http://ca.sports.yahoo.com/mma/news?slug=mmajunkie-Doc_Benjamin_concussions_mental_illness&prov=mmajunkie&type=lgns
Is this news? Boxers and the like have been the test subjects of this along with football players etc.
I don't know how much money needs to be spent determining that a career in getting the crap knocked out of you can have long-term health effects. Unless they plan on using research to change the rules of the sport, thus weakening the allure (yeah, right), then game on, good luck and consider yourselves warned.