RT Book, Section A1 Wied, Heather M. A1 Standridge, Shannon M. A2 Hershey, Andrew D. SR Print(0) ID 1195236384 T1 Autism Spectrum Disorder and Regressive Developmental Disorders T2 CURRENT Diagnosis & Treatment Pediatric Neurology YR 2023 FD 2023 PB McGraw Hill Education PP New York, NY SN 9781260457520 LK neurology.mhmedical.com/content.aspx?aid=1195236384 RD 2024/03/28 AB Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in communication and social interactions, occurring with restricted patterns of behavior or interest.1 The ASD diagnosis focuses on the presentation of these behaviors and includes both identifying deficits and restrictions and determining their severity, which may range from mild to severe. Signs of ASD typically manifest within the first 2 years of life, but diagnosis may be delayed until a later age, especially with mild symptoms.