Good afternoon, honourable members of Parliament. Thank you for the invitation to address this committee on the important topic of medical cannabis and veterans' well-being.
At Queen's University, Kingston, I'm an associate professor of psychiatry and medical director of the early psychosis intervention program for southeastern Ontario. I also hold a cross-departmental position with the department of psychology, and hold accreditations in psychiatry and addictions.
My cannabis-related research explores knowledge, attitudes and perceived benefits of cannabis across different demographic groups; cannabis use and mental disorders, primarily psychosis, anxiety and PTSD; and the objective quantification of cannabis products. Against this backdrop, we're developing a cannabis consult clinic, applying current evidence to reducing the risk of harms in youth and young adults.
I've also been involved in a number of initiatives with the Canadian Armed Forces, Health Canada and health professionals toward better understanding of cannabis products and potential impacts on mental health in some individuals.
The military veterans and their families make incredible sacrifices through the course of their careers, and in some cases for many years after active duty. As a psychiatrist who has worked with a number of veterans and their families over the years, I'd like to acknowledge this sacrifice; health consequences in some cases being physical, psychological or both.
I support evidence-based and objective decision-making by informed adults for both medical and recreational use, while advocating minimizing the risk of harms in children, adolescents and young people.
While cannabis products have been consumed for medical purposes for centuries, the scientific evidence base supporting its use at the same level of rigour as medicines and pharmaceutical preparations is still in relative infancy. There's a growing body of evidence regarding medical effects of cannabis. However, considerably more research is required. Some of the current cannabis legislative frameworks serve to position Canada as a leader in this sphere. Likewise, the anecdotal reports of individuals consuming cannabis for symptom relief cannot be ignored, as history has taught us with the development of other medications.
For my presentation, I would like to present the framework around medical cannabis using three Ps: the patient, the physician and the plant as a pill. The patient, with individual idiosyncrasies, includes comorbidities, family impact and socio-economic factors that influence health or well-being. I will speak about physicians, their experience, knowledge and attitudes, and cannabis, a plant as a pill for medical use.
With regard to the patient, in my experience in working with veterans, I would like to make a few observations, perhaps stating the most obvious. Veterans with health issues sometimes struggle with adjustment and negotiating their new identity and roles outside the military, including children, parents, partners and peer support systems.
Veterans range from individuals in late adolescence to elderly members of our communities. With these age differences are also significant differences in physical brain maturity—below the age of 25, in some—and the mental impact of exposure to different substances and situations. Furthermore, different military may influence trauma exposure or re-exposure. This exposure and individual responses are not homogeneous.
For instance, PTSD, a mental disorder, has unique subjective and experiential components for each individual that cannot be generalized. This is also the case with pain and sleep symptoms. Individual distribution of endocannabinoid systems within the body also have an interplay with cannabis that is unique to each of us.
As a pill, there's no single cannabis, and reference of cannabis indicates a very broad and heterogeneous range of plant product with shared core components in different ratios. While we refer to THC and CBD, there are many others as well.
On standardization, while some licensed cannabis products such as gels have been developed to stringent standards, the quantification and standardization of other products, such as dried flower, are less exacting. For instance, there can be considerable difference in the composition of a smoked joint with different joint sizes, THC potency, THC-to-CBD ratios and terpene profiles. Some early findings from research I'm doing at the moment have identified close to a 65-fold difference in the THC milligram potency of some joints compared to others.
With respect to dosaging, several factors can have an effect on the dose of active cannabis product delivered to the body: potency, quantity consumed, route of consumption—whether it's smoked, ingested or topical application—and individual tolerance. Furthermore, with smoking, significant dose differences can be achieved with different inhalation methods, such as the mouth hold and the puff frequency, to mention two. In light of this, more research needs to be done to identify optimum doses or dosing regimes for individual disorders and consumption styles.
Turning to side effects, like many products consumed for medical purposes, cannabis can present a range of adverse or side effects. Some of these may be genetically determined, such as the risk of psychosis in some individuals, while others may show direct dose response effects. In addition, adverse effects may reflect the product ratios, and this needs to be studied in greater detail.
On drug interactions, a number of veterans received treatment for different health conditions that may or may not be directly related to military duty. For instance, an individual with PTSD, heart disease and respiratory difficulties may be on multiple medications, requiring specialists' interventions. Drug interactions can have an influence on the overall effectiveness of multiple health condition interventions when different substances are used with cannabis.
In terms of risk versus benefit, with each medical cannabis product, route of consumption and application require careful thought regarding the risk versus the benefits, and it's not uncommon for individuals to tolerate harmful effects because the benefits override.
The next P is the physician or health professional. Many, if not the majority of physicians, have had only limited exposure to military medicine. The limited awareness of military experience among physicians can present a therapeutic gap. In light of this, the veteran seeking help is faced with bridging this gap with a health professional. The development of medical curricula in military medicine or a faculty of veterans involved in medical education may serve to bridge this gap, and invariably the experience of care. In addition, physician experience with cannabinoids is also quite limited, with some historical bias from the days of having to say cannabis was bad for you.
Next, I'll speak to the inadequate evidence to support clinical confidence and the absence of drug identification numbers from cannabis products. The range of cannabinoids and their effects require considerably more medical education and training. With authorization, and the use of cannabis from a licensed producer, the patients and health professionals are better informed of the content produced, with a duty to monitor response and effects. The development of support of centrally funded centres of research excellence in veteran health could enhance this, such as the Canadian Institute for Military and Veteran Health Research, CIMVHR, and international collaborations.
I have some brief comments on the study topics. As the study topics are far-reaching, I will limit my comments to those within the scope of my knowledge and understanding.
As mentioned earlier, the number of grams, for instance, three grams of dried flower, presents a very broad and unstandardized range of THC potencies and THC-to-CBD ratios, allowing for individual differences in health conditions, metabolism and tolerance. While this may be considered heavy consumption for recreational use, there's a distinction with specific symptom reduction and medical use, and we need more research to understand this better.
Current research regarding the use for PTSD and chronic pain shows that with PTSD there's emerging evidence of benefit in some individuals; however, larger randomized controlled trials are lacking, and studies require more specific dosage and composition data. For instance, frequent use of high-potency THC cannabis in a younger veteran may trigger psychotic symptoms, or worsen mental health, particularly if there is a family history. Given these points, the evidence is inconclusive and should be considered on an individual basis for now.
With respect to access to health practitioners to obtain medical authorization, there's a dearth of health professionals with in-depth understanding of military or veterans' well-being to provide specific medical authorizations for cannabis. With regard to veterans, a specific training and accreditation program for physicians, in conjunction with relevant medical colleges, may serve to bridge this gap.
Turning to the effect of legalization of cannabis for recreational purposes on the use of medical cannabis for veterans, this presents both challenges and benefits to understanding the use of medical cannabis. Research into recreational use allows a much better understanding of the physiological response, dosage effects and side effects of cannabis on healthy individuals and across the health spectrum. This new knowledge will ultimately benefit medical cannabis science. With veterans, the potential consumption of both medical and recreational cannabis concurrently can pose challenges with dosing and monitoring.
Additional thoughts would be on the development of a national information registry and specific advisory information for the military, and sensitively designed and tailored information campaigns for military families.
In conclusion, these are my preliminary thoughts on the study topics, and I look forward to answering questions or clarifying any points made. Thank you for the opportunity to share them with you.