Autisms

Autism spectrum disorder (ASD) is a neurodevelopmental condition with onset in early childhood, characterized by deficits in social interaction and communication, stereotypic behaviors, insistence on sameness, restricted interests, and abnormal sensory processing. Its prevalence has risen during the last three decades from 2–5/10,000 to 1:59 children. ASD encompasses a collection of neurodevelopmental conditions sharing similar behavioral features but extremely heterogenous etiopathogenetic underpinnings. This chapter initially reviews the history of the concept of “autism,” the clinical diagnosis, epidemiology, comorbidities, developmental trajectories, and early signs. The pathophysiology of ASD is then described, spanning neuropsychology, neuroanatomy, functional brain imaging, and electrophysiology, as well as systemic gastrointestinal and immune dysfunction. The complex etiology of ASD spans from genetic syndromes and nonsyndromic autisms due to rare and common variants to environmental forms and epigenetic contributions. Current evidence-based clinical pharmacological and behavioral intervention paradigms are finally outlined, as well as therapeutic perspectives opened by experimental psychopharmacology and induced pluripotent stem cell models.