Assessment of children's restricted and repetitive behaviours offers potential opportunities to improve early diagnosis of autism spectrum disorder (ASD) and timely access to interventions and support. To facilitate this requires understanding of the phenomenology of repetitive behaviours in ASD, including differentiating behaviours seen in ASD…

The etiology of autism spectrum disorders is unknown but there are claims of increasing prevalence in many countries. Despite more than a decade of epidemiological investigation, it is still unclear whether the rising trend in prevalence reflects a true increase or changes in diagnostic trends and improvements in case ascertainment. This paper…