The Psychology of Back Pain

I've got a new article on the psychology of back pain in the February issue of Best Life (the one with Jeff Gordon on the cover):

I've put the entire article below the fold:

Dr. Marc Sopher, a family physician in Exeter, New Hampshire, is drenched in sweat. He's just run eight miles on a humid summer morning and played a game of tennis. (He's going for a bike ride later, after he sees his patients.) His short hair is salted with whiteâ¯Sopher is 46â¯but he has the taut body of a young athlete. Whenever he moves, you can see his muscles flex and twitch. He shakes my hand, ushers me into his office, and then excuses himself to take a shower.

When Dr. Sopher returns, he begins telling me the story of his back pain. "It began in my early thirties," he says. "I couldn't even sit down. I would get this throb in my lower back and then a sharp pain down one leg or the other. I was really in a pretty bad state." At first, Sopher tried to ignore the pain. He assumed that he had aggravated something in his back and waited for the aggravation to subside. "I'm a traditionally trained physician," he says, "so I started taking some anti-inflammatories, and then, when the pain wouldn't go away, I just tried to endure it. I honestly believed that I wouldn't be able to sit down again for the rest of my life."

Sopher no longer has back pain, but he wasn't healed by conventional medicine. He didn't undergo surgery, or get epidural injections, or take painkillers. Physical therapy didn't help. Instead, Sopher is one of the thousands of patients suffering from chronic back pain who got better by treating their mind. He learned to think differently about his pain, and that's when his pain went away. This narrative might sound suspiciousâ¯there's no shortage of phony treatments for chronic back painâ¯but it's supported by a growing body of scientific evidence. Chronic back pain is now predominately seen as a disease of the nervous system, not the spine; it's a problem suited for psychologists and neuroscientists, not surgeons. The best treatments are often the least invasive.

For Sopher, the road to recovery began with a book. It was Healing Back Pain, by Dr. John Sarno, a physician at NYU. "Once I started reading this book," Sopher says, "I couldn't stop. It was like a revelation. As the hours go by, I become aware that I've been sitting for a long period of time without any pain." While nothing had changed in Sopher's backâ¯it was still a mess of herniated discsâ¯he was learning how to think about his pain in a new way. "That's when I reminded myself that I'm a serious doctor, and that just reading a book isn't supposed to cure pain. But my pain was gone. That's when I decided to contact Dr. Sarno. I needed to learn how this is done."

The Rusk Institute of Rehabilitation Medicine lies on the eastern edge of Manhattan. It's a squat brick building overlooking the highway. Watching patients enter the Institute is a sobering experience. The full variety of human limps is on display. People hobble through the doors wearing cervical collars and shoulder slings and elaborate knee braces. They lean on canes and crutches. It's like a parade of pain.

Dr. John Sarno's office is hidden away on the ground floor. He keeps his door locked, even during office hours. When I first enter Sarno's waiting room, I wonder if I've mistakenly wandered into the closet. The room is musty, windowless and full of stacked cardboard boxes. A few crooked impressionist posters line the walls. There are no glossy magazines.

Sarno is eighty-five years oldâ¯he's been practicing medicine since 1950â¯but he still sees new patients three days a week. He talks slowly, with the pedantic patience of someone used to explaining his ideas.

"When I first started treating patients with back pain," Sarno says, "I practiced conventional medicine. I relied on all the usual tools, like injections and strengthening exercises. As the years passed, I grew very frustrated because I realized that all the conventional treatments were utterly useless. My patients weren't getting better. In fact, I was probably making them worse."

Sarno's failure caused him to question a fundamental assumption of modern medicine. In general, doctors assume that bodily pain is a response to bodily injury. Our back hurts because a disc is herniated or a nerve is pinched or a muscle is strained. The agony has a structural cause. Fix the structure and the agony goes away.

But Sarno began to doubt this explanation, at least when it came to chronic back pain. "Once I started thinking about it," he says, "the structural diagnosis stopped making sense. It couldn't explain a whole range of issues, like why these chronic pain patients never got better, or why they also suffered from a range of other illnesses." So Sarno started to search for another cause. If nothing was wrong with the body, then where did the pain come from? Why were healthy people hurting? That's when Sarno had his epiphany: chronic back pain was caused by the mind.

