Last updated: Sat, Nov 9, 2024
A large amount of research has been done on the applicability of the CBT model to chronic pain and the utility of CBT therapeutic techniques in aiding chronic pain patients. In this part of the book I'll assess that research. First I present the basic analysis of the psychologists who advocate this approach, in their own words. In following sections I'll present and evaluate the strength of evidence supporting their view.
Uncontrollable, prolonged pain produces depression, inability to work, and persistent stress. People's beliefs and emotions can amplify or diminish the experience substantially. Prolonged pain is also influenced by the social environment, particularly how significant others, including health care providers, respond to reports of pain.1
Here, authored by psychologists Dennis Turk and Ronald Melzack (one of the discoverers of the "gate control" theory) is the CBT view of pain in a minimal form. The pain experience can be amplified "substantially" by beliefs and emotions, and is influenced by the social environment, including caregivers. Although vague, it's a moderate claim.
Behavioral models explain the maintenance and generalization of pain and pain-related disability through both non-associative (habituation and sensitization) and associative (respondent and operant) learning and, in addition, through the role of a wide variety of cognitive factors.2
Here again is Dr. Turk, writing with psychologist Herta Flor, an excellent researcher, in a chapter on Cognitive and Learning Aspects of pain, in Wall and Melzack's Textbook of Pain, an advanced text on pain. They are explaining pain psychology to non-psychologists, many of whom must be medical doctors. Behavioral models here are said to "explain" both pain and pain-related disability.
The trick to interpreting their statement as true is that, in inferential statistics, to "explain" is to find some degree of correlation between measurements of one set of variables (beliefs and emotions, etc.) and another set of variables (level of experienced pain, disability, etc.). As in the first quote, their chapter is nowhere explicit about what portion of pain and disability they claim to have accounted for. Sadly most doctors understand hardly more about inferential statistics than do most patients, and hence the above statement is an invitation to exaggerate the premise that the link is strong and well-established. I've found this tendency to be consistent in the psychological literature on pain. (And, of course, note that the role for pain in pain and pain-related disability is not assessed.)
These CBT techniques proceed from the view that an individual’s interpretation, evaluation, and beliefs about his or her health condition and coping repertoire, with respect to pain and disability, will affect the degree of emotional and physical disability associated with the pain condition.3
This sentence comes from an article explaining the role of CBT in "The BioPsychoSocial Approach to Chronic Pain" to fellow psychologists, published in the Psychological Bulletin in 2007. Again the amount of effect these cognitive factors will have is not the focus, and in fact the source article doesn't address either the size of effect, its variability, nor the ability to identify or measure it.
According to operant theory...these initially reflexive responses may be maintained by reinforcement contingencies; that is, attention or financial gain may be positively reinforcing and thereby contribute to the maintenance of the behaviors long after the initial cause of pain has been resolved.4
So, the link between behaviors and rewards may teach people to maintain pain behaviors despite the resolution of pain. Certainly that is a hypothesis that can be derived from the theory of operant learning. In fact, operant theory teaches that such behaviors could be learned in the absence of any pain at any time....
The potential that individuals can claim the "benefits" of a disabled role without being in one sense or another truly disabled didn't of course require psychologists or operant theory to arise, and it isn't clear that the tools of psychology are even important to investigate the probabilities. Aspects of this issue are covered in several sections of this work, including Secondary Gain.
Five general assumptions characterize the cognitive-behavioral perspective:
- People are active processors of information and not passive reactors.
- Thoughts (e.g., appraisals, expectancies) can elicit or modulate mood, affect physiological processes, influence the environment, and serve as an impetus for behavior. Conversely, mood, physiology, environmental factors, and behavior can influence thought processes.
- Behavior is reciprocally determined by the person and by environmental factors.
- People can learn more adaptive ways of thinking, feeling, and behaving.
- People are capable and should be involved as active agents in changing maladaptive thoughts, feelings, and behavior.
