Study finds CTE in 215 of 235 donated brains from former NFL players

A study of former National Football League players who died between 2016 and 2021 found chronic traumatic encephalopathy in 215 of 235 brains donated for examination.

The 235 donors were drawn from 878 former NFL players who died during the six-year period. Because families who suspect neurological illness may be more likely to donate a brain, the findings from the donated sample should not be read as a prevalence estimate for all former players.

CTE is a degenerative brain disease associated with repeated head impacts and can currently be confirmed only after death. Reported symptoms may include problems with memory and attention, dementia, mood disorders and headaches.

Researchers from Mass General Brigham, Boston University and the Concussion + CTE Foundation said dementia was common among the donors. They argued that prevention should focus on reducing repetitive head impacts not only in professional football but also at collegiate, high-school and youth levels, where players accumulate many exposures.

Lead author Daniel Daneshvar said earlier research has found former NFL players have a higher rate of death from neurodegenerative disease than the general population. He also pointed to practice as a major source of head impacts and urged athletes with cognitive symptoms to seek assessment from a neurodegenerative-disease specialist.

The NFL said it continues to pursue measures intended to reduce concussions and head impacts and encourages former players to use health and wellbeing resources. The study was reported on August 25, 2026.