This theory, which Sarno has expounded in a series of popular books, has an alluring simplicity. He argues that much of our physical suffering is rooted in the machinations of the unconscious brain. Sometimes, when we repress our anger, deal with undue amounts of stress, or experience some upsetting emotion, the mind induces bodily pain as a form of distraction. It mischievously turns a minor physical incidentâ¯like lifting a heavy objectâ¯into a set of debilitating physical symptoms. Our back hurts so that we don't think about our emotional hurt. The suffering, of course, is yet another source of stress, which only makes the suffering worse. The pain becomes a downward spiral.

According to Sarno, the only way to cure chronic back pain is through rigorous psychological treatment, which seems to consist mainly of believing in Sarno's theories. Patients need to continually remind themselves that the pain, though real, is rooted in their own mind. (Sarno recommends that his patients read his lecture notes at least once a day.) Unless the patient unconditionally accepts Sarno's diagnosis, he or she won't get better. It is the faith that sets them free.

There is little scientific evidence for Sarno's theories. He hasn't published a medical paper in years. Sarno's notions of the unconscious mind are largely derived from Freud, and Freud isn't exactly cutting-edge science. One back pain specialist told me that, while he was sympathetic to Sarno's "psychological theme," he was troubled by his "penchant for constructing theories without the necessary foundation of facts." But the criticism doesn't concern Sarno. He's convinced that he's discovered something important about chronic back pain. As Sarno puts it, "My proof is that my patients get better. That's the only proof I need."

Sarno's clinical success shouldn't be dismissed as just another instance of the placebo effect. While there have been no independent studies of Dr. Sarno's success rate, the anecdotal evidence is certainly suggestive. Entering one of the numerous forums dedicated to Sarno on the Internet is like wandering into a Pentecostal revival meeting. New testimonials appear everyday, with people confessing that years of chronic pain ended as soon as they read one of Sarno's books. They tell stories of expensive surgeries that didn't help, and scary spinal diagnoses that couldn't be treated. And then, after years of suffering, they talk about how they stumbled upon Sarno, and how they were saved. (Howard Stern is a particularly devoted fan. He dedicated his memoir to Sarno, and frequently mentions Sarno's approach to back pain on his satellite radio show.)

In a 1999 investigative report on ABC News, reporter John Stossel randomly selected twenty of Sarno's former patients from his medical files. After tracking these people down, Stossel found that all twenty reported being "better or much better." Stossel himself was treated by Sarno after suffering for years from recurring bouts of lower back pain. "It's so embarrassing," Stossel said, "but after one lecture, Sarno cured me." Although his back still acts up, Stossel has learned to ignore the pain. "Instead of fixating on the pain, I just wait for it to go away, try to think about the stress or emotions that may have triggered it, and then the pain goes away," he says.

According to Stossel, he has gotten more positive comments about his Sarno report than anything else he's ever done. "All these years later, I still get people coming up to me on the street saying that they saw my piece on Sarno, and that it changed their life."

America is in the midst of a back pain epidemic. The numbers are sobering: there's a 70 percent chance that, at some point in your life, you'll suffer from severe back pain. There's a 30 percent chance that you've suffered from severe pain in the last thirty days. At any given time, about 1 percent of working age Americans are completely incapacitated by their "lower lumbar regions". Treating this chronic back pain is expensive (more than twenty-six billion dollars a year), and currently accounts for 2.5 percent of total health care spending. If worker compensation and disability payments are taken into account, the costs are far higher. "Unless you believe that something catastrophic has happened to the backs of Americans in the last few decades," Sarno says, "this epidemic is hard to explain."

The conventional medical treatment for back pain follows a predictable script. After the patient is interviewed and given a physical exam, he or she undergoes a series of diagnostic tests. This normally includes X-rays, CT-scans and MRI imaging. The end result is an astonishing array of detailed anatomical pictures. Doctors no longer need to imagine the layers of tissue underneath the skin. Now they can see everything.

Unfortunately, all this seeing has limited results. After undergoing the full range of diagnostic tests, 85 percent of patients suffering from lower back pain still don't receive a precise diagnosis. The pain can't be pinpointed; there are just too many moving parts. Instead, their suffering is parceled into a vague category, like a "lumbar strain" or "spinal instability".