From the cognitive-behavioral perspective, people suffering from chronic pain are viewed as having negative expectations about their own ability to control certain motor skills such as performing specific physical activities (e.g., climbing stairs, lifting objects) that are attributed to one overwhelming factor (i.e., a chronic pain syndrome). Moreover, many chronic pain patients seeking treatment tend to believe that they have limited ability to exert any control over their pain. Such negative, maladaptive appraisals about the situation and personal efficacy may reinforce the experience of demoralization, inactivity, and over-reaction to nociceptive stimulation.5
This is Drs. Turk and Flor in the "Wall and Melzack" text. Assumption 1 is a false dichotomy. People aren't either active processors or passive reactors. We are either or both to some degree in different situations. Further, modern neuroscience demonstrates clearly that most of our reactions are automatic and unconscious.
Assumption 2 ignores that thoughts are clearly not the only things that influence either mood or physiology. Assumption 3 neglects to assign the pain to either the person or the environment. Where is the pain in this model? If the pain is considered to be part of the environment, then It is involved in determining behavior, and this must be part of CBT pain thinking. Similarly if it is part of the person.
Assumption 4 neglects the crucial question of what is truly adaptive. The assertion that people can learn how to feel pain certainly can't be assumed in a scientific theory without in some sense denying pain. Assumption 5 combines "should" and "maladaptive" in a single thought as if they have a natural place in a medical discussion. While most should agree that adaptive is good and maladaptive is bad, the question of what is adaptive and what is maladaptive in a pain condition can't be assumed, and it is worth questioning whether the question can be answered by behaviorist psychological analyis.
The paragraph that follows the assumptions should point out a clear conflict between the therapist and the sufferer. While the therapist may view the sufferer's struggles as a question of "ability" to perform, the sufferer may well view the situation as providing a set of punishments that far outweigh the rewards of "adaptive" action. This aspect seems to be invisible to the CBT adherents.
The operant model distinguishes between the private pain experience and observable and quantifiable pain behavior (i.e., overt communications of pain, distress, and suffering such as moaning, grimacing, or intake of medication). It is such behavior rather than pain per se that is assumed to be amenable to behavioral assessment and treatment.
The operant conditioning model proposes that acute pain behavior may come under the control of external contingencies of reinforcement and thus develop into a chronic pain problem. Pain behavior may be positively reinforced (e.g., by attention from a spouse or health care providers). Pain behavior may also be maintained by the termination of unpleasant states, such as a reduction in pain level by analgesic medication or inactivity or the avoidance of undesirable activities such as work or unwanted sexual activity (negative reinforcement). In addition, “well behavior” (e.g., functional activities, including working, homemaking activities, and self-care) may not be sufficiently reinforcing, and the more rewarding pain behavior may therefore be maintained (i.e., punishment type 2).6
The first of the two paragraphs above, again from the Flor/Turk explication, specifies a characteristic of the CBT theory that is not always acknowledged, but seems to be a feature of this view of pain and pain therapy. Pain itself is not treatable by this method, and in fact is not accounted for explicitly. The treatment acknowledges and targets only what are called "pain behaviors," and seems to either ignore or at least overlook the pain that the patient complains of. It is noteworthy that the pain behaviors listed there are the behaviors that the sufferer uses to communicate his problem. This raises once again the question of adaptiveness. Why is it more adaptive, in terms of the sufferer's interests, that they not communicate about their distress?
This explanation explicitly contains the theory that chronic pain may be caused by a learning process, as opposed to a medical or physiological one. The very actions that might be undertaken to comfort the sufferer may condemn the sufferer to prolonged unnecessary suffering. !Que problema! This is quite a different view than that put forward in the page's first quote from Turk and Melzack, above. This theory should raise the question of whether and how "learned pain" might be clinically distinguished from medical/physiological pain. I have argued in several sections of this work that there isn't a good answer to this question. (See A Complex Nervous System, In a Complex Body, and The Basic Problem with Behavioral Pain, for example.)
Non-occurrence of pain is a powerful reinforcer for reduction of movement. An operant process whereby the nociceptive stimuli need no longer be present for the avoidance behavior to occur may complement the original respondent [classical or pavlovian] conditioning. People who suffer from acute back pain, regardless of the cause, may adopt specific behavior (e.g., limping) to avoid pain and may never obtain corrective feedback because they fail to perform more natural movements and fail to learn that they may not induce pain (Vlaeyen et al 1995). Reduction in physical activity may subsequently result in muscle atrophy and increased disability.7
This is a further elaboration of the CBT theory of pain from Turk and Flor. They propose that a sufferer may initially make changes in their movements because it hurts, but the changes may persist after the pain stops. Sufferers may avoid once-painful actions, or may perform the actions in an unhealthy way, thus impeding a return to normal function. Such processes have been a concern for physical therapists for a long time. They tend to think of it in terms of "motor habits" or similar ideas, and encourage their clients to return to normal biomechanics as soon as pain levels allow. A key consideration for PTs is the continuing presence of pain, and good PTs are alert for signs that increased or corrected activities are aggravating an incompletely-healed condition.
