Massachusetts General Hospital

Pervasive Developmental Disorders

What are pervasive developmental disorders (PDD)?

Pervasive developmental disorders, also called autism spectrum disorders, most often can be identified in the early years of a child's life. Children with PDD have difficulty in areas of development or use of functional skills, such as language, communication, socialization, and motor behaviors. Examples of PDD include the following:

• Autism

• Asperger's disorder

• Rett syndrome 

• Childhood disintegrative disorder (also called disintegrative psychosis)

What causes pervasive developmental disorders?

The specific causes of pervasive developmental disorders are not known. Children with PDD have problems processing information, thus the causes of PDD have something to do with differences in brain function. However, parenting behaviors are not the cause, or even a contributing factor, to the cause or causes of PDD.

Who is affected by pervasive developmental disorders?

An average of one in 110 children has some form of PDD. PDD is found four to five times more frequently in boys, with the exception of Rett syndrome, which is found only in girls.

What are the symptoms of pervasive developmental disorders?

The following are the most common symptoms of some pervasive developmental disorders. However, each child may experience symptoms differently.

The symptoms of autism may include:

• Does not socially interact well with others, including parents

  • Shows a lack of interest in, or rejection of, physical contact. Parents describe autistic infants as "unaffectionate." Autistic infants and children are not comforted by physical contact.

  • Avoids making eye contact with others, including parents

  • Fails to develop friends or interact with other children

• Does not communicate well with others

  • Is delayed or does not develop language

  • Once language is developed, does not use language to communicate with others

  • Has echolalia (repeats words or phrases repeatedly, like an echo)

• Demonstrates repetitive behaviors

  • Has repetitive motor movements (such as rocking and hand or finger flapping)

• Is preoccupied, usually with lights, moving objects, or parts of objects

• Does not like noise

• Has rituals

• Requires routines

The symptoms of Asperger's disorder may include:

• Normal development of speech, self-help skills, thinking skills (cognitive development), and curiosity about their environment

• Difficulty with social interactions such as making friends, sharing ideas, sharing pleasures or accomplishments, facial expressions (smiles), or eye contact with others

• Repetitive and stereotyped patterns of behavior or play such as strange routines or rituals (hand or finger flapping, collecting strange objects such as lint)

• Capable of originality and creativity focused on isolated areas of interest

The symptoms of Rett syndrome may include:

• Normal pregnancy, birth, and newborn growth and development

• Normal growth and development during the first 5 to 18 months of life

• Normal head circumference at birth

Following a period of normal development of at least five months, all of the following changes occur:

• Size of the child's head does not grow as much as it should between the ages of 5 and 48 months

• Loss of previously learned useful hand skills (such as reaching for and grasping an object) and the development of stereotyped hand movements that are not useful to the child, such as hand wringing

• Loss of socially engaging behaviors, such as smiles and eye contact (however, these behaviors may be re-developed later)

• Loss of coordinated walking or body movements

• Expressive (ability to verbally express thoughts) and receptive (the ability to understand and use language that is heard or seen) language skills become impaired and severe psychomotor retardation develops

The symptoms of childhood disintegrative disorder may include:

• At least two years, and usually up to four years, of normal development including speech, social interactions and relationships, and play and adaptive behavior

• Over a short period of time (a few months), severe loss of functioning in social, communication, and behavioral skills occurs. Without any obvious illness or cause, children experiencing disintegrative disorder become anxious, irritable, negative, and disobedient with frequent temper tantrums and outbursts for no apparent reason. These children have a complete loss of speech and language, understanding of language, and a decrease in thinking (cognitive) skills.

The symptoms of PDD often resemble other conditions or medical problems. Always consult your child's doctor for a diagnosis.

How are pervasive developmental disorders diagnosed?

Pervasive developmental disorders are usually identified by the age of 3 years. A child psychiatrist or other mental health professional usually makes the diagnosis of any of the PDD following a comprehensive medical and psychiatric evaluation.

It is important to diagnose PDD early and accurately as some PDD put children at risk for developing other mental disorders (i.e., depression, attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, and schizophrenia).

Treatment for pervasive developmental disorders

Specific treatment for PDD will be determined by your child's doctor based on:

• Your child's age, overall health, and medical history

• Extent of the disorder

• Type of disorder

• Your child's tolerance for specific medications or therapies

• Expectations for the course of the disorder

• Your opinion or preference

Treatment plans are individualized based on each child's symptoms and the level of severity. Multidisciplinary treatment approaches are utilized as needed to address the individual needs of each child.

Treatment may include:

• Speech therapy

• Occupational therapy

• Social skills training (to help children learn to perform activities of daily living, or ADLs, and ways to communicate and relate to others)

• Behavioral therapy

Specialized behavioral and educational programs are designed to treat developmental disorders. Behavioral techniques help children learn to behave in more acceptable ways. Parents may be taught behavioral techniques to help them provide consistent rewards and set limits at home. While some children with PDD require specialized classrooms which are highly structured and provide attention to a child's specific academic needs, others are able to function in a regular classroom with less specialized attention.

Medication may be helpful in treating some symptoms of PDD, in some children. Child and adolescent mental health professionals help families identify and participate in treatment and educational programs based on an individual child's treatment and educational needs.

Prevention of pervasive developmental disorders

Preventive measures to reduce the incidence or severity of any type of PDD are not known at this time. However, it is believed that early identification, diagnosis, and treatment can provide the best chance for decreasing the symptoms of autism spectrum disorders.