New Model Puts CTE Rate in Dead NFL Veterans at Three-Quarters

A research team based in Boston estimated that approximately 75% of former National Football League players who died between 2008 and 2023 had signs of chronic traumatic encephalopathy. The study, published in Jama Network Open on Wednesday, represents the first attempt to measure the prevalence of the disease across all deceased former players in that period, not just those who donated their brains for examination.

The analysis relied on records for 2,362 deceased former players who averaged five years in the league. Of that group, nearly 400 donated their brains for study. Researchers found evidence of CTE in 93.5% of those donated brains. They used this data to model the likely rate for the entire population of deceased players from that era.

The estimated rate stands in sharp contrast to findings from the general public. The authors noted that fewer than 1% of brain samples in community-based brain banks show signs of CTE. The physical markers of the condition include brain atrophy and the buildup of tau protein, a substance also associated with Alzheimer’s disease.

Yorghos Tripodis, the study’s senior author, said the team recognizes the findings may cause concern among living players and their families. He stated that researchers are standing by to provide support and that the discoveries from the brain bank have brought the medical community closer to diagnosing the condition while patients are still alive. The next priority, he said, is developing effective treatments.

The researchers emphasized that having CTE-related changes in the brain does not guarantee dementia or cognitive decline. Some individuals never develop noticeable symptoms. However, the study estimated that around 27% of the former players in the analysis had dementia. The condition can also affect emotional control and behavior, potentially causing depression, memory problems, and severe mood changes.

This new data follows an August study that found at least one in four former NFL players who died between 2016 and 2021 had CTE. After that report, the NFL stated it continuously strives to make the game safer by implementing strategies to reduce concussions and head impacts. Several high-profile former players, including Junior Seau, Dave Duerson, and Aaron Hernandez, were found to have had CTE after their deaths.