People taking placebos experienced the same level of relief as those taking cannabinoid substances.
Since its use and consumption have been legalized in various parts of the world, marijuana has begun to be used more and more as an option to deal with intense pain ; however, a study reveals that many times the success of this therapy could be due to the placebo effect.
Researchers at the Karolinska Institutet in Sweden found that those taking placebos experienced the same level of pain relief as those taking active cannabinoid substances.
The study is based on an analysis of published clinical studies in which cannabis has been compared with placebo for the treatment of clinical pain. The change in pain intensity before and after treatment was the main outcome measure of the study.
Results of the study published in JAMA Network Open show that pain is rated as significantly less severe after placebo treatment, with a moderate to large effect.
“There is a distinct and clinically relevant placebo response in studies of cannabis for pain,” says the study’s first author, Filip Gedin, a postdoctoral researcher in the Department of Clinical Neuroscience at the Karolinska Institutet in Sweden.
The researchers also found no difference in pain reduction between cannabis and placebo, corroborating the results of another recently published meta-analysis.
The results come from a review of 20 clinical studies that examined the pain-relieving benefits of marijuana use, involving more than 1,500 people.
Media attention
The researchers say that even though marijuana has the same results as placebo, these studies receive significant media coverage regardless of the clinical outcome.
“We see that cannabis studies are often described in positive terms in the media, regardless of their results,” Gedin points out.
The researcher believes that this positive media attention can influence patient expectations and cause side effects.
“This is problematic and may influence expectations when it comes to the effects of cannabis therapy on pain. The greater the supposed benefit of a treatment, the more potential harm can be tolerated,” Gedin stated.