CTE May Affect at Least a Quarter of Recently Deceased NFL Players
A retrospective study estimated that at least one in four former NFL players who died from 2016 to 2021 had chronic traumatic encephalopathy (CTE). The possible prevalence ranged from 24.5% to 97.7% among that group, and from 18.5% to 98.7% for those who died from 2008 to 2021. Severe stage IV CTE was associated with dementia symptoms.
The study, published in The BMJ, tracked 1,712 former NFL players who died between 2008 and 2021, with 338 brain donations confirming CTE in 315 cases. Most specimens came from Boston University's UNITE Brain Bank, with additional contributions from Mount Sinai and UC San Francisco. Researchers used inverse probability weighting to correct for the likelihood that symptomatic players were more prone to donate their brains.
Earlier brain bank research found CTE in 110 of the first 111 former NFL players examined at Boston University, though community studies show the disorder affects under 1% of the general population. Since CTE can only be diagnosed postmortem, researchers relied on the National Death Index and masked neuropathological assessments to estimate prevalence ranges.
This study could reshape how the NFL and medical communities approach player safety, given that CTE prevalence estimates among recent deceased players may be substantially higher than previously acknowledged. Families of former players may face heightened anxiety about long-term neurological risks, while the league could face renewed pressure to fund research and modify rules. The wide prevalence range also highlights ongoing uncertainty in measuring a condition that remains undetectable until autopsy.