Nearly three-quarters of former NFL players who died between January 2008 and December 2023 may have had CTE, according to a new study. Researchers also estimate that around one in four had dementia, a condition affecting memory and thinking that is common in advanced CTE.
CTE is a brain disease linked to repeated blows to the head. People later diagnosed with it can experience memory problems, difficulty concentrating, depression and trouble controlling their actions. The disease can only be confirmed by examining the brain after death.
The Boston University team studied more than 2,300 former players, including almost 400 whose brains had been donated to the university's brain bank. The remaining players were identified through national death records. Families of players with CTE-related symptoms were five times more likely to donate a brain than families of players without those symptoms.
After adjusting for this difference, the researchers estimated that 74.5 per cent had CTE. A 2017 study of donated brains had put the figure at 99 per cent, but donations may have overrepresented players with symptoms. The new research, published in JAMA Network Open, provides the first estimate for the wider NFL player population.