But even when a patient is given a specific structural diagnosis, it's not clear how meaningful the diagnosis actually is. Look, for example, at herniated discs, one of the most common "causes" of back pain. A 1994 study published in The New England Journal of Medicine imaged the spinal regions of ninety-eight people with no back pain or any back related problems. The pictures were then sent to doctors who didn't know that the patients weren't in pain. The end result was disturbing: two-thirds of the pain-free patients exhibited "serious problems" like bulging, protruding or herniated discs. In 38 percent of patients, the MRI revealed multiple damaged discs.

The disconnect between "disc degeneration" and back pain increases with age: more than 80 percent of people over the age of 60 who don't have any back pain still demonstrate "significant disc degeneration". These structural spinal abnormalities are often used to justify expensive treatments like surgery, and yet nobody would advocate surgery for people without pain. In the latest clinical guidelines issued by the American College of Physicians and the American Pain Society, doctors were "strongly recommended...not to obtain imaging or other diagnostic tests in patients with nonspecific low back pain." In too many cases, the expensive tests proved worse than useless.

Despite these flawed diagnostic tests, about 90 percent of patients suffering from back pain get better within seven weeks. The body heals itself, the inflammation subsides, the nerve relaxes. These patients go back to work and pledge to avoid the sort of physical triggers that caused the pain in the first place.

But the remaining ten percent of patients don't get better. For these desperate people, there are no good medical options. The longer their pain persists, the less likely they are to ever recover. Chronic pain is the pain that won't go away.

From the perspective of the brain, there are two distinct types of pain. The first type of pain is sensory. When we stub our toe, pain receptors in the foot instantly react to the injury, and send an angry message to the somatosensory cortex, the part of the brain that deals with the body. This is the type of acute pain that doctors are trained to treat. The hurt has a clear bodily cause: if you inject an anesthetic (like novocaine) into the stubbed toe, the pain will quickly disappear.

The second pain pathway is a much more recent scientific discovery. It runs parallel to the sensory pathway, but isn't necessarily rooted in signals from the body. The breakthrough came when neurologists discovered a group of people who, after a brain injury, were no longer bothered by pain. They still felt the pain, and could accurately describe its location and intensity, but didn't seem to mind it at all. The agony wasn't agonizing.

This strange conditionâ¯it's known as pain asymboliaâ¯results from damage to a specific subset of brain areas, like the amygdala, insula and anterior cingulate cortex, that are involved in the processing of emotions. As a result, these people are missing the negative feelings that normally accompany our painful sensations. Their muted response to bodily injury demonstrates that it is our feelings about painâ¯and not the pain sensation itselfâ¯that make the experience of pain so awful. Take away the emotion and a stubbed toe isn't so bad.

Chronic pain is the opposite of pain asymbolia. It's what happens when our brain can't stop generating the negative emotions associated with painful sensations. These emotions can persist even in the absence of a painful stimulus, so that we feel an injury that isn't there. It's like having a permanently stubbed toe.

Doctors have traditionally focused on the bodily aspects of chronic pain. They assume that a healed body is a painless body. If a patient has chronic back pain, for example, then he is typically prescribed painkillers and surgery, so that the pain signals coming from his spinal nerves are stopped. But the dual pathways of pain mean that this approach only treats half of the pain equation. Unless you find a way to treat the emotional pathway, then the chronic pain will continue.

"The standard model of painâ¯the same model that is still taught in every medical schoolâ¯is that you treat the pain by fixing the underlying pathology," says Dr. Sean Mackey, a Professor at Stanford and Associate Director of the Pain Management Division. But the reality of pain, Mackey says, is much more complicated. "We're now beginning to recognize that you can't talk about chronic pain without talking about its psychological aspects. It's a condition in which signals from the body are literally distorted by the brain."

Mackey is at the forefront of a new paradigm in pain research. In many respects, he is an unlikely revolutionary. "My Ph.D was in electrical engineering," Mackey says. "Nobody was more mechanistic than I was. When I began treating patients, I was very interested in trying to identify the structural source of the pain. I'd do lots of injections, stuff like that. But what I found, much to my surprise, was that my patients were getting better more from my talking than from any medical procedure. I was intrigued by that, and so I started to look into the mechanisms of why talking to my patients might reduce the pain. That's what led me to study the brain, and not just the body."

