Pervasive developmental disorders (PDDs) are conditions which are characterized by developmental delay in basic skills such as peer socialization, communication and the use of imagination. A child with a pervasive developmental disorder might have problems relating to other people and understanding how social interactions work. These conditions are called pervasive developmental disorders because they generally are diagnosed at a young age, when a typical child undergoes a period of rapid development. A child with one of these disorders is developmentally delayed in comparison to his or her peers.
There are five pervasive developmental disorders. The two most well-known are autism and Asperger’s syndrome. Two much less common PDDs are Rett syndrome and childhood disintegrative disorder. The fifth, known as pervasive developmental disorder not otherwise specified (PDD-NOS), is the most common of the five. This category includes atypical autism and conditions that do not fit into any of the other four categories.
Children with autism have problems with communication and social interactions and with using their imagination, especially during play. About 75 percent have an intellectual disability. Children with Asperger’s syndrome have problems with social interactions and communication, and they might have a reduced ability to concentrate, but they often are of above-average intelligence. Children with Rett syndrome are delayed in physical development as well as social and communicative development. Childhood disintegrative disorder is a very rare condition in which children have developmental delay in multiple areas and might lose control of bodily functions.
There is little information concerning the causes of pervasive developmental disorders, although there is evidence to suggest that defects in the nervous system are involved. These conditions generally are diagnosed during early childhood, when parents begin to notice that their child is less developmentally advanced compared to others in his or her age group. The diagnostic process might take some time, as there can be several stages involved. For example, physical causes of symptoms might need to be ruled out before the child can be referred to a specialist in childhood developmental disorders.
Treatment for pervasive developmental disorders is most effective when a child is diagnosed early. Treating these disorders typically involves a comprehensive plan that might include behavior modification therapy for children who display inappropriate behavior, structured education for children with learning difficulties and other types of therapy such as physical or speech therapy. With an effective therapy plan, children can learn to socialize and communicate more effectively and to cope with the world around them, but they are not likely to catch up to their peers in terms of development. None of these disorders are fatal, and the expected lifespan is not reduced for a child diagnosed with a PDD.