Autism is a developmental disorder that affects many aspects of how a child sees the world and learns from his or her experiences. Children with autism lack the usual desire for social contact. The attention and approval of others are not important to them in the usual way. Autism is not an absolute lack of desire for affiliation, but a relative one. Autism is the best recognized and most frequently occurring form of a group of disorders collectively known as the pervasive developmental disorders (PDD).
The use of slightly different ways of labeling autism and related conditions at different times in the past and in different countries can be confusing: The term pervasive developmental disorders (or PDDS) is most accurately used to describe autism (autistic disorder) plus an array of non-autistic PDDs (such as PDD, NOS, Asperger's syndrome, fragile X syndrome, Rett syndrome, and childhood disintegrative disorder). When we discuss autism and "PDD," We are really referring to "PDD, NOS," unless it is otherwise explicitly stated. This is because both parents and professionals tend to talk about children who have received a diagnosis of PDD, NOS as having "PDD." The full term PDD, NOS will be used only when PDD, NOS is being specifically compared with or contrasted to other non-autistic PDDS. (Cohen, Shirley 2005) The term PDD, NOS is an awful, awkward use of language that conveys virtually no specific information by the addition of the "NOS", but is meant to convey that the child is affected in the areas of both social and communication development in the manner of a child with a full syndrome of autism.
Autism ("autistic disorder") stands among the various other PDD diagnoses, as well as its relationship to other developmental disorders with which it is sometimes confused............
