CNN
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Some people suffering from cancer and other chronic illnesses are turning to marijuana to relieve their pain, but much of that relief may come from simply believing it will help, a new study finds.
In research, the tendency to have a positive expectation that a virtual pill, surgery or treatment will help is known as the placebo effect.
“The placebo response accounted for 67% of the true cannabinoid-related pain relief,” said Karin Jansen, an associate professor at the Pain Neuroimaging Laboratory at the Karolinska Institutet in Stockholm and head of the research group.
“Factors such as patient expectations of relief may influence the analgesic efficacy associated with cannabis-based treatments,” Jensen said in an email.
Recent research results, Published in JAMA Network Open on November 28, echoing another large analysis of existing evidence in 2021 by the International Association for the Study of Pain.Based on these findings, the association issue a statement Against the use of marijuana for pain relief.
“There is currently insufficient high-quality human clinical evidence of safety and efficacy for the IASP to endorse the current widespread use of cannabis and cannabinoids for the treatment of pain,” the association said at the time.
For example, a 2020 study found that marijuana use prior to hospital admission Make pain significantly worse during recovery. people who use weed It also requires more anesthesia during surgery beforehand, and receiving anesthesia can be risky for some people, such as the elderly or those with chronic diseases such as diabetes. Cannabis users also require more opioids during recovery.
Another 2020 analysis of six randomized controlled trials involving nearly 1,500 cancer patients in the UK and Europe found No change in mean pain intensity Between people who use marijuana and those who take fake drugs. In this study, some marijuana users experienced side effects that were sometimes severe enough to lead to withdrawal from the study. Reported side effects include dizziness, nausea, vomiting, fatigue, and drowsiness.
“I think we make patients expect a certain outcome,” says Harriet DeWitt, a professor of psychiatry and behavioral sciences at the University of Chicago and an experimental psychologist who studies the placebo effect.
“No doubt there are people who will expect to be given active medications, and they will experience some of these positive result. The same goes for antidepressants.it is The same goes for painkillers,” said DeWitt, who was not involved in the new study on marijuana.
“It’s an interesting and very real phenomenon,” she added. “It’s certainly not ‘all in your head.'” However, there are brain circuits involved in generating these thoughts and expectations. ”
The placebo effect is First discovered in the late 1700s. It quickly became the basis for many of the dreaded treatments of the time, such as bleeding, blistering and leeching, to name a few Journal Articles from 1990.
“The immense power of placebos helps explain why physicians remain useful, respected, and respected members of society despite painful, repulsive, unscientific, and often dangerous treatments,” author, Charmane Eastman, founding director of Biorhythm Research, writes. Laboratory at Rush University Medical Center in Chicago.
In modern clinical trials, researchers typically give the drug being tested to half of the study participants, while so-called sugar pills are given to an equally matched group of people. Neither group should know which pill they received.if it is a double blind studyand even the researchers didn’t know which pill the participants swallowed.
But sometimes people can tell if a pill is producing an effect they might feel, such as a marijuana high. Even if they couldn’t tell, people believed they did get the experimental dose.
In fact, the optimism generated by the placebo was enough to significantly influence the study results.For example, the placebo effect can explain 50% to 75% Positive results found in trials of antidepressant drugs, According to a 2002 study.
In part to counteract this effect, scientists argue that the results of a study are only significant until chance is ruled out.
The new study examined 20 studies of the use of cannabis for pain management involving more than 1,450 people, aged 33 to 62. All studies were conducted as double-blind, placebo-controlled clinical trials — meaning that even the researchers didn’t know which study participants received cannabis or the sham treatment.
The researchers found no difference in self-reported pain reduction between the use of weed or a placebo in clinical trials: both showed large improvements in pain. There was also no difference in the length of treatment (45 days or months), and both showed improvement in pain.
In the most successful clinical trials that were blinded — where people didn’t know which treatment they were receiving — the placebo response was highest.Participants reported a moderate to significant reduction in their pain after receiving placebo compared to placebo before therapy.
A unique part of the study looked at the role of news and social media on the placebo effect in marijuana clinical trials, Jensen said.Researchers find positive media coverage after every cannabis clinical trial Experiment, even if the findings are less dramatic, she said.
“Active and widespread media attention may have influenced placebo response in subsequent clinical trials, but the current study was unable to address this possibility,” the study said.
More research is needed to understand if this placebo response formation is real Happened, Jensen said.
“It’s really hard to say where people are getting their information about what to expect from a drug,” DeWitt said. “I don’t think you can account for the placebo effect Or blame it on social media. But you could argue that’s where they’re expecting the drug to ease their pain – there’s a lot of social media saying cannabis is good for everything under the sun. ”