The language used to refer to autism has been a topic of ongoing debate. Research in English-speaking countries indicated an overall preference for identity-first language ('autistic person') among autistic adults rather than person-first language ('person with autism'). We examined terminology preference in Dutch autistic adults (n = 1026; 16-84…

Autism spectrum disorders are diagnosed globally, but recognition, interpretation and reporting may vary across cultures. To compare autism across cultures it is important to investigate whether the tools used are conceptually equivalent across cultures. This study evaluated the factor structure of the parent-reported Autism Spectrum Quotient…

Pre- and post-term children show increased autism risk. Little is known about gestational age (GA) prevalence among autistic children, and their respective autism phenotype. We compared prevalence of pre-, full- and post-term birth between a population-derived sample of N = 606 (137 females, 22.61%) autistic children and adolescents (mean age =…

Autism is often associated with early developmental delays in language and motor skills. However, little is known about the complex dynamic processes that drive the co-development of such early difficulties. The aim of the present study was to model the parallel growth of language and motor skills in a cohort of infants and to explore differences…

This RCT investigated whether participants' sibling configuration moderated the effect of a Theory of Mind (ToM) intervention for children with autism. Children with autism aged 8-13 years (n = 141) were randomized over a waitlist control or treatment condition. Both having more siblings, as well as having an older sibling were related to better…

Autism is a heterogeneous diagnosis with symptoms that present in different ways. There is a large variety of interventions for autistic individuals. However, little is known about who chooses which specific interventions. We aimed to explore intervention prevalence and predict intervention use, based on demographic and autism-specific…

Youth with ASD often show limited or atypical empathic responsiveness. The direct effects of social skills interventions on enhancing empathic responsiveness is unknown. Data from a randomized controlled trial were used to investigate whether a Theory of Mind training improves the empathic responsiveness, measured through structured observations.…

Children and adolescents with Autism Spectrum Disorder (ASD) often show comorbid emotional and behavior problems. The aim of this longitudinal study is to examine the relation between emotion control (i.e., negative emotionality, emotion awareness, and worry/rumination) and the development of internalizing and externalizing problems. Boys with and…

Anticipating future interactions is characteristic of our everyday social experiences, yet has received limited empirical attention. Little is known about how children with autism spectrum disorder, known for their limitations in social interactive skills, engage in "social anticipation." We asked children with autism spectrum disorder…

Phenotypic elements of autism spectrum disorder can be masked by attention-deficit/hyperactivity disorder symptoms, potentially leading to a misdiagnosis or delaying an autism spectrum disorder diagnosis. This study explored differences in the age of autism spectrum disorder diagnosis between participants with previously diagnosed…

This RCT investigated whether the effect of a Theory of Mind (ToM) intervention for children with ASD was moderated by parental education level and employment, family structure, and parental ASD. Children with autism aged 8-13 years (n = 136) were randomized over a waitlist control or treatment condition. At posttest, children in the treatment…

The understanding of emotions based on counterfactual reasoning was studied in children with high-functioning autism spectrum disorders ("n" = 71) and in typically developing children ("n" = 71), aged 6-12 years. Children were presented with eight stories about two protagonists who experienced the same positive or negative…

Few instruments have been developed that measure impairments in reciprocity, a defining feature of autism. We introduce a new test assessing the quality of reciprocal behaviour: the interactive drawing test (IDT). Children and adolescents (n = 49) with and without high functioning autism spectrum disorders (HFASD) were invited to collaborate with…

This study highlights differences in cognitive strategies in children and adolescents with and without autism spectrum disorders (n = 52) on a verbal fluency task (naming as many words as possible (e.g. animals) within 60 s). The ability to form clusters of words (e.g. farm animals like "cow-horse-goat") or to switch between unrelated…

To examine differences by sex in the timing of identification of individuals with autism spectrum disorders (ASD), survey data were collected in the Netherlands from 2,275 males and females with autistic disorder, Asperger's syndrome and PDD-NOS. Among participants less than 18 years of age, females with Asperger's syndrome were identified later…