A licensed psychologist can administer cognitive tests that are specially designed to assess problem-solving skills without using language. This requires expertise in working with children with developmental delays and language impairment. A child may have delays in social development and delays in one or more of the other categories. The profiles of children with a PDD can vary tremendously. PDD is not one disorder but a category that encompasses a wide range of delays of different magnitude in different domains.
Autism is the most severe of the pervasive developmental disorders.
Autism indicates a primary disturbance in the individual's ability to relate to others. Language delay and cognitive delays are also common. This is a diagnosis given to a child who exhibits impairment in the development of reciprocal social interaction, verbal and non-verbal communication, or when stereotyped behavior or activities are present. However, the child does not meet the criteria for any specific pervasive developmental disorder. There is no cure for autism at present.