The objectives were to characterize behavioral signs of autism spectrum disorder (ASD) in younger siblings of diagnosed children (high-risk; HR) and examine classification features of the Autism Observation Scale for Infants (AOSI). Participants (501 HR and 180 low-risk [LR]) were assessed between 6 and 18 months using the AOSI and at age 3 for…

This study examined the potential of the short form of the Quantitative Checklist for Autism in Toddlers (Q-CHAT-10) to identify autism spectrum disorder (ASD) in a high-risk sibling cohort. High-risk (HR; siblings of children diagnosed with ASD) and low-risk (LR; no family history of ASD) toddlers were assessed prospectively at 18 and 24 months…

This study described empirically derived profiles of parents' personal and social coping resources in a sample of 207 families of children diagnosed with autism spectrum disorder. Latent Profile Analysis identified four family profiles based on socieoeconomic risk, coping strategy utilization, family functioning, available social supports, and…

Several studies have suggested an association between vitamin D in childhood and autism spectrum disorder. No prospective studies have evaluated whether lower vitamin D levels precede ASD diagnoses -- a necessary condition for causality. The objective of this study was to prospectively evaluate whether vitamin D serum levels in early childhood was…

The American Academy of Pediatrics recommends universal screening for autism spectrum disorder at 18 and 24 months. This study compared the cost-effectiveness of universal or high-risk screening to surveillance monitoring. Simulation models estimated the costs and outcomes from birth to age 6 years. The incremental cost per child diagnosed by…

Social-emotional behavior in autism spectrum disorder (ASD) was examined among high-risk (HR; siblings of children diagnosed with ASD) and low-risk (LR; no family history of ASD) toddlers. Caregivers completed the Infant-Toddler Social Emotional Assessment (ITSEA) at 18 months, and blind diagnostic assessment for ASD was conducted at 36 months.…

Possible gender differences in manifestations of autism spectrum disorder (ASD) were examined using data on production of narratives. The Expression, Reception and Recall of Narrative Instrument (ERRNI; Bishop, Expression, Reception and Recall of Narrative Instrument, Harcourt assessment, London, 2004) was administered to a sample of matched…

We examined the stability of cognitive and adaptive behaviour standard scores in children with autism spectrum disorder (ASD) between diagnosis and school entry approximately age 6. IQ increased 18 points in 2-year-olds, 12 points in 3-year-olds, and 9 points in 4-year-olds (N = 281). Adaptive behaviour scores increased 4 points across age groups…

Considerable evidence on autism spectrum disorder emergence comes from longitudinal high-risk samples (i.e. younger siblings of children with autism spectrum disorder). Diagnostic stability to age 3 is very good when diagnosed as early as 18-24 months, but sensitivity is weaker, and relatively little is known beyond toddlerhood. We examined…

This study examined whether a novel parent-report questionnaire, the Autism Parent Screen for Infants, could differentiate infants subsequently diagnosed with autism spectrum disorder from a high-risk cohort (siblings of children diagnosed with autism spectrum disorder (n = 66)) from high-risk and low-risk comparison infants (no family history of…

Background: The Autism Diagnostic Interview-Revised (ADI-R) is a gold standard assessment of Autism Spectrum Disorder (ASD) symptoms and behaviours. A key underlying assumption of studies using the ADI-R is that it measures the same phenotypic constructs across different populations (i.e. males/females, younger/older, verbal/nonverbal). The…

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…

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…

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…

Background: Standard case criteria are proposed for combined use of the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule to diagnose autism and to define the broader category of autism spectrum disorders. Method: Single and combined Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule…