D. Healthy Living · Healthy LivingCannabis: Facts and Effects
D1.2 A1.6About 45 minutes
Learning goals- I can explain what cannabis is and the different ways people use it.
- I can describe the range of effects of cannabis: on the body, the brain, mental health, safety, relationships and the law.
- I can explain why cannabis use is a bigger risk for young people.
Words to know
cannabis
A plant that contains chemicals that can change how a person thinks, feels and acts. Also called marijuana, weed or pot.
THC
The main chemical in cannabis that causes the "high" (changes in thinking, feelings and senses).
CBD
Another chemical in cannabis. It does not cause a "high."
edible
A food or drink that contains cannabis.
impaired
When a person's thinking, reactions or movements are weakened, for example by alcohol or cannabis.
dependence
When a person feels they need a substance to feel normal or to get through the day.
Getting the facts
You've probably heard about cannabis: in the news, on social media, maybe from older kids or family conversations. Some of what people say is true, and some isn't. Today you'll learn the facts so you can think critically about what you hear and make safe choices.
Remember from Grade 5
You learned about the effects of alcohol on the body and brain, and about the factors that influence decisions about alcohol and cannabis. This year you'll look closely at cannabis itself and the range of its effects.
What is cannabis?
Cannabis is a plant. Its dried flowers and leaves, and products made from them, contain chemicals. The two best known are:
- THC, which causes the "high": changes in how a person thinks, feels, sees and hears.
- CBD, which does not cause a high.
People use cannabis by smoking it, vaping it, or eating or drinking it in edibles (like baked goods, candy or drinks). Some people are prescribed cannabis by a health care practitioner for a medical reason; that's different from using it to get high.
The law: In Canada, cannabis became legal for adults in October 2018. In Ontario, you must be 19 or older to buy, use, have or grow cannabis. It is illegal to drive while impaired by cannabis.
| Kind of effect | Examples |
|---|
| Short-term body effects | Red eyes, dry mouth, faster heartbeat, feeling hungry, feeling dizzy or sleepy, trouble with coordination |
| Short-term brain effects | Slower reaction time, trouble paying attention, remembering and making decisions; changes in senses and sense of time; some people feel anxious, panicky or paranoid (suspicious or scared for no reason) |
| Long-term effects (regular use) | Problems with memory, attention and learning; smoking can harm the lungs; risk of dependence (finding it hard to stop) |
| Mental health effects | Regular use, especially starting young, is linked to a higher risk of mental health problems, including psychosis (losing touch with reality) in some people; it can make anxiety or depression worse |
| Safety effects | Injuries from slower reactions; car crashes from impaired driving; accidental poisoning of children or pets who eat edibles; taking too much because edibles act slowly |
| Social and legal effects | Problems with school, sports and friendships; spending money; breaking family rules; trouble with the law for people under 19 |
Why young people are at higher risk
Your brain is still developing, and it keeps developing until about your mid-20s. Cannabis can affect the parts of the brain that handle memory, learning, attention and decision making. The younger someone starts and the more often they use, the greater the risk of problems with learning, mental health and dependence. That's one reason the law sets a minimum age.
Most young people do not use cannabis. Choosing not to use it is common, healthy and easy to explain.
Edibles: a special warning
- Edibles can look like ordinary treats such as cookies, gummies or chocolate.
- Their effects can take 30 minutes to 2 hours to be felt, so people sometimes eat more, thinking it's "not working," and take too much.
- Children and pets who eat edibles by accident can become very sick.
- Never eat a food or candy if you don't know what's in it or where it came from.
- If someone may have eaten cannabis by accident, tell an adult right away. They can call the Ontario Poison Centre (1-800-268-9017), or 911 if the person is very unwell.
Worked exampleLet's check a claim
An older kid says, "Cannabis is natural, so it's totally safe." Let's think critically.
- What's the claim? "Natural" means "safe."
- Test it: Lots of natural things aren't safe: poison ivy, some mushrooms, tobacco. "Natural" does not mean harmless.
- What do the facts say? Cannabis can slow reaction time, affect memory and learning, and harm mental health, especially for young people whose brains are still developing.
- Conclusion: The claim is false.
"Natural" isn't the same as "safe." Asking "How do I know that's true?" is a great critical thinking habit.
Worked exampleLet's connect an effect to a danger
Why is it dangerous to drive a car, ride a bike or go swimming after using cannabis?
- Effect: cannabis slows reaction time and affects coordination and judgment.
- Driving or biking: you need to react fast to a car braking or a child running out. A slow reaction can cause a crash.
- Swimming: poor judgment and coordination raise the risk of drowning.
