Health & Wellbeing

Cannabis and pain: New findings on headaches add a piece to the puzzle

Cannabis and pain: New finding...
Why are there so many conflicting studies about whether cannabis is an effective painkiller?
Why are there so many conflicting studies about whether cannabis is an effective painkiller?
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Why are there so many conflicting studies about whether cannabis is an effective painkiller?
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Why are there so many conflicting studies about whether cannabis is an effective painkiller?

Despite long-standing anecdotal reports suggesting cannabis is an effective pain-relieving drug, the medical research community is still somewhat divided on the topic. A variety of studies in recent years have come to dramatically conflicting conclusions. New research from Washington State University is presenting evidence that cannabis can significantly reduce the severity of headaches and migraines. But the question still remains, why are scientists consistently coming up with such discordant results when trying to answer whether cannabis can reduce pain?

The new Washington State research focuses specifically on the effect of smoked cannabis on headache and migraine severity. Over one third of medical cannabis users report using the drug to treat headaches or migraines, however, there has been very little real-time study exploring the efficacy of the treatment. Outside of studies that rely on self-reported use in the past, there has only been one clinical trial, and that was exploring a synthetic cannabinoid’s effect on acute headaches.

“We were motivated to do this study because a substantial number of people say they use cannabis for headache and migraine, but surprisingly few studies had addressed the topic,” says Carrie Cuttler, lead author on the new study.

The novelty of the new research came from its analysis of data gathered by an app called Strainprint. This Canadian app was designed to offer personalized information for patients, enabling real-time tracking of medical symptoms against specific strains of cannabis. This means patients can report the severity of headaches, before and after cannabis use, offering scientists a useful way to follow the efficacy of cannabis as a medical treatment in real-time, and in relation to the varying THC or CBD levels from strain to strain.

“We wanted to approach this in an ecologically valid way, which is to look at actual patients using whole plant cannabis to medicate in their own homes and environments,” explains Cuttler. “These are also very big data, so we can more appropriately and accurately generalize to the greater population of patients using cannabis to manage these conditions.”

The study ultimately evaluated data from nearly 2000 medical cannabis users who reported up to 20,000 individual sessions using cannabis to treat headache or migraine. The results reveal nearly 90 percent of all recorded cannabis sessions reported reductions in headache or migraine severity. On average, the perceived reduction in headache and migraine severity was about 50 percent.

One of the more interesting findings in the study was that individual patients did seem to increase their cannabis use over time, which may indicate continual use can lead to the development of a tolerance to the drug.

Another finding of note is that efficacy of cannabis in treating headache or migraine did not vary according to the specific strain used, or the differences in THC and CBD volumes within specific strains. The researchers suggest this indicates a combination of the hundreds of phytocannabinoids in cannabis may play a role in its medical properties and medical cannabis users need not focus on THC or CBD levels to guide their strain selection.

Of course, the fundamental limitation of the study is one continually faced by medical cannabis researchers, and that is sampling bias. Those that use medical cannabis are most likely already sold on the perceived benefits of the drug. The researchers behind this new study are very aware of this problem and suggest one of the benefits of using data from the Strainprint app is that it was developed to identify which specific strains best treat certain symptoms. This means users are less likely to overestimate beneficial effects for a specific cannabis strain.

“I suspect there are some slight overestimates of effectiveness,” says Cuttler referring to the study’s overall conclusions. “My hope is that this research will motivate researchers to take on the difficult work of conducting placebo-controlled trials. In the meantime, this at least gives medical cannabis patients and their doctors a little more information about what they might expect from using cannabis to manage these conditions.”

Last year, a large Australian study published in the journal The Lancet found no evidence cannabis reduced general pain severity after tracking 1500 subjects for four years. One of the stranger anachronistic elements of the Australian study was the fact that although the adjusted longitudinal analyses of the data found no difference in pain severity between cannabis and non-cannabis users, the self-reporting of individual cannabis users suggested it was indeed effective for their pain.

What this oddly discordant result implies is that cannabis may not exactly work like the analgesic drugs modern medicine is currently accustomed to administering. The Australian researchers suggested the inconsistency in their results could be due to cannabis' effects on other lifestyle aspects, such as improving sleep, which subsequently improves well being.

