Trends in Cannabis Use Prior to First Admission to Inpatient Psychiatry in Ontario, Canada, Between 2007 and 2017 (Report at a Glance)
After alcohol, cannabis is the second most commonly used substance in Canada. There is a lot of information available on the Internet about the health impacts and potential benefits of cannabis use. Some of this information is accurate and some is inaccurate. The research section summarizes the current scientific evidence on the health impacts of cannabis, the potential medical benefits of cannabis and peoples’ perceptions of cannabis.
While the evidence on the medical applications of cannabis is limited, there are risks associated with regular cannabis use. Ongoing research is improving what we know about both risks and benefits.
We know that there are complex interactions between cannabis use and mental illness, including an established relationship between regular cannabis use and psychosis. New research analyzes the correlation between cannabis use and admission to inpatient psychiatric care.
The report in short and infographic, Trends in Cannabis Use Prior to First Admission to Inpatient Psychiatry in Ontario, Canada, Between 2007 and 2017, are based on research that analyzed trends in nonmedical cannabis use in the 30 days before individuals were first admitted to inpatient psychiatric beds.
Key points include:
Between 2006 and 2015, the rate of hospitalizations related to cannabis use and mental and behavioural disorders more than doubled. In the same period, the rate of hospitalizations specific to cannabis-related psychotic disorders tripled. These findings are presented in the summary report, Psychotic Disorder and Cannabis Use: Canadian Hospitalization Trends, 2006– 2015.
Additional key findings include:
Please see the infographic as an additional resource to the report.
Since the beginning of the COVID-19 pandemic, there has been growing interest in the potential health benefits and medical application of cannabis to prevent and treat COVID-19 symptoms. There is no scientific evidence that demonstrates the benefits of either THC or CBD in preventing or treating COVID-19. Inhaling cannabis smoke can harm the lungs, which might increase susceptibility to COVID- 19 and worsen the symptoms of the disease.
The brief also includes four tips to reduce health risks for those who smoke cannabis.
This evidence summary outlines eight important facts people should know about COVID-19 and cannabis smoking or vaping.
The Clearing the Smoke on Cannabis series looks at how cannabis use affects mental and physical health, and discusses implications for policy and practice. Prepared and peer-reviewed by expert researchers in the field, this series addresses what we know about the health effects of cannabis use, what we don’t know and what needs further investigation.
This report provides a summary of the seven publications in the Clearing the Smoke on Cannabis series.
The common belief that smoke inhaled from smoking cannabis is safe because cannabis is a natural plant is mistaken. Cannabis smoke contains many of the same chemicals (toxins, irritants and carcinogens) as tobacco smoke.
The latest report in the Clearing the Smoke on Cannabis series, Respiratory and Cardiovascular Effects of Cannabis Smoking highlights the risks to your heart and lungs from inhaling cannabis smoke. Report highlights include:
In addition to the report, CCSA has developed two public education resources to help Canadians understand and reduce the health risks associated with smoking cannabis:
A completely new line of cannabis products is now available for purchase in Canada. Edible cannabis products, cannabis extracts and cannabis topicals have unique health and safety risks that are different from the risks associated with dried cannabis.
With these products, it is important to know that:
Promising research indicates that cannabis and cannabinoids are effective in relieving symptoms associated with certain severe and chronic conditions. As of June 2018, over 333,000 Canadians had registered to access cannabis for medical purposes.
This report summarizes what is known about the recent emergence of severe lung injury associated with vaping, including probable causes and next steps for research. It incorporates the most current evidence and information available about the link between vaping and severe lung and pulmonary illnesses as of October 31, 2019.
Key findings from the report:
Starting to smoke cannabis earlier in life — before 16 or 17 — is one of the strongest predictors of noticeable cognitive difficulties. However, the impact of regular cannabis use on cognitive functions is generally mild for most people. Many of the measurable effects on these functions disappear after sustained periods of not using cannabis.
People who use cannabis regularly — one or more times per week over a period of months or years — could be at greater risk of developing psychosis or schizophrenia. This finding was determined through a review of the current body of research about the relationship between cannabis and a number of mental health conditions.
