Teens Who Start Smoking Marijuana Early See Doctors More Often

A new Canadian study confirms what most parents probably suspected: teenagers who start using marijuana before 15 end up at the doctor more often than kids who wait or skip it.

Published in JAMA Network Open in late October, researchers tracked nearly 1,600 young adults and found one in five started smoking cannabis before their 15th birthday. Those early starters hit up doctors, ERs, and hospitals more frequently for both mental health problems—anxiety, depression—and physical issues ranging from injuries to various health conditions.

Pablo Martínez Díaz, who co-authored the study, kept his advice simple: if teens are going to use marijuana, infrequent use is key. Better yet, wait until you're older.

Not exactly groundbreaking advice, but now there's data behind it.

The Regulation Twist

Here's the unexpected part: marijuana advocates aren't using this study to push for stricter laws. They're arguing the opposite.

Adam Smith from the Marijuana Policy Project called the findings a "giant argument" for regulation. His reasoning? When states legalize and regulate cannabis, teen use actually drops.

CDC data from late 2024 backs this up. In 19 states where marijuana is legal, just 4.3% of eighth graders reported using it over 30 days. Compare that to 7.2% of eighth graders back in 2011. Legalization came with fewer kids smoking weed, not more.

Paul Armentano from NORML pushed the point further. Keeping marijuana illegal doesn't keep it away from kids, he said. It just keeps it unregulated. Black markets don't card. Licensed dispensaries do.

Canada legalized recreational marijuana in 2018 for adults 18 and up. U.S. states that allow it set the age at 21.

How They Did This Study

Researchers pulled data from the Quebec Longitudinal Study of Child Development, following kids born in 1997 and 1998 through age 23. Participants reported their marijuana use at ages 12, 13, 15, and 17.

What separates this from typical teen behavior studies is how researchers controlled for other variables. They identified nine confounding factors—parental demographics, socioeconomic status, cognitive development, peer pressure—then factored those in when analyzing medical care patterns.

This matters because correlation isn't causation, and most teen studies don't account for the general chaos of adolescence properly.

Breaking Down the Numbers

About 325 participants—roughly 20%—reported frequent marijuana use before 15. These weren't kids who tried it once at a party. They were using anywhere from weekly to daily.

Another 20%—318 people—started after 15. This group sought mental health care less than early starters but still needed more physical medical attention compared to non-users.

The early starters logged the most doctor visits for both mental and physical health.

The Parent Factor Nobody Wants to Discuss

One finding stands out: teenagers whose parents used drugs were way more likely to use marijuana themselves and need medical care later.

"You should put an eye not only on cannabis use but what is happening early in these children's lives," Díaz said. If parents are using, kids are at higher risk.

Armentano raised a point the study authors acknowledged too: some young people might be turning to marijuana because they're already struggling. Their self-medication is just a symptom of a bigger issue.

"It is possible that they are turning to these substances as a coping mechanism because they're growing up in very difficult environments," Armentano said.

That complicates things. Are these kids seeking care because marijuana hurt them, or were they already dealing with problems and marijuana was just part of the struggle?

Missing Pieces

Researchers admitted their numbers might actually be low. Some teens probably avoided seeking medical care due to stigma or other barriers, meaning the real impact could be higher.

Self-reported data on stigmatized behavior involving minors has obvious limitations. Not everyone's honest, and not everyone has equal healthcare access anyway.

What It Actually Means

The study doesn't prove marijuana causes health problems in teens. It shows early use correlates with more medical visits, even after accounting for other variables.

The regulation argument gains weight when you factor in CDC data. States that legalized saw teen use decline. Prohibition doesn't keep weed away from kids—it just keeps it off store shelves where someone might check ID.

Whether you think teenagers should never touch marijuana or believe regulation beats prohibition, the pattern is clear: early and frequent use means more doctor visits. Parents who use drugs raise kids who are more likely to do the same.

Not shocking. But now there's research with 1,600 people confirming it.

Did you find this information useful? Feel free to bookmark or to post to your timeline to share with your friends.