2 New Canadian Studies Show Marijuana Impairment in Teens

Two recently released studies document the impact marijuana is having on teens.  The first study published in the American Journal of Psychiatry from work done by the University of Montreal, shows that students who used marijuana showed more declines in cognitive functioning compared to those who just used alcohol.  This means that adolescents that begin regular use of marijuana may suffer lasting repercussions in their think ability.  The study followed 3800 high school students in Montreal over a 4-year period beginning at age 13.  The students agreed to report their usage and take computer-based cognitive tests that measured recall memory, perceptual reasoning, inhibition and short-term memory.

The other study, from Montreal-based Research Institute of the McGill University Health Centre and McGill University, showed that marijuana use impairs teen driving for up to 5 hours after inhaling.  A total of 45 study participants, 21 of whom were women, were put in a driving simulator and exposed to "the kinds of distractions common on the road." Research participants also took computerized tests that assess attention abilities.  Participants completed simulations at one, three and five hours after inhalation of a standard 100-mg dose of cannabis through a vaporizer (a typical joint is 300-500 mg of dried cannabis). Participants were also tested with no cannabis in their system.

While the cannabis dose did not affect simple, distraction-free driving, there was "significant impairment on complex and novel driving-related tasks," according to the peer-reviewed findings, which were published in CMAJ Open, an open-access journal published by the Canadian Medical Association. The complex or novel tasks included situations such as avoiding sudden obstacles, like a child crossing the street unexpectedly or driving through a busy intersection.

At Gobi we hear often from parents that their teens think “weed” is safe.  Marijuana is not a harmless plant (tobacco and poppies are plants too).  And the marijuana available today is typically four times stronger than “Woodstock weed” of the 1960’s. Our brains are not fully developed until about age 25 and the last part to mature is responsible for important decision-making, including how we respond to gratification.  Also, this part of the brain is most affected by substance use.  A new study showed that marijuana can stay in the brain affecting decision making for up to 3 days.  There is also some significant new research that shows that if your family has a history of mental illness, marijuana may hasten some forms of mental health issues like depression and schizophrenia.  Not to also mention weed is a mood-altering substance that can lead to addiction.