The Current

How changes in today's marijuana make it more addictive

Legalized marijuana is on its way next year. And one of the big questions looming is what it will mean for Canadian teens. A CBC investigation looks into the potency of today's pot.

What's really in your weed?

7 years ago
Duration 2:50
CBC's Marketplace explores how smoking pot affects the brain

Read story transcript

In less than a year, legal pot should be a reality in Canada. And while you've likely heard it said that today's pot is stronger than it was in the past - it may surprise you to learn just how much.

​Josie (we agreed to only use her first name) is 24 years old and started smoking pot when she was a teenager.

"I don't remember how it happened, but by the 10th grade I was a full-fledged pot-head," Josie tells The Current's Friday host Duncan McCue.

Josie was hospitalized twice because of psychosis and addiction and is still unable to quit smoking pot.

I often say it feels like I'm living my life with one hand tied behind my back.- Josie, a young pot addict

In an investigation by CBC's Marketplace, 12 of the most popular strains from marijuana dispensaries in Toronto were tested. The findings suggest THC levels were as much as six times higher than the pot of the 1980's — THC being the component responsible for most of the psychological effects of pot.

A teenager smokes a marijuana joint at the Vancouver Art Gallery during the annual 4/20 day, which promotes the use of marijuana, in Vancouver, British Columbia April 20, 2013. REUTERS/Ben Nelms (CANADA - Tags: HEALTH SOCIETY POLITICS CIVIL UNREST DRUGS) - RTXYU3C (Ben Nelms/Reuters)

Josie says that legalizing pot would help "diminish the polarity between popping a non-issue and popping a drug." 

"I feel with alcohol because it was normalized in our society I was able to say, like you know I can have a beer once in awhile," Josie tells McCue. 

"I felt like I had the elbow room to do that but when it's sort of this underground culture of people smoking pot illegally and things like that it becomes an isolated community."

Josie adds she hopes the regulation of marijuana will make people feel safe smoking.

The teenage brain is particularly vulnerable to the effects of pot, says scientist. (Mark Blinch/Reuters)

Safety is a hard one to garner as researchers are finding there's a lot to learn about marijuana's effects — particularly on young, developing brains.

Steven Laviolette, an associate professor with the Schulich School of Medicine at the University of Western Ontario,  says "the teenage brain is particularly vulnerable to the effects of THC."

He explains that his studies suggest adults who had exposure to "relatively high levels of THC, [don't] produce nearly the same sort of negative effects as it does in the teenage brain."

His research also points to today's pot causing schizophrenic reactions.

For more on this story, tune in to CBC Television Friday Nov. 25, at 8 p.m. for the results of Marketplace's story about what's in today's weed...and what it does to your brain.

Listen to the full conversation at the top of this web post.

This segment was produced by The Current's Julian Uzielli and Ines Colabrese.