Athletes who began playing tackle football before the age of 12 had more behavioral and cognitive problems later in life than those who started playing after they turned 12, a new study released on Tuesday showed.

The findings, from a long-term study conducted by researchers at Boston University, are likely to add to the debate over when, or even if, children should be allowed to begin playing tackle football.

The results of the study by researchers at Boston University, published in the journal Nature’s Translational Psychiatry, was based on a sample of 214 former players, with an average age of 51. Of those, 43 played through high school, 103 played through college and the remaining 68 played in the N.F.L.

In phone interviews and online surveys, the researchers found that players in all three groups who participated in youth football before the age of 12 had a twofold “risk of problems with behavioral regulation, apathy and executive function” and a threefold risk of “clinically elevated depression scores.”