However, after years of research, professionals have proven that parents do not cause this disorder in their children. We now expect to find something about the way a child's brain develops so differently. They make the diagnosis by comparing your child's behaviors and abilities with others that have the disorder. Autism occurs in about one out of every 2,000 births. The incidence of PDD appears to be about one in 1,000 births.
Boys are more likely than girls to have the disability.
In almost every case, autism is a lifelong condition. As PDD is a much more recent diagnosis, long term prognosis is still more uncertain. Those with autism are often also mentally handicapped, which makes the disorder much more challenging for them. Many experience minor lack of muscle coordination. Those with PDD are less likely to be mentally handicapped, but often have the a lack of muscle coordination.