Imagine this scene…Your phone pings and it’s your older friend who’s a PhD in French literature, is still working, and always amuses you with her emoji and gif-filled messages. She tells you that she has some arthritic pain, is having some trouble sleeping, and that she doesn’t like the side effects of the medications her physician prescribed. She wants to try cannabis for her pain and sleep problems, but she doesn’t want to “get high” and asks if you know of a product she should try. You send her back a “thumbs up” emoji and a message that you’ll get back to her soon after you’ve done some research.
Hopefully, “doing research” means a lot more than asking a bud tender at a cannabis dispensary for a recommendation, polling friends to see what they use for pain and sleep, reading about some blogger’s experiences with cannabis, or reading the claims made by a cannabis company’s website.
We don’t want to burst any bubbles, but “doing research” is not that simple and for the average consumer it can take hours. It’s hard to vet what’s true and what’s not, especially when the science about cannabis is still emerging.
Many well-established cannabis companies hawk the curative powers of their products. The health claims are varied and wide-ranging; the problem is that the scientific evidence to support most claims in humans simply doesn’t exist. Theoretically, the claims might make sense based on chemistry or cell biology and this is an important first step, but it doesn’t tell us what’s actually happening inside our own bodies. Polling friends, asking bud tenders, and reading individual reviews on-line turns out to be an accumulation of anecdotes that might lead researchers to investigate something important but sadly, it does not advance the evidence and it’s a shaky foundation on which to give advice.
Given the fact that 91% of US adults say that marijuana should be available for medical and/or recreational use why hasn’t there been more research on this plant-drug??
The first thing to remember is that marijuana, which is any cannabis product with greater than 0.3% THC, remains Federally illegal. This is a huge barrier to cannabis research because it limits the availability of research funding. Plus, the Federal law impacts the type of cannabis that can be tested in humans and interferes with much needed large, multi-site investigations into the plant’s safety and effectiveness in humans. To date, most research done with humans uses synthetic, FDA approved products or a cannabis crop from one Federally approved source, not the plant-based cannabis that people are purchasing in dispensaries to help with health-related issues.
With this in mind, here’s a brief primer on scientific research and evidence, so that you can go beyond anecdotes and begin to better answer the cannabis questions you and/or your clients may have.
The highest level of evidence is a Systematic Review with or without a Meta-Analysis. The intent of a systematic review (SR) is to provide an exhaustive summary of the current evidence relevant to a clinical or medical question. In the case of your older friend, you might search for an SR that addresses the clinical question, “For people with arthritis pain does cannabis reduce pain?. If you find one, you would expect to see that the authors of the SR used a systematic method to gather up all the research papers on a given topic, in this case “arthritic pain and cannabis”. Typically, they would also provide a critical appraisal of each study’s quality, followed by a qualitative and/or quantitative synthesis. This process gives the authors the basis to explain how the research they reviewed did or didn’t answer their clinical question, discuss the overall strength of the evidence, and make recommendations for needed research based on observed gaps and unanswered questions. (By the way, we searched for a systematic review to answer the question, “For people with arthritis pain does cannabis reduce pain?” and couldn’t find one.)
When the authors of a systematic review (SR) combine data and apply statistical measures to determine the best aggregate answer to the clinical question it’s called a meta-analysis. Generally speaking, findings from a meta-analysis are a more precise estimate of treatment effect when compared to either an individual study or studies included in an SR.
When an SR or meta-analysis isn’t available, the next highest level of evidence we should turn to is a randomizedcontrolled clinical trial (RCT). Let’s unpack this together. Randomized means that the subjects who’ve agreed to participate in the research project are randomly assigned to either the treatment group or the control (placebo) group. Placebo controlled means that one group of subjects receives treatment that looks and feels exactly the same as the treatment group but it’s not real. In cannabis research this means that the treatment group would receive cannabis and the placebo group would receive something they believe to be cannabis but contains no active ingredients. The treatment and the control (placebo) groups would undergo the same tests and measures to evaluate cannabis’ effect. In this way, real comparisons can be made between the two groups. Did the cannabis intervention make a meaningful and significant difference compared to the group that had sham (aka fake or placebo) cannabis treatment? This is a type of question that can be answered by an RCT and can be very helpful when making clinical decisions, IF the people in the study are similar to our friend or patient of interest.
RCTs with a placebo are not the only types of studies that can shed light on the usefulness of cannabis for our 75-year-old friend with pain and sleep issues. When a placebo isn’t available, people can still be randomized to a treatment group that receives cannabis, or a control group that receives no treatment at all, but does undergo the same tests and measures as the treatment group. Ideally, there would be no significant differences between the groups in terms of age, sex, level of pain, and sleep problems, so that the researchers can compare “apples to apples”.
This type of study can be valuable because it controls for what happens over time AND the possibility that some people in the control group may have a reduction of symptoms simply because they are part of a study. So, significant differences between the groups can help to inform some clinical hypotheses and future research.
Sometimes, it’s hard to recruit people to join a study when they know that they might end up in a control or placebo group. If that’s the case, then scientists will modify the research design and conduct a pre-test/post-test clinical trial. This implies that the participants have NOT been randomized, and there is NO control group.
For example, in setting up a study to investigate cannabis in older people with arthritis pain and sleep problems, the researchers could identify a group of people like our friend. Everyone would be assessed at baseline, followed by a cannabis treatment for a pre-determined number of days and at pre-determined dosages. At the end of the defined period of time the same tests and measures would be done again to see if any significant changes occurred. This type of research is pretty common when it comes to investigating cannabis and results from these types of studies can help to move the science forward. The problem is that we only get to know that something changed before and after the treatment (in this case cannabis). We don’t have any idea if the element of time or doing nothing contributed to the change, nor do we know if an optimum dose or duration was administered.
When clinical trials aren’t available, but we want to know something about an intervention, a survey study can be consulted. A survey study about cannabis would typically include some information about the person answering the survey (demographics) and several questions about how, what, where and why the person is using cannabis. Hopefully the survey method was sound, and the researchers were able to recruit hundreds if not thousands of people to answer their questions. Once the survey closed and the gathered information was reviewed, the researchers would likely publish some descriptive statistics about the demographics (sex, age, city of residence, etc.) as well as summaries of the responses to their questions. Sometimes the researchers might apply some other statistics to the data to give us information about correlations.
When thinking about our friend, the results of a survey might give us some insight as to whether other people are using cannabis for pain and sleep and if so, has it been helpful? The challenge is that most surveys leave us still wondering about the type of product, the dose, possible adverse effects, etc. never mind the very real concern that some of our friends and clients will have health conditions, for which the effects of cannabis may be detrimental.
And now we find ourselves back where we started. How will you answer your friend’s question about cannabis for arthritic pain and sleep troubles? A place to start might be to read the descriptions or labels on a variety of cannabis products, or ask an experienced bud tender at a dispensary, or perhaps better yet, a pharmacist, but doing your own research shouldn’t stop there. Take the next step and search for any available scientific evidence (SR, meta-analysis, RCT, clinical trial) on cannabis for pain and sleep. That way, you’ll not only be able to include the state of the science in your conversations about cannabis with your friends and clients, you’ll also be able to support them as they make decisions about their own health and well-being.