3. Cannabis and Mental Health

As discussed in the previous section, there is consistent evidence that links frequent, early onset cannabis use with negative effects, including mental health problems. And while there is no evidence at this time that cannabis causes mental illness, research shows that it is a risk factor for the development of psychosis,^[1]McInnis, O. & Porath-Waller, A. (2016). Clearing the Smoke On Cannabis: Chronic Use and Cognitive Functioning and Mental Health. The Canadian Centre on Substance Use. Retrieved from: http://www.ccdus.ca/Resource%20Library/CCSA-Chronic-Cannabis-Use-Effects-Report-2016-en.pdf especially if there is a personal or family history of psychosis, or cannabis is used frequently.^[2]Degenhardt, L., & Hall, W. (2007). The relationship between cannabis use and psychosis: epidemiological evidence and biological plausibility. Advances in Schizophrenia and Clinical Psychiatry, 3, 2–7. One study found that those who use cannabis regularly as adolescents have twice the risk of psychotic symptoms or of a schizophrenia diagnosis in adulthood compared to those who do not use it.^[3]Hall, W. (2015). What has research over the past two decades revealed about the adverse health effects of recreational cannabis use? Addiction, 110(1), 19–35. For young adults who have psychosis, ongoing cannabis use can worsen symptoms over the long term.^[4]Canadian Psychiatric Association. (2017). Implications of Cannabis Legalization on Youth and Young Adults. Retreived from: https://www.cpa-apc.org/wp-content/uploads/Cannabis-Academy-Position-Statement-ENG-FINAL-no-footers-web.pdf Recent research also found that high THC content in cannabis products is linked to a higher risk of developing psychotic symptoms.^[5]Di Forti, M., Marconi, A., Carra, E., Fraietta, S., Trotta, A., Bonomo, M.,& Stilo, S.A. (2015). Proportion of patients in south London with first-episode psychosis attributable to use of high potency cannabis: a case-control study. The Lancet Psychiatry, 2(3), 233–238. Some studies have suggested that cannabis may also increase the risk of anxiety and depression.^[6]Lev-Ran, S., Roerecke, M., Le Foll, B., George, T.P., McKenzie, K., & Rehm, J. (2014). The association between cannabis use and depression: a systematic review and meta-analysis of longitudinal studies. Psychological Medicine, 44(04), 797–810.

More research is needed to better understand the relationship between mental illness and cannabis use. In the meantime, there are essential components of a campus strategy to address cannabis use among post-secondary students. These components include education, health promotion, and harm reduction strategies that encourage reducing cannabis use and that increase access to community-based mental health and addictions supports.

Risk and protective factors

There are factors that could potentially increase the risks of problematic substance use, such as low self-esteem, stressful life events, and lack of connection to a community. These risk factors can result in negative health effects, including an increased risk of developing substance use problems.

Young people transitioning from secondary school to university or college face unique challenges that can affect their mental health, such as moving away from their social support structures, developing new routines and social networks, and adapting to independent life.^[7]Centre for Addiction and Mental Health. (2016). Transition-Age Youth Evidence Brief. Mental Health Promotion, Prevention, and Early Intervention through Campus Interventions and Integrated Service Centres. Retrieved from: http://eenet.ca/sites/default/files/TAYEnglish_EENetEvidenceBrief_Final.pdf As a result, these transitional-age youth, who are typically between 16- and 25-years-old, often need help to cope with the challenges they face during this period.

On the other hand, protective factors (such as education and supportive relationships) can have positive impacts on a person’s health and mitigate their risk of mental health problems. While the chart below is not a comprehensive list of risk and support factors, it provides an overview of the campus supports that can enhance these protective factors.

Figure 3: Risk Factors and Protective Factors that Impact Student Mental Health^[8]Adapted From: Public Safety Canada. (2018). School-Based Drug Abuse Prevention: Promising and Successful Programs. Retrieved from: https://www.publicsafety.gc.ca/cnt/rsrcs/pblctns/sclbsd-drgbs/index-en.aspx#ch01a