CHAPTER 7 The Psychology of Acupuncture Therapy: Placebo and Nocebo Effects in Acupuncture Pain Management

INTRODUCTION

Pain, especially chronic pain, results in psychological and physical dysfunction. The expression of pain is a personal characteristic and is influenced not only by abnormal neurophysiologic processes, as discussed in previous chapters, but also by environmental and cultural factors, as well as psychological aspects such as personal experiences, learning, beliefs, and expectations related to the pain and its treatment. All these factors are woven together to form the individual psychological characteristics of a pain patient, and have a significant influence on the efficacy of treatment. In addition, practitioner-patient interactions can exert powerful positive or negative effects on the outcome of treatment.

Once the pain impulses from the peripheral sensory receptors reach the neural networks of the brain, what happens is no longer a purely sensory neurophysiologic mechanism. The perception becomes a complex cognition of the sensory information from the injured tissue, and the processing cannot be independent of the patient’s unique and individual psychological background. Here the pain perception enters a higher level of the hierarchy of biological organization: the psychological. If acute pain is still an element at the neurophysiologic level, chronic pain has been incorporated into the psychological organization. Thus patients with chronic pain show special psychological characteristics in their pain symptoms, in the areas of pain perception, emotion, cognition, expectancy, assigning meaning, and decision making.

Interactions between the factors of neurophysiology and cognitive psychology can produce positive placebo effects or negative nocebo effects. If the interaction favors self-healing, the patient experiences positive placebo effects. If the interaction promotes an internal environment of self-destruction, negative effects occur. Changes in pain over time reflect complex interactions between physiologic processes and psychological syntheses and environmental factors.

A pain patient views his or her pain as a personal experience. The quality and intensity of this experience are influenced by the patient’s unique history, by the meaning he or she gives to the pain-producing situation, and by his or her state of mind at the moment. All these factors modify the actual patterns of pain impulses that ascend from the body to the brain and travel within the brain itself. In this way pain becomes a function of the whole person, including his or her current thoughts and fears as well as hopes for the future.

The same injury can have different effects on different people or even on the same person at different times. Psychological variables may intervene between the stimulus and the perception of pain and can produce different expressions of the pain and a different response to the same medical treatment.

For decades pain professionals have been puzzled by the phenomena of placebo and nocebo effects. In fact these effects are expressions of self-healing or self-destruction that result from interactions between neurophysiology and cognitive psychology. In some patients, both placebo and nocebo effects affect application of every medical modality—drugs, surgery, psychotherapy, acupuncture, physical therapy, biofeedback, manipulation, and massage—in every treatment. Thus these effects are inevitable processes that must be taken into account in every field of medical practice. If the psychological condition of the patient and the mechanism of placebo and nocebo effects are properly understood, the practitioner and the patient can work together to exploit these factors for better pain relief.

OVERVIEW OF THE PSYCHOLOGICAL ASPECTS OF PAIN

The study of the psychology of pain is a rapidly growing field that has developed from behavioral and cognitive psychology. Its fundamental assumptions, although still neuroscientifically based, differ markedly from those of medical disciplines that are based on neurophysiology, such as neurology, psychiatry, and anesthesiology. Neurophysiology is concerned with biological organization and the chemical and physical laws that relate to the structure and function of the nervous system, whereas psychology is a complex of physiologic, cognitive, emotional, and social factors.

Cognition is a self-organizing process that gives coherence to an individual’s life and sense of self, extending across various external settings and through long periods of time.¹ Cognition, for our immediate purposes, consists of the perception of events in the internal (bodily) and external environments, along with the higher-order rational processes of reasoning and decision making. An intensive dialogue between neurophysiology and cognitive psychology is needed to achieve the level of integration that the study of pain management requires, and such an integration will be a path toward better pain management.

Clearly pain is both an important mechanism of biological protection and an aversive psychological experience toward tissue trauma, inflammation, or disease. The following section briefly describes the psychological processes of patients with chronic pain.

Attention

Attention refers to the selective filtering of information from the internal and external environments.¹ A pain patient cannot concentrate his or her attention on normal work and the ordinary routines of life because the pain frequently or constantly intrudes on awareness.

Pain diminishes when attention is intentionally directed toward other events, such as exciting games, books, or films. Distraction of attention, however, is effective only if the pain is steady or increasing in intensity at a slow rate.

Imagery

Our sensory information always creates some sort of image; for example, thinking about a family member may draw the visual image of this person from the memory. Listening to an old melody may bring back an image of a past event. Awareness of pain is one of many types of psychological image that recall for us a kind of aversive experience associated with bodily injury, trauma, or inflammation. Pain as a personal image can be described as a mental representation of the actual sensory activity associated with an injurious external event.²

Expectation

A patient with acute pain may expect the pain simply to go away. A patient with chronic pain gradually becomes hypervigilant for pain and will try to determine whether the pain will worsen, whether it might be associated with some sort of tumor, or perhaps whether the pain is the inevitable result of an inherited genetic disposition. Positive expectation helps the patient respond to medical treatment, whereas negative expectation can induce psychological disorganization and physiologic self-destruction.

