Conventional wisdom suggests that the placebo effect should only work if the patient believes they are taking a medication with an active ingredient, but the new study suggests that may not be the case.
“These findings turn our understanding of the placebo effect on its head,” said joint senior author Ted Kaptchuk, director of the Program for Placebo Studies and the Therapeutic Encounter at Beth Israel Deaconess Medical Center and an associate professor of medicine at Harvard Medical School. “This new research demonstrates that the placebo effect is not necessarily elicited by patients’ conscious expectation that they are getting an active medicine, as long thought. Taking a pill in the context of a patient-clinician relationship — even if you know it’s a placebo — is a ritual that changes symptoms and probably activates regions of the brain that modulate symptoms.”
For the study, researchers recruited 97 individuals with chronic low back pain and split them into two groups. Both groups watched a 15-minute video explaining the placebo effect, then one group continued their normal treatment, while the other group took daily placebo pills that were stored in a container marked “placebo pills” that clearly stated that they had no active ingredient. Both groups continued their specific treatment options for three weeks.
At the end of the three week period, patients in the placebo pill group reported 30 percent reductions in typical and maximum pain, while those in the treatment as usual group experienced 9 and 16 percent reductions respectively. Individuals in the placebo group also reported a 29 percent drop in pain-related disability, while those in the treatment as usual group did not report improvement in that measure.
“Our findings demonstrate the placebo effect can be elicited without deception,” said lead author, Claudia Carvalho, PhD. “Patients were interested in what would happen and enjoyed this novel approach to their pain. They felt empowered.”
However, Dr. Carvalho cautioned that the placebo effect may only provide mild relief for patients with undiagnosed chronic back pain, and that patients with specific conditions like herniated discs or pinched nerves will not experience similar results.
“You’re never going to shrink a tumor or unclog an artery with placebo intervention,” he said. “It’s not a cure-all, but it makes people feel better, for sure. Our lab is saying you can’t throw the placebo into the trash can. It has clinical meaning, it’s statically significant, and it relieves patients. It’s essential to what medicine means.”