Additional findings of the report include:
An estimated 16.9% of individuals of childbearing age (15–44 years) reported past-year use of cannabis in 2015 and 2% to 5% of pregnant individuals reported using cannabis during pregnancy. There is little evidence to suggest an association between cannabis use during pregnancy and increased risk of premature birth, miscarriage or major physical abnormalities. However, frequent cannabis use during pregnancy is associated with:
On October 17, 2019, the federal government made it legal to purchase and consume edible cannabis products, cannabis extracts and cannabis topicals.
What are these products? In the simplest terms, they are defined as follows:
These new cannabis products carry with them unique health and safety risks that are not associated with consuming dried cannabis. It is important to be aware and informed of these risks before choosing to use edible cannabis products, cannabis extracts or cannabis topicals in order to minimize adverse health outcomes.
In the months leading up to legalization, CCSA released a series of public education resources about the new cannabis products. The resources include information about the associated health and safety risks, how to lower the risks or adverse health outcomes, the differences between ingesting and inhaling cannabis products, and how to safely store your cannabis products.
Each of these types of cannabis product has its own attributes and uses.
Edible cannabis can come in a range of products that are meant to be consumed by eating or drinking. Although some edible cannabis products might look like normal food items, they are not. These products provide no nutritional value.
Cannabis extracts can be in solid form (hash or hashish) or in liquid form (oil intended for vaping). These products can be vaped, smoked or ingested. Cannabis extracts can vary widely in their THC and CBD concentrations. Some extracts, such as cannabis oil distillates and shatter, can have up to 99% THC, whereas others can be mostly CBD with little THC. High-strength extracts can increase the risk of over-intoxication, especially among those who are new to cannabis.
Cannabis topicals are for application directly to the skin, hair or nails. The risk of intoxication and impairment following the application of cannabis topicals is believed to be low, although there has yet to be thorough research evaluating these potential effects.
Our primer provides a brief overview of each of these different type of cannabis products and their associated properties.
Inhaling and ingesting are the two most popular ways to consume cannabis. People need to know how each method can affect their health.
The way we consume cannabis determines how it enters the body. One method passes through the lungs and the other through the stomach. The differences between inhaling and ingesting have a great impact on:
Consuming edible cannabis is an alternative method to smoking cannabis. When edible cannabis becomes legal this fall, many Canadians might be interested in trying the variety of options that become available. Before they do so, they need to be aware of the risks.
Eating or drinking cannabis affects the body differently than smoking or vaping it. People who choose to use edible cannabis products must educate themselves on how to do so in a lower-risk manner.
7 Things You Need To Know about Edible Cannabis provides guidance on what these products are and how to lower your risk. The topics covered include:
Cannabis extracts are products containing cannabinoids extracted from the cannabis plant. THC (tetrahydrocannabinol) and CBD (cannabidiol) are the most common cannabinoids, but they have different effects. THC makes people intoxicated or high, while CBD is non-intoxicating and might provide therapeutic benefits.
Cannabis extracts vary widely in their THC and CBD concentrations. Some extracts can contain up to 99% THC, whereas others can contain mostly CBD with little THC.
Extracts can be solid (hash or hashish) or liquid (oil intended for vaping). Certain types are named after their appearance or texture including shatter, wax, honeycomb and budder.
You can consume cannabis extracts through:
7 Things You Need to Know about Cannabis Extracts provides information you should know about cannabis extracts and how to lower your risk when using them. The topics covered include:
Edible cannabis comes in a wide range of products including cookies, chocolates and beverages. The amount of THC in edible cannabis products can vary. However, in Canada, packages containing edible cannabis products are legally limited to a maximum of 10 mg of THC.
To reduce your risk of over-consumption, read the label before consuming an edible cannabis product. People who are new to cannabis should start low — no more than 2.5 mg of THC — and go slow!
This infographic highlights what people should know before they consume an edible cannabis product, including:
Cannabis is one of the most commonly used substances in Canada. According to the 2018 National Cannabis Survey, 15.6% of all Canadians reported using cannabis in the past three months. While the non-medical use of cannabis can result in numerous health impacts, it also contributes to the overall cost of substance use. The greatest impact is in the criminal justice sector, and other sectors impacted include healthcare, business and industry, as well as other areas such as research and prevention, damage to property and motor vehicles, and workplace costs not covered in lost productivity.
