Risk of Harm


Happy Youths

Research is growing on the link between cannabis use and negative health and social harms. Youth are often misinformed on harms associated with cannabis use, perceiving it to be less harmful than alcohol and other substances (CCSA, 2017).


Age of initiation

Research shows that brain development is not complete in a person until the age of 25. When cannabis is introduced early and frequently to the body, the developing brain may alter with some adverse effects being irreversible. Early cannabis use is also associated with a higher likelihood of developing cannabis use disorder, mental health problems and use other illicit drugs. One in six of those who initiate cannabis use in adolescence will become dependent (CCSA, 2016). Research in this age group also suggests poor educational outcomes, reduced life satisfaction and achievement from early cannabis use (CAMH, 2012)


Cannabis can be addictive

Although the risk of addiction to cannabis is lower than it is for alcohol, tobacco or opioids, regular cannabis use can result in the long-term harm of addiction (George & Vaccarino, 2015).


Cannabis and Respiratory Effects

Cannabis smoke contains many of the same cancer-causing toxins as tobacco smoke. Health risk of cannabis may be even more harmful with increased exposure of the toxins to the lungs (CCSA, 2016)


Driving while using

Using cannabis and driving a motor vehicle doubles the risk of a collision (CCSA, 2017). Depth perception, concentration, a decreased reaction time and muscle tone (strength and steadiness) are affected while using cannabis. Impairment is intensified when combined with alcohol.

Enforcement offices have the authority to detect drivers who are impaired by cannabis and lay drug impaired driving charges (CCSA, 2016).


Cannabis and Maternal Health

Cannabis use during pregnancy should be avoided due to the ability of THC and other chemicals to pass through the placenta. Cannabis exposure while in the womb may affect the development of the child, as well as cognitive functioning behaviour and mental health (CCSA, 2016)


Cannabis Use and Mental Health

There is a link between cannabis use and mental health. Those who initiate use early in life appear to be particularly vulnerable to psychosis and psychotic symptoms (CCSA, 2016).



Canadian Centre on Substance Abuse. Clearing the Smoke on Cannabis Highlights. September 2016.

Centre for Addictions and Mental Health. (2012). Retrieved December 22, 2016

George, T., & Vaccarino, F. (Eds.). (2015). Substance abuse in Canada: The Effects of Cannabis Use during Adolescence. Ottawa, ON: Canadian Centre on Substance Abuse.

McKieran, A., & Fleming, K. (2017) Canadian Youth Perceptions on Cannabis, Ottawa, Ont.: Canadian Centre on Substance Abuse.


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