Cannabis is often one of the first drugs a teen is offered.

Although cannabis is now legal in Canada, it doesn’t change the fact that all mind-altering substances - including cannabis - can impact the still-developing teen brain.

Explore with your kids the impact that early use of substances in a child’s life and explain to them that the use of any of these substances while still in their teens or younger can significantly increase the risk of problems with their health, education and social life.

Cannabis and Youth 

The rate of cannabis use is three times higher among Canadian youth than adults. 1

  • Canadian youth have one of the highest rates of cannabis use worldwide. In 2016, the World Health Organization compared past-30-day cannabis use among youth aged 15 across 40 countries and found that use by Canadian youth (13%) was the second-highest. 2
  • One in 5 teens aged between 15 and 19 have used cannabis in the past year. 3
  • In 2017 cannabis use increased in Ontario with high school grade level to a high of 36.9 % among 12th-grade students. Ontario Student Drug Use and Health Survey (OSDUHS) 2017 reported High School use of cannabis: Gr. 9-9.3%, Gr. 10-19.9%, Gr. 11-30.4%, Gr. 12-36.9%. 4
  • Cannabis use is still more prevalent among males than females, although the rate of use among females is on the rise.  5
1 CTADS 2017 2- Health Behaviour in School-aged Children 2016, World Health Organization, 3 - Statistics Canada 2016, 4- OSDUHS 2017, 5 - Statistics Canada 2016

There is no single reason that teens might use cannabis.

They may try cannabis for social reasons, as a way to fit in or socialize with their peers, or because they think “everyone is doing it.” They may also use cannabis as a coping mechanism to deal with life stresses. 6 A teen might also use cannabis to help them sleep, stimulate their appetite or reduce worry or stress.7

If a young person is using cannabis to cope with anxiety or stress, they may be more likely to continue if it works for them. They might think “ When I feel stressed out, I smoke pot and it relaxes me”. They may continue to use cannabis instead of finding healthy behaviours as alternatives – like sports, hanging out with a friend, playing music, talking to someone about their feelings, or reading a book – that can help in coping with the stress they feel.

Cannabis, just like any other drug, can lead to addiction. It has an effect on the brain's reward system - as do all other addictive drugs - the likelihood of developing problem use or addiction increases considerably for those who start young. 8

6,7 McKiernan &Fleming 2017 Canadian Youth Perceptions on Cannabis, CCSA - 8 Drug Alcohol Depend, Winters and Lee 2008.


Cannabis is a product of the plant Cannabis Sativa.

The main active chemical in cannabis is THC (delta-9-tetrahydrocannabinol). Of the roughly 400 chemicals found in the cannabis plant, THC affects the brain the most. It is a mind-altering chemical that gives those who use cannabis a high.  Another active chemical in cannabis is CBD (cannabidiol), which is becoming increasingly known for its potential medical properties and the ability to moderate the effects of THC.

For more information about the medical use of cannabis: CCSA’s Clearing the Smoke on Cannabis: Medical Use of Cannabis and Cannabinoids.

Cannabis is also called marijuana, bud, blunt, chronic, dab, dope, ganja, grass, green, hash, herb, joint, loud, Mary Jane, MJ, pot, reefer, shatter, skunk, smoke, trees, wax, weed.

How is cannabis used? 

Cannabis can be consumed in several ways; inhaled, ingested, or applied topically. It’s important to understand that there are significant differences in the way the effects are felt.

Cannabis is commonly rolled into a cigarette (called a “joint”) or in a cigar (called a “blunt”). It can be smoked in a water pipe (called a “bong”) or vaped in an e-cigarette or other vaping devices.

Cannabis edibles can be brewed as tea, infused into drinks or mixed into food and ingested as candies, cookies, and brownies. Consuming cannabis edibles like brownies or cookies is considered by some youth to be a less risky way of consuming than smoking it. Ingesting cannabis can have delayed and unpredictable effects. A long waiting time is recommended when ingesting cannabis products to avoid the accumulation of effects. 

Cannabis extracts, which include oils and tinctures can also be ingested or inhaled in a pipe or bong and/or vaped with an e-cigarette or other vaping devices. Cannabis extracts can often have more concentrated levels of THC.

It’s important to note that cannabis products like cannabis oils and concentrates for use in vaping devices are legal for retail sale only at licensed outlets.  Quebec and Newfoundland and Labrador will not allow the sale of cannabis vapes amid concerns about a possible connection between vaping products and severe lung disease.

Click here for more information on youth and vaping. 

Cannabis products should be produced by licensed producers and purchased only from licensed vendors. Evidence suggests that illegal cannabis products can be contaminated with pesticides and harmful chemicals. Synthetic cannabinoids like K2 or Spice should be completely avoided.

