Pervasive development disorder (PDD) is a group of five disorders characterized by delays in development in areas like socialization and communication. The five groups of disorders are pervasive development disorder not otherwise specified (PDD-NOS), autism, asperger syndrome, rett syndrome, and childhood disintegrative disorder (CDD). Since PDD contains five different disorders, PDD itself does not refer to a specific disorder. General symptoms of people with one of the five PDD disorders are difficulty using and understanding language, difficulty relating to other people (not making eye contact, no facial expressions), usual play with toys, difficulty changing a set routine, repetitive body movements and behavior patterns (hand flapping, hair twirling, foot tapping), not wanting to cuddle or be comforted, and frequent temper tantrums, anxiety, and aggression. Children are usually diagnosed with PDD around the age of three when parents and physicians notice the child does not show normal social behavior. Some medications can be used to help with behavioral problems, and small class sizes and one-on-one instruction can help with education. Talk with your doctor to find the best treatment for your child if he or she has been diagnosed with pervasive development disorder.