A new study out of Canada says teenagers who use marijuana are more likely to seek physical and mental medical attention than their counterparts.

Published in the JAMA Network Open journal on Oct. 28, the study found that 20% of nearly 1,600 surveyed teens consumed marijuana before the age of 15. Acknowledging confounding factors like parental demographics, socioeconomic status, cognitive development and peer influence, the researchers argue that marijuana drove these teens to seek medical care from a primary care physician, hospital or emergency room more than their counterparts.

Specifically, the study found that the teens and young adults required medical care for common mental disorders like anxiety and depression, a physical health condition, injuries and poisoning, and other physical diseases.

Pablo Martínez Díaz, co-author of the study, told USA TODAY that his key takeaway of the study is that adolescents should avoid marijuana use, but if they do use, the frequency should be low.

Marijuana advocates say study points to importance of regulation

Adam Smith, executive director of the Marijuana Policy Project, which aims to legalize cannabis in the U.S., said the study serves as a "giant argument" for marijuana regulation.

Smith pointed to data released by the Centers for Disease Control and Prevention (CDC) in late 2024, which found that in states where marijuana was legalized, adolescent use decreased.

In 2024, 4.3% of eighth graders in 19 states where marijuana is legalized reporting using marijuana over a 30-day period. This was down from 7.2% of eighth graders in 2011.

Paul Armentano, deputy director of the National Organization for the Reform of Marijuana Laws (NORML), echoed Smith.

"I think the most important takeaway is that if we want to keep young people away from using marijuana ... until they are much older, then the best and most effective way to do that is not by continuing the status quo of cannabis prohibition and non-regulation but by advancing policies that legalize and regulate cannabis and cannabis products to licenses cannabis businesses," Armentano told USA TODAY.

Canada legalized adult-use marijuana with the Cannabis Act in 2018. Under the legislation, adults 18 and up may purchase and consume marijuana. This is in contrast to the U.S. where regulation is held by the states and in states where marijuana is legal, it is for adults 21 and up.

How was the study conducted?

The researchers studied 1,591 individuals as part of the Quebec Longitudinal Study of Child Development, a cohort that studied children born in 1997 and 1998 through age 23. Specifically, the team analyzed self-reported marijuana use in participants at ages 12, 13, 15 and 17.

What makes the study unique, Díaz said, is how the researchers were able to parse through variables that can skew results.

The researchers identified nine confounding factors in the study, like parental demographics, socioeconomic status, cognitive development and peer influence. They then took these factors into consideration when analyzing why young adults would seek medical attention and how these factors worked in tandem with or separate from early marijuana use.

A deeper look at the study's findings

The study found that 325 individuals – about 20% of the sample size – reported frequent use of marijuana before they were 15 years old. These individuals consumed marijuana anywhere from 1-2 times a week to every day, according to the study.

Another 20% of the sample – 318 individuals – reported using marijuana after they turned 15. These individuals, who began using marijuana in their late teens or early adulthood, did not seek out mental health care as frequently but had higher odds of seeking physical medical attention than individuals who didn't use marijuana at all, the study outlines.

The family factor

Though the researchers tried to weed out confounding factors in the study, some affected the outcomes regardless.

Notably, Díaz said, teenagers with parental drug use were more likely to consume marijuana and in turn, seek medical attention.

"You should put an eye not only on cannabis use but what is happening early in these children's lives, their parents are using or not," Díaz said. "We should try to ... prevent substance abuse in parents of children who may be at risk of later cannabis use."

Armentano agreed and added that in many cases, young people turn to marijuana as a means to cope with pre-existing mental and physical illnesses, making the study's findings unsurprising.

"It is possible that they are turning to these substances as a coping mechanism because they're growing up in very difficult environments," he said. "In fact, the use of cannabis is in response to individuals suffering from those (physical and mental) symptoms and trying to address those symptoms through self medication."

The study's researchers also acknowledged that the number of reported teens and young adults who sought out medical attention may be skewed lower, as some may avoid health care due to stigma or other risk factors.

Greta Cross is a national trending reporter at USA TODAY. Story idea? Email her at gcross@usatoday.com.

This article originally appeared on USA TODAY: Teens who use weed before 15 are more likely to seek medical care, study says

Reporting by Greta Cross, USA TODAY / USA TODAY

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