Teen brain primed for addiction
Use by adolescents could lead to adult addictions
On the heels of Liberal Party Leader Justin Trudeau’s revelation that he smoked marijuana after being elected to the House of Commons, a study by the Université de Montréal cautions that consuming cannabis during adolescence may hard-wire some teens to develop addictions in adulthood. Aaron Derfel reports.
Federal Liberal Leader Justin Trudeau may have admitted to toking in a bid to win over younger voters, and police chiefs may be pushing for tickets instead of arrests for simple possession of pot, but medical science is still warning of the risks of smoking marijuana — especially for teens.
A new study by researchers from the Université de Montréal and New York’s Icahn School of Medicine concludes that “the nature of the teenage brain makes users of cannabis among this population particularly at risk of developing addictive behaviours and suffering other long-term negative effects.”
A review of more than 120 studies — including original research by the authors — strongly suggests that consuming cannabis during adolescence interferes with natural brain development and may hardwire some teens to develop addictions in adulthood.
Cannabis consumption during teenage years could also make some individuals more susceptible to suffering from schizophrenia — mainly in those teens who have a genetic predisposition to the mental illness, said Dr. Didier Jutras-Aswad, one of the authors of the study.
“What we know is that for most adults who will use cannabis, the side effects and the negative events are relatively rare and, when they happen, they are most of the time quite mild,” said Jutras-Aswad, a psychiatrist and researcher at the Centre hospitalier de l’université de Montreal.
“What we know now, though, is when exposure to cannabis occurs during adolescence we see that in the long-term there are quite severe adverse effects of that cannabis on mental health and addictive disorders.”
The review, to be published in the journal Neuropharmacology, disputes the “growing perception, particularly in adolescents and young adults, that cannabis is harmless, especially when compared to other abused substances like nicotine and alcohol that are legal.”
Rather, the review warns, marijuana could be considered a “gateway” drug to highly addictive heroin and cocaine. The paper actually uses the term “gateway,” long used in the United States by politicians opposed to the legalization of marijuana.
Jutras-Aswad and his colleagues examined numerous studies of lab rats that were exposed to cannabis in their early lives. These animals were much more prone to become addicted in lab experiments to cocaine and heroin when they grew older com- pared with rats that never consumed cannabis.
The review, however, does note that only one-quarter of teens who smoke pot go on to develop addictions. This suggests that cannabis is not the sole factor in addiction, and that genetic and childhood behavioural factors also play an important role.
Jutras-Aswad explained that the active ingredient in cannabis — THC — interferes with the endocannabinoid system in the developing teen brain. He suggested that such scientific research should be taken into account in the debate to legalize marijuana.