New York Times. The illness is presumably the result of repeated blows to the head suffered during games. According to a telephone survey of retired players and/or their caretakers, 6.1% of retired players over the age of 50 had such a diagnosis, compared with the widely published estimates of 1.2% in the population at large. For younger men, age 30 to 49, the diagnosis was 19 times more common: 1.9% in retired players compared with 0.1% in the population at large, according to the study conducted by the University of Michigan's Institute for Social Research. The study was distributed to league officials earlier this month, but has not been released publicly and not published in a journal.
The findings correlate well with previous studies. The league has largely ignored those earlier studies, however, saying it needed to perform its own. Now that it has, players are waiting to see what action it will take to minimize future risks.
-- Thomas H. Maugh II