Health Effects of Cannabis Use
This section addresses the effects from using non-medical cannabis. The legalisation of cannabis could make some people believe that cannabis is safe to use. It is important to understand all the health effects of cannabis and to make an informed choice with all the current known evidence around cannabis use. As with alcohol, there are negative effects that can have long term implications for health and social welfare.
The short-term effects of taking cannabis can be felt within seconds when smoking, vaping or dabbing cannabis. The effects from edibles are less immediate and can be felt within 30 minutes to 2 hours following ingestion. All effects can last for up to 24 hours. Drug testing can detect cannabis for several days following use.
Users may experience effects such as:
• Heightened sense of well being
• Increased sensory effects to sight, taste, smell and sound
• Increased appetite
• Decrease in blood pressure, with possible fainting
• Increased heart rate, leading to an increase risk of heart attack in people with heart conditions
Brain function may be affected with some users experiencing:
• Poor concentration
• Slow reactions
• Anxiety and/or fear
• Panic attacks
• Psychotic episodes
Long term users who consume cannabis daily or regularly throughout the week over a prolonged period of weeks, months or years may develop an addiction. Additionally, memory, concentration, intelligence and decision-making ability may be affected.
Lung health may be affected in individuals who smoke cannabis long term. The effects are similar to smoking tobacco and include:
• Lung infections
• Chronic cough
• Mucus buildup in the chest
The long term effects appear to be worse in individuals who started using cannabis during adolescence when the brain is still developing. Some of these effects will remain, even once an individual has stopped using cannabis.
For more information on the therapeutic uses of cannabis, please consult a medical professional.
Cannabis Use During Pregnancy and Breastfeeding
Cannabis use during pregnancy and breastfeeding poses a risk to the child. Use has been linked to lower birth weights, and difficulties with learning, behaviour and mental health in later life. Recent research has also shown that both maternal and paternal cannabis use is linked to psychotic like experiences in their children.
Since there is no known safe amount of cannabis to use during pregnancy or breastfeeding, the safest approach is to not use cannabis.
Mental Health Risks in Young People
Research shows that the brain is not fully developed until around the age of 25. Cannabis use can have an impact on brain development as the THC in cannabis affects the same parts of the brain that directs brain development. Some of the harm done to the brain by using cannabis during adolescence may not be fully reversible once cannabis use stops.
In some people, cannabis use increases the risk of developing mental illnesses such as psychosis or schizophrenia. The risk increases if there is a family or personal history of psychosis and/or schizophrenia. Schizophrenia usually emerges at the end of adolescence or in early adulthood, with heavy cannabis use emerging as a direct cause. The prevalence of schizophrenia in the general adult population is 1%, which doubles to 2% in heavy cannabis users.
Frequent cannabis use has also been associated with an increased risk of suicide, depression and/or anxiety disorders.
Increased harm is likely if cannabis use during adolescence is frequent and continues over time. The younger someone starts using cannabis, the greater the risk of harm. Cannabis products with concentrated levels of THC can also increase the risk of mental health harm in adolescents.
Support for Parents
The 2013 BC Adolescent Health Survey indicated that 26% of youth had tried cannabis, with 14 years being the most common age to first try. Most youth obtained cannabis from youth outside of their family.
Parents can access a number of resources to help them talk to their children about cannabis.
Westcoast Community Resources Society
Tel: 250-726-2343, or visit The Hub at 500 Matterson Drive, Ucluelet between 10am and 4pm.
• Youth and Family Counselling
• Youth Outreach Services
Drug Free Kids Canada
Health Canada: How to Talk with your Teen - Communication Tips for Parents
Here to Help: Learn about Cannabis
Kids Help Phone: Cannabis Important Things to Know
Canadian Paediatric Society: Marijuana - What parents need to know
Canadian Public Health Association: Pot and Driving
Government of Canada: Don’t Drive High