Thank you, Benedikt.
Honourable members, thanks for the opportunity to talk about the treatment of cannabis use disorder. By way of introduction, I am a clinician scientist working at the Centre for Addiction and Mental Health. I practise addiction medicine. I have done research on the impact of cannabis, doing studies on cannabis administration in human subjects as well as clinical trials studying a treatment approach for cannabis use disorder.
I would like to start by describing a variety of clinical presentations we can see. We can have subjects presenting with cannabis intoxication. The symptom may be euphoria, but it can be also tachycardia, impaired judgment, and psychiatric complications associated with intoxication. I'm talking here primarily of physiological symptoms and psychosis symptoms.
There is no overdose associated with cannabis, so it's much less risky than opioids, which can lead to death.
There are also a clear symptoms that can occur when a subject discontinues exposure to cannabis after regular prolonged use. There is a typical cannabis withdrawal syndrome. It presents with anxiety, dysphoria, sleep disturbance, irritability, anorexia. Cannabis withdrawal can be distressing, but it's not life threatening. Even so, we know that withdrawal symptoms make cannabis cessation more challenging and that these symptoms are associated with a higher risk of relapse.
The main challenge is the loss of control over the use of cannabis. This can develop in a fraction of users and can result in an addiction problem. Currently in the field, we are defining this as cannabis use disorder. Cannabis use disorder is characterized by a pattern of cannabis use that causes clinically significant distress or social impairment resulting in negative consequences such as the inability to stop using.
Previously the field was using the terminology of “abuse” and “dependence”, with dependence being the most serious form of addiction. The research based on epidemiological surveys clearly indicates that 7% to 9% of those who use cannabis during their lifetime will develop a dependence at some point in their lives. There is a fraction of people who will lose control of their use and will develop cannabis use disorder. It is estimated that the fraction is 30% to 40%.
It is important to realize that those numbers are lifetime numbers, which means that you have subjects who will experience problematic cannabis use only for a restricted period of time in their lives and who will get over this kind of problematic use without necessarily requiring specialized treatment. This is currently seen as a growing problem, however, because we see more and more people coming to addiction treatment who require treatment for cannabis use disorder or who have addictions associated with cannabis.
I would like to make it clear that at this point the number of subjects coming for addiction treatment with cannabis use disorder as the main reason is very small compared with the number of subjects who seek treatment for alcohol or opioid addiction.
Treatment of cannabis use disorder can be performed in an out-patient setting, but sometimes patients can be treated as in-patients or in a residential setting, but usually that is more for the subjects who have concurrent psychiatric or polysubstance use. It is recommended that the treatment provider evaluate precisely the treatment goals of the patient and understand that these goals may vary greatly. Some subjects may want to be completely abstinent; others may want to reduce their level of use or avoid risky use.