9 - Journal of Toxicology, 2013 Nicholas Sullivan et al.

Inhalation vs Ingestion - What happens in the body?

Inhaled - Smoking or Vaping

When cannabis or cannabis extracts like oils are inhaled or vaped, THC is delivered directly to the lungs, passes through the bloodstream and on to the brain where the effects (the “high”) are felt within minutes of inhaling.

  • A few seconds or minutes to start to feel the effects
  • 30 minutes to feel the full effects
  • 6 hours for acute effects to subside
  • Residual effects last up to 24 hours

Please note: Vaping cannabis is not considered safe for youth, young adults, pregnant women or any adult who does not already use tobacco products.


Ingesting – Eating or Drinking

The effects of ingesting cannabis are delayed – they can take much longer to appear. When cannabis edibles or beverages are ingested, THC travels to the stomach, then to your liver before reaching your bloodstream and brain. The liver metabolizes the THC to a stronger chemical called 11-hydroxy-THC, which combined with the THC consumed, often making the “high” seem more intense.

Depending on the individual, the effects can take 30 minutes to two hours to be felt.
• 2 hours to start to feel the effects
• 4 hours to feel the full effects
• 12 hours for acute effects to subside
• Residual effects last up to 24 hours

For more information, download our booklet on Cannabis Edibles. 

What's the Big Deal?

Early and regular cannabis use does affect the health of youth. Regular use of cannabis can have several negative consequences, including bad grades, broken friendships, and family problems. Most importantly, teens' brains and bodies are still developing, and substance use can interfere with their emerging independence and efforts to establish their own identity.

Substance use can change the direction of a young person's life – physically, emotionally, and behaviourally. It can weaken the ability to concentrate and retain information during a teen's peak learning years, and impair judgment leading to risky decision making that could involve sex or getting into a car with someone under the influence of drugs.

With the exception of impaired driving, cannabis use is unlikely to result in permanent disability or death, but too much of the drug in a person’s system can have harmful effects.

Short Term Effects

Although cannabis affects people in different ways, short term effects can include: feeling happy, relaxation, increased sociability and heightened sensation. Problems with memory and learning, distorted perception (sights, sounds, time, touch), trouble with thinking and problem solving, body tremors, loss of motor coordination, increased heart rate and anxiety and panic attacks. coordination, increased heart rate, and anxiety and panic attacks. These effects may be even greater when other drugs are mixed with cannabis. 10

10 CCSA, 2015; Beirness and Porath-Waller, 2017

Long Term Effects

Cannabis is an addictive substance. The risk of developing dependence is one in six among those who start using cannabis frequently during adolescence.11  Regular cannabis use in adolescents is associated with experiencing psychotic symptoms (changes in thoughts, feelings, and behaviours), especially when there is a family or personal history of psychotic disorders. Some studies have suggested that cannabis may also increase the risk of anxiety and depression over time.12  

What’s regular cannabis use? Regular use of cannabis means that the use of cannabis occurs regularly over time. It may involve using cannabis every day, or every weekend over a period of several months or over a number of years.

Early and frequent cannabis use is linked with poor performance in school, lower grades and increased risk of dropping out. The evidence is still unclear as to whether regular use affects an adolescent’s IQ,13 however, research suggests that early, regular, heavy and long-term use of cannabis by teens may impair their cognitive abilities and may not be fully reversible.14

Youth might be particularly vulnerable to these negative outcomes due to the extensive changes that are taking place in the brain during adolescence, especially the ongoing development and maturation of the prefrontal cortex, which is critical to higher-order cognitive processes such as impulse control, working memory, planning, problem-solving and emotional regulation.15

Cannabis, just like any other drug, can lead to addiction. It has an effect on the brain’s reward system – as do all other addictive drugs - the likelihood of developing problem use or addiction increases considerably for those who start young.16

11-12-13-16 - George & Vaccarino, 2015 14 Meier et al, (2012) 15 Drug Alcohol Depend, Winters & Lee, 2008

Cannabis and Driving

It is illegal to drive while impaired by cannabis.

Drug-impaired driving has the same penalties as alcohol-impaired driving. Driving after consuming cannabis raises the risk of a crash. Yet many young people still get behind the wheel after smoking pot.

