Path analysis within a structural equation modeling framework was employed to examine the relationships between two types of parent stress and children's externalizing and internalizing behaviors over a 4-year period, in a sample of 184 mothers of young children with autism spectrum disorder. Parent stress was measured with the Parenting…

This study assessed sensory processing differences between 24-month infants at high-risk of autism spectrum disorder (ASD), each with an older sibling with ASD, and low-risk infants with no family history of ASD. Sensory processing differences were assessed using the Infant/Toddler Sensory Profile, a parent-reported measure. Groups were compared…

The latent class structure of autism symptoms from the time of diagnosis to age 6 years was examined in a sample of 280 children with autism spectrum disorder. Factor mixture modeling was performed on 26 algorithm items from the Autism Diagnostic Interview-Revised at diagnosis (Time 1) and again at age 6 (Time 2). At Time 1, a…

The purpose of this study was to examine the measurement properties of the Social Responsiveness Scale in an accelerated longitudinal sample of 4-year-old preschool children with the complementary approaches of categorical confirmatory factor analysis and Rasch analysis. Measurement models based on the literature and other hypothesized measurement…

Sex differences were examined in 3-year-olds with autism spectrum disorders (ASD) ascertained from a high-risk cohort, and high- and low-risk comparison groups. Participants included 319 high-risk siblings and 129 low-risk controls. Eighty-five siblings were diagnosed with ASD, including 57 of 176 boys (32.4%) and 28 of 143 girls (19.6%), implying…

While self-injurious behaviors (SIB) can cause significant morbidity for children with autism spectrum disorders (ASD), little is known about its associated risk factors. We assessed 7 factors that may influence self-injury in a large cohort of children with ASD: (a) atypical sensory processing; (b) impaired cognitive ability; (c) abnormal…

This study examined the phenotypic overlap between core diagnostic features and emotional/behavioral problems in a sample of 335 preschool children with autism spectrum disorder (ASD). Results from principal component analysis (2 components; 49.70% variance explained) suggested substantial phenotypic overlap between core diagnostic features and…

This study examined the factor structure of the Repetitive Behavior Scale-Revised (RBS-R) in a sample of 287 preschool-aged children with autism spectrum disorder (ASD). A confirmatory factor analysis was used to examine six competing structural models. Spearman's rank order correlations were calculated to examine the associations between factor…

It has been proposed that females at risk for autism are protected in some way, so that only those with the greatest genetic liability are affected. Consequently, affected male siblings of females with autism should be more impaired than affected male siblings of male probands. One hundred and ninety-four (194) families with a single child with…

Parents (N = 19) of children with autism spectrum disorders (ASD) and adult controls (N = 17) underwent positron emission tomography (PET) using [[superscript 18]F]setoperone to image cortical serotonin type-2 (5-HT2) receptors. The 5-HT2 binding potentials (BPs) were calculated by ratioing [[superscript 18]F]setoperone intensity in regions of…

Asperger syndrome (AS) is differentiated from high-functioning autism (HFA) largely on a history of "language delay." This study examined "specific language impairment" as a predictor of outcome. Language skills of 19 children with AS and 45 with HFA were assessed at 4-6 years of age (Time 1) and 2 years later (Time 2). Children's symptoms and…

Two experiments investigated how persons with and without autism plan manual aiming movements when advance information is direct and when strategic planning is required. In Experiment 1, advance information about hand, direction, and/or movement amplitude was manipulated. Reaction times suggested both groups adopted a hierarchical pattern of…

Given the recent findings regarding the association between alexithymia and Autism Spectrum Disorder (ASD) and the accumulating evidence for the presence of the Broader Autism Phenotype (BAP) in relatives of individuals with ASD, we further explored the construct of alexithymia in parents of children with ASD as a potential part of the BAP. We…

The present paper documents the development of autism/autistic spectrum disorder in a consecutive series of nine high-risk infants followed prospectively from 6 months of age. Evidence is provided for two broadly defined subgroups: the first subgroup (n = 6) showed a decrease in IQ between 12 and 24 or 36 months (from average/near average to…

This study examined motor behaviors in a longitudinal cohort of infant siblings of children with autism. Stereotypic movements and postures occurring during standardized observational assessments at 12 and 18 months were coded from videotapes. Participants included eight infant siblings later diagnosed with autism spectrum disorder (ASD), a random…