- The law: driving while impaired by cannabis is illegal in Canada.
Never get in a car with a driver who has used cannabis or alcohol. Call a trusted adult for a ride instead.
Hands-on activityFact or myth sorting game
You need: 8 index cards or paper slips and a pencil.
- Write one statement on each card:
- "Cannabis can slow your reaction time."
- "Natural means safe."
- "Most teens use cannabis."
- "It's legal for adults 19 and older in Ontario."
- "Edibles work right away."
- "Young people's brains are still developing."
- "Driving after using cannabis is okay if you feel fine."
- "Cannabis can cause anxiety or paranoia in some people."
- Sort them into FACT and MYTH piles with a family member.
- For each myth, say what the truth is.
Answer key: Facts: reaction time, legal at 19, developing brains, anxiety or paranoia. Myths: natural means safe; most teens use it (most don't); edibles work right away (they can take 30 minutes to 2 hours); driving is okay if you feel fine (impaired driving is dangerous and illegal).
Your turn
A plant containing chemicals (like THC) that can change how a person thinks, feels and acts.
2Which chemical in cannabis causes the "high"?
3Name three ways people use cannabis.
Smoking, vaping, eating or drinking (edibles).
4How old must you be to buy or use cannabis in Ontario?
5Name two short-term effects of cannabis on the body or brain.
Any two: red eyes, dry mouth, faster heartbeat, slower reaction time, trouble with memory or attention, poor coordination, anxiety or paranoia.
6Why are young people at higher risk?
Their brains are still developing (until about the mid-20s), so cannabis can affect memory, learning, attention and mental health more.
7Why can edibles be especially risky?
They take 30 minutes to 2 hours to take effect, so people may take too much; they can look like ordinary treats that children or pets eat by accident.
More practice: warm-up
1True or false: CBD causes a high.
False. THC causes the high.
2True or false: it's legal to drive while impaired by cannabis.
3What should you do if you find a candy and don't know what's in it?
Don't eat it. Give it to an adult.
4Until about what age does the brain keep developing?
5True or false: most young people use cannabis.
More practice: on your own
1Explain how cannabis could affect a student's schoolwork.
It can make it harder to pay attention, remember and learn, so schoolwork can suffer.
2What is paranoia, and how is it related to cannabis?
Feeling suspicious or scared that others want to hurt you, without a real reason. Some people feel this after using cannabis.
3Name one social effect and one legal effect of cannabis use for a 13-year-old.
Social: problems with friends, family trust, sports or school. Legal: it's illegal for people under 19 to have or use cannabis.
4A little brother finds a gummy bag in a relative's purse and eats some. What should you do?
Tell an adult right away. They should call the Ontario Poison Centre (1-800-268-9017) or 911 if he seems very unwell. Keep the package to show them.
5Why is "I feel fine" not a good reason to drive after using cannabis?
Cannabis can slow reaction time and affect judgment even when the person feels fine, and impaired driving is illegal.
Challenge
1Explain the difference between medical cannabis and cannabis used to get high.
Medical cannabis is authorized by a health care practitioner for a health condition, and its use is supervised. Using cannabis to get high isn't for treating an illness. Either way, it can still have side effects.
2Someone says, "It's legal, so it must be safe." Explain why that's faulty thinking. Use another example.
Legal doesn't mean safe. Alcohol and tobacco are legal for adults but cause serious harm. Cannabis is legal for adults, but it still has risks, especially for young people. Laws set age limits because of those risks.
3Design a short message (one or two sentences) to teach a Grade 4 student about edible safety.
Example: "Some treats can have cannabis in them and look just like candy. Never eat something if you don't know what's in it, and tell a grown-up if you find it." Look for: don't eat unknown treats, and tell an adult.
Quiz
1. What is the minimum age to buy cannabis in Ontario?
2. Which chemical causes the high?
3. Why are young people at higher risk from cannabis?
4. Which is a short-term effect of cannabis?
5. Edibles can be risky because...
6. Driving while impaired by cannabis is...
Big idea: This lesson covers the Grade 6 expectation to describe the range of effects associated with using cannabis (D1.2, Substance Use, Addictions, and Related Behaviours). It builds critical thinking (A1.6) through checking claims.
How to help at home:
- Share your family's values about cannabis and other substances clearly and calmly.
- If cannabis is in your home, store it locked and out of reach, like medicine, and in its original packaging.
- Encourage your child to ask questions; give honest, factual answers.
Common difficulties: Children may hear that cannabis is "natural" or "legal, so safe." They may also worry about a family member who uses cannabis; reassure them that adults make their own choices and that they can talk to you or another trusted adult about any worries. Avoid scare tactics; facts work better.