Asperger syndrome (AS) is an autism spectrum disorder (ASD), one of a distinct group of complex neurodevelopment disorders characterized by social impairment, communication difficulties, and restrictive, repetitive, and stereotyped patterns of behavior. Other ASDs include autistic disorder, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified (usually referred to as PDD-NOS). ASDs are considered neurodevelopmental disorders and are present from infancy or early childhood. Although early diagnosis using standardized screening by age 2 is the goal, many with ASD are not detected until later because of limited social demands and support from parents and caregivers in early life.
The severity of communication and behavioral deficits, and the degree of disability, is variable in those affected by ASD. Some individuals with ASD are severely disabled and require very substantial support for basic activities of daily living. Asperger syndrome is considered by many to be the mildest form of ASD and is synonymous with the most highly functioning individuals with ASD.