Developing theories of manual therapy explicitly consider this idea that pain sufferers learn to avoid normal manners of movement. (This may be one of the essential adaptive behaviors that pain is "designed" to trigger.) Some evidence indicates that when "normal" movement is mediated against by pain, the nervous system can substitute develpmentally-earlier patterns of motion. Rehabilitation then is a process of re-learning normal movement by re-playing the individual's early learning of basic motor activities like standing or walking. The authors continue the previous quote:
In this manner, the physical abnormalities proposed by biomechanical models of pain (e.g., Marras et al 1995) may actually be secondary to changes in behavior initiated through learning. Similarly, Lethem and co-workers (1983) emphasized that chronic pain patients tend to focus their attention on impending pain and subsequently avoid many types of activity, thus fostering the development of disability and depression.8
Here the authors move into the subjunctive, the possible or hypothetical. This "may actually" have happened to the patient sitting in the provider's office. Whether this has happened to this patient depends upon the presence or absence of a physiological cause of continuing pain. The absence or presence of such cause, however, is likely to be unknown to medical pain specialists, much more so to clinical psychologists. If the patient has learned movement habits that are maladaptive, they can be un-learned with the help of a coach skilled in manual rehabilitation.
A person's beliefs, appraisals, and expectancies regarding the consequences of an event and ability to deal with it are hypothesized to have an impact on functioning in two ways:
- A direct influence on mood (emotional arousal can affect muscle tension, hormonal factors, and neurotransmitters)
- An indirect influence through their impact on coping efforts (e.g., use of medication and alcohol to relieve symptoms)9
This quotation is another from Turk and Flor's chapter on "Cognitive and Learning Aspects" of pain. It introduces the cognitive element of CBT. A person's beliefs, appraisals, and expectancies can affect mood or emotional arousal, which in turn affects muscle tension, physiological arousal, and emotional tone. This in turn can affect the experienced intensity of the person's experience. In addition, the beliefs, appraisals, and expectations can affect the person's choice of coping strategies.
An important question about this hypothesis again is the impact of the beliefs, appraisals, and expectancies compared to the impact of pain itself. And, again, on what basis can these be distinguished? Granted that emotion is powerful, so is pain. I would think that such issues would be an important topic to discuss when educating a group as influential and important (to pain sufferers) as pain doctors, but it isn't broached anywhere within their chapter.
There are deeper questions about this hypothesis that need attention. The two psychologists posit a causal chain that begins with "beliefs, appraisals, and expectations" which then affect "mood," which in turn affects "muscle tension, hormonal factors, and neurotransmitters."
Findings subsequent to the development of the standard CBT model suggest that there is a causal chain that begins with pain, which in turn affects "muscle tension, hormonal factors, and neurotransmitters," which then is experienced as what could be called "mood" and drives not only the immediate reaction to pain but also whatever learning results from the episode. It seems likely to me that both these chains exist, and I expand this idea in A Rational Model of Emotion and Pain.
Cognitive-behavioral therapy (CBT) is based on a theoretical model in which patient affect and behavior are strongly influenced by how patients view and interpret their experiences. The model implies that patients' beliefs and attributions about pain impact their emotional and behavioral responses to it. However, this model also implies that the effect of the social environment on patients' pain behaviors and dysfunctions is influenced by patients' cognitions, for example, the beliefs that patients hold regarding the meaning of others' responses to pain behaviors. In addition, the model implies that the responses of patients' partners may be strongly influenced by the beliefs that they hold regarding the nature of patients' pain and disability, and the appropriateness of different responses to pain behaviors. 10
The above quote refers to a theory of social and environmental influences on the fate of the pain sufferer. It points out plausible effects that cognitions may have on and through social communication. These effects can be multi-directional, traveling from the sufferer to those socially affected by him or her, or reciprocal effects that may be felt by the pain sufferer because of the beliefs of others, both those in his/her natural social circle and those who are involved because of their roles in the medical system. Notice that pain sufferers are supposed to exhibit "dysfunction" rather than function.
