This just in on the Games for Health front. Casual games heavy PopCap has funded research with G4H on the "Cognitive Health Benefits of Digital Gameplay." Here's the official word from the press release:

Apparently initial results will be presented at the Serious Games Summit at GDC this March. Apparently PopCap got interested in this subject based on feedback from their players, who told them they played to "keep their minds sharp," so to speak. This is probably related to other widely played puzzles like crosswords and the afflictive, hipster puzzle of recent vogue, sudoku.