TORONTO, September 18, 2019 – A first of its kind study led by the Centre for Addiction and Mental Health (CAMH) published in the journal JAMA Psychiatry has found elevated levels of a protein involved in immune function and associated with chronic stress and anxiety in the brain of young long-term cannabis users.
This study was funded by a grant from the U.S. National Institute of Mental Health.
“Cannabis is the most commonly used illicit drug in the world but we know very little about the impact it has on the brain, especially in young users whose brains are still developing until the age of 25,” said Dr. Romina Mizrahi, lead author and Senior Scientist at the CAMH Research Imaging Centre, and the Campbell Family Mental Health Research Institute. “These findings are an important step forward, but more studies are needed to better understand the role of cannabinoids and neuroimmune signaling.”
Using a Positron Emission Tomography (PET) tracer developed at CAMH, this is the first study to investigate whether there is an association between cannabis and neuroimmune function in the brain. Specifically, the study found elevated levels of a brain protein – called ‘TSPO’ – associated with higher levels of stress and anxiety in young long-term cannabis users compared to young non-cannabis users.
The study does not prove a link between long-term cannabis use and stress and anxiety because it is not yet known why there are elevated levels of TSPO in the brains of young cannabis users. Dr. Mizrahi says the next step in future research is to see if TSPO normalizes following cannabis abstinence, and if stress and anxiety levels also return to normal after young people stop using cannabis.
“We are hoping we can replicate and expand this finding to further evaluate if this biomarker goes back to normal levels after people abstain from cannabis use” said Dr. Mizrahi.
CAMH experts participated in the development of the Lower-Risk Cannabis Use Guidelines – an evidence-based tool that helps people understand the risks associated with cannabis use. CAMH’s Youth Engagement Team has worked to adapt the guidelines for young people and has created a pocket-sized guide for youth that uses a conversational tone to help explain the health and safety risks of cannabis and 10 recommendations to reduce these risks.
CAMH also offers treatment for cannabis use disorder. Information about CAMH services and programs is available by calling AccessCAMH at 416-535-8501, press 2.
For further information, or to arrange an interview, please contact Sean O'Malley, Media Relations, CAMH, 416-595-6015 or firstname.lastname@example.org
ABOUT THE CENTRE FOR ADDICTION AND MENTAL HEALTH
The Centre for Addiction and Mental Health (CAMH) is Canada's largest mental health and addiction teaching hospital and a world leading research centre in this field. CAMH combines clinical care, research, education, policy development and health promotion to help transform the lives of people affected by mental illness and addiction. CAMH is fully affiliated with the University of Toronto, and is a Pan American Health Organization/World Health Organization Collaborating Centre. For more information, please visit camh.ca or follow @CAMHnews on Twitter.