I couldn't agree more that the beliefs of others affect pain sufferers. That's been my overlying motivation to do the work. I take pains in my writing to clearly distinguish theories from facts. I am struck by how unwilling the research and clinical communities are to face the possibility that some of their beliefs and practices are dysfunctional.
But most discussions of patient credibility address the issue of conscious or unconscious elaboration of symptoms by patients who have no known cognitive limitations. In this setting, questions of malingering or secondary gain arise.11
Secondary gain is a generic term to describe benefits that people who are perceived as ill may receive based on that perception. Secondary gains include everything from reduced responsibilities to medical treatment itself to disability benefits. The quotation is from a discussion of the evaluation of the medical condition of pain sufferers. Even when patients are mentally competent, the quote says, there is the problem for the evaluator that individuals may intentionally mislead the evaluator (malingering) or may have learned to hurt, or learned to hurt too much, through the action of the rewards of secondary gain. Medical doctors are assigned the function of disability evaluators in most pain cases in most disability compensation systems. The learning-based theories we are discussing in relation to CBT here are significant also in the issue of who deserves compensation, as is discussed in more depth in The Disability System.
People with chronic pain typically attempt to base their decisions about the amount of physical activity or the work that they perform on the level of pain that they experience or anticipate. Interestingly, we (Turk et al 1996) found that patients in whom fibromyalgia syndrome was diagnosed tended to overestimate the extent of their physical limitations.
Overestimation [of limitations] may lead to a self-fulfilling prophecy and inhibit activities because patients view themselves as being more disabled than they actually are, which eventually prevents them from making an effort to undertake physical activities that they believe are beyond their capacity. A specific activity (e.g., walking) is performed until pain sets in, at which point the activity is interrupted and replaced by rest. Subsequently, the pain will be reduced. This reduction of an aversive state (pain) negatively reinforces the cessation of activity. As was the case with the intake of analgesic medication, cessation of activity has to be made dependent on the amount of activity achieved, quota based (e.g., number of stairs climbed, distance walked), rather than on the amount of pain. Thus, the pain-reinforcing quality of rest is eliminated. This formulation supports the strategy of encouraging patients to perform activities to meet a specific quota and not until pain is perceived as overwhelming.12
Here Flor and Turk sketch a scenario in which resting to relieve pain would in fact be the cause of disability, rather than a simple, commonsense blessing. If true, perhaps patients should be encouraged (or forced?) to continue past their comfort limits. Such an hypothesis has serious implications, if true.
Again in this quote we find the word "may." I presume their meaning to be that in certain circumstances this would occur. Certainly they can't mean that someone with an un-set compound leg fracture should be forced to walk?? What exactly are the conditions in which it is beneficial for a patient to be encouraged or forced to continue activity?
Again I'll ask you to notice the word "may" at the beginning of the second paragraph above. Forced marches are appropriate, say these psychological researchers, when "patients view themselves as being more disabled than the actually are," and, they imply, the patient is prevented by learning from undertaking activities that they (incorrectly) believe are "beyond their capacity." Also implied: "...when we know that these activities aren't beyond their capacity."
To summarize these conditions:
Interestingly, Turk has established "that patients in whom fibromyalgia syndrome was diagnosed tended to overestimate the extent of their physical limitations." This hearkens back to the genesis of the standard CBT model, see The Fordyce Revelation. Fordyce discovered that when he had chronic pain patients in a total institution, he could motivate them (by giving or withholding rewards) to be more active than they would otherwise be. But we have already seen (The Adaptive Value of Pain) that pain doesn't disable absolutely. Pain is one of many signals that affect the organism's priorities. Just as one can get up for water or to use the toilet while in pain, one can walk a bit farther or do a few more reps. (See also The Challenge of Living in Pain.)
