Risks to Mental Health



Using cannabis can increase the risk of triggering a psychotic illness in any individual but is much riskier for individuals with close family members who have psychotic illnesses or have a history of trauma. Cannabis use can increase the risk of psychotic symptoms for all individuals, especially those with a pre-existing vulnerability to psychosis. (A person with psychosis experiences some loss of contact with reality, characterized by changes in the individual's way of thinking, believing, perceiving, and/or behaving.) Also, cannabis use may worsen the symptoms of psychosis in people with pre-existing psychotic disorders.


Cannabis, Psychosis and Psychotic Symptoms

Psychosis can be thought of as a break with reality where a person experiences thoughts and feelings and/or hears and sees things (hallucinations) that are not experienced by others. A person experiencing psychotic symptoms has a difficult time knowing what is real and what is not.


For the majority of people who experience psychosis when using cannabis, the symptoms go away as the body processes the active ingredients in cannabis (eg. THC).  Thinking, feeling and perception return to normal and the symptoms do not return though they may when cannabis is used again. Some people, including those who have a family history of serious and persistent mental illness (eg. psychotic disorders) and/or a history of trauma, may develop a longer lasting psychosis.  Of these, some will go on to develop chronic mental illnesses such as schizophrenia.


What increases the risk of harm from cannabis use?

• Risks associated with using cannabis can increase depending on a number of factors, including:

• Starting to use cannabis at an early age: young brains are still developing and are more vulnerable to the effects of psychoactive substances. Waiting until you are older can reduce the possibility of negative effects on your developing brain.

• Family history of trauma and mental health issues, especially psychotic disorders

• Frequency of cannabis use

• Quantity and potency (level of THC) of the cannabis being used

• Using synthetics and concentrates, such as "shatter"

• Activities during or after cannabis use, such as driving or using other drugs or alcohol


Play it safe: Reduce the risk of harm from cannabis use

The most important thing is to make informed choices. Be sure to make the right choice for you when it comes to cannabis - this can take courage. Our cultural traditions and teachings can guide you to make choices that are safer for your body and mind.


If you do choose to use cannabis, here are a few tips to lower the risk of harm:


• Choose cannabis with lower levels of THC

• Know your own limits when it comes to cannabis

• Use a vaporizer instead of smoking cannabis. Vaporizing eliminates most of the smoke which means that your body absorbs fewer toxins and potential carcinogens.

• If you smoke cannabis, take shallow puffs. Most THC is absorbed into the lungs in the first few seconds so big puffs and holding your breath do not help you get the "feeling". It simply exposes you to more toxins.

• Avoid using cannabis in any form if you are pregnant or breastfeeding. THC can pass through the mother to the developing fetus or through breastmilk to the baby.

• Use cannabis only occasionally and take breaks. Regular use has more risk.

• Try cannabis in a safe setting where you feel comfortable and have support.

• Know where the cannabis was bought. Legal cannabis products are the safest.

• Don't drive while under the influence of cannabis, alcohol or any other drug.

• Be aware of the negative impacts of mixing cannabis with other substances, such as alcohol.

• Check in with yourself regularly about your cannabis use. Are you using cannabis occasionally to have fun? Are you using it daily as a way to cope with feeling down or sad?

• Learn about Canada's lower risk guidelines for cannabis at https://www.camh.ca/-/media/files/pdfs---reports-and-books---research/canadas-lower-risk-guidelines-cannabis-pdf.pdf