Well, I didn't read the whole article - but I have long believed that there is a "spectrum" of brain development. On one end, you get mental retardation, disabilities, brain damage. On the other end, those with extreme intelligence, also tend to have psychiatric conditions.

Like the guy that was in the movie A Beautiful Mind. He was brilliant, but aslo schizophrenic. People speculate that Albert Einstein could have been schizophrenic, yet he was also amazingly intelligent.

I think it has a lot to do with how our brains develop, and how they react to stressful situations.