During a trip to Canada earlier this year, I wasn’t quite sure what to expect. Having enacted the Cannabis Act in October 2018, which legalised cannabis use for adults across the country, would the usual calm, compassionate and balanced traits of your average Canadian have disappeared?

Was I going to be enveloped in a fug of vaguely sweet-smelling smoke as the population exercised its new freedom to openly use the drug?

In Canada, legal cannabis is distinguished by a colour-coded excise tax stamp. The drug impairs the ability to drive a vehicle or operate equipment, and there are serious criminal penalties for doing so. The legislation also incorporates strict penalties for selling or giving cannabis to anyone under the age of 19. But the new regime means that people with disabling long-term conditions for which there is no current evidence for the effectiveness of cannabis can use the drug without needing a prescription.

With a growing global attitude of laissez-faire towards cannabis beginning to crystallise, I thought it would be useful to look at where we stand when it comes to the legitimate medical use of the drug here and in the United Kingdom.

Limited evidence

Some initial tentative steps towards the medical prescribing of cannabis have occurred. Last month saw the publication of the NICE Guideline on Cannabis-based medicinal products NG144 in Britain. It approves the prescription of the drug Savitex for people with multiple sclerosis who experience spasticity. Nabilone is recommended for nausea and vomiting induced by chemotherapy. NICE noted limited evidence for using cannabis in severe treatment-resistant epilepsy but did not make a recommendation against its use by specialists – pending further research. For the rare childhood epilepsy syndromes Lennox-Gastaut and Dravet, there is published evidence of efficacy for cannabidiol.

Meanwhile, during the summer, Minister for Health Simon Harris signed legislation which will allow for the operation of the medical cannabis access programme here on a pilot basis for five years. “The purpose of this programme is to facilitate compassionate access to cannabis for medical reasons, where conventional treatment has failed,” he said. It allows a medical consultant to prescribe a listed cannabis-based treatment for a patient for the following medical conditions: spasticity associated with multiple sclerosis; intractable nausea and vomiting associated with chemotherapy; and severe, refractory (treatment-resistant) epilepsy.

So what is the difference between medicinal and recreational cannabis?

The primary active ingredient in cannabis is THC (tetrahydrocannabinol), which is responsible for the mood-altering effects of cannabis. But it also contains cannabidiol (CBD), a non-psychoactive compound. The effectiveness and safety of manufactured medicinal cannabis products depends on the balance of THC and CBD in each.

Misinformation

Earlier this year a group of concerned Irish doctors said Ireland is “sleepwalking” into the legalisation of cannabis on the back of a campaign of misinformation about the drug. The 20 doctors accept there is “limited evidence”, some products using cannabinoids have medical benefits for “a very small number of conditions” but say this has been “grossly distorted” to imply the entire plant can be considered a medicine.

Young people’s mental health is undoubtedly threatened by cannabis use.

Dr Brendan Kelly, professor of psychiatry at Trinity College Dublin, says “It is now exceedingly rare to meet a man with new-onset schizophrenia or a related disorder who was not smoking cannabis before he experienced symptoms.” And the US National Academy of Medicine, in a 2017 report, was firm in its conclusion that: “cannabis use is likely to increase the risk of developing schizophrenia and other psychoses; the higher the use, the greater the risk.”

I certainly wasn’t aware of a malaise of demotivation among the Canadian populace this summer. The aroma on the streets hadn’t changed. But it’s early days yet for a definitive assessment of the effects of legalising cannabis on Canucks.