Research is till being done on this subject. Another topic of research is on the effect of diet on autistic children. Since many autistic children also have chronic stomach aches and diarrhea, researchers have begun to look into the stomach for the answer. They believe that the child is unable to break down milk and grain causing a hole in the stomach. This hole allows food to leak out and effect the brain.
Research shows that children with autism do better when grain and milk is taken out of their diets.
Another area that is being researched is that children or adults with autism tend to have above average head circumferences. Many children had their heads measured and it was proved that children with autism sometimes do have larger heads. Post mortem studies show that the brain is sometimes enlarged as well. It is still unknown whether this is a cause or an effect of autism. A final area of reseach is currently being done on the genetic factor of autism.