Former NFL Players Who Sustained Repeated Concussions Are More Likely To Be Depressed

Football safety has come under increased scrutiny over the past several years, as mounting scientific research suggests that NFL players who have sustained repeated head trauma are more likely to develop fatal brain diseases. And new research adds yet another dimension to the debate: concussions could be linked to depression, putting former NFL players at risk for developing mental health issues.

Two recent studies on head injuries and mental health examined a group of 34 retired NFL players between the ages of 40 and 80 years old — and both found a potential link between brain damage and depression. The first study found that the former professional football players who are depressed or cognitively impaired tend to have abnormalities in their brains’ white matter. The second study, which is still preliminary and will be presented to the American Academy of Neurology this spring, found that players who had sustained a higher number of concussions during their NFL careers tended to exhibit more symptoms of depression once they retired.

As TIME reports, researchers believe the evidence is strong enough to compel medical professionals to change the way they approach patients with a history of concussions:

Neurologist Dr. John Hart, medical science director Center for BrainHealth who was involved in both studies, says the findings may have implications not just for current and former NFL players, but also for anyone with a history of concussion. That includes military veterans, victims of car crashes, or other athletes, both professional or amateur, who hit their head.

Depression is manageable, he says, but only if doctors know to diagnose and treat it properly, and the results suggest that anyone with a history of concussion should be monitored for signs of depression. Left untreated, the mood disorder can lead to suicide — as was the case with linebacker Junior Seau, who played in the NFL for 20 seasons and took his own life in 2012. An autopsy report revealed his brain showed signs of chronic traumatic encephalopathy, a degenerative brain disorder linked to concussions.

Researchers also noted that the NFL players who participated in their studies were less likely to understand how depression manifests itself — and even if they were experiencing a lack of motivation, mood swings, or anxiety, they didn’t realize that might mean they were struggling with their mental health. “A lot of these players didn’t even recognize that the symptoms that they had were depression because they weren’t crying,” Hart told TIME.

In September, the NFL donated $30 million to concussion research following allegations that the league was intentionally obscuring the medical consequences of repeated concussions on the field. Research already estimates that retired football players are four times more likely than the general population to die of brain diseases.