Identification of Attention-Deficit/Hyperactivity Disorder in Children with an Identified Oral Language Disorder: The Diagnostic Utility of the Quotient/ADHD System and the impact of Executive Function and Working Memory on Diagnosis

Common symptomatology in oral language disorders and attention-deficit/hyperactivity disorder, including inattention, hyperactivity, and behavior associated with impaired executive function, impacts the validity of diagnostic evaluations. Research demonstrates that the identification of these disorders can be dependent on evaluation setting and clinicians' field of training. Inaccurate diagnosis predicts inappropriate and/or inadequate intervention, and hence, impaired functioning across multiple domains. Assessment instruments to improve the evaluation of attention-deficit/hyperactivity disorder in the context of impaired oral language are needed. The present study explored the impact of comorbid attention-deficit/hyperactivity disorder on attention, movement, executive function, and working memory in children with an identified oral language disorder. Utility of the Quotient/ADHD SystemTM, a continuous performance test with motion actigraphy, and the Children's Executive Functions Scale, a parent-report of executive function, for the accurate identification of an attention disorder in the context of impaired language was evaluated. The sample consisted of 51 children, between 6 and 13 years, with an orallanguage disorder; 30 child participants met diagnostic criteria for attention-deficit/hyperactivity disorder. Children with and without comorbid attention-deficit/hyperactivity disorder were compared on four domains: attention,movement, executive function, and working memory. Attention and movement were objectively measured with the Quotient/ADHD SystemTM. Executive functioning was assessed using the subscale and Total scores on the Children's Executive Functions Scale. Verbal and visual-spatial working memory were evaluated separately with Digit Span and Spatial Span subtests of the Wechsler Intelligence Scale for Children, Fourth Edition, Integrated. Ingestion of prescribed stimulant medication was delayed until after testing. Results of analyses of variance revealed significant group differences in movement, overall executive functioning, and behavioral inhibition; differences in attention and working memory were not found. Logistic regression and discriminant function analyses supported the use of the Quotient/ADHD SystemTM and the Children's Executive Functions Scale for the identification of an attention disorder in this population. Exploratory analyses raise questions regarding attention-deficit/hyperactivity disorder subtypes and the not otherwise specified category. Findings have important implications for the evaluation of attention-deficit/hyperactivity disorder. Questions regarding the role of attentional mechanisms in oral language disorders and potential new adjunct interventions for improving language are highlighted.