Adults who suffer concussions are at a heightened risk of dying by suicide, a study released Monday by researchers at the University of Toronto has found.
The study, published in the Canadian Medical Association Journal, examined more than 235,000 adults who had suffered concussions over 20 years and found an incidence rate of 31 suicides per 100,000 people. While suicides among those who suffer concussions remain extremely rare -- less than 1 percent of those studied died by suicide -- that means they occur nearly three times more often than in the broader population.
Researchers and the media have long associated concussions with increased suicide risk, in part because of high-profile suicides among NFL players like Junior Seau and Dave Duerson, who were later found to have chronic traumatic encephalopathy, a degenerative brain disease linked to repetitive head trauma.
The Toronto study is among the first to provide empirical evidence linking concussions to increased suicide rates, said Dr. Michael Fralick, a chief medical resident at the University of Toronto and the study’s lead author.
The study is significant in that it adds to the body of research linking concussions and increased risks of suicide, said Dr. Robert Cantu, a concussion expert and the co-director of Boston University’s Center for the Study of Traumatic Encephalopathy. Still, Cantu said, more research is needed to assess whether brain injuries themselves or other factors, including depression, are more responsible for the heightened risk of suicide.
“Right now I don't think there is any definitive science that tells us how much of it is the concussion and how much of it is the other stuff that's going on around it,” Cantu said. “How much of the problem is really due to structural brain injuries, and how much of it is due to the fact that these people are often the set with depression symptoms and/or addictive behaviors ... is the $64,000 question. … It's really not clear why there is this increased risk. But it's there.”
While much of the focus on concussions has centered around how they are managed and treated in professional sports, the study’s authors said it has broad implications for the general public.
“The most straightforward implication is that the association between concussions and suicide is not just confined to professional athletes or military veterans, but might also extend to normal individuals in the community who are undertaking everyday activities,” said Dr. Donald Redelmeier, a professor of medicine at the University of Toronto who helped author the study.
A key finding in that regard is that the rate of suicides increased even further when concussions were suffered on weekends. A possible explanation for that finding, Redelmeier said, is that weekend activities like recreational sports or home improvement often lack injury protections that are standard in the workplace, and because people who suffer brain injuries during those activities may be less likely to seek medical attention or treat the injuries seriously. That could increase the likelihood that symptoms like depression and anxiety develop later, he said.
The study also found that suffering multiple concussions can increase the risk of suicide.
These risks, the researchers behind the study said, should raise awareness about the importance of seeking proper medical attention to manage and treat concussions, not just among athletes but also in the general public.
And when it comes to professional and youth sports, further evidence of another damaging effect of concussions should lead to even more emphasis on the prevention and management of the injuries, particularly in terms of making sure athletes are fully healed before they return to play, the researchers said.
“There's nothing worse than sustaining a concussion and then being told to go back on the field only to put yourself at risk for a second event. That is just setting up a potentially perilous situation,” Fralick said. “That is not the time to get right back into sports. We've seen that with athletes who came back too quickly. If you don't rest for a significant period of time, you're at risk for a second concussion.”
“The value of this study,” Cantu said, “is one more piece of evidence that we shouldn't be blowing off concussions.”