Medicinal Cannabis is a term that covers a broad range of products developed from the cannabis plant or the chemical compounds it produces, such as cannabinoids. These products are used for medical purposes to treat or relieve the symptoms of a variety of diseases, illnesses and injuries.
Cannabis contains over 400 individual compounds, including cannabinoids, terpenes and flavonoids. The two most commonly researched and used cannabinoids are:
Cannabinoids work by interacting with receptors found throughout the body and in the brain, in a system called the Endocannabinoid System (ECS). These compounds may work individually or together (in combination) to deliver the medical benefits that patients have reported from the use of Medicinal Cannabis, including the relief of pain, inflammation, anxiety and nausea, as well as in more complex ailments such as neuro-degenerative diseases. There is some evidence to suggest that the combination of these two cannabinoids (THC and CBD) when taken together along with the other compounds found in cannabis may work better (synergistically). This enhanced effect is called ‘the entourage effect’.
Different strains of cannabis plants contain different contents and ratios of CBD and THC, as well as the other compounds. The effectiveness of Medicinal Cannabis for any specific medical condition is likely to be influenced by the content and composition of compounds present in the cannabis plant. That is why the “ideal” Medicinal Cannabis product and/or dose is likely to vary for different medical conditions as well as for individual patients.
The endocannabinoid system is a complex cell-signalling system and is involved in normal brain function to control the activity of the nervous system (that is it has a neuromodulation function).
There are two main endocannabinoid receptors involved in the ECS; the CB1 receptors, found in the central nervous system (brain and spinal cord), and the CB2 receptors, mostly found in the peripheral nervous system (nerves outside the brain and spinal cord), especially in cells involved in the body’s immunity system.
The ECS is not completely understood, but it has important role in influencing sleep, mood, appetite, memory, reproduction, and fertility. It also has a role in regulating certain functions of the body that may influence medical conditions including; muscular conditions (osteoporosis, atherosclerosis, spinal cord injury etc.), mood and anxiety disorders, obesity and cardiovascular system function (including hypertension), and neurological conditions (Parkinson’s and Huntington’s disease).
Overall, the ECS functions to help maintain homeostasis (equilibrium or a stable internal environment) inside the body. When homeostasis is disrupted for example, by pain from an injury or an increase in body temperature from a fever, the body’s ECS is activated to maintain regular function.
The ECS exists and is active in your body even if you do not take Medicinal Cannabis, via the body’s production of its own cannabinoids, known as endocannabinoids. Endocannabinoids are produced on demand, when needed, and appear to bind with CB1 receptors in the spinal cord to relieve pain. They also may bind to CB2 receptors in the body’s’ immune cells to regulate inflammation, which is important in some autoimmune disorders.
Tetrahydrocannabinol (THC), is one of the main cannabinoids found in the cannabis plant and it is the compound that can provide the psychoactive effects. Once in the body, THC binds and interacts with both CB1 and CB2 to produce a wide range of effects on the mind and the body. For example, it may help to reduce pain and stimulate appetite, but it may also slow a person’s reaction time, which may impair driving and judgement, cause memory issues and increase anxiety in some people.
The other main cannabinoid found in the cannabis plant is cannabidiol (CBD). Unlike THC, CBD is a non-psychoactive cannabinoid and generally does not cause any negative side-effects.
CBD plays a large role in the endocannabinoid system, including enhancing natural levels of endocannabinoids by occupying certain enzymes.
Research is still being done to fully understand the actions of CBD on the ECS, however the current evidence suggests that CBD may help with pain, nausea and the relief of other symptoms related to cardiovascular diseases, cancer, musculoskeletal conditions, anxiety and depression.