Word Reading and Attention-Deficit/Hyperactivity Disorder in Children With Developmental Language Disorder.

Purpose: This study evaluated the relationship between word reading and symptoms of attention-deficit/hyperactivity disorder (ADHD) in school-age children with and without developmental language disorder (DLD), considering the influence of cognitive-linguistic mechanisms associated with dyslexia (phonological memory) and ADHD (working memory).

Method: Community ascertainment and blinded assessments identified 46 confirmed DLD and 76 cases of typical language development from a screening sample of 420 second and third graders. Language, word reading, ADHD symptoms, nonverbal intelligence, working memory, and phonological memory were assessed.

Results: In all models, phonological memory was associated with word reading, and working memory was associated with ADHD symptoms. Additionally, in the new model of association that accounted for comorbidity with cognitive-linguistic indices, named the "Reading, ADHD, and Language (RE.A.L.) Comorbidity Model," word reading was uniquely mediated by phonological memory.

Conclusions: Findings highlight the unique role cognitive-linguistic indices associated with dyslexia and ADHD play in explaining the relationship between DLD, word reading, and ADHD symptoms. Results indicate that ADHD symptoms did not predict poor word reading; only phonological memory mediated the relationship between DLD and word reading difficulties associated with dyslexia. Similarly, working memory was associated with ADHD symptoms only. Findings underline the importance of including cognitive-linguistic indices associated with dyslexia and ADHD in evaluating word reading and ADHD symptoms in children with DLD.