The Placebo Response and the Power of Unconscious Healing

Richard Kradin

• Publisher: Routledge
• Year: 2011
• eBook ISBN: 9781135913090
• Topic: Psychology
• Subtopic: Mental Health in Psychology
• Index: Psychology

Placebo responses are automatic and unconscious and cannot be predicted based on conscious volition. Instead, they reflect complex interactions between the innate reward system of the nervous system and encoded procedural memories and imaginal fantasies. The placebo response contributes inextricably to virtually all therapeutic effects, varies in potency, and likely exhibits its own pathologies. The Placebo Response further considers that the critical elements required to provoke placebo responses overlap substantially with what most current psychotherapies consider to be therapeutic, i.e. an interpersonal dynamic rooted in concern, trust and empathy. The potential importance of training caregivers in how to optimize placebo responses is considered a crucial feature of both the art and science of care-giving.

1 The Placebo Response

Mind Over Matter or a Matter of Perspective?

Who shall decide when doctors disagree?

Alexander Pope

Introduction

Can the mind promote healing of the body? What is the placebo response, and how does it contribute to therapeutic efficacy? Is there one placebo response or many? If you are presently reading this book, chances are that you are interested in these questions. But, definitive answers have continued to evade scientists, and you may be surprised to learn that they remain controversial. Let us begin by examining some of the varied viewpoints concerning the placebo response.

In a recent report Dr. Andrew Leuchther, professor of psy-chiatry at the University of California, Los Angeles, reported on

Table 1.1   Perspectives on the Placebo Response

Historical basis of all prescientific medical therapeutics

Nonspecific intervention designed to placate patient's complaints

Confounding factor in therapeutic interventions

Imaginary element in the deluded minds of doctors and patients

Unaddressed factor in the philosophy of medical science

Anomalous scientific phenomenon

Complex mind—body response that is the basis of endogenous healing

the results of imaging the brains of patients with major depression (Patterson, 2002). Some of these patients had developed positive therapeutic responses, but not to an antidepressant—to a placebo. According to Leuchther, “We were just looking at the placebo group as a control group. It was really quite a surprise to us when we … could see that they had significant changes in brain function” (ibid. p. 1).

What Leuchter and his research team discovered was that the brains of the placebo responders showed changes in activity comparable to those of patients who had received antidepressant medication for several weeks. Placebo had produced therapeutic effects and changed brain activities in ways that were indistinguishable from antidepressant medication. Yet Leuchter’s remarks convey the surprise that physicians often express concerning the ability of a placebo to produce objective changes in the body’s physiology. From their perspective, placebo effects are either imaginal, or frankly fictitious, and they are incapable of leaving footprints in the material world.

The reader may also be surprised to learn that placebos come in various forms and are not only pills. Both surgical procedures and other therapeutic interventions can also be placebos. In fact, placebo effects have been reported in any situation in which an offer to treat has been made. But from another perspective, placebo effects are not primarily the source of salutary effects, rather they confound what was thought to be specific therapies. Consider the study of Moseley et al. (2002), in which a widely performed arthroscopic surgical procedure for the treatment of osteoarthritis was critically evaluated. Arthroscopy allows inspection of a joint cavity via an illuminated fiberoptic scope. In this procedure, the skin overlying the joint is anesthetized, and an incision is made, via which the arthroscope is introduced. With the arthroscope, it is possible to remove the fragments of degenerated cartilage that are thought to be causing inflammation, pain, and loss of joint function.

Prior to this study, arthroscopic knee surgery was considered standard practice, and nearly three-quarters of a million arthroscopic surgeries were performed annually. However, in this clinical trial, while one group of patients underwent arthroscopic joint surgery, another group was anesthetized and given three stab wounds to the skin with a scalpel—but no cartilage fragments were removed. Researchers refer to this as sham surgery. It is designed to control for the nontherapeutic aspects of a surgical procedure and to purposefully mislead subjects into believing that their surgery was completed. Yet both groups showed comparable levels of improvement with respect to their knee pain following their surgeries. The researchers concluded that if arthroscopic surgery was no better than sham surgery, then “the billions of dollars spent on such procedures annually might be put to better use” (Mosely 2002, p. 88).

