This paper reviews whether Rett syndrome is a subtype of pervasive developmental disorders (PDD). The paper analyzes internal and external diagnostic validity and discusses whether Rett syndrome is a neurological disorder or a mental disorder. The paper concludes that data support the idea of classifying Rett syndrome as a subtype of PDD.…

This paper presents evidence regarding the validity of the diagnostic concept of "autistic-like" childhood disintegrative disorder, also known as Heller syndrome or as disintegrative psychosis. Its inclusion in the DSM-IV (Diagnostic and Statistical Manual) is supported, and proposed criteria and narrative description are provided.…

The sources of variability residing in the environment of individuals with autism and the implications for research studies are explored. Recommendations are provided for future research including research focusing on young children, on the methods needed to produce desirable outcomes, on relationships between behaviors, and on specific teaching…

This essay notes the complexities inherent in classifying pervasive developmental disorders (PDD), especially when a single classification scheme is to be used for clinical, research, and administrative purposes. The paper considers principles of classification, symptomatology, the neuropsychiatric interface, the value of a multiaxial approach,…

This critique of facilitated communication as an aid for individuals with autism reviews its use in Australia and discusses such issues as the high degree of physical intervention provided by the assistant and the unlikely language content exhibited. An editorial comment deplores the media hype promoting facilitated communication but admits its…