Cannabis can be harmful to your long-term mental and physical health.

Cannabis is the scientific name for the hemp plant. Its dried leaves and flowers - often called marijuana - or pressed resin (hashish or hash), contain the chemical delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). It is often smoked in pipes or hand-rolled cigarettes. But it can also be vaporized, applied to the skin, cooked in food or beverages, or brewed into tea.

What are the effects of cannabis?

Cannabis affects people differently. It can make you feel happy, relaxed and talkative. Immediately following use you may have unpleasant effects such as confusion, sleepiness, anxiety, fear or panic

Cannabis can be harmful to your long-term mental and physical health:

  • Cannabis can change the way your brain grows and develops. Regular use of cannabis may affect brain development up to the age of 25.
  • Cannabis smoke has many of the same chemicals as tobacco smoke. Smoking cannabis can increase risk of respiratory tract irritation, leading to chronic coughing, shortness of breath and wheezing. 
  • Cannabis may worsen symptoms of depression or anxiety and may also trigger the onset of schizophrenia in those already vulnerable.
  • Cannabis use may lead to addiction or dependence. Addicted or dependent users typically require more cannabis over time in order to feel the same 'high'. They may also develop withdrawal effects when they stop using (such as nausea, irritability, depression, insomnia, and cravings for cannabis).

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How can I reduce my risk?

If you are planning to use cannabis, try to delay until you are older (over 25 years of age) and follow these tips to lower your risk:

  • Limit how often you use, e.g. no more than once a week.
  • Start with small amounts: It's better to use only as much cannabis as is necessary to achieve desired effects.
  • Don’t smoke it. If you are planning to smoke cannabis, take short breaths and exhale right away.
  • Choose lower risk products, e.g. vaping.
  • Don’t use synthetic cannabinoids.
  • Don’t use with alcohol or tobacco.
  • Don’t use if you are planning to drive or operate other machinery.
  • Don’t use if you are pregnant or breastfeeding
  • Don’t use if you are at risk for mental illness
  • Avoid combining the risks, e.g. smoking cannabis regularly.

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What are the risks of cannabis in pregnancy and breastfeeding?

Cannabis is not recommended for anyone while pregnant or breastfeeding. There is no known safe amount of cannabis use in pregnancy and when breastfeeding. Heavy cannabis use has been linked to lower birth weight.

If a woman is breastfeeding, the THC in cannabis and other chemicals will get into the breast milk and may affect the baby. The THC can move into the baby’s fat tissue, as well as into the brain.

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What are the effects of cannabis in youth and young adults?

The brain does not stop developing until around age 25. The younger you are when you begin cannabis use and the more often and the longer you use it, the more likely that it will have a bigger impact on your brain.

Parent and teacher resources

What is medical cannabis?

Medical cannabis is the use of this drug to help treat symptoms like pain, nausea, and lack of appetite. It may be used by people who have conditions like cancer, AIDS, or multiple sclerosis. If you think you might want to try medical cannabis, speak to your health care provider.  Learn more about medical cannabis.

Is cannabis legal?

Where can I seek help?

If you are concerned about you or a loved one, you can contact the Alcohol and Drug Information and Referral Line at 1-800-663-1441 or 604-660-9382 in Greater Vancouver. Or learn more about our substance use services.