A new study led by researchers in Massachusetts indicates that at least one in four former NFL players may develop chronic traumatic encephalopathy (CTE), a degenerative brain disease with no cure that can only be definitively diagnosed after death.
The study, published in The BMJ, analyzed data from NFL players who died between 2008 and 2021. Of the more than 1,700 deaths recorded during that period, researchers examined the brains of 338 former players. Postmortem brain analysis remains the only proven method for detecting CTE.
Among those 338 brains studied, 315 were found to have CTE. The study also noted that in the last six years of the study period, when brain donation became more common, 235 NFL players donated their brains, and over 210 were diagnosed with CTE.
More than 200 of the 338 analyzed brains came from players who had previously been diagnosed with dementia. Those with dementia were more likely to have severe CTE, with 94 cases classified as Stage 4, the most advanced level.
Understanding CTE
CTE is a brain condition linked to repeated head impacts, according to the Centers for Disease Control and Prevention (CDC). It involves the buildup of abnormal proteins that damage brain tissue and lead to cell death. While commonly associated with football, CTE has also been found in boxers, soccer and hockey players, military veterans, and first responders. Even athletes who only played through high school or college have been diagnosed.
Symptoms of CTE can take years or decades to emerge, and they may persist for months or years. The CDC notes that individuals diagnosed with CTE often exhibited problems with thinking, emotions, mood, suicidal thoughts, or behaviors that interfered with daily life. However, having these symptoms does not necessarily mean a person has CTE. The CDC encourages anyone with concerns to consult a doctor, as treatments are available for many symptoms.
Research continues at institutions like Boston University to better understand CTE, including its risk factors and how to diagnose it earlier.
Hundreds of NFL players diagnosed posthumously
According to the new study, hundreds of former NFL players have been diagnosed with CTE after death. A 2023 report from Boston University's CTE Center found that of 376 former NFL players studied, 345 had the disease.
Among recent cases, former Dallas Cowboys defensive end Marshawn Kneeland, who died by suicide in November following a police chase, was found to have Stage 1 CTE. Aaron Hernandez, who died by suicide in 2017 while imprisoned for murder, was diagnosed with Stage 3 CTE. Former Tennessee Titan Frank Wycheck, who died in 2023 after a fall, had Stage 3 CTE. Demaryius Thomas, who died in 2021, had Stage 2 CTE after struggling with depression and anxiety. Irv Cross, a former NFL cornerback and CBS anchor, was determined to have Stage 4 CTE after his 2021 death. Phillip Adams, who killed six people in South Carolina in 2021 before taking his own life, was found to have Stage 2 CTE.
Even a man who never played in the NFL, Shane Tamura, who killed four people in a New York City building that houses the NFL's headquarters, was found to have CTE. In a note, he claimed to suffer from the disease and expressed grievances with the league.
The study underscores the ongoing concern over head trauma in professional football and the need for continued research and prevention efforts.
