An independent validation was conducted of the Utah Autism and Developmental Disabilities Monitoring Network's (UT-ADDM) classification of children with autism spectrum disorder (ASD). UT-ADDM final case status (n = 90) was compared with final case status as determined by independent external expert reviewers (EERs). Inter-rater reliability…

The Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) category is a psychopathological entity few have described and is poorly, and mainly negatively, defined by autism exclusion. In order to limit PDD-NOS heterogeneity, alternative clinical constructs have been developed. This study explored the reliability and the diagnostic…

Studies on the distinction between Autistic Disorder (AD) and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS) have been inconclusive. This study examined the validity of PDD-NOS by comparing it to AD and other developmental disorders (DD) on parent-reported behavior problems. Fifty-four children with PDD-NOS were individually…

The Assessment of Basic Learning Abilities (ABLA) test is a useful assessment and training tool for persons with developmental disabilities. The present study assessed the predictive validity of the ABLA test with 16 children diagnosed with an autistic spectrum disorder, eight who performed at ABLA Level 4 and eight who performed at ABLA Level 6.…

The purpose of this study was to investigate the concurrent validity of subtests on the "Comprehensive Assessment of Spoken Language" (CASL) by comparing them with the assessment of communication and social skills on the "Vineland Adaptive Behavior Scales" ("Vineland"). The participants were 35 children and…

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.…