Neurodevelopmental Disorders begin on page 31 of the full-text manual and 17 of the desk reference. Both begin with intellectual disability or intellectual developmental disorder as the first disorder for the DSM-5, as this would be typically diagnosed in childhood, with a specification for whether mild, moderate, severe, or profound. The disorder clarifies the need for three criteria, including intellectual functioning and problem solving; deficits in adaptive functioning that limit functioning without ongoing support; the final criteria simply that deficits in adaptive and intellectual functionality develop during early childhood. Medical, educational and other professional people – as well as lay people and advocacy groups – utilize this terminology and criteria.
A table provides additional information for how to determine the specifiers accordingly. The prevalence of this diagnosis is approximately 1% of the general population, or 6 per 1,000, and occur in all races and cultures, with males more likely than females to be diagnosed with both mild and severe forms of this disorder (p. 38-39 of the full manual).
Differential diagnoses include major and mild neurocognitive disorders; communication disorders and specific learning disorders; autism spectrum disorder, which includes the disorder formerly referred to as Asperger’s Syndrome.
I once worked for a wonderful federally-funded project, the IRIS Center: https://iris.peabody.vanderbilt.edu. Supported by the U.S. Department of Education’s Office of Special Education Programs (OSEP) and located at Vanderbilt University’s Peabody College, the IRIS Center develops and disseminates free, engaging online resources about evidence-based instructional and behavioral practices to support the education of all students, particularly struggling learners and those with disabilities. Great group of people doing incredible work on behalf of teachers, professional development providers, faculty and families! If this happens to be an area of interest personally or professionally, take a look at the huge volume of resources included on the site, as well as links to nearly every related evidence-based project in the United States.