Understanding And Dealing With Pervasive Developmental Disorders

Revised: May 21, 2014


Pervasive Developmental Disorder is term used to describe a broad and complex category of behavioral problems in children which are usually evident by age 3 years and before age 10.  In all cases the child's social, communication and learning ability is impaired. Children with  pervasive developmental disorders often display very limited and rigid behavior patterns that are largely characterized as stereotyped, self-centered, disruptive, aggressive or self-injurious.

Pervasive Developmental Disorders are relatively rare and usually represent severe and unusual problems both for treatment and diagnosis. The terms Autism and Pervasive Developmental Disorders are often used interchangeably. Using these terms interchangeably can be confusing since the diagnostic term Autistic Disorder is a more specific form of the Pervasive Developmental Disorders. Autism (usually a general term) and Autistic Disorder (a specific term) may not mean the same thing to all people. Autistic Disorder is a severe and pervasive form of the Pervasive Developmental Disorders. Less severe forms of these disorders are difficult to diagnose and do not have specific diagnostic categories.

Pervasive Developmental Disorders occur at a rate of approximately 10 to 15 per 10,000 children. Approximately 30% of those children diagnosed with Pervasive Developmental Disorders are female. Male children are three times more likely to have these disorders than females.

There is a general consensus that Autism and Pervasive Developmental Disorders have biological and neurological causes. However, there is no clear understanding of how these disorders are caused. Theories include biochemical, electrophysiological and structural differences within the brain. Various studies have implicated abnormal levels of neurotransmitters (serotonin or dopamine), phenylketonuria, epilepsy, ventricular enlargement, and brain stem abnormalities. Pervasive Developmental Disorders do not appear to run in families. Parenting and other psychological factors do not cause these disorders.

Using the Diagnostic and Statistical Manual of Mental Disorders (4th ed. rev.) there are 2 diagnostic categories.

  • Autistic Disorder. Considered the primary disorder in which most children are diagnosed. This diagnostic category has specific criteria and symptoms which are fairly similar from one child to the next.
  • Pervasive Developmental Disorder Not Otherwise Specified. A little studied category for children who meet the general description of Pervasive Developmental Disorder, but not the criteria for Autistic Disorder.

Only 2 diagnostic categories have been developed since virtually no progress has been made in detecting reliable patterns in children who are pervasively disordered but do not meet all the criteria for Autistic Disorder.

The most definite characteristic of a Pervasive Developmental Disorder is a failure in socialization of which children show little or no interest in other human beings, including their own families. They lack motivation to seek out affection, play or for any other form of interaction. The second area of obvious deficiency in language. About half do not speak or use gestures, but show only primitive acts like taking a parent by the hand to a door to have it opened, or throwing a tantrum to coerce a parent to stop making a demand. The other half may use some meaningful words, but may also echo the words or phrases of others without understanding them. Most of these children will be mentally retarded.

Autistic children and other children with Pervasive Developmental Disorders can be best understood in terms of the extent and the severity of the disability. The most pervasive form will involve profound mental retardation, cerebral-palsy and a pattern of very severe impairments across intellectual, adaptive, social, language, and motor functioning. These children are usually diagnosed as having Autistic Disorder. The least pervasive form is characterized by much less severe impairments in a few area(s), such as expressive or receptive language. Most children with Pervasive Developmental Disorders fall between these two extremes and show an uneven pattern of impairments.

The least pervasive and less severe forms of this disorder are difficult to diagnose. It is difficult to distinguish autistic children with higher intelligence from other children who meet the criteria for Schizophrenia, Schizoid or Schizotypal disorders. Language and social impairments are very similar to retarded or aphasic children.

Early intervention is critical in order to take advantage of the brain's ability to adapt and change. Extensive parent training and support is crucial. The demands of raising an autistic child leave parents and caregivers with little energy for relationships and other children. The child's involvement with normal peers in integrated settings appears to be essential. Treatment approach and the extent of that approach is generally based on the child's intelligence. The main objectives for children with very low intelligence include self-care skills, a reasonable degree of compliance to directions or simple rules, learning basic social and affectional behaviors, communication of needs and wants, appropriate play, and reducing harmful behaviors. For children with higher intelligence, there is an additional emphasis on learning age appropriate language, social interaction with normal peers, and acquiring behaviors and skills expected of normal pre and elementary school children.  Severely impaired children often require the structure of an institutional setting.

There are no medications which cure or substantially mitigate the social and psychological problems of children with Pervasive Developmental Disorders. Medication is often necessary for medical problems associated with Pervasive Developmental Disorders.

Predicting the outcome can be difficult. About 1-2% of autistic children become normal when compared to other children without the disorder. About 10% can achieve near-normal functioning in terms of language and social behavior and can make satisfactory progress in school or work. Another 20% will show fair outcomes and continue to make social and educational progress in spite of significant handicap, such as lack of speech. About 70% make limited or no progress in all areas of major handicaps.

Most autistic children form real but limited relationships with familiar people as they grow older. The prognosis is very poor for children, if in addition to low intelligence, there is a lack of speech before age 5, profound unresponsiveness to sounds, profound social unrelatedness, clear evidence of a neurological impairment, chromosomal abnormalities, or delayed motor development.