WASHINGTON — New research from Canada has found that roughly 1 in 5 adolescents has probably suffered a traumatic brain injury — a figure that suggests severe concussion among children and adolescents may be far more common than has been estimated.
The new study also hints at a troubling link between a history of traumatic brain injury and poorer grades, underage drinking and use of illicit drugs.
In Ontario, Canada, 62 percent of students in grades seven through 12 anonymously completed a computerized questionnaire administered during the school day, which gauged their drug and alcohol consumption patterns and a wide range of health-related behaviors.
Among the questions, students were asked if they had ever been knocked unconscious for five minutes or more or had been kept overnight in a hospital following a blow to the head.
The survey also asked students to indicate if such an incident had occurred in the last year.
The results, published a “research letter” in the Journal of the American Medical Association, were startling.
A total of 20.2 percent of respondents reported that at some point in their average 15 years of life, they had either been hospitalized overnight after a blow to the head or had been knocked unconscious for more than five minutes.
And 5.6 percent — more than 1 in 20 students — said they had suffered such an injury within the last year.
Concussions are often diagnosed after blows to the head far milder than those causing loss of consciousness or hospitalization.