Meaning

Most pain patients attempt to attribute their pain to some physical cause, such as rheumatoid arthritis, or speculate about the origin of the tissue trauma and its effect on their immediate and long-range well-being. In some cases this search for a physical cause is difficult or impossible because medical enquiry is unable to identify it. Some patients develop a negative attitude toward personal relationships during this process of seeking the meaning of their pain because they believe that they are “victims.” This negative attitude impedes a patient’s ability to respond to medical treatment and rehabilitation.

If the cause of the pain can be determined, it will influence pain perception and the effectiveness of treatment. For example, a stomach pain may become persistent if the sufferer learns that stomach cancer occurs often in his or her family history; if medical examination excludes the possibility of cancer, the stomach pain may soon stop.

Sensory and Emotional Disturbances as Causes of Anxiety

Pain feels unpleasant, causes fatigue, impairs sleep, interferes with memory, distracts concentration, and disrupts organized action and thought. Chronic pain often becomes the theme around which the patient organizes thinking and action. Chronic pain patients may preferentially recall negative ideas and feelings. Pain can interfere with a person’s ability to see clearly and evaluate his or her situation and the factors that may be causing stress. The results are anxiety, depression, irritability, social withdrawal, and a tendency to expect the worst. All these psychological behaviors increase the intensity of the perceived pain.

Schemata

A schema is a normally unconscious pattern of concepts, assumptions, images, affects, and associations that reflects a person’s experiences and influences his or her perception of the present and expectations for the future.³ Thinking of a university brings a host of associations for those who studied in a university environment: the campus, buildings, young students, professors, and laboratories, for example. This schema is formed by activating a learned network of associations. It does not bring to mind the focused image of a particular teacher in a particular class; rather, it is a nonspecific frame of reference that the brain has collected from many aspects of the personal background.

When thinking about pain, the patient activates a complex schema that involves past pain experiences and medical history, present fear, the possible meaning of the pain, the social consequences of pain, future expectations, and more. This pain schema definitely promotes interaction between cognition and sensory pain signals.

The idea of the schema explains how the human brain can generate its own patterns of awareness and imagery from past experiences. The schema can be retrieved selectively from the memory, modified by the new experience, and put back into storage. This process of schema formation constantly builds and remodels one’s view of the world. Therefore pain is no longer a passive experience of tissue trauma; rather, it becomes a complex organization that involves multiple dimensions of cognitive psychology.

Most doctors view a patient’s description of pain as directly reflecting a sensory experience that provides an important basis for diagnosis. This view is usually accurate when dealing with acute pain. In the case of chronic pain, it is more helpful to view it as a cognitive schema that involves multiple determinants and complex patterns of association. Thus the treatment of chronic pain requires the practitioner to understand not only the neurophysiologic cause of the symptoms but also the psychological associations, such as past experiences, present circumstances, and expectations for the future.

Some Pain Behaviors Seen in Acupuncture Clinics

A patient with pain who is seeking help in the form of acupuncture therapy comes to the clinic as an individual with a unique background and psychological organization; so his or her symptoms become individualized. Each patient presents a different picture of pain. To make the best treatment decision, a practitioner should understand both the neurophysiological basis and the psychological aspects of the pain presented by each patient.

Behavior 1

We learn early in life that after an injury, such as broken skin on the knee, the pain will persist for a couple of days. A child may cry to attract attention and may solicit help after hurting a knee; he or she feels better after the parents offer attention and help. This situation shows that pain can be considered unbearable when help is unavailable, but it diminishes or vanishes when relief is at hand.

Many patients suffer from pain for several days but feel better on the day before they go to the office for treatment. The practitioner should understand that this remission can be a real sign of the beginning of natural healing, but it also can be a temporary relief obscured by psychological factors. Complete treatment should still be administered.

Behavior 2

After one or two treatments, the patient usually feels much better and may regard the result of treatments as “miracles.” Acupuncture sometimes provides fast pain relief, especially in healthy patients who are experiencing acute symptoms (mostly group A patients, see Chapter 6). If this type of “miracle” appears in patients suffering from chronic pain, the practitioner should not be overly optimistic. Chronic pain represents a long-term pathologic change of tissues, such as sensitization of neurons in the spinal cord, and thus for chronic pain there is no quick fix. The “miracle” can be enhanced by psychological elements, such as expectation, strong personal willpower, distraction, and social factors such as family support.

Often a patient with chronic pain has tried many other modalities and failed to get significant results. Acupuncture therapy is new, is “mystical,” and may be positively introduced to the patient through the media, articles, or friends. Often the first treatment produces positive effects such as a good night’s sleep, which the patient may not have had for a while. All these factors arouse in the patient great expectations related to acupuncture treatment. In a case like this, however, the patient may soon feel that the old pain is returning, and therefore that the efficacy of acupuncture is decreasing.

Acupuncture is effective in relieving pain sensation, but healing takes time. The practitioner should understand the true nature of the healing process and work to prevent drastic psychological fluctuations so that the patient’s expectations will be realistic.

A comparable situation is when a new medication is much more effective than the existing ones because it has just come to the market and both doctors and patients are overly enthusiastic about it. After a while, the perceived efficacy of the new drug declines and its real efficacy can then be more objectively evaluated.