Contributions of Working Memory, Inhibition, and Processing Speed to Writing Composition in Attention-Deficit/hyperactivity Disorder.

Children with Attention-Deficit/Hyperactivity Disorder (ADHD) often struggle with writing composition, possibly due to deficits in executive functions and processing speed. This study examined 518 children with ADHD and 851 controls to assess these effects. Multiple mediation tested whether executive functions (i.e., working memory, inhibition) and processing speed partially mediated the association between inattention and writing composition, controlling for transcription. Results showed inattention negatively predicted writing composition. Executive function accounted for nearly 10%, and processing speed nearly 17%, of the variance in this association. Findings highlight the contributions of executive functions and processing speed to writing difficulties in ADHD.