Although the precise motivations behind Duerson’s suicide remain unknown, he had complained of headaches, blurred vision and a deteriorating memory in the months before his death. His final note to his family finished with a handwritten request: “Please, see that my brain is given to the N.F.L.’s brain bank.”
The N.F.L. does not run the Boston University research group but did donate $1 million to its financing last year, after the league acknowledged long-term effects of football brain trauma.
C.T.E., a condition previously associated mostly with boxers and manifested in behavior more commonly known as dementia pugilistica, is a degenerative and incurable disease that compromises neural activity and is linked to memory loss, depression and dementia. Although groups at Boston University and elsewhere are pursuing tests for living patients, the condition can currently be detected only after death, by brain autopsy.
“We hope these findings will contribute more to the understanding of C.T.E.,” the N.F.L. said in a statement. “Our Head, Neck and Spine Medical Committee will study today’s findings, and as a league, we will continue to support the work of the scientists at the Boston University Center and elsewhere to address this issue in a forthright and effective way.”
DeMaurice Smith, the executive director of the players association, said in a telephone interview that Duerson’s having C.T.E. “makes it abundantly clear what the cost of football is for the men who played and the families.”
He added: “It seems to me that any decision or course of action that doesn’t recognize that as the truth is not only perpetuating a lie, but doing a disservice to what Dave feared and what he wanted to result from the donation of his brain to science.”
Credit NFL Photos, via Associated Press
Duerson’s death rattled players both active and retired, who after years of news media coverage are more aware that the damage done to their brains could be permanent. Pete Kendall, a recently retired offensive lineman, said, “The whole issue of C.T.E. is something that players young and old have no choice but to think about.”
Duerson’s former wife, Alicia, attended the Boston news conference with their four children. Their son Tregg, 25, made a brief statement, saying, “It is our hope that through this research questions that go beyond our interest may be answered — questions that lead to a safer game of football from professionals to Pop Warner.”
He added with regard to his father, “It is my greatest hope that his death will not be in vain and that through this research, his legacy will live on and others won’t have to suffer in the same manner.”
Duerson was an all-American defensive back at Notre Dame before spending most of his 11 N.F.L. seasons with the Bears. He played safety on the famed 46 defense that fueled their Super Bowl championship in the 1985 season, and he won the 1991 Super Bowl with the Giants.
Duerson retired after the 1993 season and became successful in the food-services industry before his businesses collapsed, his marriage failed and he went bankrupt. He began showing symptoms of repetitive brain trauma, including memory loss, poor impulse control and abusive behavior toward loved ones.
Another son, Brock, 22, said that the diagnosis of C.T.E. provided an explanation for his father’s decline and final act.
“I don’t want people to think just because he was in debt and broke he wanted to end it,” he said. “C.T.E. took his life. He changed dramatically, but it was eating at his brain. He didn’t know how to fight it.”
Duerson’s case is unique beyond the circumstances of his suicide. Since 2006, he had served on the six-member panel that considered claims for disability benefits filed by former N.F.L. players. Although individual votes are kept confidential, that board has been sparing in awarding benefits, including those for neurological damage.
Duerson himself told a Senate subcommittee in 2007 that he questioned whether players’ cognitive and emotional struggles were related to football.
However, Duerson’s legacy will almost certainly be how he apparently came to believe he had C.T.E., acted upon it and requested that his brain tissue be examined for confirmation and contribution to science.
Dr. Robert Stern, along with McKee a co-director of the Boston University research group, cautioned that C.T.E. could not explain all of a player’s actions.
“When it comes to suicide and chronic traumatic encephalopathy, it is possible that in some individuals the combination of C.T.E.-related symptoms of poor impulse control, depression and cognitive impairment may indeed lead to suicide,” Stern said. “However, we can never clearly point to any cause-and-effect relationship in any one case.”