The objective of this study was to identify subgroups of toddlers with DSM-5 ASD based on core ASD symptoms using a person-based analytical framework. This is a retrospective study of 500 toddlers (mean age 26 months, 79% male) with DSM-5 ASD. Data were analyzed using latent class analyses in which profiles were formed based on ASD symptomatology.…

The American Academy of Pediatrics recommends autism spectrum disorder screening at the 18- and 24-month well-child visits. However, despite widespread toddler screening, many children are not diagnosed until school age, and delayed diagnosis is more common among low-income and minority children. Offering autism spectrum disorder screening at…

The current study investigated longitudinal associations between parent-rated temperament, observed exuberance and accelerometer activity level at 18-months and symptoms of ASD and ADHD at 36-months in a sample of 54 children at elevated likelihood for ASD. For the specific parent-rated temperament scales, most observed significant associations…

Inconsistent findings regarding sex differences in cognition have been found in people with autism spectrum disorder (ASD). This study evaluated sex differences in cognitive-developmental functioning in a large clinical sample of young children diagnosed with ASD. The sample included children 18-68 months of age who received the Mullen Scales of…

Meta-analyses of head circumference in autistic individuals exist; however, simple meta-analytic approaches are limited. Consequently, we gathered head circumference raw data of autistic (N = 2381) and typically developing participants (N = 994) by re-analysing the data from previously published studies together. The present study found no mean…

We conducted a cross-sectional study to explore whether clinical characteristics and autism diagnostic-traits severity are associated with caregiver-reported impairment of health-related quality of life (Pediatric Quality of Life Inventory Generic Core Scales, Fourth Edition) in 93 Chilean toddlers (age: 2-4 years) with autism spectrum disorder.…

Diminished response to name, a potential early marker of autism spectrum disorder (ASD), may also indicate risk for other disorders characterized by attention problems, including attention-deficit/hyperactivity disorder (ADHD). Using a familial risk design, we examined whether response to name ability at 6, 12, 18, 24, and 36 months of age…

Studies have shown that Autism Spectrum Disorder (ASD) screening and diagnostic instruments may be affected by the presence of emotional and behavior problems (EBPs). This study assessed the impact of EBPs on the Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F). Participants included 290 children, 18-48 months of age,…

Brief, clinically feasible instruments are needed to assess autism spectrum disorder (ASD) in toddlers and preschoolers so that children can access early evidence-based intervention. Study purposes were to (1) compare scores on the 30-item Checklist for Autism Spectrum Disorder (CASD) and 6-item CASD-Short Form (CASD-SF) for toddlers and…

Parents of toddlers with an older sibling with autism spectrum disorder (ASD; high risk, HR) and parents of low risk (LR) toddlers with typically-developing older siblings read a wordless picture book to their child at 22 and 28 months. Parents' and toddlers' internal state language (ISL) was coded; parents reported on toddlers' use of ISL.…

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…

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…

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…

To investigate temperament as an early risk marker for autism spectrum disorder (ASD), we examined parent-reported temperament for high-risk (HR, n = 170) and low-risk (LR, n = 77) siblings at 8, 14, and 24 months. Diagnostic assessment was performed at 36 months. Group-based analyses showed linear risk gradients, with more atypical temperament…

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,…