The Brain’s Response to Rewards Linked to Pain Sensitivity, Study Says

The Brain’s Response to Rewards Linked to Pain Sensitivity, Study Says

By Staff

The patterns of the brain’s responses to rewards can predict pain symptoms and may be influenced by genes that affect pain sensitivity, says a study PAIN®.

German researchers say the “distributed” feedback patterns to rewards predict heightened pain sensitivity.

“Our results might provide a first step early in life in identifying possible risk factors for future pain complaints,” according lead author Frauke Nees, PhD, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.

More than 600 European adolescents aged 14-15 were studied two times – once for the initial study, and a second time two years later.  The teens earn rewards in the form of M&M candies when they performed a computer task.  Functional magnetic resonance imaging (fMRI) scans were performed to examine how the brain processed these rewards. Two years later, the teens were evaluated on a commonly used pain symptom scale.

Patterns of reward processing at age 14-15 were evaluated as predictors of pain complaints at age 16-17.  The study also examined the effects of two variants of the mu-opioid receptor gene (OPRM1) that have previously been linked to differences in pain processing.  These genetic variants may affect not only responses to opioids but also the body’s natural or “endogenous” opioids (such as endorphins).

The results showed that reward-related feedback responses in a brain area called the dorsal striatum at age 14-15 predicted the magnitude of pain symptoms at age 16-17.  Whereas responses in another brain area called the ventral striatum have been linked to reward processes, the dorsal striatum has been implicated in planning, motor (movement) processing, and habit learning.

For one of the two OPRM1 variants studied, pain complaints were predicted by reward feedback-related responses in a more widely distributed brain area, including the ventral striatum. Teens with this genetic variant had a higher magnitude of pain responses.

Pain and rewards are considered “opponent yet interacting processes” involving partly similar brain regions. Identifying brain responses to rewards and their association with pain symptoms may help in understanding the neurological basis of pain-related behaviors and lend new insights into the brain areas involved in the critical transition from acute to chronic pain.

Within the limitations of the experimental study–limited to healthy children without any clinical pain problems — the results suggest that “aversive” outcomes such as pain may be related to “appetitive” reward outcomes. “Distributed brain response patterns during reward processing may be significant predictors for pain complaints, partly depending on an opioidergic genetic predisposition,” Dr. Nees and colleagues conclude.

In an accompanying commentary, Dr. David Borsook of Boston Children’s Hospital highlights some important questions raised by the new results, including whether an individual’s “opioidergic tone” is a real indicator of pain susceptibility and risk of developing chronic pain. While further studies will be needed, he writes, “The door has been opened for an intriguing process that may have a significant influence on improving our approach to evaluating and treating patients with pain.”

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Authored by: Staff

There are 6 comments for this article
  1. Ben Geddin Wurse at 5:48 pm

    Current and future studies that may result in an action taken and said action does not include lifelong opioid medication to treat chronic pain sounds good. Current and future studies that result in action taken without opioid medication that CAN cause acute pain to resolve itself and not becoming chronic would be GREAT. Just hate the word study, it sounds like the future. Write your state politicians. Write your state medical board. Write your Governor. Write Congress. Write the President. Severe chronic pain has a tendency to NOT improve. Lives depend on current “rules” to be amended. Soon.

  2. Charlie at 5:47 pm

    Tim: The trademark is for the name of the publication, not the study. All journals’ names are trademarked. No conspiracy here.

  3. Tim Mason at 7:37 pm

    I accessed the Pain site. It is a site that sells text books and studies. Most looked to be peer reviewed. The referenced article above is a free one. Most require access by a professional or member of a research group.

  4. Tim Mason at 7:11 pm

    Sounds like some has been looking into Dr. Josef Mengele’s experiments during WWII.
    I think an interesting study would be to look at pain levels of circumcised males vs uncircumcised males for obvious reasons. No anesthesia is given during this procedure and the newborn is strapped to a specially made table to prevent thrashing from the intense pain. This pain is said to cause some learning disabilities in circumcised boys.
    The “reward feature” of this study is quite suspect in it’s intent.
    As Jean and Doug mentioned, chronic pain is the result of an identifiable pathology or organic disease. The pain is far removed from any reward mechanism we read about using mice and monkeys in addiction studies.
    Did anyone else notice the registered trademark symbol on the word PAIN? They have trademarked the study. This would indicate that some if not all of the data and means to get this data is proprietary information and is secret and protected by copyright laws.
    Was it peer reviewed?
    I am going to look into this further.

