PDD stands for Pervasive Developmental Disorder. It is a classification that includes many different conditions, including autism, Asperger's syndrome, Rett syndrome, childhood disintegrative disorder, and PDD. PDD is a syndrome of developmental delay of learning how to be in social groups and communication.
Diagnosis for this particular disorder may be attained when and if the child seems to be having trouble with age-appropriate movements or speech problems. Autism is an example of a neuropsychiatric disorder illustrated by the inability to engage in social groups and language and communication problems.
There have been numerous different ideas as to how autism is developed. It has been said that autism could come from a pregnant woman's irresponsible behaviors, who may be smoking or drinking without any thought as to how it is affecting her unborn baby. It may also come from genetic mutations or environmental causes such as heavy metals and pesticides.