For more information, see the full report:
Cannabis use in Canada is slowly on the rise: past-year use among the general population (aged 15 years and over) increased from 25% in 2019 to 27% in 2020. Provincial and territorial estimates ranged from 21% to 37%. Youth living in Canada were nearly twice as likely to report past-year cannabis use compared to adults, with people aged 16–24 years having a usage rate of between 44–52% and people aged 25 years and older having a usage rate of 24%.
For more information, see the Cannabis (Canadian Drug Summary), the National Cannabis Survey and the Canadian Cannabis Survey 2020: Summary.
The usage patterns and attitudes about cannabis of people in Canada have been shifting since legalization. These patterns and attitudes include rates of use, preferred methods of consumption, and attitudes and behaviours around the use of alcohol and cannabis together. There have also been changes in the way people acquire cannabis.
An analysis of data collected from 2017 to 2020 found that people who consume cannabis are shifting away from methods of consumption based on inhalation and towards consumption through oral ingestion. It also found a significant increase in the number of people buying cannabis through legal channels since legalization. People purchasing cannabis from illegal sources are more likely to be male and less likely to be college or university graduates. They are also more likely to be people who consume cannabis more frequently and agree more strongly that illegal cannabis is cheaper and of higher quality than legal cannabis and should not be regulated by the government.
This report provides valuable knowledge on existing beliefs around cannabis use and purchase, and can inform cannabis use prevention initiatives and education messaging.
For more information, see the report at a glance: How People Living in Canada Consume and Acquire Cannabis.
Since the Cannabis Act was passed in October 2018, people living in Canada have been voicing their concerns and perspectives about the health and safety impacts of cannabis. Immediately before legalization was enacted, CCSA commissioned a Nanos poll of 1,000 people living in Canada who were asked a series of questions about their thoughts on cannabis use. Key findings include:
For more information, see the Nanos research poll summary.
According to Health Canada’s Canadian Cannabis Survey summary report (2017), people living in Canada aged 16 years and older held the following opinions about cannabis:
For more information, see the Canadian Cannabis Survey 2017 - Summary.
A small sample of youth aged 15–19 living in Canada held the following opinions about cannabis:
Cannabis impairs the cognitive and motor abilities necessary to safely operate a motor vehicle and doubles the risk of crash involvement. Current data supports the following conclusions:
For more information about cannabis and impaired driving, please see Driving Under the Influence of Cannabis.
With the legalization of cannabis, youth are seeking credible information from individuals they know and trust on the benefits and harms of cannabis use. They want to know the whole story. Young people are ready to have the conversation, but many who interact with them are not well prepared for it.
CCSA developed a communication guide to help educate youth allies on how to have safe, unbiased and non-judgmental conversations with young people about cannabis. By taking a harm reduction approach and providing a basis for communicating accurate information about cannabis, youth allies will be able to better support young people in making informed decisions about their cannabis use.
Since launch, the guide has had successful uptake from youth allies, many of whom indicated the guide effectively facilitated their conversation with youth about cannabis. More information about uptake and usage can be found in CCSA’s Cannabis Communication Guide Impact Story.
One of the primary objectives of the Cannabis Act is to protect youth and divert profits away from organized crime and illicit markets.
Through a targeted initiative, the Canadian Centre on Substance Use and Addiction (CCSA) provided funding to Dr. Akwasi Owusu-Bempah and Dr. Scot Wortley to research youth interactions with the criminal justice system, including the nature and outcomes of those interactions.
CCSA has released Impact of Cannabis Legalization on Youth Contact with the Criminal Justice System, a report summarizing key findings from the study.
The Effects of Cannabis Use during Adolescence, a report in the Substance Use in Canada series, reviews the evidence on what we do and do not know about how cannabis affects adolescents. The report addresses several important questions and key issues, including:
The report concludes with A Call to Action. It gives parents, teachers, healthcare providers and policy makers the opportunity to develop and employ more effective youth drug use prevention and intervention programs.
For an online learning experience based on the report, see Online Learning for the Effects of Cannabis Use during Adolescence.