This document summarizes autism spectrum disorder (ASD) according to the DSM-5. It describes the key characteristics of ASD including deficits in social communication/interaction and restricted, repetitive behaviors. While the specific causes are unknown, both genetic and environmental factors are thought to play a role. Common signs in young children include lack of eye contact and difficulties with social engagement, communication, and language. Diagnosis involves developmental screening and evaluation by a team of specialists. Early behavioral intervention programs, including applied behavior analysis therapy, provide the best outcomes when started as early as possible.