A new study found that adolescents who suffer traumatic brain injury are more likely to engage in harmful behavior and that the risk of engaging in such behavior is higher among girls than boys.

The data come from the 2011 Ontario Student Drug Use and Health Survey, which anonymously polled 9,288 Ontario boys and girls between grades 7 and 12 using self-administered questionnaires. Subjects were asked whether they had a history of traumatic brain injury (TBI) – defined by the study as “a hit or blow to the head that resulted in a 5-minute loss of consciousness or at least one overnight hospitalization due to symptoms associated with it.” The questionnaires also asked the subjects whether they had experienced any of 13 distinct harmful outcomes over the past year, such as binge drinking, smoking of tobacco and cannabis products, drug abuse, psychological distress, declining grades, physical and cyberbullying, and thoughts of suicide.

Girls and boys with a history of TBI were all at an elevated risk for alcohol consumption, binge drinking, cannabis smoking, declining grades, bullying others at school, being bullied online, drug abuse, and being treated for physical injuries.

The findings revealed that of the 13 harmful outcomes, boys were at a higher risk of engaging in 9. Girls, however, were likely to engage in all 13, indicating that sex plays a major role in the long-term effects of TBI when such incidents occur at a young age (PLoS One 2014 Sept. 30).

“Both boys and girls were more likely to engage in a variety of harmful behaviours if they reported a history of TBI, but girls engaged in all 13 harmful behaviours we looked for, whereas boys were at higher risk of engaging in only nine,” Gabriela Ilie, Ph.D., lead author of the study and a postdoctoral fellow at Toronto’s St. Michael’s Hospital, said in a statement. “Sex matters when it comes to traumatic brain injuries.”

The study found that girls and boys with a history of TBI were all at an elevated risk for alcohol consumption, binge drinking, cannabis smoking, declining grades, bullying others at school, being bullied online, drug abuse, and being treated for physical injuries. But female adolescents in particular were found to be additionally susceptible to elevated psychological distress, past-year suicidal ideation, being bullied at school in the past year, and past-year cigarette smoking.

Dr. Ilie and her colleagues also found that the risk of engaging in alcohol consumption, daily cigarette smoking, and being treated for physical injuries changed depending on the age of the subjects. The average age at which subjects began smoking was 14, while the age at which subjects had their first alcoholic drink skewed similarly young. For physical injury treatment, the risk ran higher for girls aged 11-13 years, and for boys aged 17-20 years.

Across the board, children with TBI presented higher incidences of all harmful behaviors than those without a history of TBI. The study also found that the majority of TBI came from playing team sports – 63% for males and 46.9% for females. Falls were responsible for 5.1% of males and 24.7% of females with TBI histories, with bicycle accidents being responsible for 8.1% of males with TBI and 1.8% of females with TBI.

The researchers cited several limitations of the study. The most salient, they said, was that the data were based on self-reports. In addition, their sample did not include “adolescents who might be at high risk of TBI.”

Still, Dr. Ilie and her colleagues hope that the findings of this study will help shed light on the need for greater action in recognizing and treating adolescent TBI, warning that failure to properly care for these injuries at the right time will significantly increase the risk of detrimental long-term consequences down the road.

“The results point to important opportunities for prevention, such as early-stage medical interventions, as well as diagnosis and rehabilitation approaches that consider the relationship between TBI and its risk factors,” the investigators said. “We know both adolescent boys and girls with TBI are vulnerable to the co-occurrence of harmful psychological and behavioural conditions. Given that most brain injuries among adolescents occur during sports, a more ecological approach to injury prevention requiring involvement by government, schools, and parents may be needed.”

The research was funded by a Canadian Institute of Health Research Team Grant in Traumatic Brain Injury and Violence and by the Ontario Neurotrauma Foundation, with additional funding from the Ontario Ministry of Health and Long-Term Care, the Social Sciences and Humanities Research Council, Industry Canada, and AUTO21, a member of the Networks of Centres of Excellence program that is administered and funded by the Natural Sciences and Engineering Research Council.

dchitnis@frontlinemedcom.com

Traumatic brain injury in adolescence increases likelihood of harmful behavior