Cannabis Harm Reduction for Youth Living with Psychosis and Using Cannabis

Cannabis use can be more problematic for individuals who have experienced an episode of psychosis. Stephanie Coronado-Montoya, a PhD candidate in the Didier Jutras-Aswad laboratory, advocates for harm reduction as a means of helping people manage problematic cannabis use.

Through her review of over 11,400 scientific articles, Stephanie found that few cannabis-focused interventions existed for people with psychosis who wanted to reduce or prevent cannabis-related harms. Her national survey of patient preferences found two significant demands which emerged from the population: that interventions be short and technology-based.

The CHAMPS app responds to these demands (a mobile app containing a brief psychosocial intervention aiming to reduce cannabis-related harms in people with psychosis). To learn more about this initiative, please listen to the full episode and follow Stephanie on Instagram (@the.brain.diaries).


March 2023

Genetic Basis of Cannabis Use

Cannabis is one of the most widely used psychoactive substance worldwide. The increased risk of developing a cannabis use disorder has recently been associated with specific genetic variants. These findings have led to numerous studies focused on the characterization of the complex relationship between genetic background and cannabis use. In this context, the article entitled “Genetic basis of cannabis use: a systematic review” aims to summarize some of the current knowledge on the genetic determinants underlying cannabis use, identify genetic variants associated with increased risk of cannabis misuse and its related harms, and highlight the importance of further research to better understand the genetic susceptibilities associated with cannabis use.

One of the genes commonly identified among the results of genomic approaches is the CNR1 gene, which codes for the cannabinoid 1 receptor (CB1R). CB1R is highly expressed in the brain and it is the primary target of the euphoric compound found in cannabis, i.e., delta-9-tetrahydrocannabinol (THC). Studies have shown that certain variants of the CNR1 gene are associated with a greater inclination to consume cannabis, as well as increased sensitivity to the effects of THC. The same can be said about the AKT1 gene, which codes for a protein involved in the regulation of cell growth and survival. In addition, other genes that have been associated with cannabis use include the DRD2 gene, which codes for a dopamine receptor involved in reward and motivation, and the FAAH gene, which codes for an enzyme involved in the breakdown of cannabinoids in the body.

It is important to note that the genetic basis of cannabis use is complex, multifactorial and polygenic, and individual genetic variants probably have little effect on an individual’s propensity to consume. Interactions between specific genetic susceptibilities and environmental factors, such as peer pressure, product availability, and social norms, also play an important role in cannabis use and its related consequences. However, the study of genetic factors makes it possible to explain the mechanisms involved in the response to psychoactive substances, which in turn ensures the ability to identify susceptibility factors that could be used to prevent possible harm or optimize certain benefits. It is thus important to consider genetic factors in the response to different cannabis products, an effort that we are promoting in the laboratory by including different genomic approaches to experimental designs involving cannabinoid administration in humans. This approach will be implemented in our next projects that will start in the upcoming months. Stay tuned to our projects to learn more.


Hillmer A, Chawar C, Sanger S, D’Elia A, Butt M, Kapoor R, Kapczinski F, Thabane L, Samaan Z. Genetic basis of cannabis use: a systematic review. BMC Med Genomics. 2021 Aug 12;14(1):203. doi: 10.1186/s12920-021-01035-5. PMID: 34384432; PMCID: PMC8359088.


February 2023

The Decriminalization of Drugs in British Columbia: A Step in the Right Direction for People with Drug Addictions?

In British Columbia, since January 31st, 2023, it is no longer a criminal offence for adults to possess up to 2,5 grams of cocaine, methamphetamine and opioids. This change in legislation was made possible via an exemption from the Controlled Drugs and Substances Act granted by Health Canada. Drug decriminalization has been described as a critical step in British Columbia’s efforts to combat the harms associated with the misuse of several psychoactive substances, including opioids1,2. The three-year pilot project developed by the province is part of a movement to reduce the harms associated with drug use, including overdose deaths and the criminalization of people with substance use disorders3 . This would move drug use and possession from being a criminal offence to being treated as a public health issue.

For many people living with substance use disorder, decriminalization represents a significant shift in the way their situation is perceived and treated. Rather than being punished for their drug use, they would be able to access health and social services without fear of criminal charges. It would also have the potential to reduce the risk of overdose deaths by removing the fear of criminal charges for people showing early signs of overdose or for people being eyewitnesses to an overdose4.  People who use substances conveying a high-potential of misuse and overdose could access more easily life-saving interventions such as naloxone, seek treatment, support, and harm reduction services without fear of stigma or legal repercussions.

Nevertheless, the decriminalization of drugs in British Columbia, far from being a panacea for all drug-related problems in society, represents a significant step forward in addressing the harms associated with the criminalization of drug use, and is overall a positive development for people with substance use disorder5.


1. CCSA (Canadian Centre on Substance Use and Addiction). Decriminalization of Controlled Substances: Policy Brief 2018. [Internet]. 2018 [cited 2023 Feb 23]

2. Government of British Columbia. Decriminalization [Internet]. Government of British Columbia; [updated 2022 Nov 7; cited 2023 Feb 23].

3. CBC News. What you need to know about drugs in British Columbia [Internet]. CBC News; 2021 Oct 21 [cited 2023 Feb 23].

4. CBC News. ‘Toxic drug supply’: Why some experts say decriminalization is a key step to fighting the overdose crisis [Internet]. [place unknown]: CBC News; 2022 Feb 23 [cited 2023 Feb 23].

Drug Policy Alliance. Approaches to Decriminalization [Internet]. United Nations Office on Drugs and Crime; 2015 Feb [cited 2023 Feb 23].