Cannabis Act needs update to limit legal THC concentration

It’s a Saturday in August. I’m just back from a restful vacation, where I had the opportunity to immerse myself in the good things in life: family, friends, and nature. I am on call in a psychiatric Emergency Department (ED) in a large Canadian city. These on-calls are an open window into the suffering of people and families struggling with mental health issues. The first patient I meet is Johnathan, a 22-year-old man who has been living in Canada for about eight months. He was brought to the ER by his sister, who found him in his room in a dissociated, paranoid state. He is afraid of being killed by his schoolmates, hasn't slept for days, hasn't gone out, and lies motionless in bed. He hears voices telling him to kill himself. Gabriella Gobbi is a psychiatrist, neuroscientist, and professor at McGill University. Photograph courtesy of Gabriella Gobbi Johnathan was attending college and working at night at his sister’s restaurant. Integration has not been easy; he’s often bullied for his introverted character and his accent. Jonathan started smoking cannabis to “solve his problems,” buying it at first in legal stores and smoking up to once a week, then two to three times a week, and finally two to three joints a day at 35 per cent THC. THC is the addictive ingredient of cannabis, triggering the “high.” More recently, he started vaping with THC at 85 per cent. After careful evaluation and assessment, I diagnosed him with acute psychosis. He will be admitted to the psychiatry ward where he will stay for several weeks. After Johnathan, I assessed 15 more patients, eight of whom had a problem directly or indirectly linked to cannabis, including patients with schizophrenia or bipolar disorders whose symptoms (i.e. psychosis or mania) were triggered and worsened by cannabis. The Canadian Cannabis Survey shows that 48 per cent of people who use “recreational” cannabis do so because of mental illness. They use “recreational cannabis” in an attempt to relieve symptoms associated with depression, anxiety and other mental distress. Some studies have demonstrated that short-term cannabis use can relieve anxiety and increase mood. However, chronic cannabis use, especially with high concentrations of THC, can also increase the risk of depression and suicide in young people, even those without a predisposition to mental illness. Moreover, many studies have also shown that cannabis aggravates the prognosis of schizophrenia and bipolar disorder, two severe mental disorders affecting around two to three per cent of the population. Cannabis users with a predisposition to schizophrenia or bipolar disorders tend to have more severe and more treatment-resistant symptoms, and the disorder manifests earlier. The concentration of THC in cannabis has increased exponentially in recent years: from three per cent THC (in Bob Marley's time) to 10 per cent in the early 2010s. The task force that studied the legalization of cannabis in 2017-18 had proposed 10 per cent as an upper limit of THC concentration, but when the Cannabis Act was passed, there were no imposed limits. In Canada you can now legally buy a joint at 35 per cent and vape at 80 per cent of THC. There is no evidence that THC has any therapeutic effect on mental disorders. On the contrary, a large corpus of research suggests that high concentrations of THC can trigger psychosis in healthy people and aggravate psychiatric symptoms in already ill people. In other words, the current regulatory framework is not sufficiently protecting our most vulnerable people and youth. Our laws need to be updated to reflect the growing evidence about the harmful effects of THC on mental disorders. First, limits should be put on the concentration of THC in the legal market, and the illegal market (still 50 per cent of cannabis sales in Canada) should be better controlled. The maximal concentration of 10 per cent, as initially suggested by the task force working on the Cannabis Act should be reconsidered. Second, the public should be better informed of the risks associated with the use of THC through educational campaigns, and people with mental health problems who self-medicate with cannabis should be encouraged consult a doctor who can help them to treat the underlying problem Third, we need a national strategy, outlining ways to monitor the effects of cannabis use on the mental health of Canadians. This could include recording the number of emergency room visits linked to the use of cannabis, testing people who visit the emergency for cannabinoids, and monitoring cannabis intoxication in children and adolescents. Other jurisdictions that have legalized cannabis (i.e. Colorado) have already done this, while in Canada, there is no strategy at all. Fourth, it is worth noting that one day of hospitalization in a psychiatric ward costs taxpayers about $5,000. A hospitalization to treat a patient with a psychosis or mania triggered by cannabis can last days or weeks. Canadians should be aware of these economic costs, as well as the long-term human cost for young people and the vulnerable population. Fifth, Canadian physicians need to be better trained about the medical consequences of cannabis, and education in cannabis detox and rehab programs needs to be ramped up. At present, there is no national and/or provincial co-ordination for the training of doctors, specialists, and health personnel. Current policy is inadequate in dealing with the on-the-ground reality. If we are serious about helping the many Canadians like Jonathan, evidence-based policies are urgently needed, now. Gabriella Gobbi, MD, PhD, is a psychiatrist, neuroscientist, and professor at McGill University. Based in Montreal, Que., she is the Canada Research Chair in Therapeutics for Mental Health. The Hill Times

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Cannabis Act needs update to limit legal THC concentration

Our laws need to be updated to reflect the growing evidence about the harmful effects of THC on mental disorders.

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