The diagnostic category<unk> s <unk> , as opposed to specific<unk><unk> s (SDD), is a group of<unk> s characterized by delays in the development of multiple basic functions including socialization and communication. The<unk> s include autism, Asperger syndrome,<unk>  not otherwise specified <unk> -NOS, i.e., all autism spectrum<unk> s ASD), childhood disintegrative<unk>  (CDD), overactive<unk>  associated with mental retardation and stereotyped movements, and Rett syndrome. The first four of these<unk> s are commonly called the autism spectrum<unk> s; the last<unk>  is much rarer, and is sometimes placed in the autism spectrum and sometimes not. The terminology<unk>  and ASD is often used interchangeably and varies depending on location. The two have overlapping definitions but are defined differently by the Diagnostic and Statistical Manual of Mental<unk> s, 5th edition (DSM-5), and the International Classification of Diseases, 10th edition (ICD-10). DSM-5, removed<unk>  as a diagnosis and replaced it with ASD and the relative severity of the condition. ICD-10 on the other hand labels ASD as a<unk>  with the subtypes previously mentioned. The onset of<unk> s occurs during infancy, but the condition is usually not identified until the child is around three years old. Parents may begin to question the health of their child when<unk>  milestones are not met, including age appropriate motor movement and speech production. There is a division among doctors on the use of the term<unk> . Many use the term<unk>  as a short way of saying<unk> -NOS<unk>  not otherwise specified). Others use the general category label of<unk>  because they are hesitant to diagnose very young children with a specific type of<unk> , such as autism. Both approaches contribute to confusion about the term, because the term<unk>  actually refers to a category of<unk> s and is not a diagnostic label.
Pervasive developmental disorder
Multiple complex developmental disorder
Developmental language disorder
Developmental disability
Low-functioning autism
High-functioning autism
Autism spectrum
Nonverbal autism