SYRACUSE, N.Y. — Thanks to its supposed uses as everything from a stress reducer to a skincare treatment to a pain reliever, cannabidiol, or CBD, has exploded in popularity in recent years. According to some estimates, by 2024, the CBD industry may be valued at $20 billion. While customers praise its usefulness in pain reduction, there has been little experimental study on the drug’s real efficacy in humans. A recent study out of Syracuse University offers insight into CBD’s capacity to relieve pain, as well as the influence that the “placebo effect” could have on results.
The placebo effect, of course, is the idea that a product or drug that really doesn’t do anything at all to our bodies is still effective in convincing us that it does. Many users say CBD works wonders, while others say it’s useless — thus fueling the placebo effect theory.
So which is it?
“That’s a fair question because we know that simply telling someone that a substance has the ability to relieve their pain can actually cause robust changes in their pain sensitivity. These are called expectancy effects,” says Martin De Vita, a researcher in the psychology department at Syracuse’s College of Arts and Sciences, in a statement.
De Vita and co-author Stephen Maisto, research professor and professor emeritus of psychology, recently completed the very first comprehensive review and meta-analysis of experimental studies evaluating the effects of cannabis medicines on pain. They show that CBD, as well as the expectation of getting CBD, do not seem to lower the intensity of pain. Interestingly, however, they do help ease the uncomfortable feeling of pain.
For their research, the authors induced thermal pain on participants, which allowed them to evaluate how the recipient’s neurological system reacts to it. “Then we administer a drug, like pure CBD, or a placebo and then re-assess their pain responses and see how they change based on which substance was administered,” says De Vita.
The team then told some participants who took the placebo that they had received CBD, while others who’d actually taken CBD were told they were given the placebo.
“That way we could parse out whether it was the drug that relieved the pain, or whether it was the expectation that they had received the drug that reduced their pain,” explains De Vita. “We hypothesized that we would primarily detect expectancy-induced placebo analgesia (pain relief). What we found though after measuring several different pain outcomes is that it’s actually a little bit of both. That is, we found improvements in pain measures caused by the pharmacological effects of CBD and the psychological effects of just expecting that they had gotten CBD. It was pretty remarkable and surprising.”
“The data is exciting but pretty complex in that different pain measures responded differently to the drug effect, to the expectancy, or both the drug and expectancy combined — so we’re still trying to figure out what is behind the differential data with different kinds of pain measures,” adds Maisto. “The next step is studying the mechanisms underlying these findings and figuring out why giving instructions or CBD itself causes certain reactions to a pain stimulus.”
People usually consider pain to be an on-or-off button that some people have and some lack. However, as De Vita points out, pain is a multi-dimensional phenomenon impacted by both biological and psychological elements. Pain intensity, for example, denotes a “sensory” element of pain, whereas discomfort suggests an “effective,” or mental, element of pain. “If you think of pain as the noxious noise coming from a radio the volume can represent the intensity of the pain, while the station can represent the quality,” says De Vita.
His earlier research found that while cannabis medicines didn’t reduce the intensity of pain, they did “change the channel making it a little less unpleasant.”
“It’s not sunshine and rainbows pleasant, but something slightly less bothersome. We replicated that in this study and found that CBD and expectancies didn’t significantly reduce the volume of the pain, but they did make it less unpleasant–it didn’t bother them as much,” explains De Vita.
The source or type of CBD was also an essential factor in the experiment. “What we used in our study was pure CBD isolate oil,” says De Vita. “Commercially available CBD products differ in their content and purity, so results might be different for different CBD products, depending on what other compounds they may or may not contain.”
This study is published in Experimental and Clinical Psychopharmacology.