Pervasive developmental disorders (PDDs) are neurological disorders that affect a person's ability to interact socially and communicate with others. Typical signs include self-isolation, refusal to make eye contact or respond to others, and repetitive movement (e.g., arm-flapping, rocking, head-banging). Mental retardation and cognitive impairment may also occur.

PDDs are usually identified during childhood, and symptoms last a lifetime. Children with a PDD may require supervised care for the rest of their lives, depending on the severity of their disorder.

There are five types of PDDs: autism, Asperger's syndrome, pervasive developmental disorder not otherwise specified (sometimes called atypical autism), Rett syndrome and childhood disintegrative disorder. The first three are considered autistic spectrum disorders, although that term has also been used to describe all PDDs.

Most causes of PDDs are unknown. Genetics and other factors that affect brain chemistry and development are believed to be involved. For example, a specific gene mutation has been identified in 80 percent of patients with Rett syndrome. Parental age may be a factor, but vaccines, parenting style and emotional trauma do not cause PDDs.

The American Academy of Pediatrics now recommends that all children be screened for autistic disorders between the ages of 18 and 24 months. Parents are also advised to consult their child's pediatrician if they suspect their child is not meeting age-appropriate developmental milestones, or the child has lost previously acquired social, language or motor skills.

Diagnosing PDDs can be a lengthy process because it may involve specialists and numerous examinations. Blood tests and hearing tests may also be performed. In general, however, there is no test that identifies the presence of a PDD -- diagnosis is based on symptoms. Parents should be prepared to provide a thorough list of all their child's symptoms and when they began.

Although PDDs cannot be cured, parents should work with their child’s pediatrician or team of specialists to develop a treatment plan that may help reduce the child’s symptoms. Early intervention may dramatically reduce social problems faced by these children. Treatment may include behavior therapy, medication, and speech, physical and/or occupational therapy.

Caring for children with PDDs can be an extremely frustrating and stressful experience. There are numerous methods to help parents cope with their child’s PDD, including joining a support group, attending family counseling and applying for financial aid to help lessen the financial burden of long-term care for a child with a PDD.