There has been a lot of research over this topic. Consider Utah State University Dr. Singh's research as an example. Speaking of Dr. Singh, I found a great commentary from him that was published in August 2005. Here's the link:
The
Autism Research Institution
is another such example of researchers. They are a donor-funded, non-profit organization dedicated (obviously) to research on this subject. I will discuss some of the research they have done, but I recommend you check out their Website for more information. Be sure to keep checking back, because they are always researching new things.
Research Articles On Autism
MyAutismRecovery.com has a blog where you can get updates on some of the latest research:
Research Articles On Autism