The success of early intervention programs has in large part spurred increasing emphasis on identifying children with autism and Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) at the earliest possible ages. National and international professional groups have called for early screening and diagnosis, yet the technology to…

Comorbid psychopathology and challenging behaviors often occur among persons with developmental disabilities. However, little attention to this issue has been reported in young children. In this study, individuals 17 through 36 months of age with varying diagnoses, such as intellectual disability, developmental delay, and Down syndrome, among…