Concussions linked to suicides, violence

St. Mike’s study finds Ontario teens with serious brain injuries were more likely to be bullies — and be bullied

Ontario teens who have suffered concussions or other traumatic brain injuries are more likely to lead troubled lives marked by suicide, criminal behaviour and bullying, new research shows.

The study, published Tuesday in the journal PLOS ONE, shows that 19.5 per cent of Ontario students in Grades 7 through 12 have suffered brain injuries serious enough to have knocked them out for at least five minutes or caused them to spend at least one night in hospital.

Sports such as ice hockey and soccer account for more than half of injuries.

Compared with peers who have not suffered brain injuries, these students have 3.4 times greater odds of attempting suicide, 2.2 times greater odds of assaulting someone and 2.8 times greater odds of carrying a weapon.

Students who have suffered brain injuries are also more likely than their peers to be victims of bullying or violence, the study reveals. They are at 1.7 times greater odds of being bullied at school, two times greater odds of being bullied over the Internet and 2.9 times greater odds of being threatened or injured.

They also have two times greater odds of becoming bullies themselves.

They study does not conclude that traumatic brain injuries “cause” these behaviours, just that there is an association.

“Our brains define our behaviour and the way we interact with society. . . . It would make sense that damage to the brain would lead to dysfunction in the brain, whether that’s a mental-health outcome or some other physical outcome,” explained Dr. Michael Cusimano, a neurosurgeon at St. Michael’s Hospital and contributor to the study.

The physical impact of brain injuries — including dizziness and slower response times — could make teens easy targets in a Darwinian schoolyard environment, said lead author Dr. Gabriela Ilie, a post-doctoral fellow at St. Mike’s.

It’s also possible that brain injuries can exacerbate already existing mental health and behavioural issues.

Asked if it’s possible whether some of the affected students come from violent homes — a factor that could contribute both to brain injuries and behavioural problems — Ilie said the study did not investigate that.

Data used came from the responses of almost 9,000 pupils to the Ontario Student Drug Use and Health Survey, which the Centre for Addiction and Mental Health has been conducting every two years since 1977. Questions about traumatic brain injury were added for the first time in 2011.

Ilie said the study is important because brain injuries can be prevented, particularly those sustained while playing sports, through the wearing of protective gear.

The findings suggest that parents, physicians and teachers should question whether teens with behavioural problems have suffered brain injuries so that proper, early interventions can be made, she said.