Since 2000, the Autism and Developmental Disabilities Network (ADDM) has published detailed prevalence estimates for autism spectrum disorder (ASD) among 8 year-olds, which are widely interpreted as the U.S. national prevalence of ASD. Although differences in state-level ASD prevalence has been reported, state-level heterogeneity has not been…

Individuals with autism spectrum disorder (ASD) have higher rates of co-occurring diagnoses and use of psychotropic medication prescriptions than people with other developmental disabilities. Few studies have examined these trends in samples of people with intellectual and developmental disabilities (IDD) with and without ASD. Using a random…

In early training for children with autism spectrum disorders (ASDs), matching-to-sample (MTS) tasks are widely used to teach various language and cognitive skills. However, some problems in conducting MTS training for children with developmental disabilities are also recognized. In this study, we examined the effectiveness of stimulus pairing…

Despite decades of advocacy, most students with developmental disabilities continue to spend the majority of the school day in self-contained special education classrooms. However, there is tremendous variability of educational placement across the United States. Identification of geographic trends that explain this variability could provide…

Self-directed programs that allow individuals with intellectual and developmental disabilities to exercise greater control over their finances have become increasingly common in recent years. At the same time, challenges in the recruitment, retention, and training of direct support workers in the field have grown more acute. In this article, the…

Single subject research methodology is commonly used and cited in special education courses and journals. This article reviews the types of single subject research designs published in eight refereed journals between 1983 and 2007 used to answer applied research questions. Single subject designs were categorized as withdrawal/reversal, time…

We investigated if shifts in the coding of qualifying conditions in the California Department of Developmental Services (DDS) have contributed to the increase in California children with autism observed in recent years. Qualifying condition codes for mental retardation (MR) and autism in DDS electronic files were compared to hard-copy records for…

The present study examined whether Snoezelen and Stimulus Preference environments have differential effects on disruptive and pro-social behaviors in adults with profound mental retardation and autism. In N = 27 adults these target behaviors were recorded for a total of 20 sessions using both multi-sensory rooms. Three comparison groups were…

People with an intellectual disability have existed across human history, making up a part of all cultures. They represent a small part of the extremely wide variety of people in the human population at any one time. This review essay examines the 11th and latest Definition and Classification Manual published by the American Association on…

This article describes national trends in outcomes of the vocational rehabilitation (VR) program, with a focus on adults with developmental disabilities during the period of 1995 to 2005. Findings show that the VR program has made substantial progress in excluding extended employment from the array of possible employment closures. Efforts are…

Problem/Condition: Autism spectrum disorders (ASDs) are a group of developmental disabilities characterized by atypical development in socialization, communication, and behavior. ASDs typically are apparent before age 3 years, with associated impairments affecting multiple areas of a person's life. Because no biologic marker exists for ASDs,…

This is the latest edition of the "State of the States in Developmental Disabilities" study--a thorough and the only one of its kind investigation on public spending, revenues, and programmatic trends of intellectual and developmental programs and services within the United States since 1977. Directed by leading researcher, Dr. David…

Fertility rates have fallen dramatically around the world. In some countries, there are no longer enough children being born to replace adult populations. The disappearance of children is a matter of concern matched only by fears that childhood is becoming too structured or not structured enough, too short or too long, or just simply too different…

To what extent are students with intellectual disabilities included in regular education classrooms in the United States? Although inclusion is an accepted best practice in special education, little progress has been made in including students with intellectual and other developmental disabilities. Using historical and the most recent available…

Prevalence estimates often use U.S. Census Bureau estimates of the population as denominator data. Postcensal estimates are population estimates produced following a decennial census. Intercensal estimates are surrounded by 2 census years and supersede postcensal estimates. In this report we describe prevalence estimates in Atlanta for mental…