Pervasive developmental disorders (PDD) is a diagnostic category refers to a group of disorders characterized by delays or impairments in communication

Communication

Communication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...

, social behavior

Social behavior

In physics, physiology and sociology, social behavior is behavior directed towards society, or taking place between, members of the same species. Behavior such as predation which involves members of different species is not social...

s, and cognitive development.Pervasive developmental disorders include Autism

Autism

Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...

, Asperger's syndrome, Rett's syndrome, Childhood disintegrative disorder

Childhood disintegrative disorder

Childhood disintegrative disorder , also known as Heller's syndrome and disintegrative psychosis, is a rare condition characterized by late onset of developmental delays in language, social function, and motor skills...

, and pervasive developmental disorder not otherwise specified. These disorders could be noticed as early as during infancy and the onset of them usually happen before 3 years of age.

Symptoms may include problems with language, social interaction, and unusual repetitive behaviors. Unusual responses to sensory information, such as loud noises and lights, are also common among these children. Although these symptoms are common within these individuals, the variability and severity of these symptoms can differ widely.
Medication, special education, behavior modification, speech, physical occupational therapies are current treatments for PDDs.
The term for this group of five disorders was introduced by the American Psychiatric Association

American Psychiatric Association

The American Psychiatric Association is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the most influential worldwide. Its some 38,000 members are mainly American but some are international...

 in 1980.

A related category is "specific developmental disorder

Specific developmental disorder

Specific developmental disorders categorizes specific learning disabilities and developmental disorders affecting coordination.-ICD-10 taxonomy:...

s" (SDD).

Classification

The pervasive developmental disorders are:

• Pervasive developmental disorder not otherwise specified (PDD-NOS), which includes atypical autism (or is also called atypical autism), and is the most common ;
• Autism
  Autism
  Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
  
  , the best-known;
• Asperger syndrome
  Asperger syndrome
  Asperger's syndrome that is characterized by significant difficulties in social interaction, alongside restricted and repetitive patterns of behavior and interests. It differs from other autism spectrum disorders by its relative preservation of linguistic and cognitive development...
  
  ;
• Rett syndrome
  Rett syndrome
  Rett syndrome is a neurodevelopmental disorder of the grey matter of the brain that almost exclusively affects females. The clinical features include small hands and feet and a deceleration of the rate of head growth . Repetitive hand movements, such as wringing and/or repeatedly putting hands into...
  
  ; and
• Childhood disintegrative disorder
  Childhood disintegrative disorder
  Childhood disintegrative disorder , also known as Heller's syndrome and disintegrative psychosis, is a rare condition characterized by late onset of developmental delays in language, social function, and motor skills...
  
   (CDD).

The first three of these disorders are commonly called the autism spectrum disorders; the last two disorders are much rarer, and are sometimes placed in the autism spectrum and sometimes not.

PDD and PDD-NOS

There is a division among doctors on the use of the term PDD. Many use the term PDD as a short way of saying PDD-NOS. Others use the general category label of PDD because they are hesitant to diagnose very young children with a specific type of PDD, such as autism. Both approaches contribute to confusion about the term, because the term PDD actually refers to a category of disorders and is not a diagnostic label.

PDD is not itself a diagnosis, while PDD-NOS is a diagnosis. To further complicate the issue, PDD-NOS can also be referred to as "atypical personality development", "atypical PDD", or "atypical Autism".

Because of the "NOS", which means "not otherwise specified", it is hard to describe what PDD-NOS is, other than its being an autism spectrum disorder (ASD). Some people diagnosed with PDD-NOS are close to having Asperger syndrome, but do not quite fit. Others have near full fledged autism, but without some of its symptoms. The psychology field is considering creating several subclasses within PDD-NOS.

