Thursday, 2 March 2017

Saying "no" to medical cannabis

A state politician just defected to another party because that party agreed to support his stance on medical marijuana (cannabis). The politician stated that it was a moral decision because he wanted to save kids’ lives. Even if he was supporting it for other reasons, medical cannabis falls way short on effectiveness of just about anything, and it certainly doesn’t save kids’ lives. There is a real need for politicians to be more scientific in their information gathering and appraisal. This will make it less likely for them to make untrue statements, and bad decisions based on those statements. Let’s look at the evidence for the true effectiveness of medical cannabis.

The evidence for medical cannabis is far from convincing (here). There have been many reviews performed and when it comes to the main reason for using it – pain – the effectiveness is not clear, with many studies showing no significant effect. In a review published in the BMJ in 2014, cannabis appeared to have little or no effect, the trials were often biased, and it was associated with significant adverse events. For cancer pain, they concluded:

the effectiveness of cannabinoids for the treatment of chronic cancer pain remains unclear, although any benefit is likely to be modest. The available evidence indicates a risk of potentially serious adverse effects, including alterations in perception, motor function, and cognitive function

For helping spasms in patients with multiple sclerosis, where it is often considered to be effective, they concluded:

the effectiveness of cannabinoids for the treatment of muscle spasticity or neuropathic pain in multiple sclerosis is unclear and any benefit is likely to be modest, while mild to moderate adverse events are common and long term safety has not been established

And for the nausea of chemotherapy, they found the evidence wanting, concluding:

Cannabinoids are thus not recommended as first line treatment for nausea in patients with cancer

There have been multiple Cochrane reviews of cannabis (cannabinoids) showing a lack of clinically important effects and often increased adverse events for use with rheumatoid arthritis (here), multiple sclerosis (here), dementia (here), fibromyalgia (here), nausea and vomiting for cancer chemotherapy (here), and HIV/AIDS (here).

There have been no studies testing the effect of medical cannabis on child mortality (“saving kids’ lives”).

The bottom line
Cannabis is not only NOT a lifesaving drug, it is not even a good pain killer and it has little or no health benefits for any other condition. The only thing it can reliably produce is adverse events. Politicians need to stop making decisions driven by their wishes or what sounds good; they should study the science.


  1. Considering pain has its origin in the brain, and that so much pain is idiopathic, and that other, organic pain is made worse by anticipation of the pain event, the studies may not be taking an totally holistic consideration. Pain is subjective, and if a sugar pill can for a time reduce the fear of pain, then pain can reduce and a better quality of life can be enjoyed. If medical MJ helps to relax a person than there is a benefit to the patient. I know it is the perception of many doctors and the medical community that chronic pain patients are looking for secondary gain and that a few sessions of CBT will rocket them right out of the pain-thinking, but it is not always the case. In fact, it is rarely the case. Doctors don't understand chronic pain. They do not want to understand it, because it is a drain on their time, but for those suffering with it, a reasonable response would be, let them try it. Chronic pain is very complex, especially if it has existed in a person for years, so any tool that can aid in the reduction of fear, coupled with new adaptive thinking, is worth a try. Most doctors don't think so until they find themselves like one Dr. House. He too feared his pain, and he was told by his well meaning (pain free) doctor friends to "suck it up." Those kind of blunt responses trigger suicides, and that's a fact.

  2. "Do you think it possible for a man who does not know how to measure when a multitude of others equally ignorant assure him that he is four cubits tall [426e] not to suppose this to be the fact about himself?” “Why no,” he said, “I don't think that.” “Then don't be harsh with them. For surely such fellows are the most charming spectacle in the world when they enact and amend such laws as we just now described and are perpetually expecting to find a way of putting an end to frauds in business and in the other matters of which I was speaking because they can't see that they are in very truth trying to cut off a Hydra's head.” [427a] Plato's Republic

    Plato is referring to those who are deluded and suppose themselves to be in truth statesmen because they are praised by the many. The modern democratically elected western politician is a reflection of the ignorant majority. Statecraft is a skill. Thanks for the post. I was unaware of the research on cannabis.

  3. If I had cancer and thought(!) MM did something, anything for me and without killing me, why not? So now ask me about my thoughts on the evidence of vaccines and climate change ;-)