Factor analytic studies have been conducted to examine the inter-relationships and degree of overlap among symptoms in Autism Spectrum Disorder (ASD). This paper reviewed 36 factor analytic studies that have examined ASD symptoms, using 13 different instruments. Studies were grouped into three categories: Studies with all DSM-IV symptoms, studies…

Background: Autism spectrum disorder (ASD) is characterized by notable phenotypic heterogeneity, which is often viewed as an obstacle to the study of its etiology, diagnosis, treatment, and prognosis. On the basis of empirical evidence, instead of three binary categories, the upcoming edition of the DSM 5 will use two dimensions--social…

Background: While behavioural abnormalities are fundamental features of Rett syndrome (RTT), few studies have examined the RTT behavioural phenotype. Most of these reports have focused on autistic features, linked to the early regressive phase of the disorder, and few studies have applied standardised behavioural measures. We used a battery of…

Factor structure and relationship between core features of autism (social impairments, communication difficulties, and restricted, repetitive behaviours or interests (RRBIs)) were explored in 189 children from the Twins Early Development Study, diagnosed with autistic spectrum disorders (ASDs) using the Development and Wellbeing Assessment (DAWBA;…

This study investigated whether the Communication Checklist-Adult (CC-A) could identify subtypes of social and communication dysfunction in autism probands and their parents. The CC-A is divided into subscales measuring linguistic ability as well as two aspects of social communication: the Pragmatic Skills subscale assesses the level of pragmatic…

Background: Restricted repetitive behaviors (RRBs) are a core feature of autism and consist of a variety of behaviors, ranging from motor stereotypies to complex circumscribed interests. The objective of the current study was to examine the structure of RRBs in autism using relevant items from the Autism Diagnostic Interview-Revised in a sample of…

A study was undertaken to determine the relationship between assertiveness and communication apprehension by examining common factors that exist between the items on the Rathus Assertiveness Schedule and the Personal Report of Communication Apprehension. The two instruments were administered to students at a large midwestern university. Responses…