Chronic traumatic encephalopathy, known as CTE, was found in 99% of deceased NFL players’ brains that were donated to scientific research, according to a study published Tuesday in the medical journal JAMA…

“There’s no question that there’s a problem in football. That people who play football are at risk for this disease,” said Dr. Ann McKee, director of Boston University’s CTE Center and coauthor of the new study. “And we urgently need to find answers for not just football players, but veterans and other individuals exposed to head trauma.”

The JAMA study is the largest of its kind and all of those studied were required to have football as their primary exposure to head trauma. The criteria for submitting a brain was based on exposure to repetitive head trauma, regardless of whether that individual exhibited symptoms during their lifetime.