More than a dozen pro athletes are donating their brains after they die to a brand-new center studying the long-term effects of concussions.
They include former New England Patriots linebacker Ted Johnson, who has publicly struggled with depression and memory loss.
Johnson says he had 2 concussions in less than a week, yet kept on playing.
"I shouldn't have to prove to anybody there's something wrong with me, " said Johnson. who is 35 years old.
Dr. Robert Stern, the director of the new center at Boston University School of Medicine, says "I think it's huge. To have someone of Ted's stature, who has suffered so much, to be willing to tell the world enough is enough."
Another donor will be Former Archbishop Ryan star Frank Wycheck. Wycheck, a tight end, began his NFL career in 1993 with the Washington Redskins. he also played for the Houston OIlers, and the Tennessee Titans until his retirement after the 2003 season. He made the Pro Bowl twice.
Doctors at the center say tests show former Houston linebacker John Grimsley, who died last year, had brain damage similar to a former boxer who died of dementia in his 70s.
Another player whose brain showed similar damage was former Eagle Andre Waters, who took his own life 2 years ago.
An N.F.L. committee is currently doing its own study, but won't publish its findings until 2010. At a league conference on concussions last year, Commissioner Roger Goodell pointed to the lack of concussion documentation on some athletes. He noted that concussions can occur in many activities.
Grimsley's widow, Virginia, says it broke her heart to learn the findings on her husband's brain. However, she says it did help her make sense of his changing behavior before his death, of what police say was an accidental gunshot wound.