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Several years ago, scientists saw traces of a preventable disease in the autopsied brains of former N.F.L. players.

Now, experts have discovered that the symptoms tackling the minds of football players aren’t limited to disease—a full spectrum of cognitive and mood disorders can arise, particularly for those who begin playing before age 12.

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Among a set of 214 former amateur and professional players, those who started before they were 12 years old were at greater risk of depression and impaired cognitive function in their 50s. The pre-teen years are neurologically very active, and many brain-related milestones occur during this period of time. That means whatever happens to your wrinkles and synapses during this period tend to be somewhat predictive of your mental state later in life.

Kids who start playing full-contact football before the age of 12 are more susceptible to brain maladies and mental health issues later in life.

Here’s Beth Mole, writing for ArsTechnica:

There have been hints before that hard hits during this time can have lasting impacts. In 2015, Stern and colleagues studied 42 former National Football League players and found that those who began playing before age 12 had greater risks of cognitive impairment later in life. And last year, researchers led by neurologists at Wake Forest School of Medicine found that repetitive head impacts in 25 youth players, aged 8 to 13, led to structural changes in their brains—without causing concussions. But, in another study last year, researchers attempted—and failed—to reproduce a link between early football playing and greater risks of cognitive impairments in 45 retired NFL players. For the study, the players’ medical exams were sponsored by the NFL, which has been accused of meddling with research. And several of the authors, including lead author Gary Solomon of Vanderbilt University, have consulted and/or worked with the NFL in the past.

But in this new study, neurologist Robert Stern of Boston University and his colleagues found strong links between starting age and various cognitive tests (except for one test, which the team believes isn’t very thorough or accurate). Specifically, he determined that players who started earlier than age 12 were twice as likely to have “clinically meaningful impairments in reported behavioral regulation, apathy and executive function” and were more than three times as likely to have clinically elevated depression scores.

The study, published today in Translational Psychiatry , does not assess the risk of chronic traumatic encephalopathy (C.T.E.), the brain disease that has shown up time and again in deceased professional football players’ brain scans. However, the scientists urge that some of the neurological symptoms are not exclusive to the disease. The study is also limited in that it doesn’t account for different types of equipment, and the group of participants were self-selecting. But now that this data is out, rewritings of youth sports regulations could soon be in the works.