Autism spectrum disorder.

Abstract

Autism spectrum disorder (ASD) is characterized by deficits in social communication and social interaction together with restrictive, repetitive, and inflexible patterns of behavior including routines, rituals, and overfocused interests, sensory sensitivities, and motor stereotypies (e.g., hand flapping when excited or anxious). Until just a few years ago, it was thought that the prototypic individual with autism was a male with intellectual impairment. We now recognize that disabling-although less explicit-features characterize many children and adults with ASD with normal to high IQ. Unfortunately, most standardized methods of diagnosing ASD are still subject to diagnostic bias against the identification of higher functioning individuals, especially females. The apparent prevalence of ASD varies worldwide, but it is higher in countries with greater experience of diagnosing the condition. Within Europe and North America, the proportion of children with a diagnosis is at least 1.5% (Fombonne, 2020).ASD is classified in the 11th revision of the International Classification of Diseases (ICD-11; World Health Organization [WHO], 2023) as a neurodevelopmental disorder because the condition results from dysregulation of the brain's development. The use of the term spectrum is based on increasing evidence that the biological substrate of the condition is highly variable and features of the condition are heterogeneous (Robinson et al., 2016), in part reflecting gender and the age at presentation as well as the severity of any associated disorder