Also for more info, there are a couple of good books. "Driven to Distraction" and "Delivered from Distraction" are written by psychiatrists who seem to know what they are talking about and seem to be very readable even if one is not a physician.
Good luck and God Bless.
I have read those books. They have helped understanding what the problem is, though there have bee a lot more studies since they were written that has helped us to understand a lot more of what is happening.