Effects & Risks of Cannabis

Cannabis affects different people in different ways.

Short Term Effects

Short-term effects can include feeling happy, relaxation, increased sociability, and heightened sensation. Problems with memory and learning, distorted perception (sights, sounds, time, touch), trouble with thinking and problem solving, body tremors, loss of motor coordination, increased heart rate and anxiety, and panic attacks. coordination, increased heart rate, and anxiety, and panic attacks. These effects may be even greater when other drugs are mixed with cannabis. ¹

Long Term Effects

Cannabis is an addictive substance. The risk of developing dependence is one in six among those who start using cannabis frequently during adolescence.²

Cannabis Resources

Regular cannabis use in adolescents is associated with experiencing psychotic symptoms (changes in thoughts, feelings, and behaviours), especially when there is a family or personal history of psychotic disorders. Some studies have suggested that cannabis may also increase the risk of anxiety and depression over time.³ 

What’s regular cannabis use? 

Regular use of cannabis means that the use of cannabis occurs regularly over time. It may involve using cannabis every day, or every weekend over a period of several months or over a number of years.

Early and frequent cannabis use is linked with poor performance in school, lower grades, and an increased risk of dropping out. The evidence is still unclear as to whether regular use affects an adolescent’s IQ,⁴  however, research suggests that early, regular, heavy, and long-term use of cannabis by teens may impair their cognitive abilities and may not be fully reversible.⁵

Alcohol and Cannabis

Youth might be particularly vulnerable to these negative outcomes due to the extensive changes that are taking place in the brain during adolescence, especially the ongoing development and maturation of the prefrontal cortex, which is critical to higher-order cognitive processes such as impulse control, working memory, planning, problem-solving and emotional regulation.⁶

Cannabis, just like any other drug, can lead to addiction. It has an effect on the brain’s reward system – as do all other addictive drugs – the likelihood of developing problem use or addiction increases considerably for those who start young.⁷

Talk with your kids

Early and regular cannabis use does affect the health of youth.  

Get to know Canada’s Lower-Risk Cannabis Use Guidelines, as well as the Youth version of these guidelines, and discuss them together with your kids. These recommendations can greatly help reduce the potential harms of cannabis use to the health of youth and young adults.

With the exception of impaired driving, cannabis use is unlikely to result in permanent disability or death, but too much of the drug in a person’s system can have harmful effects.