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An estimated one in four Americans suffers from chronic pain. For one in 10 of those sufferers, their pain is so intense, it impacts their ability to work or take part in other life activities, leaving them feeling isolated, anxious or depressed. It is also a health issue so challenging to manage, many are prone to substance use disorders.

In response, a pair of researchers at the University of Colorado Anschutz Medical Campus are part of a movement focused on rethinking the problem and its treatment approach. The two scientists believe there is an overlooked part in managing chronic pain: the brain itself.

"We don't want people to spend years—or decades—in pain, " said Yoni Ashar, Ph.D., assistant professor of internal medicine and co-director of the Pain Science Program at the CU School of Medicine. "The more people believe that they're stuck in their symptoms, the less motivated they will be to engage in any kind of active treatment. We need to change that paradigm."

Pain specialists are making great strides in diagnosing and working with patients, said Joseph Frank, MD, MPH, an associate professor of medicine and co-director of the Pain Science Program.

"What's exciting for me as a physician in this field is that there have been important advances in how we begin to more precisely diagnose the cause of a person's pain symptoms. We're also learning how we communicate that to them so they better understand why they hurt, " said Frank, who also works at the Rocky Mountain Regional VA Medical Center-Denver as part of its Chronic Pain and Wellness Center.

In the following Q&A, Ashar and Frank discuss how we define chronic pain, how it can grow into other conditions and whether chronic pain can exacerbate substance use disorders.

How do you define chronic pain? Where does it come from?

Frank: It's an umbrella term. Pain can come from a variety of different causes. This includes tissue damage such as an injury that resulted in a fracture or sprain, but also infections or inflammation. It becomes chronic pain when pain lasts beyond when an injury was expected to fully heal—typically at least three months.

For many people, the pain persists for longer than three months. We've seen patients with chronic pain that has lasted for years or decades, well after those structural changes have healed. We also see patients living with chronic pain who might not have those initial injuries.

Ashar: What we've been learning is that changes in the brain itself can be a major cause of chronic pain. Someone could have an injury, the injury could heal, but the pain persists because the brain's pain processing pathways have sensitized: the brain has learned the pain. It is living on the loop in these brain pathways after the injury is healed, creating a very real and deep memory of pain. That's what we think is often a major cause of chronic pain.

How can chronic pain lead to other health conditions?

Ashar: Chronic pain can cause fatigue, depression, and anxiety. Those can circle back and amplify pain as people become less active or more worried about their pain.

Frank: It is very common that chronic pain interferes with people's ability to do the things they want to do. People become less active, less connected with important people and activities in their lives.

When people start to lose meaning and purpose in their life because of their chronic pain—and become more focused on looking for ways to hurt less—that's when people are at risk of other chronic health conditions. It becomes a tough cycle to break. Our health care system can do a better job of helping them see those connections and find off-ramps to break those cycles.

Can chronic pain exacerbate substance use disorder?

Ashar: Yes, people will use substances to try and manage their pain, which can lead to substance use disorders. And, there can also be a third factor driving both chronic pain and substance use disorders: emotional dysregulation. When life feels unsafe and chaotic or relationships are conflicted, those factors will drive both pain and will drive substance use disorders. What do you think, Joe?

Frank: Yoni, I really like thinking about shared upstream causes. For many people, there's initially something good about substance use, providing a semblance of relief. However, that quickly leads to more and more negative impacts on health and relationships.

I'll say in terms of the treatment of chronic pain, it is challenging when a person has dutifully participated with all the treatment options that have been recommended by their health care team and continues to hurt. At that point, they may look for something that might appear to be more helpful. "I'm not getting better, so I'm going to see if alcohol or other substances can offer some short-term relief."

If we had a highly effective and reliable treatment for chronic pain, we'd likely see less of this thinking.