If you choose to use recreational cannabis, it's important to know the risks.

Cannabis use has short-and long-term health and social risks

Short-term risks

  • Anxiety, fear or panic, and psychotic episodes
  • Confusion and fatigue
  • Impaired ability to pay attention, concentrate, and remember
  • Impaired perceptions and physical co-ordination and slower reaction times
  • Accidents and injuries resulting from the above effects
  • Heart and lung problems, especially for those with a history of heart and lung disease

Long-term risks

  • Impact on your mental health including anxiety, depression, psychosis or schizophrenia
  • Lowering your ability to concentrate, think and make decisions, and remember
  • Physical dependence or addiction to cannabis
  • If smoked, chronic bronchitis, lung infections, chronic cough

Many long-term risks are higher if cannabis use starts earlier in life, is more frequent and lasts over a long period of time.

Factors that increase your health and social risks include:

  • Age - Frequent and heavy use under the age of 25
  • Choice of cannabis products – High THC products are generally associated with higher risk for mental and behavioural problems
  • Methods of cannabis use – Regular inhalation of burned cannabis carries greater health risk, especially affecting respiratory health
  • Frequency and intensity of use – Daily or near-daily cannabis use is associated with higher risk of experiencing health and social problems

Some people have higher or special risks

Pregnant and breastfeeding women

The use of cannabis can affect the health and development of a fetus or newborn child.

The substances in cannabis are carried through the mother's blood to her fetus during pregnancy and via breast milk following birth.

Heavy cannabis use by pregnant and breastfeeding women has been linked to lower birth weight, pre-term labour and longer-term developmental effects on the child’s behavior and learning.

If you are pregnant or breastfeeding, using cannabis is not recommended.

Visit Society of Obstetricians and Gynaecologists of Canada for details


If cannabis use is started earlier in life, used frequently and over a long period of time, the health and social risks are greater:

  • Disruption of normal brain development which is underway up to age 25
  • Poor performance in school and increased risk of dropping out
  • Increased risk of mental health problems such as anxiety, depression and psychosis
  • Increased chance of addiction and dependence


Frequent cannabis use that starts in adolescence, increases the chance of addiction and dependence.

If you are under age 25, the best way to avoid the risks is by not using cannabis.

Talking with your kids about cannabis isn't always easy. The Cannabis Talk Kit offers information about cannabis and practical tips on how to get the conversation started.


Individuals with personal or family history of mental health problems or substance use disorders

The occurrence of cannabis-related mental health problems, including psychosis and substance use disorders, has been linked to people with personal or family history of such problems.

If you have a personal or family history of mental health problems, including psychosis or substance use disorders, using cannabis is not recommended.

For details on cannabis and psychosis, visit Schizophrenia Association of Canada