Interview with Scientific Director, Dr. Bushnell
Researching Pain and Treatment Approaches
Balintfy: About a month ago, in episode 162 of NIH Research Radio, Margot Kern reported about opioid receptors. In her story, Dr. Jean Chin explained that most of us would recognize how opioid receptors affect people.
Chin: The runner’s high that you hear about. When people exercise they feel really good afterwards and that’s because of the release of endorphins, and endorphins actually bind to these opioid receptors.
Balintfy: Opioid receptors are also involved in pain: when endorphins are released, or if a medication like morphine or codeine is taken, a similar binding process happens and pain can be relieved. The difference, and problem is that people can get addicted to drugs like morphine and codeine. So I’m talking more about opioid receptors, but specifically regarding pain. I’m joined by Dr. Josephine Briggs, the director of the National Center for Complementary and Alternative Medicine at the NIH, and Dr. Catherine Bushnell, the scientific director at NCCAM. Starting with Dr. Bushnell, it seems pain is kind of a complicated thing because in a way, it’s subjective but there is a lot of science behind what we know about pain, isn’t there?
Bushnell: Well there is a lot of science. It is a subjective experience. There is at this point no clear objective measure for me to say you have pain or not. If you go to a doctor and you say you’re in pain, your verbal report is really the best measure we have. Now we, in our lab and other laboratories, we use human brain imaging to actually look at what’s happening in the brain when a person experiences pain and in a sense this can give us some objective measure, but it only can be validated by looking back at what the person’s perception is.
Briggs: That’s one of the reasons I’m so excited to have recruited Dr. Bushnell to come to the NIH is that we have here on the NIH campus really wonderful methods and tools to image the human brain. We have superb resources for studying the modern neuroscience of brain function, and so having her come to join us and bring her long history of leadership in pain research together with the resources here on this campus is really exciting for us.
Bushnell: Yes. It’s not only the fantastic physical resources, which they really are, but also the intellectual resources here are amazing for us to be able to establish this research program. Because through the various neurology, mental health, National Institute of Drug Abuse, all of these institutes have scientists that have very complementary expertise and interests.
Balintfy: And researchers are looking at both the physiological pain—looking to see physical changes in the brain—as well as non-pharmacological efforts, those ways that pain can be lessened without drugs. Is that right Dr. Bushnell?
Bushnell: That’s correct. We’re interested in both how pharmacological modulation how various pills that people take for pain, but also the non-pharmacological approaches that people use. People use yoga, they use meditation, they use exercise. There are many modalities that people are using to try to help control their pain and we’re trying to understand the mechanisms as well as the efficacy of these various techniques, and also how these complementary techniques can interact with pharmacological techniques. Because in fact when you use these non-pharmacological approaches, you actually can release chemicals in the brain that are very similar to chemicals that are involved in pharmacological treatments.
Briggs: That’s one of the things I’ve learned from Dr. Bushnell is that there’s really a scientific basis for the notion that relaxation techniques, meditation, yoga may actually change your brain processing of pain in very much the same way that opioids do. So that’s a pretty exciting way to complement the drugs. We all know that the pain medications have really troublesome side effects so being able to use the body’s own mechanisms to help with pain is very exciting.
Balintfy: What are some of those side effects of opiates, like morphine or codeine. Dr. Bushnell?
Bushnell: So when you take an opiate, you have opiate receptors all over your brain and other parts of your body. So some of the side effects like constipation are related to opiate receptors in the gut and many of the side effects like respiratory depression or some of the cognitive effects those are avoided if you use psychological techniques that release only specific opiates. I mean opiates into very specific receptors. So it’s kind of a nice way of being able to avoid some of the side effects, but get the therapeutic effect for pain.
Balintfy: And pain is something that not only is subjective, but it’s affecting people in a lot of different ways. For example chronic pain. Do you have some statistics in terms of how many people are affected? Dr. Briggs?