The general idea that has been proposed is that cannabis doesn’t directly suppress or change the sensation of pain but instead improves aspects related to a person’s general well-being, allowing for pain to be better tolerated. This hypothesis would somewhat explain the inconsistent results of many studies trying to home in on the acutes pain-relieving effects of the drug.

Back in 2012 a team of researchers from the University of Oxford conducted a brain imaging study to investigate how THC influences a person’s brain when faced with an acute burning sensation. The participants reported the same pain severity scores, both with a THC dose and with a placebo.

But, when asked how much the pain bothered them, a significant difference in effect appeared. It seemed although the sensation of pain was similar with and without THC, when a subject was influenced by THC they simply cared less about the pain.

Even more fascinating was the fact the brain imaging data objectively back up these subjective reports. The research discovered the participants caring the least about the pain sensation displayed reduced activity in the anterior mid-cingulate cortex, an area of the brain previously implicated in regulating our emotional response to pain.

“Cannabis does not seem to act like a conventional pain medicine,” said Michael Lee in 2012, lead researcher on the Oxford study. “Some people respond really well, others not at all, or even poorly. Brain imaging shows little reduction in the brain regions that code for the sensation of pain, which is what we tend to see with drugs like opiates. Instead cannabis appears to mainly affect the emotional reaction to pain in a highly variable way.”

All this ultimately means is that our current tools for measuring subjective pain and evaluating the efficacy of analgesics may be profoundly limited. The extreme variability across cannabis pain research suggests the drug may confer highly specific pain-relieving effects, and subsequently be useful for some, but not all, types of chronic pain.

The new study was published in The Journal of Pain.

Source: Washington State University

8 comments
czechster
For over 100 years the US government lied, incarcerated, denied medical advancements, while pushing for they timber, chemical, and alcohol industry with their comical Reefer Madness propaganda newsreels and programs. Many scientist have been scorned for their serious research on naturally occurring medicines but out Government kept filling their pockets with lobbyist money. Science over politics please.
paul314
That description of divergence between pain level and how much people are bothered by pain would seem to track with other psychoactive pain medications: sure, the pain is still there, but you just don't care about it as much. Which in some cases is a perfectly acceptable effect.
Douglas E Knapp
I work with pain and if it is just regulating the amount people care about the pain and not the pain itself, then these result make perfect sense. Without any drugs there are people who are totally incapacitated by just a bit of pain and then those that don't care and even those that say, more pain please. I like the way it makes me feel. I would suggest that those that care the most about pain would also be those helped the most by this plant.
RangerJones
All these 'experiments and trials', blah blah. Pretty simple-Try it, if it helps take it, if it don't, don't. I have an 80 year old woman took fentanyl and vicodin as "prescribed". Was in a half trance all the time. Gave her some high grade weed to smoke-Pain gone, up and active. I created a pothead vs a drug addict. So sue me.
Wolf0579
I find this interesting. I'm a life-long pot smoker for recreational purposes. At 62, I was examined for visual field disturbances similar to those that accompany strokes. The doctors were convinced I was having migraine headaches and were puzzled that I had no pain symptoms to go with the visual symptoms. As well, looking back, I have had very, very few headaches over the years. Almost all of them associated with having a few too many glasses of wine the previous evening.
Grunchy
At Last - we finally have scientifically verifiable proof that as individual users increase use over time, that has nothing to do with drug habituation or addiction or any such imaginary effect, but only that people's resistance to the drug has increased and so they (quite logically) have to consume more to get the same effect. Lifelong users? Hardly. Anybody could quit any time they felt like it.
mystixa
"The novelty of the new research came from its analysis of data gathered by an app called Strainprint." Oh please. So potheads that are self-medicating report that their drug of choice is effective for what they already believe it to be effective on. ..thats almost the perfect case for placebo. Im not saying that weed doesn't work against pain. I'm saying low quality science utilizing apps to be cool damages credibility overall.
fen
This is pretty much horrible science. No double blind, no scientific method for gauging the pain, just asking people who are self medicating if they feel better after. The reason why they break it down into its active chemicals and then test them, is so they can do double blind tests, they can give one person the chemical, another a paracetamol, and the next a sugar tablet and if everyone says the chemical tablet works then it can start making claims. Every single time this has been done with pot, the results have been poor, but every time they ask people self medicating to report results the results are good. basically until double blinds prove that it works, then having a cup of tea works just as well.