Effects of Cannabis on Stress Response: A Double-Blind Randomized Placebo-Controlled Crossover Trial (NCT05261321)

Approximately 50% of Canadians have used cannabis at least once in their lifetime. The vast majority of cannabis users report using cannabis to reduce stress. While there is some evidence to suggest that cannabis may impact the body’s stress regulation systems via the endocannabinoid system, there remains limited experimental evidence that cannabis does indeed reduce acute stress and the effects of cannabis on the brain during acute stress are not well understood. The current randomized control trial aims to examine the effects of oral cannabis (THC and THC+CBD vs placebo) on acute stress response in humans using a combination of functional Magnetic Resonance Imaging, psychoneuroimmunological assays, and subjective assessments. With stress dysregulation being a major risk factor for a range of physical and mental health disorders, and with stress reduction being a primary reason for cannabis use, the effects of cannabis on stress regulation may have significant public health implications.  

This study is occurring at the University of British Columbia. The study team includes Karina Thiessen (awardee), study qualified investigator Dr. Christian Schütz and co-investigators Dr. Alasdair Barr, Dr. Clare Beasley, and Reza Rafizadeh. Funding support includes research grant and student stipend funding from the Canadian Centre on Substance Use and Addiction, BC Mental Health and Substance Use Services, Brain Canada, and the Michael Smith Health Research BC-CIHR CANTRAIN Clinical Trials Training Platform Doctoral Studentship. 

End of Award Update – December 2024

Results

Once the study is complete, we hope that the results will provide important insights into how cannabis might be impacting people’s cognition and stress regulation system. By analyzing a combination of functional Magnetic Resonance Imaging (fMRI), saliva sample analysis, and participant reports, we will be able to assess how cannabis affects different brain regions, acute inflammatory responses, and people’s subjective experiences while experiencing an acute stressor under the influence of cannabis. Because so many people use cannabis, including for stress reduction, we are excited to look at the potential neuropharmacological effects of cannabis on stress in humans.  

Impact & Potential Influence

About half of Canadians over the age of 12 have tried cannabis. Many people report using cannabis to manage their mental health symptoms, including stress and anxiety. There is also interest in medical and research settings in the effects of cannabis on stress response, whether it be a positive or negative effect. However, there is not very much causal evidence of the effects of cannabis on stress in humans, and we hope that this study can contribute to the currently limited body of evidence on this topic to better inform people’s decision-making around cannabis use.  

Further, there have been substantial changes to cannabis research regulations in Canada in recent years. Our federal laws and policies have regulations around the study design, including eligibility criteria and cannabis products that can be used. This study is one of the first studies to be under the current regulatory system. By assessing the feasibility of the study, such as through our recruitment rates, and through study monitoring, we can pave the way for future experimental cannabis research under the relatively new regulatory system.  

Beyond the outcomes of this study, my experience in developing a clinical trial has led to some exciting opportunities that will have some broader impacts on health research. Last year, I had the opportunity to speak on cannabis research regulations on Clinical Trial BC’s AskUs webinar series with Dr. Jean Smart. I thoroughly enjoyed being a guest speaker and I hope that this helped any viewers that are involved in cannabis research to better navigate the regulatory space. Another result of my experience with cannabis research is my work with the UBC MATRIX-N (Multidisciplinary Alliance for Translational Research and Innovation in Neuropsychiatry) and the Canadian Academy of Addiction Psychiatry to enhance local and national capacity for clinical trials and translational research for psychiatric disorders.

Next Steps

Once data collection and analysis are complete, our knowledge mobilization activities will take a multi-pronged approach to target a range of knowledge users, including other researchers, clinical professionals, government, and public audiences. As is standard for clinical trials, we will submit a final report to Health Canada and plan to continue to attend Health Canada’s consultation meetings on cannabis research policies. Academic and clinical knowledge translation activities include presentations, workshops, and publication in a peer-reviewed scientific journal. We also plan to use findings from this study to inform the design and direction of future cannabis research. 

Useful Links

To learn about projects happening in the B.R.A.I.N. Lab, including this study, visit https://brainlab.med.ubc.ca/.