Attention-deficit/hyperactivity disorder (ADHD) is a common developmental disorder often associated with other developmental disorders including speech, language, and reading disorders. Here, we review the principal features of ADHD and current diagnostic standards for the disorder. We outline the ADHD subtypes, which are based upon the dimensions…

Fragile X syndrome (FXS) is the leading inherited cause of intellectual disability. The syndrome is caused by a single gene mutation on the X chromosome. Although individual differences are large, most individuals with FXS display weaknesses across all language and literacy domains compared with peers of the same chronological age with typical…