There are many disorders that fall within this category, each with its own unique set of manifestations on the child.
However, there are commonalities in this spectrum that include impairments or delays in the cognitive development of children, abnormal social behaviors and impairment or delays in communication.
The effect of this disorder is in the brain where there is an alteration of the way that synapses and their respective nerve cells connect and organize.
How this happens is not yet fully understood by the researchers in Autism.
The common symptoms of PDD include: unusual and repetitive behavior, problems with social interactions as well as problem with language.
The child may also manifest an unusual response to loud noises and bright lights (Shah, Dalton & Boris, 2007).
Many people purport that the disorder is caused by the environmental agents that are brought about by human activity.
Some of the causes that are thought of include diet, body’s inability to utilize certain components like vitamins and minerals, changes in the digestive tract changes, sensitivity to vaccines, and mercury poisoning.
There is a vaccine that has been developed aiming at reducing the prevalence of autism in children under the age of 3.
Worldwide, surveys have shown that 1 to 2 children per every 1,000 are affected by the disorder.