What is a good thesis statement for a research paper on autism?

I have to do a 7 to 10 page research paper on autism and I am having trouble coming up with a good thesis statement.

What is a good thesis statement for a research paper on autism?
http://www.autism.com/
Reply:The reality is that autism has many levels of severity. So, my choice for an opening statement will state the differences of the behavior at the known levels of severity, what treatment modalities seem to be most successful at each level, and while the cause of autism remains a mystery, research that includes positive behavior modification, has been fairly successful.