How can an eminently rational therapeutic approach be no more effective than a sham treatment? Philosophers of science have long recognized that rational ideas do not necessarily constitute scientific proof; unfortunately, many doctors continue to ignore this fact. Too often, they base their conclusions on inference rather than on direct observation. Studies like this one are important, as they raise questions with regard to the practices that are taken for granted.

The role of the placebo response in this study was that of a “spoiler.” There was little consideration as to why sham surgery was effective, although it clearly was, as both groups showed a 50% persistent improvement in their symptoms. The aim of the study was limited to determining whether the test procedure was superior to placebo; explaining the findings was of little interest

Despite numerous studies like these that appear to offer convincing evidence for the potency of placebo responses, some skeptics continue to doubt their efficacy. Consider a recent study by Hrobjartsson and Goetzsche (2001), Danish epidemiologists at the University of Copenhagen. They conducted a meta-analysis of 114 previously published clinical trial in which subjects had received placebos, or no treatment, as controls. Meta-analysis is a statistical approach that probes data from previously reported studies. It can be helpful in determining whether a treatment is actually effective, when the results from multiple studies are ambiguous.

The trials analyzed by Hrobjartsson and Goetzsche (2001) included the administration of pills, physical manipulations, and psychological interventions. They divided these trials into those yielding binary (i.e., yes or no) responses and those with continuous outcomes, i.e., including a range of values that could be analyzed quantitatively. The results demonstrated that placebos did improve subjective outcomes, whereas objective outcomes were generally unaffected. Hrobjartsson and Goetzsche concluded that there was “little evidence that placebos in general have powerful clinical effects” (p. 1607).

In an editorial response to this report, John Bailar (2001), a Harvard public health physician, acknowledged these findings but concluded, “There is a pesky utterly unscientific feeling that some things [placebo responses] just ought to be true” (p. 1632). He hastened to add that few clinicians would be willing to abandon what they believed to be an effective and innocuous means of alleviating patient discomfort. The latter sentiment is underscored by Eric Cassells (2004), an academic physician:

I would happily give up the use of (say) calcium channel blockers, as important as they have been in the treatment of heart disease, if I could be assured a similar mastery of the placebo effect; it would be useful in more patients. One would think that something as potent as the placebo effect would have been subject to at least as much study as most pharmaceuticals, but that is unfortunately not the case (p. 113).

Can Cassells’ (2004) sentiments be reconciled with the findings of Hrobjartsson and Goetzsche (2001)? In letters to the editor in response to the article by Hrobjartsson and Goetzsche, Lilford and Braunholtz (2001), scientists at the University of Birmingham in the United Kingdom, argued that in a clinical trial with a placebo control, there is a 50–50 chance patients will receive placebo rather than active treatment, whereas patients who receive placebos in noncontrolled medical practice expect an active intervention 100% of the time. They proposed, “If subjects do not believe that they received the active treatment, no placebo response is expected, which is what Hrobjartsson and Goetzsche found” (p. 163). Doubt, these researchers insisted, has a strong negative influence on the potency of placebo responses.

The conduct of clinical trials, as the Birmingham scientists contend, may truly be at odds with the factors that promote placebo effects. However, this explanation, at least by current standards, is not scientific, even if correct. Whereas clinicians may believe that potent placebo effects occur in practice, can they prove it? Medical science requires empirical observation and controlled experimentation. But what is to be done when the scientific method itself interferes with the subject being investigated?From this perspective, the placebo response assumes yet another role—that of a potential scientific anomaly—for which the prevailing scientific methods cannot be applied. When this is the case, one may apply a new mode of experimentation that can hopefully adequately describe the phenomenon of interest. Alternatively, an entirely new scientific approach may be necessary. Anomalies are often responsible for entire paradigm shifts in science.

One might also conclude that there is no incontrovertible evidence that the placebo response exists, in which case this text ends here. The fact is that there actually is no completely convincing evidence for placebo effects and that it is virtually always possible to find alternative explanations for them. But that is to hold the placebo response to a higher standard than other elements of medical science. In addition, as philosopher of science Karl Popper (1972) opined, it is only the deniability of an explanatory model that disqualifies. Currently, no one has been able to prove that placebo effects do not exist, so thankfully there will be more to say about them.

Cause and Effect ?

