BEVERLY HILLS, Calif. -- Pro Football Hall of Famers Tony Dorsett and Joe DeLamielleure, and former NFL All-Pro Leonard Marshall have been diagnosed as having signs of chronic traumatic encephalopathy, a degenerative condition many scientists say is caused by head trauma and linked to depression and dementia, doctors have told "Outside the Lines."
The three former stars underwent brain scans and clinical evaluations during the past three months at UCLA, as did an unidentified ex-player whose test results are not yet available. Last year, UCLA tested five other former players and diagnosed all five as having signs of CTE, marking the first time doctors found signs of the crippling disease in living former players.
CTE is indicated by a buildup of tau, an abnormal protein that strangles brain cells in areas that control memory, emotions and other functions. Autopsies of more than 50 ex-NFL players, including Hall of Famer Mike Webster and perennial All-Pro Junior Seau, who committed suicide last year, found such tau concentrations.
Researchers told "Outside the Lines" that they notified Dorsett by phone Monday that they had diagnosed him as having signs of the neurological disease. Dorsett, in an appearance Wednesday afternoon on ESPN's "Dan LeBatard Is Highly Questionable" show, acknowledged he had been tested at UCLA and received results: "I'm not going to say too much more about it ... I'm trying to be proactive rather than reactive."
Two weeks ago, upon arriving in California for his evaluation and brain scan at UCLA, Dorsett described to "Outside the Lines" the symptoms that compelled him to seek testing: memory loss, depression and thoughts of suicide.
The former Cowboys running back, now 59, said that when he took his Oct. 21 flight from Dallas to Los Angeles for testing, he repeatedly struggled to remember why he was aboard the plane and where he was going. Such episodes, he said, are commonplace when he travels.
Dorsett said he also gets lost when he drives his two youngest daughters, ages 15 and 10, to their soccer and volleyball games.
"I've got to take them to places that I've been going to for many, many, many years, and then I don't know how to get there," he said.
The 1976 Heisman Trophy winner and eighth all-time leading NFL rusher said he has trouble controlling his emotions and is prone to outbursts at his wife and daughters.
"It's painful, man, for my daughters to say they're scared of me." After a long pause, he tearfully reiterated, "It's painful."
Dorsett said doctors have told him he is clinically depressed.
"I've thought about crazy stuff, sort of like, 'Why do I need to continue going through this?'" he said. "I'm too smart of a person, I like to think, to take my life, but it's crossed my mind."
CTE is a disease with no known cure, but Dorsett said he was seeking answers to explain his cognitive and emotional difficulties.
"I want to know if this is something that has come about because of playing football," he said.
Dorsett's 12-year playing career ended a quarter-century ago. He said he doesn't know how many concussions he suffered, but that they were numerous and he believes their consequences are, too.
"My quality of living has changed drastically and it deteriorates every day," he said.
Researchers involved in the UCLA testing say their brain scan uses a radioactive marker to identify the signs of CTE in the living, as was done with the eight former players. The research team, in affiliation with a company named TauMark, includes: forensic pathologist Bennet Omalu, who discovered CTE in football players; UCLA psychiatrist Gary Small and pharmacologist Jorge Barrio; and neurosurgeon Julian Bailes, co-director of the NorthShore Neurological Institute in Evanston, Ill.
Bailes acknowledged that the sample size is small and the testing is in its "very early" stages, but said, "Our preliminary data seems very strong that the areas of the brain and density of the tau signals correlates exactly with what we have found at autopsy."
DeLamielleure, 62, said he never received a concussion diagnosis during his 13-year career as an offensive lineman for Buffalo and Cleveland, but that during games and practices he endured tens of thousands of blows to his head and believes he had at least 100 concussions.
On the day he received the news that he has signs of CTE, DeLamielleure told OTL, "I can guarantee you my CTE, my tau, came from hits, came from blows to the head." He said he suffers from anxiety and chronic insomnia, and, like Dorsett, he recounted mood swings and suicidal thoughts.
