Autism is a pervasive developmental disorder. Individuals with Autism are often described as being completely indifferent to the world around them, living only within themselves. Individuals may have symptoms present at birth, or may develop symptoms between birth and age 3. There is no medical test for Autism. Diagnosis is made from careful observation of behaviour, conducting developmental tests and discussion with parents.
Language is slow to develop, if it develops at all.
If it does develop, it usually includes peculiar speech patterns or the use of words without attachment to their normal meaning. Those who are able to use language effectively may still use unusual metaphors or speak in a formal and monotone voice. Severe delays in understanding social relationships. This results in a lack of cooperative play with peers, an impaired ability to develop friendships, and an inability to understand other people's feelings. Inconsistent patterns of sensory responses.