Teen substance abuse, brain injuries linked
Study finds high head-trauma rates for young imbibers and pot smokers
Alcohol and drugs can damage a teenager’s brain in more ways than people think.
A new study has found that youths who said they frequently consume booze or pot were up to five times more likely than abstinent youths to report having suffered at least one traumatic brain injury that left them unconscious for at least five minutes or hospitalized overnight.
Overall, the survey of nearly 9,000 Ontario high school students found that, in general, one in five teens said they had had a brain injury at some time in their lives.
Nearly six per cent reported at least one brain injury in the past year.
“In the United States, more than half a million adolescents 15 years or younger need hospital-based care for head injury annually, and our data suggest a much higher number of adolescents may be experiencing these injuries,” the researchers write in this week’s issue of the Journal of the American Medical Association.
In Canada, half of all injuries that kill or disable youths involve a brain injury, according to background information released with the study.
The new study is based on the Centre for Addiction and Mental Health’s 2011 Ontario student drug use and health survey, an anonymous questionnaire completed in classrooms by 8,915 students in grades 7 through 12.
“To our knowledge, this is the longest ongoing school survey in the world,” said lead author Dr. Gabriela Ilie, a post-doctoral fellow at St. Michael’s Hospital in Toronto and a lecturer in psychology at the University of Toronto.
For the first time in 2011, students were asked if they had ever had a traumatic brain injury — a blow to the head that can cause compression within the brain, damaging or irreversibly destroying brain cells.
Symptoms include loss of consciousness, dizziness, headaches, moodiness, difficulty concentrating and increased sensitivity to light and sounds.
Concussions — the most common form of brain injuries — can be difficult to diagnose. CT scans can miss subtle, tiny, micro bleeds in the brain that, if not picked up, can lead to “second impact syndrome” — potentially fatal brain swelling, if the person suffers another head injury before recovering from the first.
Sports injuries accounted for more than half of the brain injuries reported by the students, and were more common among boys (63 per cent of brain injuries) than girls (almost 50 per cent). “Not just team sports, such as hockey and soccer, but also skiing, skateboarding and snowboarding,” Ilie said.
More males reported brain injury than females (23 versus 17 per cent) and students with grades below a 60 per cent average were four times more likely to report having had a brain injury than teens with grades above 90 per cent.
Studies have shown that brain injuries, especially repeated injuries, can cause impaired learning and memory over the long term, which is especially important for children, whose brains are still developing.
Teens who reported having 40 or more drinks in the past year had more than five times the odds of suffering a traumatic brain injury than youths who abstained. Those who smoked pot 10 or more times in the past year were more than three times as likely to report a brain injury.
Researchers can’t tell from the survey how the injuries happened. But booze and pot can make people dizzy and disoriented and alter their perception of distance and space. Until now, estimates of brain injuries have been based mostly on hospital records. But Ilie says the new survey suggests many head injuries are going uncounted if teens don’t report them to their parents or coaches.
“If we know who’s more vulnerable, if we know how the injuries are occurring, we can talk to students, we can talk to their parents, their trainers and coaches,” Ilie said.
Brain injuries need to be treated as seriously as injuries that are visible, she said. “We know from adult studies just how devastating some of these injuries can be on people’s quality of life, their ability to hold steady employment, their relationships, substance use and mental health.”