Mackey's personal experience now has strong scientific support. In recent years, it has become clear that one of the most powerful ways to treat chronic back painâ¯or any pain, for that matterâ¯is by treating the mind. When patients are taught how to deal more effectively with the negative emotions that accompany chronic pain, they often experience dramatic improvements. The pain that wouldn't disappear is suddenly diminished. Psychological interventions can heal the hurt.

Robert Kerns has been studying the psychology of pain for thirty years. He's a Professor of Psychiatry at Yale University, and the National Program Director for Pain Management at the Veterans Health Administration. When Kerns was in graduate school, back in the late 1970's, he happened to treat a patient with terrible back pain as a result of kidney disease. Even though this patient had a serious physical condition, Kerns noticed that psychological therapy helped her cope with the pain.

"That's when I began to appreciate that a person's thinking could really affect their pain experience," he says. "Our chronic pain isn't beyond our control."
At the time, there was little hard evidence to support such mental interventions. Treating chronic pain with psychological therapy was like treating cancer with a poem: the best thing most doctors could say about it was that it would do no harm. But few doctors expected it to actually help. Pain, after all, was a medical condition. Therapy was just words.

But the words work. Kerns' most recent study, published in January 2007 in Health Psychology, is also his most definitive. It's a meta-analysis of twenty-two trials that looked at the effectiveness of psychological treatments for patients with chronic lower back pain. The statistics were complicated, but the results were clear: psychological treatments made the pain go away. Patients with chronic back pain could reduce their suffering by learning how to think differently about their pain. Benson Hoffman, a clinical associate at Duke University and co-author on the study, was surprised by the robustness of the data. "Going into the study," Hoffman says, "I thought that psychological interventions would probably increase a patient's quality of life, but not actually reduce their pain. But my hypothesis was wrong. These psychological treatments reduced the pain more than anything else."

Think, for a moment, about what this means: these patients didn't do anything to treat their bodily symptoms. And yet, after just a few treatment sessions, their pain started to subside. According to the meta-analysis, the two most effective psychological interventions were cognitive behavioral therapy and "self-regulatory therapies," like biofeedback. Cognitive behavioral therapy is a popular form of talk therapy that teaches patients how to adopt a problem-solving approach to their pain.

The simple premise of the treatment is that we are capable of controlling our own thoughts, emotions and experiences. Therapists teach patients specific mental exercisesâ¯such as keeping a journal, or practicing relaxation techniquesâ¯that help them manage their negative feelings and alleviate their suffering. The goal of the therapy is to re-train the brain, so that the cycle of pain is stopped. Self-regulatory therapies, on the other hand, show people how to take back control of their body. By giving patients information about their own internal processesâ¯such as readouts of their blood pressure and brain wavesâ¯the therapy teaches them how to modulate these processes. The mind needn't be a slave to the flesh.

"Many patients with chronic back pain develop a deep sense of hopelessness," Kerns says. "These therapies show them that they can develop everday strategies that make them feel better. I think one of the things that modern medicine has forgotten is that it's important to treat the whole person, and this means addressing both the physical and psychological aspects of the pain. When it comes to back pain, just fixing a 'broken' body part often isn't enough."

One of the first studies to demonstrate the importance of psychological factors for back pain came from an investigation of 3,000 employees at Boeing in the 1980's. Over a four year period, nearly ten percent of these employees developed chronic back pain. When doctors analyzed the factors that predicted the onset of this pain, they were surprised to learn that structural back problems played a negligible role. Factory workers who constantly lifted heavy objects were no more likely to experience disabling pain than office workers. Instead, the best predictor of chronic pain was emotional distress. Employees who were suffering from depression, stress, or just disliked their boss, were much more likely to suffer from debilitating back pain.

A study recently published in Spine made a similar point. Dr. Eugene Carragee, a professor of orthopaedic surgery at Stanford, was the lead author. He tracked nearly 100 patients over several years, attempting to better understand the specific structural ailments that cause chronic back pain. The researchers imaged people in MRI machines and used discographies to pinpoint the structural source of the discomfort. They also put the patients through regular psychological evaluations.

Carragee's results, like earlier studies, demonstrated that neither discographies nor MRI's were reliable predictors of chronic back pain. While two-thirds of patients with chronic pain had small cracks in their discs, so did 24 percent of patients with no pain at all. "The real issue," says Carragee, "is, why do some people have a mild backache and some have really crippling pain?"

