A Canadian study has found that adults who have had a concussion have triple the risk of committing suicide compared to the general population.
The researchers analyzed medical records for adults in Ontario. They collected information on more than 230,000 people who had a concussion that was not serious enough to require hospitalization and followed them from 1992 to 2012, with an average follow-up of 9 years. During that time, 667 people who had experienced concussions committed suicide, a rate of 31 suicides per 100,000 people per year. This is more than three times higher than the suicide rate in the general Canadian population, which is 9 suicides per 100,000 people per year.
The day of the week when the concussion occurs seems to make a difference. Concussions that happen on the weekends seem to carry a higher risk of suicide than those that happen on weekdays. The authors note that concussions that happen at work may be less likely to be shrugged off than those that happen on the weekend.
The risk of suicide after a concussion rose whether or not the patient had a history of psychiatric conditions.
Concussions and serious head injuries have been linked to an increased risk of suicide in professional athletes and military veterans, said senior author Dr. Donald A. Redelmeier of the University of Toronto in Ontario, in an interview with Reuters Health.
"I always worried that even mild concussions acquired in normal community settings might also be a risk, and might cause lasting damage," he told Reuters Health.
However, the study does not prove that concussions cause some suicides, Redelmeier said. There may be some other connection. Those who suffer concussions could be predisposed to thoughts of suicide beforehand or the concussion might cause lasting brain injury, he noted.
"It's incredibly important to put these things into perspective - the vast majority of people in this study did not die from suicide."
The study appeared in the Canadian Medical Association Journal.