Interrelationships between Reading Disability and Attention-Deficit/Hyperactivity Disorder

Abstract

Evidence from a number of investigations suggests a considerable overlap between reading disability (RD) and attention deficit-hyperactivity disorder (ADHD). We investigate the relationship between RD and ADHD in a cohort of 186 children 7.5–9.5 years of age, recruited explicitly to address classification and definitional issues in these disorders. Using multivariate methods, we examine the hypothesis that RD and ADHD represent separate diagnostic entities that frequently co-occur in the same individual. The results suggest that RD is characterized by deficits within the language system, in particular a subcomponent within that system, phonological processing; in contrast, such linguistic deficits are not characteristic of ADHD unless ADHD is associated with RD. When children with both RD and ADHD are examined, both the linguistic deficits associated with RD and the behavioral characteristics associated with ADHD are apparent, but these deficits are not synergistic. We conclude that RD and ADHD represent separate disorders that frequently co-occur.