WEDNESDAY, Oct. 19, 2016 (HealthDay News) — Even if they know the pills are fake, chronic back pain sufferers may get relief from placebo drugs, a new study indicates.

Researchers found that patients who knowingly took a placebo pill while undergoing traditional treatment for lower back pain had less pain and disability than those who received traditional treatment alone.

"These findings turn our understanding of the placebo effect on its head," said Ted Kaptchuk, a joint senior author of the study and director of the Program in Placebo Studies and the Therapeutic Encounter at Beth Israel Deaconess Medical Center in Boston.

"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," Kaptchuk added in a hospital news release. "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."

Kaptchuk's team gave 97 patients with chronic low back pain a 15-minute explanation of the placebo effect. Most were already taking medications for their pain, including non-steroidal anti-inflammatories (NSAIDS). None was taking strong prescription painkillers known as opioids.

The patients were divided into two groups: those who only received traditional treatment and those who used traditional treatment along with a placebo pill. The dummy pills were provided in a bottle labeled "placebo pills," so it was clear they were a sham medication.

After three weeks, the placebo group experienced a 30 percent reduction in their usual and maximum pain levels. The traditional treatment group reported a 9 percent drop in their usual amount of pain and a 16 percent reduction in their maximum pain, the researchers said

Pain-related disability was essentially unchanged among those who only received the traditional treatment, while those who took the placebo pill experienced a 29 percent drop in disability.

"It's the benefit of being immersed in treatment: interacting with a physician or nurse, taking pills, all the rituals and symbols of our health care system," Kaptchuk said in the news release. "The body responds to that."

The study authors said people with other conditions that cause pain, fatigue, common digestive or urinary symptoms or depression may benefit from knowingly taking placebo pills.

"You're never going to shrink a tumor or unclog an artery with placebo intervention," Kaptchuk said. "It's not a cure-all, but it makes people feel better, for sure."

The researchers noted, however, that the effectiveness of placebo pills also hinges on a strong doctor-patient relationship.

"Patients were interested in what would happen and enjoyed this novel approach to their pain. They felt empowered," said study lead author Claudia Carvalho of the Instituto Superior de Psicologia Aplicada (ISPA) in Lisbon, Portugal. "Taking placebo pills to relieve symptoms without a warm and empathic relationship with a health-care provider probably would not work."

The study results were published Oct. 13 in the journal Pain.

More information

The U.S. National Center for Complementary and Integrative Health provides more information on the placebo effect.