A new study has concluded that players who began playing tackle football before the age of 12 showed the signs of chronic traumatic encephalopathy (CTE) on average 13 years earlier than other players, CNN reported.

Researchers from the VA Boston Healthcare System and Boston University’s school of medicine examined some 250 players and found that of the 211 players who were diagnosed with CTE after death, those who played tackle football before age 12 developed cognitive, behavioral and mood symptoms earlier than players who began playing tackle football after the age of 12. Problems with memory, planning and organization as well as emotional problems and problems with depression were among the issues reported during telephone interviews with the family and friends of players.

“What this study found was that playing tackle football lowers your resilience by about 13 years, and that is pretty profound, because that is a big difference,” said Dr. Ann McKee, chief of neuropathology at Boston VA Healthcare System and director of Boston University’s CTE Center.

The findings are sure to ignite even further debate about children playing football. According to data cited by CNN, many Americans say that kids should not begin playing tackle football until high school. Dr. McKee echoed those sentiments.

“Some argue that players should play even later than 12, maybe 18, when they are adults and can make fully informed decisions,” she said. “The study adds to the accumulating evidence that if you’re going to play football, you should do so later.”