Entertainment Sports Jason Hairston Had CTE Symptoms Before Death — Here Are Other Football Players Who Had the Disease This week, former San Francisco 49ers player Jason Hairston died by suicide just two years after revealing he had the symptoms of chronic traumatic encephalopathy, or CTE By Jason Duaine Hahn Jason Duaine Hahn Jason Hahn is a Human Interest and Sports Reporter for PEOPLE. He's worked at PEOPLE's Los Angeles Bureau as a writer and reporter since 2017 and has interviewed the likes of Kobe Bryant, Arnold Schwarzenegger and Tom Brady. He has a B.A. in English from the University of California, Berkeley, and a Master's degree in Journalism from Columbia University. He previously worked for Complex Magazine in New York City. People Editorial Guidelines Published on September 7, 2017 12:40 PM Share Tweet Pin Email Photo: Jason Hairston Instagram This week, former San Francisco 49ers player Jason Hairston died by suicide just two years after revealing he had the symptoms of chronic traumatic encephalopathy, or CTE. The degenerative brain disease is linked to repeated head trauma or concussions. Its symptoms depression, short-term memory loss, impulsive behavior and confusion — and these symptoms can begin to appear long after a player’s career. Evidence is mounting suggesting a link between playing football and the disease. CTE can only be diagnosed after death, and in a 2017 study of the brains of 111 deceased NFL players, a Boston University researcher found that 110 of them had the disease. “It is no longer debatable whether or not there is a problem in football—there is a problem,” the researcher of the study, Dr. Ann McKee, told the New York Times. Hairston told CNBC in 2016, “I played linebacker, and the way I played the game, I led with my head. I played the way they tell us not to play now. I have all the symptoms of CTE.” Former San Francisco 49ers Player Jason Hairston Dead by Suicide at Age 47 Some have cautioned that the findings of the 2017 study might have a selection bias because the brains were submitted by family members of players who showed possible symptoms of the disease. The disease was the focus of the 2015 movie, Concussion, starring Will Smith as Dr. Bennet Omalu, who, in September 2002, was assigned to do an autopsy on former NFL player Mike Webster of the Pittsburgh Steelers. Webster, in his final years before his death, was zapping himself with a Taser gun to calm his nerves. Omalu’s findings on Webster’s brain would lead him to bring the disease to national prominence. Here are just a few of the dozens of NFL players who have been diagnosed with the disease. Tony Tomsic via AP Junior Seau The legendary San Diego Chargers and New England Patriots linebacker, Junior Seau, killed himself at age 43 in May 2012. After his brain was studied, it was determined the Hall of Famer suffered from CTE. AP Jovan Belcher In 2012, former Kansas City Chiefs linebacker Jovan Belcher fatally shot his girlfriend and then drove to team headquarters and shot himself in front of coaches and team management. The 25-year-old showed signs of pervasive brain damage and signs of CTE, a neuropathologist said. AP Ray Easterling The former Atlanta Falcons safety fatally shot himself at the age of 62 in 2012 after suffering from dementia and depression. An autopsy revealed he had CTE. AP Ralph Wenzel The former NFL guard for the Steelers and Chargers couldn’t recognize his wife by the time he died of complications from dementia at age 69 in June 2012. He was subsequently diagnosed with CTE. NFL/AP Mike Webster Pittsburgh Steelers Hall of Fame center Mike Webster was the first NFL player diagnosed with CTE. He died in 2002 at age 50, and he was the focus of the 2015 movie, Concussion. Webster’s son said his father took Ritalin to control his mood swings, and was shocking himself with a Taser gun to calm his nerves. NFL Photos/AP Ken Stabler Oakland Raiders quarterback and former NFL MVP Ken Stabler died in July 2015 and suffered from CTE, researchers at Boston University found. AP Terry Long Former Steelers lineman Terry Long killed himself by drinking antifreeze at age 45 in June 2005. An autopty revealed Long suffered from CTE. Getty Chris Henry Chris Henry, the former wide receiver, was found to have CTE after he died after falling from a moving truck in December 2009, according to researchers at the Brain Injury Research Institute. Icon Sportswire via AP Tom McHale The former Tampa Bay Buccaneers lineman became the second former NFL player to be diagnosed with CTE when he died at age 45 in May 2008 from an accidental combination of oxycodone and cocaine, which he took to relieve depression and chronic pain in his shoulders and joints. Dimitrios Kambouris/Getty Frank Gifford Sportscaster and former NFL star Frank Gifford died from natural causes at age 84 in August 2015, but was found to have CTE by pathologists after his death. “While Frank passed away from natural causes this past August at the age of 84, our suspicions that he was suffering from the debilitating effects of head trauma were confirmed when a team of pathologists recently diagnosed his condition,” Gifford’s family said in a statement at the time. NFL/AP Andre Waters Former Philadelphia Eagles safety Andre Waters killed himself in November 2006. After his death, Omalu said sustained brain damage from playing in the NFL led to Waters’ depression and suicide.