"When I sit still for any length of time, I get depressed for no reason," DeLamielleure said. "I have CTE. Let's see what the heck we can do about it."
Marshall, 52, told "Outside the Lines" that when he received his diagnosis Sunday it was "very emotional."
"I knew there was something going on," he added. "I've had short-term memory loss, erratic behavior where the least little thing would set me off, and I've experienced fogginess and even been in a daze at times.
"It's been a rough road and hopefully now there'll be a light at the end of the tunnel."
Said Bailes: "Until we had the ability to see it in a living, breathing person, we had no chance of helping them, we had no chance of really understanding what happens to the disease. It gives us the ability to track it, to see if it gets worse, or hopefully, maybe it gets better with medication, with intervention, with new discoveries.
"There's a lot more scientific investigation and rigor and publication and peer review that needs to be done on this, but initially, we're optimistic and excited about the potential of the test."
Other researchers also are developing tests to diagnose CTE in the living. Among them is Dr. Ann McKee, a Boston University neuropathologist.
No one has examined more brains of deceased NFL players than McKee, who found CTE in 47 of the 48 brains she has studied. McKee is also developing a test for the living, and said it is not yet clear if currently available scans are actually showing signs of CTE or if they are indicative of other conditions, such as Alzheimer's disease.
Omalu, also a neuropathologist, said that it is the combination of symptoms, clinical evaluations and brain scan findings that led to his group's diagnoses of CTE indicators in the former players and that there is a "reasonable degree of certainty that this is CTE until proven otherwise." He said that in posthumous examinations, as well, a history of cognitive impairment and emotional problems is an important factor in diagnosing CTE.
Bailes, a former team physician for the Steelers, said he looks forward to more testing and considers his group's scan a "game-changer." The first tests, published in a medical journal in February, concluded that Fred McNeill, a 59-year-old former Vikings linebacker; Wayne Clark, a 64-year-old former quarterback for three teams; and three unidentified ex-players: a 73-year-old former guard; a 50-year-old former defensive lineman; and a 45-year-old former center, had CTE indicators.
The NFL, which declined to comment, has repeatedly asserted that there is not enough evidence to draw a conclusion that playing football causes CTE or other brain damage. After denying the severity of concussions for years, and disputing the research of doctors like Omalu and Bailes, the league reversed its position in 2009 and acknowledged a scientific connection between football and long-term brain damage -- but has not made a similar statement since.
Dorsett, Marshall and DeLamielleure are among the 4,500-plus plaintiffs in a class-action lawsuit filed against the NFL that is in the midst of being settled for $765 million. The plaintiffs argued that for years the NFL had concealed a link between playing football and brain damage. As part of the settlement reached in August, the NFL did not admit to wrongdoing.
In January, Dr. Richard Ellenbogen, a Seattle neurosurgeon who serves as co-chair of the NFL's Head, Neck and Spine Committee, told Mark Fainaru-Wada and Steve Fainaru of "Outside the Lines" that the UCLA CTE study was "promising work," adding the researchers were "honest about the limitations as well as being excited about the findings."
"This is the holy grail if it works. This is what we've been waiting for, but it looks like it's probably preliminary to say they've got it," Dr. Robert Cantu, a senior adviser to the NFL's Head, Neck and Spine Committee and co-director of Boston University's Center for the Study of Traumatic Encephalopathy, told ESPN in January. "But if they do have it, this is exactly what we need."
Omalu said diagnosing CTE in the living is a promising step.
"I think we can develop a treatment for this," he said. "Everybody should come to the table."
His advice to the diagnosed ex-players: "Use the power of positive thinking, don't let the disease overwhelm, this is not a diagnosis of death."
Prior to his test, Dorsett said he drew hope from its potential benefits.
"I'm trying to slow this down or cut it off," Dorsett said. "I'm going to be 60 years old here next year, so I'm hoping that I've got another good 30 years or so."
William Weinbaum is a producer and Steve Delsohn a correspondent in ESPN's Enterprise and Investigative Unit. Associate producer Simon Baumgart contributed to this report.