Semantic-Pragmatic disorder demonstrate difficulty in communication skills and pragmatics. Semantic-Pragmatic language disorder is a condition in which complex language is intact, but either the content of the communication or the functional purpose of the communication is not clear. Children diagnosed with Pervasive Developmental Disorder may also be diagnosed with a developmental language disorder. These children usually continue to be interested in communicating using non-verbal modalities. Other non-verbal abilites are spared.
Regression is confined to the area of language.
Although some children show autistic patterns of social interaction almost from birth, it is difficult to give a definitive diagnosis of autism before age three. This is because rates of development in infants and young children are widely variable. Some behaviors associated with autism are also frequently found in children who are mentally retarded. This may make it difficult to discriminate between the two conditions, or determine that both conditions are present, in very young children. By the time a child is three or four, cognitive development can be more accurately assessed.