Executive function challenges are commonly reported in the home setting for children with an autism spectrum disorder diagnosis (hereafter, autism), but little is known about these challenges in the school setting. A total of 337 youth (autism, N = 241 and typically developing, N = 96) were assessed using Behavior Rating Inventory of Executive…

Motor abnormalities are highly prevalent in children with autism spectrum disorder and are strongly predictive of adaptive functioning. Despite the documented sex bias in the prevalence of the disorder, the impact of sex differences on motor abnormalities has been overlooked. The goal of this study was to investigate differences in the motor…

Adaptive functioning, or the suite of skills essential for real-world, day-to-day functioning, includes daily living, communication, and socialization abilities. Even in the absence of co-occurring intellectual disability (IQ < 70), difficulties in adaptive functioning are prominent in autism spectrum disorder (ASD). Further, ASD individuals…

There is a critical need for validated screening tools for autism spectrum disorder in very young children so families can access tailored intervention services as early as possible. Few screeners exist for children between the recommended screening ages of 18-24 months. This study examined the utility of a new autism-specific parent-report…

A reliable autism spectrum disorder (ASD) diagnosis can occur as early as 18 months; however, the average age at diagnosis in the United States is over 2 years later. While there are numerous well-known barriers to seeking an ASD diagnosis, no research has examined if separation between a child's biological parents affects timing of ASD diagnosis…

Atypical motor development has frequently been reported in infants at elevated likelihood for autism spectrum disorder. However, no previous study has used detailed motion capture technology to compare infant siblings of children with autism spectrum disorder and infant siblings with no familial history of autism spectrum disorder. We investigated…

Autism spectrum disorder symptom emergence is heterogeneous, yet literature comparing young children diagnosed early versus later is relatively scant. Toddlers diagnosed with autism spectrum disorder between 12 and 18 months (n = 20), 19 and 24 months (n = 65), or 25 and 41 months (n = 27) were compared on demographics, developmental functioning,…

The development of an expressive language score for people with autism based on the ADOS-2 was recently reported by Mazurek et al. (2019). The current study examined the construct validity of the ADOS-2 expressive language score (ELS) in a sample of adolescents with fragile X syndrome (n = 45, 10 girls), a neurodevelopmental disorder with high…

The sources of anxiety for a sample of 132 young males with Autism Spectrum Disorder (ASD) were investigated from standardised scales and verbal responses to a series of open-ended questions asked to them and their mothers. As well as using parametric statistics to test for effects on standardised scales, verbal responses were analysed via NVivo…

This study aimed to investigate factors associated with a delayed autism spectrum (ASD) diagnosis when compared to children with either no or early ASD diagnosis. Among 893 children assessed for ASD before age 8, 39% had no ASD at baseline, of which 21% received a later ASD diagnosis. Autism symptoms, diagnostic history of other developmental…

Purpose: Extant research indicates that children and adolescents with autism spectrum disorder (ASD) without an intellectual disability (ID) often experience difficulty comprehending written texts that is unexpected in comparison with their cognitive abilities. This study investigated the development of two key skills, narrative and inference…

Children with autism spectrum disorder (ASD) demonstrate heterogeneous writing skills that are generally lower than their typically developing (TD) peers and similar to peers with attention difficulties like attention-deficit/hyperactivity disorder (ADHD). Recent evidence suggests children with ASD spend less time engaging in writing tasks…

We examined differences between children with autism spectrum disorder and typically developing children over an 8-month period in: (a) longitudinal associations between expressive and receptive vocabulary and (b) the extent to which caregiver utterances provided within an "optimal" engagement state mediated the pathway from early…

The associations between sons' challenging behaviour and mothers' anxiety and depression were investigated in four age-subgroups of boys with Autism Spectrum Disorder and their mothers (n = 49). Significant correlations were found only for the 6-yr-old boys' irritability and their mothers' anxiety (r = 0.808) and depression (r = 0.762), and for…

Siblings play an important role in shaping the developmental trajectories of individuals with autism spectrum disorder. Having siblings has been associated with better social communication, non-verbal communication, and theory of mind abilities in autism spectrum disorder. However, little is known about the impact of siblings on adaptive skill…