Briggs: The Institute of Medicine just completed a very thorough assessment of pain and pain research in the country. The numbers cited by the Institute of Medicine are that more than a hundred million people in the US are estimated to live with chronic pain. So the impact is really huge. The commonest complaint is chronic back pain and the portion of Americans who in their lifetime will have chronic back pain is huge. In fact, most people have chronic back pain at some point in their life. So learning more about management strategies that will help with this problem is really critical for the country.
Bushnell: And research is showing us that chronic pain goes beyond the pain itself. That when people have pain for many years, in fact it has detrimental effects on their brain. It can lead to some cognitive impairment that people can’t remember things as well as they did before and we find that when we look at the brain in fact it’s kind of like a premature aging of the brain that we see with somebody who has chronic pain.
Balintfy: Those sound like troubling findings and I’m sure there’s lots of misconceptions about pain as well. For example, I may think that the pain is in my back, but it’s actually in my head.
Bushnell: You’re right. All pain is ultimately in your head and it’s interesting because some pain it’s very obvious where it’s coming from if you’ve smashed your foot in an accident and everybody feels sorry for you then because they see this horrible injury and you have pain. But many people have pain that you can’t see the injury and it has a problem socially that people they’re not believed and then they start doubting themselves even. More and more the chronic pain disorders that we’re finding with our aging population, neuropathic pain related to diabetes or even after cancer treatments people can have nerve damage that leads to chronic pain that you can’t see the origin of. So it’s a social problem as well as a medical problem.
Balintfy: Are there resources available for people to look into regarding pain management? Dr. Briggs?
Briggs: Well we have on our website a variety of resources available to the public to help them understand some of the strategies for non-pharmacologic management of pain. The National Institute of Drug Abuse also has a lot of resources. So the NIH does a lot of work to develop strong resources for the public. One of the things that we’re proud of right now is a video that we recently developed, which shows several of or investigators who are studying yoga and one of them is an investigator George Salem who studies the mechanics, how yoga postures affect the body. And is an investigator Karen Sherman who is an investigator in Washington State and she’s done some studies on yoga for chronic back pain. But in this video, we explained to people that they really should when they’re looking for help with this kind of condition first of all talk to their primary care doc, but also really listen to their bodies when they’re doing yoga and also look for an instructor who will be attentive to their personal needs. Many yoga instructors have become quite expert at helping people find the right postures for them and we find that in a number of healthcare settings people are incorporating, offering yoga classes by instructors who are experienced at working with people with pain conditions. But making sure that the approach is gentle and appropriate to you is very important.
Bushnell: I guess another technique that NIH has investigated is tai chi as a more gentle form of exercise that frequently can be used with chronic pain patients and older patients.
Briggs: Now I want to interject one interesting thing about Dr. Bushnell. Dr. Bushnell is also a rock climber and so—
Briggs: And she describes when she talks about pain the experience of clamoring up this cliff and stubbing your toe and how when you’re up there in this terrifying situation you don’t notice the pain of stubbing your toe. It’s of course one of the interesting things about pain is that you can get distracted from pain by the circumstances you’re in. But Dr. Bushnell can talk about that—
Bushnell: Well we’ve been looking at the brain mechanisms and something so simple as distraction we find there are powerful mechanisms in the brain that lead to pain reduction that can be comparable to giving somebody a clinical dose of morphine and just by learning to distract one’s self from pain. So I think these are things that can be incorporated into people’s everyday life and I think it’s something that healthcare professionals need to be aware of. Because certain things like giving a patient a pain diary to fill out, well it’s useful to get that information to understand the nature of somebody’s pain, but if you have them thinking about their pain every hour of every day, then in fact you’re teaching them to focus on the pain. So I think it’s important for healthcare professionals and the general populace just to be aware of these simple factors can have such a profound effect.
Balintfy: Thanks to both Dr. Catherine Bushnell and Dr. Josephine Briggs, from the National Center for Complementary and Alternative Medicine here at the NIH. For more information about pain research and alternative medicine, visit www.nccam.nih.gov.