According to a newly released study, teens are endangering the development of their brains when consuming marijuana. The Canadian study, performed by researchers from the University of Montreal, found that the use of cannabis had a more negative impact than those of teens consuming alcohol.

The study

The American Journal of Psychiatry published the study’s findings on October 3rd, 2018. It followed over 3,800 adolescents from Montreal and area, starting from the age of 13 over a four year period.

The teens provided the study with annual reports of how often they consumed marijuana and alcohol. In addition, they were quizzed by taking computer-based cognitive tests that measured recall memory, perceptual reasoning, inhibition and short-term memory.

In order to receive more truthful answers, the teens who participated were promised the study would not share their answers with their parents or teachers — unless there was a safety risk.

The marijuana use found in the study was lower than alcohol. Only 28% of the participants admitted to some kind of cannabis use, while 75% of the teens said they consumed alcohol.

The study concluded that marijuana was more damaging on the participants’ long-term cognitive skills than alcohol. An alarming fact the study found was that, when students stopped using marijuana, their cognition did not improve.

“Cannabis causes cognitive impairment and delayed cognitive development in adolescents,” Patricia Conrad, the lead author and professor of psychiatry at the University of Montreal, told NBC News. “This study focuses on the neuropsychological effects of cannabis. We think it’s important because it is linked to how someone functions in life.”

“Their brains are still developing, but cannabis is interfering with that,” Conrod, told “They should delay their use of cannabis as long as they can.”

Not the first study

Previous research has found that cannabis can be detrimental to teens brains when used.

University of Pennsylvania scientists published a study this past June in JAMA Psychiatry that analyzed 69 studies involving adolescent marijuana users. They found that the participants who used marijuana often were more prone to have slightly lower scores on tests of memory, learning new information, and higher-level thinking involving problem-solving and processing information — compared to non-users.

Scientists say that more research is needed to understand how and why the brain is impacted by early marijuana use. But the longer-term social implications of marijuana use in teens are more well known.

The Lancet Psychiatry published in 2014 that teens who smoke marijuana daily are 60 percent less likely to graduate from high school or college than those who never use, and seven times more likely to attempt suicide.

A study conducted in 2017 by Josiane Bourque and her colleagues at the University of Montreal found that frequent marijuana use in teens and psychotic symptoms may be largely caused by depression.

Legalization around the corner

Nine states and the District of Columbia have legalized recreational marijuana for adults over the age of 21, and it will be fully legal countrywide within Canada on October 17th.

With it being more accessible, your teen will easily be able to get their hands on it. Think about when you were young and wanted alcohol – all you needed to do was find someone of age who was willing to buy it for you. It’s more important than ever to start a discussion with your teen about the dangers of marijuana.

Drug Free Kids Canada has created a “Cannabis Talk Kit” to aid you in your discussions with your teen. You can find sections that include facts about cannabis, including what it is, why it’s risky for teens, how to talk to your teen about it, what words to avoid using, etc. It also includes how to respond to your teen’s questions and arguments, as well as other resources.

Read More: Fighting Teen Drug Use Through Innovation With Drug Free Kids Canada

In the ‘what to say’ section, an example of your teen asking, “Marijuana is a plant. It’s natural. How harmful could it be?” – the kit provides many answers including “Not all plants are necessarily healthy or good for you—think about cocaine or heroin or even poison ivy.”

By using this answer, you’ll help your teen rethink their point.

You can find the full kit for download here.