To answer this question, Carragee analyzed the psychological evaluations of his patients. He soon discovered that a person's emotional stateâ¯and not the anatomical state of their backâ¯was the best predictor of back pain. As Carragee notes, "The structural problems were really overwhelmed by the psychosocial factors. Almost without exception, people without any of these mental risk factors were able to accommodate to the back pain. They were able to deal with their back ache. But people with a psychological problem had a much tougher time doing that. For them, the pain was often crippling and catastrophic."

While scientists have yet to find the specific mechanisms that connect our psychological problems to chronic pain, there are beginning to uncover some tantalizing clues. One possibility is that mental disorders make people more vulnerable by weakening the specific brain regions and neurotransmitter systems that are also involved in the perception of chronic pain. For example, a brain-imaging study published last August by researchers at the University of Wisconsin found that people with clinical depression were much less able to regulate their negative emotions than a control group. According to Tom Johnstone, a neuroscientist who led the research, when depressed individuals tried to turn off their own emotions, these attempts ended up backfiring. "The more effort they put in," he says, "the more activation there was [in the emotional areas of the brain]." As a result, bad feelings tended to spiral out of control.

A similar process might be at work in chronic pain. According to this hypothesis, the pain persists in the emotional areas of the brain because patients are literally unable to turn it off. Whenever they think about the pain, they just make it worse. (The Wisconsin researchers speculate that depressed individuals might have a "broken link" in the brain, which makes the regulation of negative emotion impossible.) What makes this research valuable is that it opens up new possibilities for the treatment of chronic pain. In recent years, for example, doctors have found that anti-depressants, especially tricyclics, are often effective treatments for chronic back pain. These drugs help control the emotions that the patients cannot.

Chronic stress is another important risk factor for chronic pain. One back surgeon, who wished to remain anonymous for fear of offending his patients, said that he's seen several men develop lower back pain shortly after getting engaged. "Weddings are stressors," he says, "and that stress can exacerbate the experience of pain." Intriguing clues are beginning to emerge about how, exactly, stress might modulate pain. Joyce Deleo, a neuroscientist at Dartmouth, has discovered that chronic pain is often triggered by a response from the immune system. When Deleo bred mice that were missing a specific type of immune receptor, the mice proved much less vulnerable to the lingering effects of pain. Of course, it's long been recognized that bouts of stress can profoundly alter the nature of our immune response. "I think the medical community is finally beginning to understand just how complicated the phenomenon of chronic pain is," Carragee says. "There are so many different psychological variables that can amplify and distort our experience of pain. You can't just wield a scalpel and make it go away."

The moral of these studies is clear. Modern medicine has been trying to fix chronic back pain by fixing the back. We spend tens of billion dollars every year imaging our degenerated discs, fusing our vertebrae, popping painkillers and engaging in a vast array of injections, massages and physical therapies. But for many people suffering from chronic back pain, these medical interventions won't work. Their doctors have been looking in the wrong place. The best way to treat chronic pain is to treat the brain.

Imagine you are a doctor, and a patient comes into your office with a serious case of back pain. Instead of doing the usual physical exam and patient interview, you decide to just study his mind. You don't even look at his back. It turns out that, by simply paying attention to a few variables inside his headâ¯the size of certain brain regions, the concentration of certain brain chemicalsâ¯you'll be able to predict about 80 percent of the individual variance associated with chronic back pain. You'll have a rather accurate sense of how intense his pain is and how long he's been suffering from the pain. In contrast, the conventional method of diagnosisâ¯this involves looking at the back and spineâ¯can account for less than 25 percent of the variance of back pain. When it comes to diagnosing chronic back pain, the brain reveals more than the body.

Dr. A. Vania Apkarian is a Professor of Neuroscience at Northwestern. He's been studying the neural underpinnings of chronic pain for more than twenty years. In 2004, he published a paper demonstrating that chronic back pain appears to cause brain damage. For each year of agony, people lose about a cubed centimeter of gray matter. With time, the centimeters add up: Apkarian found that subjects with chronic back pain had anywhere from 5 to 11 percent less gray matter than control subjects. The suffering is literally toxic.

