Cannabis use in young adults: 5 realities we can’t ignore
Given that brain development continues into the mid-20s, cannabis use for youth under 25 can harm cognitive function and mental health. GETTYIMAGES
Cannabis use among young adults has become increasingly normalized, especially following Canada’s legalization in 2018. According to the 2024 Canadian Cannabis Survey by Health Canada, close to half of those who reported non-medical cannabis use at least once in the past year were 20- to 24-year-olds (48%), followed by 16- to 19-year-olds (41%) and then those over 25 (23%). Cannabis use is now a common part of social settings and even medical conversations, however, despite its growing acceptance, there are still many unknowns, particularly when it comes to its impact on developing brains.
“While research continues to advance, we still have a lot to learn about the physical, mental and emotional effects of cannabis use among young people,” says Dr. Johann Blignaut, an addiction physician at Homewood Ravensview, in North Saanich, British Columbia.
“However, our knowledge about brain development – and the fact that it continues into the mid-20s – highlights the potential harms associated with cannabis use for youth under 25.”
Cannabis affects the same biological system in the brain that is responsible for development. “For younger adults, whose prefrontal cortex is still maturing, cannabis can carry significant risks,” he explains. “These include impaired cognitive function, increased vulnerability to mental health issues and long-term consequences that are not yet fully understood.”
Below, Dr. Blignaut shares five key things to know about cannabis use and young people.
#1: Cannabis Is culturally accepted, but that doesn’t mean it’s harmless
The biopsychosocial factors relating to cannabis use in young adults must be examined. Cannabis has become a common part of everyday life, often viewed as a socially accepted recreational substance. Dr. Blignaut’s insights align with research by McKiernan and Fleming (2017)1, which suggests that youth cannabis use is often shaped by social influences from significant figures (such as respected peers or family), as well as factors like increased availability, growing acceptance, normalization and the pursuit of social connection. This normalization in social settings, combined with media influence, can downplay the risks associated with frequent use, especially for young adults whose brains are still developing.
#2: Limited research: the knowledge gap is wide with cannabis
Cannabis has been used widely for medicinal and recreational purposes for thousands of years. Today, there is renewed interest in analyzing its chemical composition, with recent data indicating that it contains over 550 compounds. Despite growing use, research into how these compounds affect cognitive and psychiatric disorders, particularly among the under 25 population, is still limited. The prefrontal cortex, which governs decision-making, impulse control and emotional regulation, continues to develop into the mid-20s, making youth more vulnerable to the drug’s effects.
#3: Prescribed or not, cannabis comes with limits
Medical professionals may prescribe cannabis for certain conditions; however, medical use is carefully monitored and tailored to individual needs. Recreational use, especially without guidance, can carry risks that differ significantly from controlled medical applications. Misuse can occur and is associated with increased intake, impaired regulation of dosage and frequency, and heightened risk of dependency.
#4: It can severely impair cognitive function and mental health
Research indicates that cannabis is a depressant and can impair attention, executive functioning, learning, memory, language, motor coordination and social cognition2. In some individuals, particularly those with a genetic predisposition, it may trigger or worsen mental health conditions such as psychosis, paranoia and depression.
“For younger adults, whose prefrontal cortex is still maturing, cannabis can carry significant risks. These include impaired cognitive function, increased vulnerability to mental health issues and long-term consequences that are not yet fully understood. ”
#5: Individuals respond to cannabis in different ways
Genetics can influence susceptibility to addiction, mental health disorders, and how the body metabolizes this compound. This means that while some may use cannabis without noticeable harm, others may experience significant negative effects, even with occasional use.
Further to a person’s genetics, other factors can include their brain receptors, current stressors, medical and mental health conditions, ability to metabolize the drug, and socio-economic status/vulnerabilities, among others.
Conclusion and treatment Options
As cannabis becomes more accessible and accepted, it’s crucial to approach its use with informed caution, especially for young adults. Understanding the science, risks and individual factors can help foster healthier choices and better support.
My Path is Canada’s first and only dedicated inpatient mental health treatment program designed specifically for young adults aged 19 and over, developed to meet the unique needs and challenges faced by this age group. Cannabis use is one of the key mental health concerns that can be addressed in the program, which helps participants explore their relationship with substances in a safe, non-judgmental environment.
Learn more about the My Path program for young adults at https://ravensview.com/who-we-help/young-adults
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To view the full report as it appeared in The Globe's print edition Life beyond addiction