By definition, childhood disintegrative disorder
can only be diagnosed if the symptoms are preceded by at least 2 years of normal development and the onset of decline is prior to age 10.
The most severe ASD is autistic disorder (which often is called simply "autism"); other forms include Asperger syndrome and the much rarer childhood disintegrative disorder
According to the DSM-IVTR (American Psychiatric Association, 2000) PDD includes Autistic Disorder, Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS), Asperger's Disorder, Childhood Disintegrative Disorder
, and the related disorder of Rett's Syndrome.
In addition to autism, PDD includes Rett's Disorder, Childhood Disintegrative Disorder
, Asperger's Disorder, and Pervasive Developmental Disorder-Not Otherwise Specified.
All conditions identified as a PDD in the DSM-IV (American Psychiatric Association, 1994; Autistic Disorder, Rett's Disorder, Childhood Disintegrative Disorder
, Asperger's Disorder, Pervasive Developmental Disorder Not Otherwise Specified) share three common areas of developmental delay: skills in reciprocal social interaction, communication, and stereotypic behaviors or interests (Szatmari, 1992, 1998).
Specific labels included under the broader heading of Pervasive Developmental Disability include: Asperger's syndrome, autism, Rett's disorder, and Childhood Disintegrative Disorder
(American Psychiatric Association, 1994).
These three conditions, along with Rett's syndrome and childhood disintegrative disorder
, make up the broad diagnostic category of pervasive developmental disorders.
As currently proposed, the DSM-5 would create a new name for the category - autism spectrum disorder - that would include autistic disorder, Asperger's disorder, childhood disintegrative disorder
, and pervasive developmental disorder not otherwise specified.
Specialists in these disorders, as well as genetics, pharmacology, pathophysiology, neurology, neuroimaging, and other fields, from North America, Europe, and Japan, cover the history of autism; assessment; Asperger's syndrome, pervasive developmental disorder not otherwise specified, childhood disintegrative disorder
, and Rett syndrome; symptoms; causes; neuroanatomy and imaging; comorbidities; the role of the immune system; and traditional and alternative treatment approaches, including medication, complementary and alternative therapies, and behavioral, educational, and psychosocial treatments.
The most commonly known PDD is autism, with the remaining identified as Rett syndrome, childhood disintegrative disorder
, Asperger syndrome, and pervasive developmental disorder not otherwise specified.
Recent prevalence studies suggest that more than 1 million Americans are living with an autism spectrum disorder, such as Asperger Syndrome, Autistic Disorder, Childhood Disintegrative Disorder
(CDD), Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS) or Rett Syndrome.
Present studies suggest that, in general, children with classical autism have an approximate 30% risk of developing seizures, while those with Asperger Syndrome and with Pervasive Developmental Disorders-Not Otherwise Specified (PDD-NOS) have a less than 10% risk grid those with Disintegrative Disorder
or with Rett syndrome have a greater than 75% risk of developing seizures.