Symptoms

Symptoms of PDD may include communication problems such as:

• Difficulty using and understanding language
• Difficulty relating to people, objects, and events; for example, lack of eye contact, pointing behavior, and lack of facial responses
• Unusual play with toys and other objects
• Difficulty with changes in routine or familiar surroundings
• Repetitive body movements
  Stereotypy
  A stereotypy is a repetitive or ritualistic movement, posture, or utterance, found in people with mental retardation, autism spectrum disorders, tardive dyskinesia and stereotypic movement disorder. Stereotypies may be simple movements such as body rocking, or complex, such as self-caressing,...
  
   or behavior patterns, such as hand flapping, hair twirling, foot tapping, or more complex movements
• Unable to cuddle or be comforted

Degrees

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.

Diagnosis

Diagnosis is usually done during early childhood. Some clinicians use PDD-NOS as a "temporary" diagnosis for children under the age of five when, for whatever reason, they are reluctant to diagnose autism. There are several justifications for this. Very young children have limited social interaction and communication skills to begin with, so it can be tricky to diagnose milder cases of autism in toddlers. The unspoken assumption is that by the age of five, unusual behaviors will either resolve or develop into diagnosable autism. However, some parents view the PDD label as no more than a euphemism for autism spectrum

Autism spectrum

The term "autism spectrum" is often used to describe disorders that are currently classified as pervasive developmental disorders. Pervasive developmental disorders include autism, Asperger syndrome, Childhood disintegrative disorder, Rett syndrome and Pervasive Developmental Disorder Not Otherwise...

 disorders, problematic because this label makes it more difficult to receive aid for Early Childhood Intervention

Early Childhood Intervention

Early childhood intervention is a support system for children with developmental disabilities or delays and their families.The mission of Early Childhood Intervention is to assure that families who have children ages birth to three, with diagnosed disabilities, developmental delays or substantial...

.

Cure and care

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. Early intervention, including appropriate and specialized educational programs and support services, play a critical role in improving the outcome of individuals with PDD.

See also

• Overactive Disorder Associated with Mental Retardation and Stereotyped Movements
  Overactive disorder associated with mental retardation and stereotyped movements
  Overactive disorder associated with mental retardation and stereotyped movements is a pervasive developmental disorder in Chapter V of the tenth revision of the International Statistical Classification of Diseases and Related Health Problems ; its diagnostic code is F84.4.-ICD-10 clinical...
  
  
• Specific developmental disorder
  Specific developmental disorder
  Specific developmental disorders categorizes specific learning disabilities and developmental disorders affecting coordination.-ICD-10 taxonomy:...
  
  
• Multiple-complex Developmental Disorder
  Multiple-complex Developmental Disorder
  Multiple complex developmental disorder is a research category, proposed to involve several neurological and psychological symptoms where at least some symptoms are first noticed during early childhood and persist throughout life...
  
  
• Multisystem Developmental Disorder
  Multisystem Developmental Disorder
  Multisystem developmental disorder is a term used by Stanley Greenspan to describe children under age 3 who exhibit signs of impaired communication as in autism, but with strong emotional attachments atypical of autism.-Other uses of the term:...
  
  
• Infantile neuroaxonal dystrophy
  Infantile neuroaxonal dystrophy
  Infantile neuroaxonal dystrophy is a rare pervasive developmental disorder that primarily affects the nervous system. Individuals with infantile neuroaxonal dystrophy typically do not have any symptoms at birth, but between the ages of about 6 and 18 months they begin to experience delays in...
  
  , a rare and severe neurological disorder which shows developmental regression in infants and toddlers

External links

• CDC's "Learn the Signs. Act Early." campaign - Information for parents on early childhood development and developmental disabilities
• NINDS Pervasive Developmental Disorders Information Page
• NICHCY fact sheet on Pervasive Developmental Disorder (note: not in the public domain)
• Information about Pervasive Developmental Disorders Yale Developmental Disabilities Clinic
• http://childstudycenter.yale.edu/autism/pddnos.html
• http://www.medicinenet.com/pervasive_development_disorders/page3.htm#treated