Chess and the challenged student

I have seen plenty of sharp smart kids do well in chess, but what is particularly intriquing to me is the way in which some students who cannot seem to concentrate and focus otherwise, can calm down and focus on a chess game. Also I have seen students who are in special ed classes, students with ADD, and students with serious mental disabilities perform at the chessboard at a level that is beyond expectations. The way in which this lifts up the kids self-esteem and gives them confidence and detrmination in other areas is priceless.