Sweet Spot in Brain Responsible for Placebo-Related Reduction in Chronic Pain Found

Sweet Spot in Brain Responsible for Placebo-Related Reduction in Chronic Pain Found

by Staff

We’ve all heard of the “placebo effect,” but until now scientists had no idea where in the brain changes were occurring that result in people taking placebos experiencing reduced pain.

New research from Northwestern Medicine and the Rehabilitation Institute of Chicago (RIC) has pinpointed the “sweet spot” of the pain-killing placebo effect that scientists say, “Could result in the design of more personalized medicine for the 100 million Americans with chronic pain.”

The fMRI technology that was developed for the study has the potential to turning into individualized pain therapy based on an individual’s brain response to a drug.

So, where in the brain is this placebo effect happening?

The scientists discovered a unique brain region within the mid frontal gyrus that identifies placebo pill responders in one trial and can be validated (95 percent correct) in the placebo group of a second trial.

“Given the enormous societal toll of chronic pain, being able to predict placebo responders in a chronic pain population could both help the design of personalized medicine and enhance the success of clinical trials,” said Marwan Baliki, research scientist at RIC and an assistant professor of physical medicine and rehabilitation at Northwestern University Feinberg School of Medicine.

Baliki and Vania Apkarian, professor of physiology at Feinberg in whose lab the research was conducted, are both corresponding authors on the paper published in PLOS Biology.

“The new technology will allow physicians to see what part of the brain is activated during an individual’s pain and choose the specific drug to target this spot,” Apkarian said. “It also will provide more evidence-based measurements. Physicians will be able to measure how the patient’s pain region is affected by the drug.”

“Currently, placebo response is primarily studied in healthy subjects within controlled experimental settings. While such experiments aid understanding of the biological and behavioral underpinning of placebo response in experimental (applied) pain, they translate poorly to the clinic, where pain is mainly chronic in nature,” Baliki said.

In this study, scientists used functional magnetic resonance imaging (fMRI) combined with a standard clinical trial design to derive an unbiased brain-based neurological marker to predict analgesia associated with placebo treatment in patients with chronic knee osteoarthritis pain. Scientists showed placebo pill ingestion is associated with a strong analgesia effect, with more than half of the patients reporting significant pain relief.

“If future similar studies can further expand and eventually provide a brain-based predictive best-therapy option for individual patients, it would dramatically decrease unnecessary exposure of patients to ineffective therapies and decrease the duration and magnitude of pain suffering and opioid use,” Baliki and Apkarian said.

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Authored by: Staff

There are 3 comments for this article
  1. Tim Mason at 8:49 am

    I would assume the goal of this research would be to find to most effective placebo for pain relief. Here, the equation would be any complicated math problem in which the next to last reduction of the equation is to divide by Zero.
    Studies like this have no value when dealing with patients that have spinal and limb pathologies confirmed by X-ray, MRI and CT scans.

  2. Jean Price at 6:35 am

    Drug trials in general always allow for the placebo effect…even for blood pressure medication and antibiotics!! So it’s no wonder the placebo effect is part of pain control too…and bears further study to come up with something to stimulate that effect intentionally. However, it makes me wonder if ALL pain has the same area of placebo effect, or does knee pain versus back pain versus migraines, etc. involve a different area of the brain for the placebo effect. This would be an important issue, one to differentiate so a “one size fits all” approach wouldn’t fail some people. I wonder also if the effect is lessened when the patient’s KNOWS they are taking placebo…which in my mind would be important for an honest health care approach… and would also possibly reduce the chance of some mismanagement of the patient’s medications and lessen further stigmas! Many people will insist pain IS all in your head if placebos work! And that’s so far from the truth that it has to be addressed!

  3. Bob Schubring at 11:03 pm

    The Placebo Effect is one of distraction. Momentarily ignoring pain enables one to process other information that one ignored because of the pain. That’s interesting information, if understood in the proper context. What’s disturbing is that these “scientists” define success in terms of opioid use reduction. The proper measure is one of actual pain relieved.

    The irony is that fMRI technology affords a means of measuring the pain that patients experience. Measuring actual pain felt and actual pain relief, is useful for treating the particular patient who feels the pain.

    Dumbing the results down to something a political speechwriter might be smart enough to comprehend and lie about, is contributing more to the problem while subtracting from it’s solution.