Dallas Cowboys player Marshawn Kneeland was diagnosed with early-stage chronic traumatic encephalopathy (CTE) following his death by suicide. The disease, caused by repeated head impacts, has been found in the brains of hundreds of former NFL players.
The Boston University CTE Center reported in 2023 that it had diagnosed CTE in 345 out of 376 former NFL players studied. Athletes in American football, rugby, and combat sports have a significantly higher risk of developing CTE compared to the general population.
CTE can only be definitively diagnosed after death. According to the CTE Society, initial stages of the disease can manifest as short-term memory problems, depression, aggression, and issues with executive function. As the disease progresses, symptoms can intensify, including mood swings and suicidal thoughts. In its final stages, individuals may experience severe cognitive decline, memory loss, and dementia.
While Boston University's CTE Center has stated that the cause of suicide is complex and a CTE diagnosis is not a known direct risk factor for suicide, researchers emphasize that cases like Kneeland's indicate that more must be done to mitigate the risks of the disease for athletes. Dr. Chris Nowinski, co-founder and CEO of the Concussion & CTE Foundation, noted that Kneeland played during an era with modern concussion protocols and improved helmets, yet still developed CTE. He expressed concern that current generations of athletes may not be at a lower risk.
The NFL has reached a $1 billion settlement with over 5,000 former players who sued the league, with more than 21,000 former players potentially eligible for compensation.