Chapter 3 - Assessment of attention-deficit/hyperactivity disorder and comorbid reading disorder with consideration of executive functioning

Abstract

This chapter provides an overview of current knowledge regarding the frequency, implications, and etiology of comorbidity between attention-deficit/hyperactivity disorder (ADHD) and reading disorder (RD). Results from community studies indicate that 20%–50% of individuals with ADHD also meet criteria for RD, and the presence of comorbid RD is associated with increased functional impairment and less positive long-term outcomes. The association between RD and ADHD is strongest for symptoms of inattention and more complex aspects of reading such as reading fluency and comprehension. Family and twin studies indicate that RD and ADHD are both significantly familial and heritable, and multivariate analyses indicate that nearly all of the phenotypic covariance between RD and ADHD is due to shared genetic influences that are associated with slower and more variable cognitive processing speed. Key future directions include studies that incorporate additional aspects of reading and more sophisticated neuropsychological and neuroimaging phenotypes, along with studies that may fill the important gap in the literature regarding the treatment implications of comorbidity between ADHD and RD.