All but one of 111 former pro football players had brain injury CTE in study

The study looked at the players from high school to pro levels.

— -- “Football is not a contact sport, it’s a collision sport.”

Now, a new report from researchers at Boston University suggests that this often devastating neurological disease may be even more common to the sport than previously thought.

But the study’s lead author, Dr. Ann C. McKee, said that one of the most alarming findings is that nearly one quarter of the 14 high school players in the study had CTE.

“The finding that the earliest beginnings of CTE can be found in high school indicates that things can go wrong at a very young age,” she said.

Dr. Gil Rabinovici, a neurologist at the University of California San Francisco, who wrote an accompanying editorial to the study, also expressed concern.

“From a public health perspective, this is a much bigger problem, since very few players make it to the professional level,” Rabinovici said. “The question everyone has is, ‘Is there a risk in playing youth football?’”

Researchers also conducted questionnaires with players’ loved ones after their deaths to assess for hallmark symptoms of CTE, which can manifest as cognitive, behavioral, or mood problems. Among players who had evidence of severe CTE, 85 percent had symptoms of dementia and 89 percent had mood disturbances.

“A lot of these guys with even early CTE were very symptomatic –- they have impulse control, rage and explosivity," McKee said, adding that mood disturbances were often severe. One in three players with CTE had signs of suicidality, which means thoughts, attempts or completions of suicide.

Additionally, the study found that CTE occurred in isolation only about half of the time. The other half of cases had evidence of an additional neurological disorder like Alzheimer’s disease, Parkinson’s disease or ALS.

But though the high prevalence of CTE identified in this study was striking, it involved only subjects whose families consented or even volunteered to have their loved ones’ brains studied. These family members may have noticed concerning neurological or psychiatric symptoms in the players, and may have been looking for answers, which means that no conclusions about the overall prevalence of CTE in football players can be made.

“[The study] undoubtedly overestimates the prevalence of CTE,” lead author McKee said. “It’s a skewed population based on the fact that many of these players had symptoms.”

Still, she sees the striking results as a call to action.

“I don’t think it’s debatable whether this disease exists,” she said. “Though our findings raise more questions than answers, it’s time to come together as scientists to combat this disease.”

Nicole Van Groningen, M.D., is a hospital medicine fellow at the University of California, San Francisco.

Top Stories

Top Stories

Top Stories

Top Stories

ABC News Live

ABC News Live

24/7 coverage of breaking news and live events