Medicinal Cannabis – Is it Useful?
Anyone who has listened to those currently using cannabis as pain relief probably thinks that their arguments and stories are persuasive. However, there is no scientific evidence that medicinal cannabis has any benefits. That is the bottom line here I’m afraid.
In fairness studies into medicinal cannabis are quite rare (presumably because it’s illegal in most countries round the world), but the 2015 Penny Whiting-led study into Cannabinoids for Medical Use was substantial and found only moderate-quality evidence supporting the benefits of medicinal marijuana, and then only for certain conditions. The majority of other studies in medicinal marijuana are of lesser quality and therefore more likely to be biased and provide unreliable results.
Whiting and her colleagues analysed 79 randomised trials, the gold standard in medical research in which volunteers are randomly assigned to take a cannabis-related product or a placebo.
The studies evaluated cannabis’ ability to treat a range of symptoms including nausea from chemotherapy, multiple sclerosis muscle spasms, anxiety, depression, sleep disorders, loss of appetite among HIV patients and Tourette syndrome. Most of the studies showed improvements among the participants taking the cannabinoid products over those using placebo, but in many, the scientists admitted that they could not be sure that the effect wasn’t simply due to chance because the association was so insignificant.
The strongest trials supported cannabinoids’ ability to relieve chronic pain, but cannabinoids were connected to other adverse events such as nausea, vomiting, dizziness, disorientation and hallucinations.
Another major problem is that cannabis is a psychoactive substance. This means that it affects the brain. Marijuana use affects co-ordination, time perception and memory. It also affects other parts of our body. It increases pulse rate, decreases blood pressure and increases appetite. The drug has a mild sedative effect but the experience very much depends on individual mood at the time it is taken. Every cannabis user knows how quickly a switch can be flicked to go from laughing out loud to crying uncontrollably.
Cannabis doesn’t produce physical dependency, but some people who use it regularly can become psychologically dependent on it. In high doses it can cause addiction, paranoia and psychosis and trigger schizophrenia.
Smoking particularly strong weed has been linked to nearly a quarter of new psychosis cases, and the risk of psychosis is three times higher for “skunk-like” weed smokers than non-smokers. And if that’s not enough cannabis smoke is just as dangerous as cigarette smoke in causing lung disease and driving while even mildly stoned is a no no.
There have been zero studies done on the long-term effects of cannabis and we still need to evaluate cannabis just like we evaluate every other medicine. The evidence so far is not promising as the side-effects are far greater than any benefits.
Cannabis will never be an ideal medicine for pain relief, not least because there are other more effective medications with fewer side-effects which can and should remain first-line agents in the management of pain.
Many of these other medications do not present risks to mental health and they still offer substantial benefits to people with chronic pain or enduring physical health problems. Even if legalised in the future, I will not be prescribing cannabis.