What exactly is medical cannabis?
There’s no universal definition of ‘medical cannabis’, ‘medicinal cannabis’, or ‘cannabis used for medical purposes’ so these terms can mean different things to different people, or in different countries.
‘Medical cannabis’ usually refers to special preparations made in laboratories by pharmacists or scientists. Scientists are able to separate the components that make up cannabis and isolate the ‘cannabinoids’ that might help with some medical conditions, while reducing the other cannabinoids that make people high or don’t help. However for some people ‘medical cannabis’ can also refer to the use of the whole plant through smoking, vaping or eating.
Although Canada has provided legal access to medical marijuana since 1999, laws and regulations continue to change and develop. The latest set of regulations, the Access to Cannabis for Medicinal Purposes Regulations (ACMPR), were established on August 24, 2016. It allows for licensed producers to produce and sell cannabis products for medical use and allows individuals to grow their own cannabis for medical purposes.
Cannabis and Cannabinoids
- The main psychoactive chemical in cannabis that produces the intoxicating effects desired by recreational users is delta-9-tetrahydro-cannabinol (THC).
- Cannabis contains more than 500 other chemicals, including more than 100 compounds chemically related to THC, called cannabinoids.
- The human body produces cannabinoids that are similar to those found in the cannabis plant. The areas of the brain that influence pleasure, memory, thinking, concentration, movement, coordination and sensory and time perception are affected by these cannabinoids. THC is able to take advantage of this similarity and attach to cannabinoid receptors on neurons in these brain areas, activating them and consequently disrupting several mental and physical functions.
- Acting through the cannabinoid receptors, THC also activates the brain’s reward system, which includes parts of the brain that respond to healthy pleasurable behaviors like eating. THC is similar to other misused drugs in that it stimulates neurons in the reward system to release the signaling chemical dopamine at levels higher than occur naturally. This flood of dopamine contributes to the pleasurable effects that recreational cannabis users are looking for.
What conditions can medical cannabis help with?
The pharmaceutical preparations of medical cannabis have had mixed success with particular medical conditions:
- Patients with nausea, vomiting and loss of appetite from HIV or cancer have had some relief with cannabis.
- A pharmaceutical cannabis product known as Sativex is legal in some countries to treat spasticity in patients with Multiple Sclerosis.
- There is some evidence that Sativex has been used to treat people with chronic neuropathic pain.
- Tests using one particular cannabinoid, known as CBD, to treat seizures in certain types of epilepsy are currently underway but more research is needed.
- There are no studies that show cannabis cures cancer!