A pervative development disorder (PDD) will usually make itself known in a child around the age of 3, manifesting in any combination of social complications, troubles understand and using language (including stuttering or muteness), communication issues, lack of adaptive capabilities to routine changes and difficulties in imagination, often seen through unusual play habits (NINDS). There are four main, named types of pervasive development disorder:
- Autism - the child has pronounced difficulty relating in social and play situations and is resistant to change. Many cases of autism include an intellectual disability or low muscle tone and/or seizures. The child is usually fascinated by a small range of activities and may be frustrated when encouraged to perform non-related tasks.
- Asperger's Syndrome - Much llike autism in terms of the social and communication difficulties and highly focused interests, but the child with Aspergers develops normally in terms of language and cognition and often exhibits an above-average level of intelligence in these areas. May have unusual speech patterns and dislike change.
- Child disintegrative disorder - the child develops normally until some age between 2 and 10 whereupon they suddenly begin to regress, losing their grip on language, social and motor skills and sometimes bladder control etc. as well. This condition is quite rare and its classification remains under debate.
- Rett's Syndrome - Almost exclusively ocuring in girls as a result of an X chromosome abnormality, this child with Rett's loses their physical skills and may cease to walk or use their hands dexteriously.Co-ordination abilities fail but there is no affect on the cognitive side of development.
Other PDDs are classified as 'not otherwise speficied' and are often called, loosely, 'milder forms of autism' - the child has some difficulty in social, linguistic or motor development but is "too social to be considered autistic" (Hircsh).
1. Brinks, S. (2013, July 16). One thing we know about autism: Vaccines aren't to blame. Retrieved from http://news.nationalgeographic.com/news/2013/07/130716-autism-vaccines-mccarthy-view-medicine-science/
Hircsh, D. (n.d.). Retrieved from http://www.webmd.com/brain/autism/development-disorder
NINDS. (n.d.). Retrieved from http://www.ninds.nih.gov/disorders/pdd/pdd.htm