You can call it grass, herb, pot or weed, but whatever you call it Quebec adolescents are smoking marijuana a lot. A team of researchers at McGill University and Université de Montréal estimates that a third of 15- and 16-year-old Quebec teens have smoked marijuana more than 5 times. Of that group, 74% use the drug at school, and 64% are bicycling, in-line skating and swimming while under its influence. The results were published recently in the Journal of the American Academy of Child and Adolescent Psychiatry (1999;38[7]:900-7).
Dr. Mark Zoccolillo, a psychiatrist at the Montreal Children's Hospital and the lead author, wonders why chronic marijuana use by teens is rarely discussed. "I don't know why people don't talk about it. Adolescents really dive into it - it becomes part of daily life. What kind of drug is this, when such a high proportion are using it and spending much of their day high? Is this a drug that is reinforcing its own use?"
The research group interviewed a cohort of almost 2000 Quebec teens who had been evaluated at regular intervals since kindergarten. The sample was divided into 2 groups, 1 that was randomly selected to represent various regions of the province and another that comprised children who had been identified in kindergarten as disruptive by parents and teachers. There were no significant differences between the 2 groups in terms of drug-related problems - randomly selected 15- and 16-year-olds were just as likely as high-risk teens to use marijuana, and to use it often. This dispels the myth that only troubled teenagers or those from impoverished backgrounds use drugs routinely. However, Zoccolillo says it remains to be seen whether teens who have an early history of behavioural problems begin to use illegal drugs at a younger age or progress to using hard drugs more often than their peers.
Although alcohol is cited more often in high school prevention programs, the study found that drinking is not as pervasive as marijuana use. Once past the threshold of using illegal drugs more than 5 times - this accounted for two-thirds of the sample members who had ever tried drugs - adolescents incorporated marijuana into their daily lives. This was not true of alcohol, which tended to be consumed less frequently. Adolescents were found to be less likely to drink in the morning or to be drunk at school or while playing sports or driving a car. Zoccolillo states that given the high rates of marijuana use in teens, family physicians and pediatricians should include queries about use of the drug whenever they examine adolescents.