Pervasive developmental disorderThe diagnostic category pervasive developmental disorders (PDD) refers to a group of disorders characterized by delays in the development of multiple basic functions including socialization and communication. Parents may note symptoms as early as infancy and typically onset is prior to 3 years of age. Symptoms may include communication problems such as * using and understanding language; * difficulty relating to people, objects, and events; * unusual play with toys and other objects; * difficulty with changes in routine or familiar surroundings, and * repetitive body movements or behavior patterns. Autism (a developmental brain disorder characterized by impaired social interaction and communication skills, and limited range of activities and interests) is the most characteristic and best studied PDD. Other types of PDD include Asperger's syndrome, childhood disintegrative disorder, Rett's syndrome, and PDD not otherwise specified. Children with PDD vary widely in abilities, intelligence, and behaviors. Some children do not speak at all, others speak in limited phrases or conversations, and some have relatively normal language development. Repetitive play skills and limited social skills are generally evident as well. Unusual responses to sensory information - loud noises, lights - are also common. Is there any treatment? There is no known cure for PDD. Medications are used to address certain behavioral problems; therapy for children with PDD should be specialized according to the child's specific needs. Some children with PDD benefit from specialized classrooms in which the class size is small and instruction is given on a one-to-one basis. Others function well in standard special education classes or regular classes with support. What is the prognosis? Early intervention including appropriate and specialized educational programs and support services plays a critical role in improving the outcome of individuals with PDD. PDD is not fatal and does not affect normal life expectancy.