Cannabis Use Linked to Rising Anxiety, Depression & Suicidality in Canada

The increasing availability of cannabis in Canada since legalization in 2018 has coincided with a concerning rise in reported mental health challenges, particularly among young people. New research suggests these trends aren’t occurring in isolation, but are increasingly linked – a connection that warrants closer examination as cannabis becomes a more normalized part of Canadian life.

A Strengthening Connection: Cannabis Leverage and Mental Wellbeing

Researchers at McMaster University analyzed data from over 35,000 Canadians aged 15 and older, using data from two large, nationally representative Statistics Canada surveys spanning 2012 to 2022. The study, published in The Canadian Journal of Psychiatry on February 26, 2026, revealed a strengthening association between cannabis use and reported symptoms of anxiety and depression. Although the research doesn’t establish a direct cause-and-effect relationship, the findings highlight a growing public health issue.

The number of individuals reporting generalized anxiety disorder and major depressive episodes nearly doubled during the study period, rising to 5.2 percent and 7.6 percent, respectively. Notably, suicidality increased by 44 percent among youth – a particularly alarming trend. Alongside these increases, cannabis use also climbed, with the number of people using cannabis multiple times a week more than doubling, and 20.7 percent reporting cannabis use in the past year.

In 2022, Canadians who used cannabis regularly (two or more times a week) were approximately five times more likely to report symptoms of anxiety, depression, or suicidal thoughts compared to those who did not use cannabis. This suggests a significant correlation, though further research is needed to understand the underlying mechanisms.

The Role of Legalization and Potency

The timing of Canada’s cannabis legalization in 2018 is a crucial factor in understanding these trends. Legalization brought with it wider availability, increased marketing, and a greater variety of cannabis products. Research examining the period around legalization has noted a lack of evidence on the association between cannabis legalization and psychosis, but the current study adds to the growing body of evidence suggesting potential mental health impacts.

Today’s cannabis products often contain significantly higher levels of THC – the primary psychoactive compound – than those available in the past. This increased potency may have a different effect on the developing brains of adolescents and young adults, whose brains continue to develop into their mid-20s. The endocannabinoid system, which plays a role in regulating mood, stress, and memory, may be particularly vulnerable to disruption from regular, high-dose cannabis use.

Jillian Halladay, an assistant professor at McMaster University and researcher at the Peter Boris Centre for Addictions Research, explains, “We see that Canadians who use cannabis tend to be more likely to meet criteria for anxiety and depressive disorders, and more likely to report suicidality. We also see that this co-occurrence has strengthened over time.” This observation builds on previous research from the same team, which found a similar strengthening of the link between cannabis use and mental health problems between 2002 and 2012.

Adolescent Brain Development and Cannabis Use

Adolescence and young adulthood are critical periods for mental health development. Many anxiety and mood disorders emerge during these years, as the brain undergoes significant wiring and refinement, particularly in areas responsible for decision-making, emotional regulation, and impulse control. Mental health disorders can significantly impact life expectancy, highlighting the importance of early intervention and prevention.

Cannabis interacts with the brain’s endocannabinoid system, which is involved in regulating mood, stress, and memory. Regular cannabis use, especially at high doses, may disrupt these systems, potentially contributing to mental health challenges. Some young people may turn to cannabis to self-medicate for stress or sadness, but this short-term relief may mask underlying problems and delay seeking appropriate help.

Implications for Public Health and Guidelines

The researchers emphasize the need for earlier detection of cannabis use in mental health settings and advocate for routine screening. They also call for updates to Canada’s Lower Risk Cannabis Use Guidelines to reflect the strengthening associations observed in the data. These guidelines, designed to help Canadians minimize potential harms associated with cannabis use, may need to be revised to incorporate the latest evidence regarding mental health risks.

The authors stress the importance of recognizing the interplay between cannabis use and mental health. “It’s important for people to recognize when and how their cannabis use may be impacting their mental health and how their mental health may be influencing their cannabis use,” they wrote. “It’s also increasingly important for health and mental health providers to assess and address both cannabis use and mental health concerns together.”

What’s Next: Refining Guidance and Expanding Research

The findings from this study underscore the need for a comprehensive approach to cannabis policy and mental health care. Ongoing surveillance of cannabis use and mental health trends is crucial to monitor the evolving relationship between the two. Further research is needed to investigate the specific mechanisms by which cannabis may contribute to mental health problems, and to identify individuals who are most vulnerable to these effects. The Canadian government and public health agencies will likely review existing guidelines and consider implementing targeted prevention and intervention programs, particularly for young people. Recent studies have shown few changes in cannabis use pre-versus post-legalization among Canadians experiencing mental health conditions, but this new research suggests a more nuanced picture is emerging.

Individuals concerned about their cannabis use or mental health are encouraged to consult with a qualified healthcare professional. Resources are available through provincial and territorial mental health services, as well as national organizations dedicated to addiction and mental wellbeing.