Abstract
Attention Deficit/Hyperactivity Disorder (ADHD) symptoms are well known to be associated with impairments in academic functioning. However, symptoms alone do not account for all of the variance in academic functioning among those with ADHD symptoms, additional factors such as executive dysfunction and language impairments are also associated. Past research has suggested that expressive and pragmatic components of language partially mediate the relation between ADHD symptoms and academic functioning. Drawing on this research, the present study proposed and tested a model in which executive functioning, ADHD symptoms, expressive and receptive structural language skills, and functional and pragmatic expressive language skills all contribute to academic functioning. Specifically, the model proposed that these language skills would partially mediate the relation between ADHD symptoms and academic functioning, while controlling for executive functioning. The study sample included 130 children aged 6 to 12 years, 42 of whom met diagnostic criteria for ADHD. Parents completed measures of ADHD symptom severity and overall child functioning, including components measuring language skills; teachers completed measures of academic functioning and overall child functioning, including components measuring language skills; and children were administered standardised measures of cognitive and neuropsychological functioning, including components measuring executive functioning and language. The main findings of this study suggest that receptive, expressive, and pragmatic language skills partially mediate the relation between ADHD symptom severity and academic functioning. However, the strength of this mediation effect was reduced when controlling for executive functioning, particularly in the case of receptive and expressive language skills. Overall, these findings highlight the heterogeneity of ADHD, suggesting that a variety of factors contribute to ADHD-related dysfunction, including ADHD symptomatology, executive dysfunction, and deficits in language skills. Among other theoretical and practical implications for ADHD, these findings suggest that language skills should be considered and emphasised by clinicians during ADHD assessment and treatment, particularly regarding support of academic functioning.