Curious and surrounded by close friends, Mike McDowell says he was 16 when he decided to try cannabis for the first time.
Smoking cannabis with friends then became a frequent pastime for him. Once he moved out and got a job, he was smoking cannabis daily, spending nearly $200 a month.
“Give a pothead a gram, and he would become MacGyver. I would grab those two litres, drink the pop, and make something out of it for us to smoke,” McDowell says.
Using cannabis while the brain is developing can affect cognitive development, relationships, and increase the chances of addiction or dependency.
Amy Porath, director of research and knowledge mobilization with the Knowledge Institute on Child and Youth Mental Health and Addiction, says frequent cannabis use can have negative impacts on cognitive development.
The hippocampus, the part of the brain that's responsible for memory, is one of the areas of the brain impacted by cannabis use.
There’s consistent evidence that individuals who regularly use cannabis experience deficits in memory, attention, executive functioning, and decision making, Porath says.
“The hippocampus’s executive functioning, the thinking part of the brain, is tied to the prefrontal cortex, and we know that that particular area of the brain is developing up until the age of 25,” she says.
Porath says reducing the amount, potency, and how often one smokes is key to reducing cognitive risks when using cannabis.
Choosing to delay cannabis use until full cognitive development is the most efficient way to prevent cannabis related risks. And there's some indication that is happening among users. According to the Canadian Cannabis Survey from 2024, the average age of starting cannabis was 20.7, an increase from 18.9 years in 2018.
However, Canadians 16 and older who reported cannabis use in the last 12 months were 26 per cent in 2024 compared to 22 per cent in 2018.
To protect brain development, Porath recommends delaying the onset of use for as long as possible. Not using cannabis during adolescence is the best way to prevent risk.
A recent study published April 20 in California of 11,036 participants between nine and 17 showed that teens who used cannabis showed signs of restricted growth in many skills, including memory, attention, language and processing speed, compared to those who did not use it.
McDowell says his memory from the period of daily cannabis use is cloudy, and he believes early cannabis use may have contributed.
Sue Cook, a registered social worker and owner of Family TLC, says it's not always obvious to the person using cannabis or the people around them that it’s an addiction.
“When young people come in, and someone says you're addicted to cannabis, they end up in a place where they get defensive or offensive about that,” Cook says.
She says if there’s a loss of control, such as continuing to use cannabis even after trying to stop, it might be an addiction.
“It becomes a primary coping tool, and it's a way they regulate themselves,” she says.
The impacts usually show up around the person using cannabis. Other people tend to see the problem first before the person using cannabis does, Cook says.
“What we're watching for is impact on relationships, school and work attendance, isolating, or loss of motivation,” she says.
Cook says counselling is important because it lets people dive deeper and understand why they choose certain actions.
“What really interests me is understanding why. What is it that it does for them? For them, it's a friend, and you don’t ever want to be talking badly about a friend,” Cook says.
Alleviating boredom and changing the habit are some things people can do to control their addiction, she says.
“Sometimes it's about having a buddy or partner that can help motivate you," Cook says. "Physical activity might help in so many ways. It helps with alleviating stress and anxiety. It gives people a sense of accomplishment."
Cook says understanding the habit is key to quitting.
“They might’ve started taking a little at a time, then it became a habit. They actually have the capacity to try something new for the first time. You formed a habit with marijuana, so you have the capacity to form a habit,” Cook says.
Not everyone sees cannabis as harmful. For some, it serves a legitimate purpose under proper supervision.
Apollo Cannabis Clinic said in an email response that it supports Canadians' access to cannabis under the guidance of licensed healthcare practitioners.
“Medical cannabis is only considered when clinically appropriate. Patients are most commonly assessed for chronic pain or persistent symptoms that haven’t responded adequately to conventional therapies, or where standard treatments have caused intolerable side effects,” the clinic says.
The clinic said it does not authorize cannabis for youth outside of rare and medically supervised circumstances.
“Cannabis use by children and adolescents should be approached with significant caution, as it carries potential risks to the developing brain,” it stated.
Apollo has a firm stance on educating young people so they can make informed health decisions.
“We believe education is the most effective harm reduction strategy. We support parents, educators, healthcare providers, and community organizations in sharing clear, evidence-based information,” it said.
Looking back on decades of cannabis use, McDowell has one piece of advice for his younger self.
“With all the money I spent, I could have bought a house.”