Another underappreciated aspect of the pain experience, which is also elaborated in The Challenge of Living in Pain, is that the harmful effects of pain accumulate over time. That is, it is quite a different thing to experience a brief shock in a psychology laboratory than it would be to live with continual or on-going intermittent shocks. Just one aspect of this multi-dimensioned problem is stress, physiological stress, the experience of a routinely-high amount of cortisol in the system. Or, consider cognitive degradation due to pain. The more time that anyone exists under this handicap, the larger the effects in all facets of life. One implication of the cumulative nature of pain harm is that what can be tolerated briefly can't necessarily be tolerated chronically. When the researcher or care provider encourages the pain sufferer to go the extra mile, they experience (vicariously) only the immediate effect. The pain sufferer experiences the chronic effects of the encouraged activity increase directly, but this becomes at most subjective testimony to the observer. The fact that you can get CPPs to do more than they are comfortable with is important, but it doesn't imply that enforced activity isn't harmful.
The importance of patients' appraisal about the cause of their symptoms on reports of pain was observed around 30 years ago. For example, Spiegel and Bloom (1983) reported that the pain severity ratings of cancer patients could be predicted not only by the use of analgesics and the patients' affective state but also by their interpretation of pain. Patients who attributed their pain to worsening of their underlying disease experienced more pain despite comparable levels of disease progression than did patients with more benign interpretations.13
This quotation from the Flor and Turk chapter on "Cognitive and Learning Aspects" of pain is a typical argument for the effect of beliefs (here, beliefs about the significance of worsened pain) on pain outcomes. Again there is a semantic trick to correctly interpreting their claim. To "predict" in this context means to correlate. The patient may believe that their condition is worse because their pain has increased, or their pain may have increased because, for whatever reason, they have concluded that their condition has worsened, or their pain may have increased "in reality." Because in general reported pain doesn't correlate well with medically-assessed disease progression, it isn't reasonable to expect disease progression to correlate with expected pain. It is necessary to establish causality between belief in a worsening condition and heightened pain, rather than some other chain of causality through this complex set of variables. Mightn't increased pain simply be interpreted by its owner as a sign of a worsening cancer?
In order to help the patient with musculoskeletal pain understand the psychosocial aspects of pain, attention should focus on the patient's reports of specific thoughts, behaviors, emotions, and physiological responses that precede, accompany, and follow pain episodes or exacerbation, as well as the environmental conditions and consequences associated with cognitive, emotional, and behavioral responses in these situations. To establish salient features of the target situations, including the controlling variables, during the interview the clinician should attend to the temporal association of these cognitive, affective, and behavioral events, their specificity versus generality across situations, and the frequency of their occurrence. The interviewer seeks information that assists in the development of potential alternative responses, appropriate goals for the patient, and possible reinforcers for these alternatives.14
This advice is offered to those who evaluate pain conditions. In the scenario contemplated here, the investigator is looking for temporal links among aspects of the pain experience, physical, emotional, and social. He or she can't do this without suggesting to the patient that such links are important in the search for a solution to the pain problem. The patient has an incentive to find such links for the investigator, regardless of whether the investigator is working based on good or bad theory. The investigator may have such incentives as well. This procedure has a curious lack of synchrony with the behavioral principles upon which the CBT approach is based. Certainly any such links must be viewed with suspicion? Anyone with pain that is worsened by activity has experienced the sad reality that physical demands morph into pain. The time sequences that are involved are quick and the emotional suffering highlights itself.
Things that Close the Gate
Physical: Drugs, surgery, reduced muscular tension
Cognitive: Distraction or external focus of attention, thoughts of control over pain, beliefs about pain as predictable and manageable
Emotions: Emotional stability, relaxation, and calm, positive mood
Activity: Appropriate pacing of activity, positive health habits, balance between work, recreation, rest, and social activity
Social: Support from others, reasonable involvement from family and friends, encouragement from others to maintain moderate activity
Sensory information can also close the gate. This is why when you bump your shin, rubbing it often helps. When you rub your knee you are stimulating different types of nerves at [actually, adjacent to] the site of injury. These nerves send a signal to close the gate so less pain information can get through to the brain.15
This quote comes from a different source, a manual intended for use in applying CBT principles to pain sufferers. The ideas listed above are intended to be "taught" to pain sufferers. The list is terribly misleading in a number of ways that could be damaging to various classes of patients.
For starters, the metaphor of a "gate" is unfortunate. Gates are either open or closed, unlike the pain modulatory system, which has a number of interacting but separate feedback systems, most of which are continually variable, like a valve, not on-off switches as the gate metaphor implies.
