What’s the difference between medicinal and recreational cannabis?
A doctor writes: There is evidence that cannabis preparations may be useful for treating some forms of pain
The medicinal use of cannabis has become increasingly common, as a number of states in the US and several countries in Europe have legalised possession and use for this purpose. Photograph: Reuters/Amir Cohen
Ireland is “sleepwalking” into the legalisation of cannabis on the back of a campaign of misinformation about the drug, according to doctors who have set up a new group to campaign against liberalisation. They say they are treating ever-growing numbers of patients suffering a range of side effects caused by 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.
How has medical advice around cannabis use changed in recent years?
The medicinal use of cannabis has become increasingly common, as a number of states in the US and several countries in Europe and South America have legalised possession and use for this purpose. In some places the crude cannabis plant is permitted to be used, while there are also some registered pharmaceutical preparations developed from the plant, such as Sativex.
A cannabis derivative, nabilone, is used to treat nausea and vomiting brought on by chemotherapy treatment in cancer patients. Cannabis has been shown to reduce the increased pressure in the eyeball that leads to glaucoma. Sativex, which contains two active cannabis derivatives, is an oral spray that has been shown to improve symptoms in MS patients with moderate to severe spasticity. There is evidence that cannabis preparations may be useful for treating some forms of pain. Cannabis is also used in the treatment of two rare forms of epilepsy.
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 will depend on the balance of THC and CBD in each.
How much cannabis use is considered damaging to your health?
In general the more cannabis you smoke, the greater the likelihood of harm. A 2017 National Academy of Medicine report stated: “Cannabis use is likely to increase the risk of developing schizophrenia and other psychoses; the higher the use, the greater the risk.”
What are the negative health impacts associated with cannabis use?
Short-term effects include: panic reactions, confusion and feelings of paranoia; nausea, headaches and reddened eyes; increased heart rate for up to three hours after smoking; and dizziness, with impaired concentration.
Over the long term, cannabis smoking damages lung function. Regular users may become apathetic and neglect their work and appearance. The decrease in concentration produced by cannabis can be dangerous when driving or operating heavy machinery. And there is no doubt that in susceptible individuals, it can precipitate a psychotic episode, and trigger the onset of schizophrenia.
Are there concerns around the potency of the drug?
Cannabis can be genetically engineered to make it stronger. “Skunk” has much greater potency compared with “weed” or “grass”. The fourth drug prevalence survey, recently published by the National Advisory Committee on Drugs and Alcohol, shows what type of cannabis people are using in Ireland. It found that almost 50 per cent of those who used cannabis in the last month reported using weed; 28 per cent used grass; 2 per cent herb; and 2 per cent had used skunk.
Is cannabis considered addictive?
Yes it is. About 10 per cent of users become dependent. Latest treatment figures from the Health Research Board show cannabis was the second most common drug of abuse, accounting for 25 per cent of cases treated in 2017.