Outdated Pain Models & The Rise of New Science on Chronic Pain

Yoni Ashar, Ph.D., Clinical Advisor at Lin Health

More than 50 million adults in the United States – more than 20% – suffer from chronic pain, and more than 19.6 million adults have pain that interferes with their lives more days than not. The estimated cost of chronic pain is $635 billion – more than heart disease and cancer combined – due to the number of days missed from work, treatment costs, and other factors. Chronic pain is the leading cause of disability, but the current pain treatment system isn’t working. This is because it hasn’t recognized the new science around chronic pain. After decades of trying a myriad of costly, largely ineffective approaches such as surgeries, injections, and pharmaceuticals, the pain care paradigm is shifting to consider the newest science, revolutionizing the pain treatment industry.

The Outdated Pain Model

Chronic pain is one of the leading causes of waste in terms of low-value medical care in the United States due to the current “kitchen sink” approach to pain. This idea of throwing everything at the pain – such as costly and ineffective surgeries and harmful pharmaceuticals – in hopes of curing it, yet more than 50 million people are still suffering from chronic pain.

Surgeries are a continuous part of treatment plans, despite clinical data that proves their ineffectiveness. In several studies, there was no significant difference in pain among patients who participated in surgeries and procedures from those who received the placebo treatment. In a study from the University of Oxford, patients with shoulder pain were given a decompression surgery to alleviate pressure and relieve pain, a fake surgery in which there was only an incision but nothing removed, and no treatment. The groups with the placebo surgery and real surgery both saw the same pain relief.

There are many more studies that showcase the results of these costly approaches, finding the benefits are not statistically significant compared to placebo treatments in research. This is in large part due to the effect hope and expectations can have on a person’s body. Patients had hope that they would see a difference because treatment was occurring, even from placebo groups, so the study found both groups that received treatment saw relief from pain.

Medications have also traditionally been a large component of the historical treatments of pain. Most notoriously, opioids rose to popularity in the late 1990s, unknowingly causing mass addiction to the drugs for pain relief reasons, and leading to the opioid epidemic. While opioids can help with pain temporarily, they can actually increase long-term pain sensitivity, known as opioid-induced hyperalgesia.

Despite studies like these, pain treatment hasn’t changed. That is, until now. The World Health Organization recently released its newest diagnostic code, ICD-11, which allows physicians to correctly diagnose chronic primary pain – pain that arises as a result of the brain’s overzealous pain signaling. Common chronic primary pain presentations include fibromyalgia, lower back pain, shoulder pain, migraines, irritable bowel syndrome, and many arthritic presentations. In primary pain, the pain itself is the problem; whereas in secondary chronic pain, the pain is secondary to – or caused by – a problem in the body. Understanding the underlying causes of chronic pain is key to treating it more effectively.

Finding the root of pain

It’s largely believed that chronic pain is due to a structural problem in the body and that surgeries and procedures are a key way to address the problem. However, while abnormalities, such as bulging discs, can cause pain in some cases, they’re often unrelated to pain. For example, a recent study found that anatomical findings are often present in pain-free populations: 87% of pain-free necks have bulging discs, 72% of pain-free shoulders have superior labral tears, and 97% of pain-free knees show abnormalities of some kind. These body characteristics don’t always dictate pain. Instead, there are a number of changes in the brain that can cause chronic pain.

Chronic pain engages a different set of brain circuits than acute pain. Northwestern University recruited a sample of people who had recently injured their backs. 12 weeks after their injury, the pain showed itself in the typical areas of the brain where pain is processed. After that point, half of the patients recovered, while the other half of patients went on to experience chronic pain one year later. In these patients, other areas of the brain were engaged. These engaged areas were areas where emotions are prominent. In this transition from acute to chronic pain, it shifted to the regions of the brain related to learning and meaning. This indicates that pain is a learned activity, causing the pain to persist independently of the pain input from the body.

The new science and life beyond pain

There are a large number of changes in the brain that can drive chronic pain, and not all chronic pain is alike. The WHO’s new diagnostic code is changing the way we treat chronic pain by differentiating primary chronic pain from all other types of pain, ensuring treatments can effectively treat the appropriate diagnosis of pain. Pain management solutions like Lin Health are relying on the latest science to provide a proper diagnosis to ensure pain is properly treated. In fact, my research in JAMA looked at pain reprocessing therapy (PRT) as a way to support that psychological treatment for chronic pain is effective with long-lasting relief. The study found that changing patients’ beliefs about the causes and threat value of pain may provide substantial and durable pain relief for people with chronic back pain. Two-thirds of chronic back pain patients were pain-free or nearly so after treatment, as compared to less than 20% of patients from the control group.

The traditional view has been that pain is a direct sensory readout of tissue damage, but there is a new model for viewing pain as a learning signal for guiding behavior. The chronic pain treatment industry is only just beginning to shift with this newest research. The more streamlined the industry can make treatment of pain, the more effective and cost-efficient it will be.

About Yoni Ashar, PhD
Yoni is a clinical advisor at Lin Health, a digital solution for chronic pain, he is also a clinical psychologist, neuroscientist, and father of three. Yoni’s research uses functional MRI brain imaging, natural language processing, and other tools to understand how mind and brain processes influence health and chronic pain. Yoni is an NIH-funded postdoctoral associate at Weill Cornell Medicine. He completed his doctorate at the University of Colorado Boulder. His research in chronic pain has been featured in several news outlets, including the Wall Street Journal, the Washington Post, and CBS.