I work with autistic and aspergers children and adults and have for years. I think diet is the cure. The results are amazing. Dairy, gluten and sugar free. I've seen nothing but good results even with just good effort. These things are not in a 'doctor's' repretoire at all so it's up to you to do it yourself. The only problem I've seen is most autistic children have a parent in the spectrum, and are too set in their ways to do things differently, they would rather accept that there is no treatment than change their diets. I really commend both the parents and adults with AS here that are willing to try do something about it.
I agree, dietary changes have made a difference for my daughter, even at the age of 20, when she began the gluten free/casein free diet. She is also corn free. Parents might think their child is too old to benefit. I wish we had started younger. A gluten free diet is not very hard anymore.