  5. Jean Price at 2:15 pm

    Hmmm…a little hard for me to figure out just what they were trying to find out! It would seem logical to me that the responses triggered from receiving rewards (i.e. feeling “good”) would involve the same chemical responses in the nervous system achueved from the good feeling of having your pain lessened…by any means! And it would also seem logical that people have varied capacities for their responses…just because we are all individuals…in every way! And we even have different motivators and triggers for achieving any good feelings! For instance, I find joy in watching a little lizard’s activities…while some others might not be interested at all…or even be repulsed or fearful of lizards!

    So what does this all mean as related to pain? Does it tell us some are more sensitive, some are less likely to have enough of the bodies’ own pain relieving chemical responses, or does it only tell us some may not view M&Ms as a reward?? Pain differs from its intensity…a heart attack’s pain is surely different than the pain of a badly cut finger! Yet if you’ve only had a cut finger, how do you perceive that pain? How does your body react? I think trying to find out the whys of pain is important…yet almost all medications are listed as having an UNKNOWN mechanism of how they work! So isn’t it more important to first just find WHAT does work for reducing pain…instead of finding out all the intricacies of the why first?! Especially when aging itself can affect all our body processes…not to mention that increased numbers of situations causing pain could potentially alter brain responses too…making this data not as helpful in the long run! Lots to think about…while millions are in pain!!

  6. Doug at 11:26 am

    But our ( the chronic pain community) battle still remains. Yes, the United States has the highest rate of opioid prescribing in the world and there has to be more than a single reason for this. Also, there does need to be both regulating and acceptance in opioid prescribing.
    Currently, the rate of people suffering from a disease or an injury that may cause chronic pain should be the major concern. Why do so many people in the United States suffer from pain related issues? While hereditary disease such as Cancer, Osteoarthritis and Fibromyalgia should be a major concern, My personal concern is pain caused by Trauma. This boils down to poorly treated work related injuries that cause future chronic pain issues.
    Far too many injuries that happen in the place of employment are what I have come to call, “Bandade & Back to Work Medicine”. Injuries that happen due to unsafe work environments, improper equipment/tools to preform duties, forced production minimums and lack of proper safty training programs contribute to a very extreme percentage of people in the United States who now have to use opioids to control pain.
    The Occupational Safety and Health Agency (OSHA) regulations are not enforced and lack enforcement in a lot of areas especially prevention and treatment of spinal related injuries. 1st. A spinal related injury should be diagnosed by a proper medical professional, not an Occupational Medicine Doctor paid by workman’s comp to only do minimal diagnoses. An X-ray only will determine if there is bone fractures or dislocation. They do not detect soft tissue or nerve related damage, and that’s what myself and so many of my peers suffer from today. These doctors are paid to Not find disk damage. They diagnose back injuries most of the time as muscle strains and bruised bones or cartilage, prescribe muscle relaxers, ibuprofen, small doses of opiates and physical therapy and send us home until therapist releases us to return to work. No MRI’S are given unless the worker is taken to the emergency room by an ambulance so the true extent of the injury is not known until months, or more to the point years after the injury. Long after the chronic pain condition we now have can be connected to the initial injury so the patients are left out on there own to now pay for something that was our employers fault.
    The issues in our government about opiates should not be the opioid medications themselves. It should be about preventing the need for opioids in the first place. My analogy is, “The Government is putting the Rubber on after she’s already Pregnant.”
    Safety and Prevention is the key to curbing the amount of prescription opiates used in our country. Nothing can be done about those of us who already are to the point of disability. But the federal government can prevent future developments of chronic pain caused by Trauma. So they need to leave our medical professionals alone to treat our ailments.