Pervasive Developmental Disorders are characterized by “severe and pervasive impairment in several areas of development” (Tsai, 1998). In the 1994 edition of the Diagnostic Statistic Manuel version IV, three new categories were introduced under Pervasive Developmental Disorders. These include: Childhood Disintegrative Disorder, Asperger's Disorder, and Rett's Syndrome (Volkmar, 2005). All these disorders occur in early childhood and are often not noticed by a parent or primary caregiver until it is noticed that the child is not achieving normal developmental milestones.
Childhood Disintegrative Disorder is a severe condition in which a child will develop normally until age 3 or 4, then rapidly lose already learned skills such as communication skills, motor ability, nonverbal behaviors, and social skills over the course of a few months (Zieve, 2012). Theodore Heller originally described the condition and reported his findings in 1908. It has been only recently that the disorder has been recognized as a clinical condition and was included into the DSM-IV in its 1994 release (Westphal, 2014).
CDD is an uncommon condition. Since Heller's original description in 1908, there have been approximately 100 reported cases in literature (Volkmar, 2005). In case by case studies, the prevalence has shown to have about an equal sex ratio, although more recent studies have shown that CDD is slightly more common in males (Barber National Institute, 2013).
Symptoms of Childhood Disintegrative Disorder consist of: a lack or delay of spoken language, loss of social skills, loss of bowel and bladder control, overall loss of communication skills, both verbal and nonverbal, loss of motor skills, inability to begin or maintain a conversation, and problems forming relationships with other children and family members (Medline, 2014). CDD shares a great deal of comorbidity with the Autism Spectrum Disorder although it differs in outcome, pattern of onset, and course (Westphal 2014). Similarities have also been shown with childhood schizophrenia.
Currently, the etiology of Childhood Disintegrative Disorder is unknown. However, evidence suggests that the cause of this disorder is the result of a variation of a central nervous system pathology (Westphal, 2014). CDD is similar enough to Autism that treatment is relatively the same in terms of using medication to slow the progression. The general prognosis of the disorder is very poor. By age 10, children with CDD exhibit the same level of impairment as shown by children with severe autism (Hanada, 1999).
Asperger's Disorder, like many disorders, involves a significant impairment in the ability to engage in meaningful social interactions. Repetitive and restricted stereotyped behaviors are evident with this disorder, though it lacks the severe delays in language or other cognitive skills that are expressed by those diagnosed with Autism. Hans Asperger was the first to describe the disorder in 1944, but it was Lorna...