Recent worldwide epidemiological surveys of autism conducted in 37 countries are reviewed; the median prevalence of autism is 0.97% in 26 high-income countries. Methodological advances and remaining challenges in designing and executing surveys are discussed, including the effects on prevalence of variable case definitions and nosography, of…

Background: Individuals with autism spectrum disorder (ASD) form a heterogeneous group, posing a challenge for clinical definition. Additional problems regarding the diverse clinical presentation arise from changes in diagnostic criteria according to the latest Diagnostic and Statistical Manual of Mental Disorders (DSM-5), with exclusion of…

The Individuals with Disabilities Education Act (IDEA; P.L. 108-446) is the primary source of federal funding to states for the identification and education of children with disabilities. The majority of IDEA appropriations are allocated to states by formula to carry out activities under Part B, which covers 14 disability categories. Each state is…

This briefing paper is intended to provide basic information about the diagnosis, educational programming, and special needs of children and youth with Pervasive Developmental Disorders (PDD), a group of neurological disorders usually evident by age 3 and characterized by impairments in social interaction, imaginative activity, and verbal and…

This "Packet of Information for Professionals" (PIP) was developed for professionals who work with gifted and talented students who have an autism spectrum disorder (ASD). The purpose of PIP is to offer recommendations that will lead to a positive experience for twice-exceptional students who participate in specialized programs for…