Even within the PDD or Autism categories, these children are not all alike. They differ widely in intelligence, language skill, attentional ability, behavior, and academic performance just like other children do. The diagnosis (or “label”) they are given actually often depends on their profile of strengths and weaknesses in these areas, and in particular prognosis can be greatly improved by strong underlying intelligence, which is hard to assess at age 2 (the age most such children are diagnosed).
It is very import for parents of kids with Autism or PDD not to give up hope, and keep advocating for their child. The prognosis is quite VARIABLE and hard to predict in any one child, even for the best experts and teams. I’ve seen kids who look low functioning at age 2 or 3 make huge progress and not look so bad by age 7-8. I’ve seen some (at all functional levels) evolve into adult schizophrenia and psychosis. But I’ve also seen kids with PDD seem to put the “disability” part behind them and become very successful, albeit eccentric, adults both professionally and socially – essentially “evolving” away from PDD/Autism and towards more of an Asperger’s picture. The children most likely to have this happy outcome are those who receive EARLY diagnosis and institution of a treatment program that incorporates ABA techniques.