Study finds CTE in at least 1 in 4 former NFL players who died between 2016-2021

A study released Tuesday in The BMJ reports that at least 1 in 4 former NFL players who died between 2016 and 2021 had chronic traumatic encephalopathy, or CTE. Researchers from Mass General Brigham, Boston University and the Concussion & CTE Foundation examined the brains of deceased former players to reach this conclusion. The team identified 878 former NFL players who died during the six‑year window. Of those, 235 had donated their brains for post‑mortem analysis, and 215 — roughly 91% — showed pathological signs of CTE. Because individuals with neurological symptoms may be more inclined to donate tissue, the authors cautioned against treating the 91% figure as representative of all former players. Instead, they derived a conservative minimum prevalence of 24.5%, noting that the true rate could be substantially higher. CTE is a progressive neurodegenerative condition linked to repeated blows or impacts to the head. Definitive diagnosis presently requires neuropathological examination after death. The investigation also uncovered a strong association between advanced CTE and dementia: 61.3% of players with CTE who donated their brains met objective criteria for dementia, and more than 90% of those with the most severe Stage 4 pathology exhibited dementia. The authors stressed that the findings do not reveal how many surviving former NFL players live with CTE, nor do they imply that one‑quarter of current players suffer from the disease. They observed that many of the repetitive head impacts tied to CTE likely occurred before athletes reached the NFL, including during youth, high school and college football. According to the study’s authors, reducing cumulative exposure to head impacts — rather than concentrating solely on diagnosed concussions — remains essential for lowering long‑term risk. The work adds to mounting evidence connecting prolonged head‑impact exposure with neurological illness among football players. Researchers urged continued efforts to limit unnecessary contact at every level of the sport while enhancing evaluation and care for former athletes who experience cognitive, behavioral or mood‑related symptoms.