (male = 74%; Mage= 6.57 years) who participated in an earlier study (Maiman, 2019). At Time 1, participants completed performance-based measures of general cognitive ability (Kaufman Brief Intelligence Test, 2nd Edition), fine motor (Bruininks-Oseretsky Test of Motor Proficiency, 2nd Edition), and executive function (Missing Scan Task, NIH Dimensional Change Card Sorting Task, NIH Flanker Task) skills. Parents of these children also completed an FM questionnaire (Developmental Coordination Disorder Questionnaire). At Time 2, 1.5 years later, participants again completed the performance-based EF measures. Their parents completed questionnaires assessing behaviors associated with ADHD (ADHD Rating Scale-IV, Inattention and Hyperactivity Scales) and everyday EF difficulties (Behavior Rating Inventory of Executive Function, Second Edition). Results: Earlier parent-reported and performance-based FM abilities predicted parent-reported EF, inattention, and hyperactivity/impulsivity 1.5 years later in our sample of school-age children with DS. Specifically, parent-reported and performance-based FM abilities accounted for 30% to 66% of the variance across these outcome measures. These associations were also observed to be relatively stronger in those with DS than their typically developing peers, although statistical significance was only reached for parent-reported executive skills. Conversely, earlier performance-based FM abilities did not significantly predict performance-based EF abilities 1.5 years later in this group. Finally, an exploratory analysis was completed to examine if the relation between FM and EF abilities was moderated by cognitive ability level in the DS group. Statistical support for the moderating effect of cognitive ability was not observed. Conclusion: This study provides preliminary support that earlier performance-based and parent-reported FM abilities can predict both parent-reported EF skills and ADHD symptomology 1.5 years later in school-age children with DS. Given the strength of these relations, future studies should examine FM-EF relations in younger children with DS to evaluate the predictive validity of initial FM skills, which can be assessed in toddlerhood using standardized measures for later executive function difficulties and ADHD symptomatology.