In 2017, youth who participated in a qualitative research study by the Canadian Centre on Substance Use and Addiction believed that cannabis-impaired driving was safer, or less dangerous, than alcohol-impaired driving. This belief was partly related to the fact that youth didn’t associate the feelings of being high (calm, happy, and relaxed) with risky behaviours that could impair driving skills.17

Among youth who have used cannabis in the past 12 months, 27.8% of those aged 16 to 19 and 43.1% of 20 to 24-year-olds reported having driven within 2 hours of using cannabis.18 Many young people get into a car with a driver who has consumed cannabis. 40.9% of youth 16 to 19 and 55.6% of those 20 to 24 reported being a passenger in a vehicle driven by someone who had used cannabis in the past 2 hours.19

 17 McKiernan, A., & Fleming, K. (2017). Canadian Youth Perceptions on Cannabis. Ottawa: Canadian Centre on Substance Abuse.  18, 19 - Canadian Cannabis Survey, 2017

Get more information about high driving here. 

Cannabis and Alcohol

While some teens may argue that cannabis is safer than alcohol, research shows that teens don’t typically use alcohol OR cannabis; they use both, often at the same time 20 - a dangerous combination, especially behind the wheel of a vehicle.

The use of cannabis alone is enough to impair judgment. The biggest impact of mixing cannabis and alcohol is the significant increase in impairment of judgment. The level of intoxication and side effects experienced can be unpredictable. When cannabis and alcohol are used at the same time there is a greater likelihood of negative side effects occurring either physically or psychologically (panic, anxiety, and paranoia).21

The use of both alcohol and cannabis before driving can greatly increase the risk of getting into a car accident. This is similarly the case when mixing cannabis and other drug use.22

20 -Partnership Attitude Tracking Study 2013, 21- National Cannabis information and support Australia 2016, 22-CCSA 2016

Keeping the lines of communication open can make a big difference in preventing substance use.

What to say…

If your children are young:  Just as you would talk to your younger children about the dangers of not wearing a helmet, running across the road, talking to strangers, or consuming anything unknown - cannabis can become a part of your general “safety” conversation.

Important to remember: Cannabis edibles can look just like the cookies or chocolate you bought at the grocery store – which can be very attractive to young children. If you do have edible cannabis products in your home, don’t leave them in plain sight, Label them properly and securely store them out of reach in child-resistant containers.

If your children are teens:   Chances are your kids already have many questions about cannabis. Together, you and your teen can learn more about cannabis products by using reliable sources like DFK Canada, the CCSA and Health Canada. Help teens understand that the best way for them to protect their health is not to use cannabis at all.

Important: 90% of addictions began with substance use during adolescence. Cannabis in all its forms is an addictive substance. Adolescents who start consuming cannabis frequently or regularly have a much higher risk of developing cannabis use disorder.

If your children are the age of majority or young adults:  Remind them that every form of cannabis can be a risk to their health – and that the best way to avoid those risks is not to use at all.   One of the biggest mistakes made with first-time use of cannabis edibles is to accidentally consume too much and then consequently experience a stronger, unpleasant and unintended high.

Important: The exact same dose can affect two people differently – so people experimenting or using for the first time should Start Low and go Slow. Start with a low dose of THC and wait at least two hours before consuming any more.

Get to know Canada’s Lower-Risk Cannabis Use Guidelines, and discuss them together with your kids.  These recommendations can greatly help reduce the potential harms of cannabis use to the health of youth and young adults.

Parents are the most important influence in a child's life. There is research that shows that parents are central to preventing adolescent substance abuse. Kids themselves say that losing their parents' trust and respect are the most important reasons not to use drugs.

Talking to teenagers about difficult subjects like drugs and alcohol can be a challenge for some parents. However, creating a safe and receptive environment to begin a conversation with your teen can promote open and positive communication.

Be patient. Remember to be clear about your goals, be positive and offer compassion. These skills can take practice, so if the talk doesn’t go the way you hoped it might, remember that you will have other opportunities to try them. Continue to create a safe environment for conversation, where you can have a respectful and open dialogue that stays balanced and calm. Have more than one conversation, which will give you many opportunities to get it right and improve upon what didn’t go so well the last time.


We've created the Cannabis Talk Kit to help spark informed, balanced and open discussions between you the parent and your pre-teen or teen. You can download it or order printed copies here. 

You matter!

“As a community educator, I present regularly to parents, youth, teachers, and administrators about the risks associated with marijuana use during adolescence. Teens are often telling me that marijuana is helping them cope with disorders such as anxiety, depression, and ADHD. What is alarming is that not only are teens unclear about the effects and harms of marijuana, but parents too are confused and uninformed regarding the risk of potential developmental harms with regular marijuana use. We need to continue to have these important conversations with our youth. A message that I share with parents is their kids are listening to them. Parents play a key role in moderating the influences of alcohol and drug use by their children.

—Dr. Jackie Smith, RN, Ph.D., Addiction and Family Wellness Counselor, Calgary