The phrase “never underestimate the power of the placebo” is typically used as a snarky response to symptoms that seemingly improve from therapies that have shown to have no real biological effect. Yet now, investigators at Northwestern University’s Feinberg School of Medicine believe they can reliably predict which chronic pain patients will respond to a sugar placebo pill based on the patients' brain anatomy and psychological characteristics.
“Their brain is already tuned to respond,” explains senior study investigator A. Vania Apkarian, Ph.D., professor of physiology at Northwestern University Feinberg School of Medicine. “They have the appropriate psychology and biology that puts them in a cognitive state that as soon as you say, 'this may make your pain better,' their pain gets better.”
Findings from the new study were published recently in Nature Communications through an article titled “Brain and psychological determinants of placebo pill response in chronic pain patients.”
Amazingly, the authors noted that there is not even a need to fool the patients when giving them the placebo. “You can tell them, 'I'm giving you a drug that has no physiological effect, but your brain will respond to it,'” Dr. Apkarian remarks. “You don't need to hide it. There is biology behind the placebo response.”
In the current study, the Northwestern team looked at 63 chronic back pain patients that were randomized into two arms of the study. In one arm, subjects didn't know if they got the drug or the placebo. Researchers didn't study the people who got the real drug. The other study arm included people who came to the clinic but didn't get a placebo or drug. They were in the control group.
The individuals whose pain decreased as a result of the sugar pill had similar brain anatomy and psychological traits. The right side of their emotional brain was larger than the left, and they had a larger cortical sensory area than people who were not responsive to the placebo. The chronic pain placebo responders also were emotionally self-aware, sensitive to painful situations and mindful of their environment.
The investigators were excited by their findings and felt that there are a few key benefits from the study:
Prescribing non-active drugs rather than active drugs. “It's much better to give someone a non-active drug rather than an active drug and get the same result,” Dr. Apkarian says. “Most pharmacological treatments have long-term adverse effects or addictive properties. Placebo becomes as good an option for treatment as any drug we have on the market.”
Eliminating the placebo effect from drug trials. “Drug trials would need to recruit fewer people, and identifying the physiological effects would be much easier,” Dr. Apkarian adds. “You've taken away a big component of noise in the study.”
Reduced health care costs. A sugar pill prescription for chronic pain patients would result in vast cost savings for patients and the healthcare system.
“Clinicians who are treating chronic pain patients should seriously consider that some will get as good a response to a sugar pill as any other drug,” Dr. Apkarian concludes. “They should use it and see the outcome. This opens up a whole new field.”