"A study has found overwhelming evidence that a brain disease is linked to football playing. So how will the N.F.L. take care of its players? A study of the donated brains of 202 men who had played football across various age levels showed that 177 had the graphic scars confirming the diminished powers from chronic traumatic encephalopathy, a disease caused by repeated blows to the head. The study, in JAMA, is the strongest yet tracking the relationship between gridiron concussions and such cognitive ailments as progressive dementia and suicidal depression that football fans have become familiar with. The study found C.T.E. in all but one of 111 brains donated by NFL retirees and their concerned families. It suggested a relationship between the number of years played at the game and the symptoms of C.T.E., a disease that can be examined only posthumously."