Council of Chief Medical Officers of Health remind Canadians of the harms and risks associated with cannabis use


October 25, 2018

On October 17, the Cannabis Act came into force, putting in place a new legal framework for cannabis. This fundamental shift to a new legal approach is an important step in reducing harms to Canadians and removing the burden and stigma of criminalization.

Canada will need to maintain a strong regulatory approach to current legal products, and take a similar approach to new products such as edibles in order to protect the health of all Canadians, especially children and youth.

As with other regulated substances, such as alcohol and tobacco, cannabis is not harmless. While there is some evidence of potential therapeutic uses for cannabis, the long-term effects remain unknown, and more research needs to be done.

Cannabis can be addictive, and frequent use can cause harm to your physical and mental health. In fact, close to 10% of adults who have ever used cannabis will develop cannabis use disorder. The younger you are when you start using cannabis, and the more often and the longer you use it, the more likely that it will have a negative impact on your brain.

This is why, collectively, we are stressing the importance of following guidelines for lower-risk cannabis use in order to reduce the risk of harms to the health of Canadians. That includes avoiding illegal cannabis and purchasing only from retailers authorized by provinces and territories. 

If you choose to use cannabis or are considering using cannabis, follow the Lower-Risk Cannabis Use Guidelines developed by the Centre for Addiction and Mental Health:

  • You can avoid risks by not using cannabis.
  • Delay use of cannabis to later in life (note legal age for your province or territory).
  • Avoid smoking burned cannabis and if you do smoke cannabis, avoid inhaling deeply or holding your breath.
  • Limit how often you use cannabis.
  • Choose low-potency products with low tetrahydrocannabinol (THC) and/or high cannabidiol (CBD) content.
  • Never drive or operate machinery after using cannabis.
  • Avoid use if you’re pregnant or breastfeeding, or if you or your family has a history of psychosis or substance use problems.

In addition to the above guidelines, we recommend that you:

  • Talk to the children in your life about cannabis; providing young people with balanced information about the effects associated with cannabis can help them make informed choices.
  • Keep cannabis, like any other drug or medication, out of the reach of children and avoid exposing children to cannabis second-hand smoke.
  • Avoid combining cannabis with alcohol and other substances as it increases impairment.

An important aspect of a public health approach to cannabis is to monitor and evaluate the impact that these new policies will have on the health and social well-being of Canadians over time, something we are committed to doing.

As Canada's Chief Medical Officers of Health, we encourage all those who use cannabis or who are considering using cannabis to be aware of the ways they can minimize the potential negative impacts of cannabis use.

Get informed. Protect your health and the health of your family.

Dr. Theresa Tam
Chief Public Health Officer of Canada

Dr. Bonnie Henry
Provincial Health Officer, British Columbia
Chair, Council of Chief Medical Officers of Health

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