I just watched a video with Dona Gates where she says she's had success treating autistic children by putting them on a special diet (Gluten free, casein free, sugar free with lots of vegetables, sea vegetables and fermented foods). It does not surprise me that changing a person's diet would help alleviate, at least some of the symptoms.

Scroll down to the end of the page for this video
http://www.bodyecology.com/video.php
http://bodyecology.com/autism.php