Scientists have shown for the first time that people with chronic lower back pain who knowingly take a placebo, or 'fake pills', along with traditional treatment see more improvement.
Conventional medical wisdom has long held that placebo effects depend on patients' belief they are getting pharmacologically active medication.
"These findings turn our understanding of the placebo effect on its head," said Ted Kaptchuk, an associate professor of medicine at Harvard Medical School in the US.
"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," said Kaptchuk.
"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," he said.
Researchers studied 97 patients with chronic lower back pain (cLBP), which causes more disability than any other medical condition worldwide.
All participants were screened and given a 15-minute explanation of the placebo effect. The group was then randomised into one of two groups; the treatment-as-usual (TAU) group or the open-label placebo (OLP) group.
The vast majority of participants in both groups (between 85 and 88 per cent) were already taking medications - mostly non-steroidal anti-inflammatories (NSAIDS) - for their pain.
Participants in both the TAU and OLP groups were allowed to continue taking these drugs, but were required not to change dosages or make any other major lifestyle changes, such as starting an exercise plan or new medication, which could impact their pain.
In addition, patients in the OLP group were given a medicine bottle labelled "placebo pills" with directions to take two capsules containing only microcrystalline cellulose and no active medication twice daily.
At the end of their three-week course of pills, the OLP group overall reported 30 per cent reductions in both usual pain and maximum pain, compared to 9 per cent and 16 per cent reductions, respectively, for the TAU group.
The group taking placebo pills also saw a 29 per cent drop in pain-related disability. Those receiving treatment as usual saw almost no improvement by that measure.
"Our findings demonstrate the placebo effect can be elicited without deception," said Claudia Carvalho, from Instituto Superior de Psicologia Aplicada (ISPA) in Portugal.
"Patients were interested in what would happen and enjoyed this novel approach to their pain," Carvalho said.
Kaptchuk speculates that other conditions with symptoms and complaints that are based on self-observation (like other kinds of pain, fatigue, depression, common digestive or urinary symptoms) may also be modulated by open-label treatment.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)