Surprising Twist of Placebo Effect Revealed

A new study finds that patients who knowingly took a placebo, in combination with standard treatment, experience greater pain reduction than patients who receive standard treatment alone.

Researchers at Beth Israel Deaconess Medical Center (BIDMC; Boston, MA, USA) and Instituto Superior de Psicologia Aplicada (ISPA; Lisbon, Portugal) conducted a randomized controlled trial in 97 adults with persistent low back pain confirmed by a board-certified pain specialist. All patients were given a 15-minute explanation of the placebo effect. Half of them were then randomly allocated to a treatment as usual (TAU) group, in which patients were required to continue with their standard treatment.


The other half were allocated to an open-label placebo (OLP) group, in which alongside with standard treatment, patients were instructed to take one placebo pill twice daily. The pills were presented in a bottle clearly labeled "placebo pills” that stated the pills contained microcrystalline cellulose and no active medication. Pain severity was assessed on three scales scoring maximum pain, minimum pain, and usual pain, and a composite total pain score. In all, 83 adults completed the trial.

The results showed that patients in the TAU group experienced a 9% reduction in usual pain and a 16% reduction in maximum pain at the end of the three weeks; however, patients in the OLP group reported a 30% reduction in both usual and maximum pain, and a 29% decline in pain-related disability. The researchers suggest the results show that patients do not necessarily need to believe they are receiving an active medication in order for the placebo effect to arise. The study was published on October 13, 2016, in Pain.

“The benefit of being immersed in treatment - interacting with a physician or nurse, taking pills, all the rituals and symbols of our healthcare system; the body responds to that,” said senior author Professor Ted Kaptchuk, DAOM, director of the program for placebo studies at BIDMC. “You're never going to shrink a tumor or unclog an artery with placebo intervention; 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 trashcan. It has clinical meaning, it's statically significant, and it relieves patients. It's essential to what medicine means.”

The placebo -- Latin for 'I will please' -- effect is a phenomenon wherein about one third of those taking a sham drug for various complaints (including pain, headache, and seasickness) will experience relief from symptoms. The underlying mechanism remains mysterious, but the effect has been attributed to many things, such as regression to the mean, spontaneous improvement, reduction of stress, misdiagnosis in the first place, subject expectancy, classical conditioning, and more.

Related Links:
Beth Israel Deaconess Medical Center
Instituto Superior de Psicologia Aplicada