The fact that placebo effects are not separable from other therapeutic effects presents a serious challenge to medical science. We are inclined to think that medical interventions cause therapeutic effects, but this view may be too simple. Most of us rarely ponder what is meant by causality. But 18th-century philosopher David Hume (1888; Figure 1.1) did. He insisted that all scientific observations be grounded in experience rather than in

Figure 1.1  David Hume. Hume was one of the great Scottish philosophers of the Enlightenment. His views on empiricism and causality had a great impact on the philosophy of science in the West.

abstraction. Hume was a radical empiricist. When he addressed the question of causality, his conclusions were unsettling. To understand his reasoning, consider the following two examples. First, a white billiard ball hits a red billiard ball, and the red billiard ball moves. Second, you are walking down a highway and discover an automobile crushed against a tree; its windshield is broken, and there is a man inside the car who is unresponsive. A dog walks by and pays little attention to what has occurred.

The proximity of events in space and time is often the compelling argument for causality. The white ball hits the red one, the red one moves; Q.E.D. As for the other scene, here no action has actually been observed, yet causality is still inferred. However, the dog, whose mind may not be comparably inclined to view events as causal—at least not for the situation that has been described—infers nothing. Rather, it sees only what is there (i.e., a car, a tree, and a man); that’s all.

In Hume’s (1888) opinion, in neither example is the observer justified in attributing causality to the events. He argued, rather, that all of these events are separate. Whereas, the red ball does move when struck by the white one, did anyone observe a cause , or is one being inferred? But what does this have to do with placebo effects or, for that matter, with any therapeutic effect?

Consider the following. Suppose a patient receives a drug for a set of symptoms. The next day, he is better. What caused the improvement? The answer is that we do not know because we were unable to observe what transpired. But in practice, doctors and patients both often attribute causes for changes in medical conditions with little proof other than the proximity of an intervention. According to Hume (1888), scientists must recognize how the mind tends to create explanations like causality and not be enticed by them.

As will become increasingly evident, only when therapeutic interventions are strictly controlled can they be judged effective; cause and effect can rarely be established. This perspective was encountered in the sham surgery trial. The only question that could be answered was whether arthroscopic surgery was better than placebo. It was not possible to conclude that either arthroscopic surgery or sham surgery caused the beneficial effects that were observed.

In practice, few therapies are subjected to sufficient rigor to determine whether they are even effective. As a consequence, many eventually prove to be placebos. While this does not diminish the importance of placebo effects, it does caution that medical science must take care to distinguish between what human nature and human ingenuity each bring to the realm of therapeutic success. Only in recent times has there been any recognition that treatment effects might be attributable to multiple sources; before, there simply was no conception of placebo effects. The progress of medical therapeutics has largely been due to the increasing discernment of how placebo effects contribute to treatment. But, to clarify what placebo effects are, it is first necessary to explore the nature of disease and healing.

2 The Basis of the Placebo Response in Sickness and Healing

All is flux; nothing stays still.

Diogenes

Healing and Placebo

It is impossible to know what first motivated man to care for the sick by augmenting the healing processes of nature. Healing is not unique to man; it is seen in all forms of life. Extraordinary healings occur regularly in other species. Reptiles and amphibians can spontaneously regenerate entire limbs, without ever consulting a physician. Snakes shed their old skins and develop new ones in a process of biological renewal. Man was undoubtedly curious and wished to benefit from the knowledge of how these processes occurred. The caduceus, a wooden staff entwined by two snakes, was one of the earliest symbols of medical therapeutics, symbolizing man’s regard for the achievements of nature.

Although man does not possess the extraordinary healing capacities of reptiles, he does exhibit a wide variety of restorative processes that operate in the service of health, including the cellular repair of g...

Table of contents

• Front Cover
• The Placebo Response and the Power of Unconscious Healing
• Copyright
• Dedication
• Contents
• Acknowledgments
• Introduction
• 1 The Placebo Response
• 2 The Basis of the Placebo Response in Sickness and Healing
• 3 A Brief History of Medicine and the Changing Implications of Placebos
• 4 Placebo Effects—Who Gets Them?
• 5 What Do We Know About How Placebos Act?
• 6 The Anomalous Placebo Response
• 7 Placebo and the Truth
• 8 The Challenge of Harnessing the Placebo Response
• Bibliography
• Index