While all the pain-control strategies that the list includes are reasonable and defensible in some or even most patients, none of these strategies, nor all in conjunction, will "close the gate" for most patients, if by closing the gate you mean stopping the pain. (Certainly the patient is likely to prefer that meaning.) The list fails to mention this, making it almost inevitable that patients and their therapists will miss this important point. This will set up expectations that will lead the patient to erroneous beliefs about the reasonable efficacy of the strategies. This in turn will lead to negative consequences for the patient. Such half-truths ought to be unexpected and remarkable in an intervention that claims to be about correcting cognitions. I've not seen, however, any recognition of this in any of the literature that I've encountered on this subject, including that targeted to professionals.
(The evidence about the effectiveness of this approach to limiting pain shows that it has low but measurable effectiveness that persists for much less than a year. This profile of effect is consistent with a placebo effect. See Overview and Evidence of CBT for Pain and Placebo Analgesia. I've yet to see evidence that a "gate-closing" effect can be achieved.)
As a fairly innocuous example of incorrect information in the above, consider the assertion that "reduced muscle tension" closes the gate. There is a positive correlation between tension and pain, but it has nothing directly to do with Wall and Melzack's gate. More tension is believed to generate more nociceptive signals. The harm, in one easily-imagined scenario, could come when the patient succeeds in decreasing muscle tension and doesn't feel a commensurate decrease in pain. This may seem like a small harm, and perhaps it will be, but we must bear in mind that the typical pain patient won't benefit from the challenge of working out the discrepancy between what their therapist told them and what their own senses say. In fact, it seems to me quite unlikely that most patients would gain positive learning from such an experience.
"Distraction or external focus of attention" is known to reduce perceived painfulness in acute cases, in a lab where certainly the attention and the pain are temporary and evanescent. But the efficacy of distraction hasn't been established in the chronic conditions with which we're concerned, in which the pain is physiologically different. (Chronic Pain Redefined.) My reading of the science (along with my personal experiences) tell me that while it's not helpful to let pain overwhelm you, it's necessary in many pain conditions to be quite aware of how, when, and why pain is increased. The cost of battling against your pain (an attention signal), and how sustainable such a contest is, is unknown for various classes of patients. It is easy for me to imagine sufferers who would be seriously harmed by trying to ignore pain signals.
This is not to say that distraction is not beneficial. I'd venture to say that most experienced pain sufferers know this. It is to say that generic and unqualified advice about such things is hazardous to the sufferer. Once again, there are undoubtedly sufferers who would benefit from distracting themselves more and focusing on their pain less. Neither a psychologist nor an M.D. nor a manual therapist has access to the information upon which the balance ought to be set. The sufferer does.
And so on through this list. Of course it is good to be "appropriate," "positive," and "balanced," but the patient knew this when they came in your door. It is important to acknowledge the limitations of these techniques to the patient, who may be desperate enough to accept any proferred help by the time they end up in a psychologist's office. The typical pain patient doesn't have access to quality independent sources of information, hasn't been well-served in this respect by his or her M.D., and will likely be dealing with their pain for years and years. The patient has a need for correct information about the degree of certainty that exists about the effectiveness of these methods, the likely power of them, and their inherent risks. This implies explicit acknowledgement of the uncertainties.
I've presented statements on this page from researchers and therapists in the CBT school of pain treatment, and made some general criticisms based on their statements. Nevertheless, if the treatments are effective, that is what's important. In the sections that follow I will look at that evidence in some detail. The evidence creates a complex picture. There is always "something there" behind the CBT-based concepts, some of the theories suggest worthwhile therapeutic strategies, but the significance of the phenomena is much more complex than the way they are presented in CBT therapy. It is very common to see extravagant claims for their effectiveness.
[These promised sections haven't been written, however.]
Within this section...
Pain Behaviors in CBT (This page is incomplete.)
Evidence for Pain Conditioning (This page is incomplete.)
Cognitions (This page is incomplete.)
Cognitions, Conditioning, and Learning
Catastrophizing in CBT (This page is incomplete.)
Fear-avoidance (This page is incomplete.)
Coping Strategies (This page is incomplete.)
Control and Self-efficacy (This page is incomplete.)
Social Effects on Pain Behavior (This page is incomplete.)
Adaptation to Pain (This page is incomplete.)
Or skip to...
Overview and Evidence of CBT for Pain (This page is incomplete.)