Distinctive patterns of language and executive functions contributing to reading development in chinese-speaking children with ADHD

Reading comprehension skills, which involve numerous executive functions (EFs), are crucial for the academic success of school-aged children. Because children with attention-deficit/hyperactivity disorder (ADHD) have difficulties with language comprehension and EFs, achieving reading comprehension may be challenging for them. This study evaluated the distinct contributions of language comprehension and EF components to reading comprehension in order to reveal the possible mechanisms underlying poor reading comprehension among children with ADHD. A total of 69 Chinese-speaking children aged 8-12 years who were typically developing (TD, n = 36) or had ADHD (n = 33) participated in this study. All participants were assessed through intelligence, reading, and language comprehension tests. EF skills were measured using a verbal working memory (WM) test and four behavior tasks: the go/no-go task, a spatial WM (SWM) task, the Tower of London (ToL) task, and the Wisconsin Card Sorting Task (WCST). Results indicated that the ADHD group exhibited significantly lower language and reading comprehension scores than did the TD group. Moreover, the TD and ADHD groups had equivalent ToL scores but notably different go/no-go, WCST, SWM, and verbal WM test scores. After age, sex, and nonverbal intelligence quotient were controlled for, hierarchical regression models revealed the contributions of language skills to reading comprehension in both groups, but the contributions of EFs differed between the groups. Inhibition and verbal WM were significant predictors of reading comprehension in the ADHD group. In sum, the abilities to disregard irrelevant information and maintaining linguistic information of multiple episodes are important for Chinese-speaking children with ADHD to build a coherent mental representation of the text during reading comprehension.