Placebo effect of CBD could boost pain-relieving benefits

A new study sheds light on the impact of the placebo effect and adds to the growing body of evidence suggesting that CBD could be effective for relieving pain.

While many CBD users tout the supplement as an effective pain killer, there has, up until recently, been limited human research on its efficacy.

A new study led by researchers at Syracuse University in New York has ‘shed light’ on the ability of CBD to reduce pain, along with the impact that the so-called placebo effect may have on pain outcomes.

Among other findings, the data showed that CBD and expectancies for receiving CBD do not appear to reduce pain intensity, but do make the pain feel less unpleasant.

The study was co-authored by Martin De Vita, a researcher in the psychology department at Syracuse University’s College of Arts and Sciences.

“For science and the public at large the question remained; is the pain relief that CBD users claim to experience due to pharmacological effects or placebo effects,” De Vita said.

“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.”

Having previously conducted the first systematic review and meta-analysis of experimental research examining the effects of cannabinoid drugs on pain, De Vita and Syracuse emeritus psychology professor, Stephen Maisto said they were “uniquely prepared” to answer this question.

Martin De Vita, co-author of the study

De Vita and Maisto developed advanced pain measurement protocols to carry out the study. The pair used equipment that safely induces experimental heat pain, which allowed them to measure how the recipient’s nervous system reacted and responded to it.

The scientists then administered either pure CBD or a placebo, and then re-assessed the participants’ pain responses.

Researchers took it a step further by manipulating the information given to participants about which substances they received.

In some cases, participants were told that they were administered CBD when they in fact received a placebo. Others were told that they would be getting a placebo when they were actually given CBD.

“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,” De Vita added.

“We hypothesised that we would primarily detect expectancy-induced placebo analgesia (pain relief). What we found though after measuring several different pain outcomes is that it is actually a little bit of both.

“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.”

According to De Vita, pain is a complex phenomenon with several dimensions that are influenced by both psychological and biological factors.

Pain intensity, for example, is a “sensory” dimension of pain, whereas the unpleasantness of that pain is regarded as an “affective” or emotional aspect 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,” said De Vita.

Results from his previous study showed that while cannabinoid drugs were not reducing the volume of pain, they were “changing the channel making it a little less unpleasant.”

According to De Vita: “We replicated that in this study and found that CBD and expectancies did not significantly reduce the volume of the pain, but they did make it less unpleasant – it didn’t bother them as much.

“We were going into this thinking we were going to primarily detect the expectancy-induced pain relief but what we found out was way more complex than that.”

Maisto added: “We’re still trying to figure out what is behind the differential data with different kinds of pain measures. 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.”