In a 2006 paper published in The Journal of Neuroscience, Apkarian's lab located the specific brain areas triggered by chronic back pain. The scientists found that chronic painâ¯unlike acute painâ¯activated brain regions typically associated with negative emotions, thus providing further evidence that chronic pain is really an emotional disorder. It's a malfunction of the second pain pathway. "It's as if people with chronic pain have internalized the pain," Apkarian says. "It's become part of who they are. That's why you can't just treat the body."

At first glance, this data is dispiriting. The pain of long-time sufferers appears to be literally built into their brain, cemented in the soul. But Apkarian is also working on treatments that might alleviate the suffering at its neural source. In June 2007, Apkarian's lab published a paper in Pain documenting the ability of a pre-existing drug, D-Cycloserine, to end chronic pain in rats. While D-Cycloserine was originally designed to fight tuberculosis infections, it also appears to suppress the emotional component of chronic pain. After thirty days of pharmaceutical treatment, the rats were living pain free lives. Apkarian is hoping to begin a clinical trial with chronic back pain patients later this year. "When we do this in a clinical trial, we expect people to say 'I still have the pain, but it's not bothering me anymore,'" Apkarian says. "We think they will have a physical awareness of the pain, but its emotional consequences will have decreased." The chronic part of chronic pain will have been erased from the brain.

Despite the persuasive body of evidence demonstrating the psychological component of chronic back pain, the vast majority of patients still reject any diagnosis that smacks of psychology. Sarno holds the medical establishment responsible for this state of affairs. "What's going on now is a disgrace," he says. "You have well-meaning doctors making structural diagnoses despite a serious lack of evidence that these abnormalities are really causing the chronic pain. All these incorrect diagnoses actually make it harder for the patients to benefit from psychological treatments. I can't help people until they accept the mind-body aspect of their pain."

Everyone agrees that a big part of the solution is better patient education. "A lot of what I do is educate people about what their MRI's are showing," says Dr. Mackey. "I remind them that the only perfectly healthy spine is the spine of an eighteen year old, and that degeneration is often part of a normal process. Patients have to get beyond their fear of pain, because the fear keeps them from progressing. It's like they slip into a state of learned helplessness."

Many patients also find the possibility of a psychological diagnosis insulting. They assume that, if the pain has a mental component, then it must be make-believe. "When you first tell a patient that their mind might be responsible for the pain, they think you're calling them crazy," Dr. Sopher says. "I always tell that the pain is no less real because it's being caused by the mind. The pain is still real and it's still debilitating. It just means that getting better means changing something in your mind, not your back."

The good news is that, while we can't realign our spines or fix our ruptured discs, we can control our perception of chronic pain. With the proper training, we can alleviate our own suffering. That, at least, is the optimistic conclusion of a recent Stanford study performed by Mackey and other researchers. The study used real time fMRI brain imaging to teach people with chronic pain how to modulate their conscious response to the pain. Some of the subjects distracted themselves with pleasant thoughts, while others recited mantras, or listened to soothing music. Despite the diversity of strategies, each of the patients could see the direct impact of their palliative thoughts. They watched as the specific parts of their brain associated with chronic painâ¯like the anterior cingulate⯠gradually subsided in activity. They had become their own painkiller.

The results of the experiment were dramatic. Every single chronic pain patient reported a decrease in pain intensity, with an average decrease of 64 percent. The patients had stopped being the helpless victims of a structural abnormality in the body, and could now focus on dealing with the pain in their mind. Simply knowing that they could control the pain somehow made the pain less terrible.

Dr. Christopher deCharms, a lead author on the Mackey paper, is trying to take this therapeutic approach mainstream. He's started a company, called Omneuron, that makes the experimental treatment available to a wider audience. A standard treatment session goes like this: a patient lies in a brain scanner while experiencing pain. They watch as their brain flares up in agony. Then, with the help of a trained therapist, the patient learns how to consciously turn off the brain areas that correlate with the chronic pain. It's a perfect example of mind over matter.

The science of back pain has come a long way since Dr. John Sarno, frustrated by his medical failures, decided that the mind played a crucial role in chronic back pain. His unscientific hunches have been replaced by a bevy of new scientific facts. More importantly, this increased understanding has led to an assortment of new treatments. And yet, the single biggest obstacle to treating chronic back pain remains our old beliefs. Until we accept the psychological component of chronic pain, the pain won't go away. It will just linger on, not in our backs, but in our mind.