Written expression in boys with ADHD: The mediating roles of working memory and oral expression

• Published in: Child neuropsychology 2019-08, Vol.25 (6), p.772-794
• Main Authors: Eckrich, Samuel J., Rapport, Mark D., Calub, Catrina A., Friedman, Lauren M.
• Format: Article
• Language: English
• Subjects: Attention Deficit Disorder with Hyperactivity - psychology; Attention-deficit/hyperactivity disorder (ADHD); Child; executive functions; Humans; Male; Memory, Short-Term - physiology; Neuropsychological Tests - standards; oral expression; working memory; Writing - standards; written expression
• ISSN: 0929-7049; 1744-4136
• DOI: 10.1080/09297049.2018.1531982

The written expression difficulties experienced by children with ADHD are widely recognized; however, scant empirical evidence exists concerning the cognitive mechanisms and processes underlying these deficiencies. The current study investigated the independent and potentially interactive contributions of two developmentally antecedent cognitive processes - viz., working memory (WM) and oral expression - hypothesized to influence written expression ability in boys. Thirty-three boys with ADHD-Combined Presentation and 27 neurotypical (NT) boys 8-12 years of age were administered standardized measures of oral and written expression, and multiple counterbalanced tasks to assess WM central executive (CE) processes, WM phonological short-term memory (PH STM), and WM visuospatial short-term memory (VS STM). Bias-corrected bootstrapped mediation analyses revealed a significant mediation effect, wherein the independent and interactive effects of PH STM and oral expression collectively explained 76% of the diagnostic status to written expression relation. The implications of the obtained results for clinical practice suggest that children with ADHD may benefit by incorporating a blended approach that simultaneously strengthens PH STM capacity and oral expression abilities as antecedents to engaging in writing-related activities.