Study Estimates CTE in at Least 24.5% of Former NFL Players Who Died From 2016 to 2021

At least one in four former NFL players who died between 2016 and 2021 may have had chronic traumatic encephalopathy, or CTE, according to a study published August 25 in the British Medical Journal and reported by Smithsonian Magazine. The researchers examined former NFL players who had participated in at least one league game. Of the 878 players who died during the six-year study period, 235 had their brains donated for research. CTE was identified in 215 of those brains. Because families may be more likely to donate the brains of athletes who experienced cognitive or behavioral problems, the donated brains could overrepresent people with the disease. To account for that possibility, the researchers used statistical methods to estimate the prevalence among the players whose brains were not studied. Their calculations produced a wide range: from a minimum of 24.5% to a maximum of 97.7% of former players who died during the period. The researchers said the true figure probably lies somewhere between those estimates. By comparison, previous research has found CTE in less than 1% of the general population. CTE is a progressive, degenerative brain disease believed to be associated with repeated head injuries. It has been linked to symptoms including memory loss and mood changes, but it can only be diagnosed after death by examining physical changes in the brain during an autopsy. The disease was first diagnosed in a former NFL player in 2005. Since then, it has been confirmed through autopsy in more than 300 former league athletes, according to the source. Researchers had not previously been able to determine how common CTE was among deceased NFL players. Randall Chesnut, a neurological surgeon at the University of Washington who was not involved in the study, described the research as significant and well controlled within the limits of its statistical methods. Lead author Daniel Daneshvar, a physician and brain-injury researcher, said the findings should prompt stronger efforts to protect athletes at every level of football. There is no cure for CTE, though physicians can help people with suspected disease manage symptoms. The NFL said it continues working to improve player safety and provide health resources. The NFL Players Association called the findings a reminder that football carries lasting risks for players and their families.