The Placebo Effect and Alternative Therapies
By Dónal P. O’Mathúna, PhD
When patients report improvements with a unique therapy that has little scientific support and possibly no known physiological basis, some immediately assume the benefits are explained by the placebo effect. Alternative medicine includes therapies and remedies that are sometimes poorly understood, leading some to wonder if alternative therapists have learned to make the most of the placebo effect.1 Such interest led the National Center for Complementary and Alternative Medicine to sponsor a workshop on the placebo effect that received widespread recognition from many conventional authorities.2
Some advocates of specific therapies recoil at the mention of the placebo effect, fearing it will lead to the intervention being viewed as quackery or snake oil. So many apparently physiologically inactive treatments have been used throughout the history of medicine that it has been claimed that "until very recently, the history of medical treatment was largely the history of the placebo effect."3 But if a therapy works via the placebo effect is this necessarily a bad thing? For example, some critiques of psychotherapy claim that its effects are due to a placebo response, which therefore "invalidates the professional utility of the field."4 Yet others claim that if psychotherapy maximizes the placebo effect "it should be applauded rather than condemned for exploiting a useful therapeutic process which is under-utilized in general health care."4 The same positions are taken when people claim that alternative therapies work via the placebo effect.
This type of controversy has led to studies that are starting to produce intriguing results. As a result, better understanding of what some call the mind-body connection is starting to emerge. Interest in alternative medicine has legitimized research into how one’s thoughts, feelings, relationships, and spirituality impact one’s physical health. Some of these studies have addressed how the patient-therapist interaction impacts the patient. Some claim that interest in alternative medicine arises in part from dissatisfaction with the impersonal nature of conventional medicine, while others point to a shift in values and philosophies.5 Are alternative therapists better at developing a healing relationship with patients? Are alternative therapists more adept at exploiting the placebo effect? And if so, is this a good or a bad thing?
These types of questions point to the importance of the "art of medicine." The art of medicine once again is being viewed as an integral part of the healing dynamic. "Placebo research and psychoneuroimmunology are beginning to clarify a role in which caring is no longer an act of compassion or indulgence but has everything to do with curing or, in the preferred modern term, effectiveness.’"6 The placebo effect is no longer just an inconvenient set of subjective responses that interfere with the collection of good, hard research data. Rather, the placebo effect is an important way by which clinicians can promote caring and healing in their interactions with patients—regardless of the type of medicine practiced or therapies employed.
Although placebos are generally well-respected in medical research, using placebos in the clinic raises some difficult issues. Does deliberately giving patients placebos conflict with the values of openness and honesty?6 If so, and patients later discover they have been given placebos, will their trust in physicians be diminished? Research subjects who reported improvements and later discovered they received the placebo have reacted negatively, viewing themselves as foolish or gullible.7 Some assume that those responding to a placebo have nothing really wrong with them, which may delay further treatment.
Many of these reactions are based on misconceptions and myths regarding placebos. These myths will be examined here, and evaluated based on the most recent research. Although much remains to be learned about the placebo effect, it has the potential to significantly impact health care outcomes, especially in such difficult-to-treat conditions as pain, anxiety, and chronic illness. These also tend to be among the most popular conditions for which alternative therapies are used.
A Brief History of the Placebo
The mid-1950s were important years in the history of the placebo. In 1954, the British medical journal Lancet published an editorial entitled "The Humble Humbug," describing the dubious role of placebos in medicine.8 It concluded that a placebo was "a means of reinforcing a patient’s confidence in his recovery, when the diagnosis is undoubted and no more effective treatment is possible." With the "humbug," physicians could offer patients placebos when they believed none of their treatments would be truly effective. They would then know that by pretending to have effective treatments they could help their patients at least feel better. Thomas Jefferson (1743-1826) called this the "pious fraud," noting that "one of the most successful physicians I have ever known has assured me that he used more bread pills, drops of coloured water, and powders of hickory ashes, than of all other medicines put together."9
Such use of sugar pills and colored water underlies the meaning of the term. In Latin, placebo means, "I shall please." It was first used to refer to hired mourners at funerals because they would begin their wailing with Psalm 116:9, which in Latin states: Placebo Domino in regione vivorum (I shall please the Lord in the land of the living).10 Just as mourners substituted for the grieving family, placebos would stand in for "real" medicines. By the early 1800s, the Shorter Oxford Dictionary defined a placebo as "a medicine given more to please than to benefit the patient."11 Richard Cabot, a professor at Harvard Medical School, stated in 1903 that he was "brought up, as I suppose every physician is, to use placebo, bread pills, water subcutaneously, and other devices ... I doubt if there is a physician in this room who has not used them and used them pretty often ... I used to give them by the bushels."12
This aspect of the placebo effect reflects one way they have been used. It also brings with it much of the negative reaction people can have to the term. Few would find problems using placebos to truly please a patient, as in helping them feel better, especially when nothing else seems to work. But it seems too easy to move from this to frustrated practitioners condescendingly dishing out placebos to appease patients and get them out of their offices, in much the same way that antibiotic prescriptions have been written for flu patients. With the current emphasis on informed consent, many raise ethical questions about giving patients placebos while apparently deceiving them into thinking these are active medications. This same concern underlies many criticisms of specific forms of alternative medicine: If the therapy is proven to be just a placebo, it is deceptive to present it as an effective intervention.
In 1955, the publication of another article was to change the way placebos were viewed. Entitled "The Powerful Placebo," and authored by the distinguished Harvard physician, Henry Beecher, it concluded that "placebos have a high degree of therapeutic effectiveness in treating subjective responses, decided improvement ... being produced in 35.2 ± 2.2% of cases."13 Since that seminal article, the placebo effect has been regarded as a potent, yet mysterious force, "an entity with occult-like powers that could mimic potent drugs."12 Placebos have become integral to the design of the gold standard in medical research: the randomized controlled trial. And claims have filled the medical literature that any therapy is virtually guaranteed to help one-third of patients.
However, re-analysis of placebo data, and Beecher’s article in particular, recently has led some to wonder if the powerful placebo is actually "powerless."14 This controversy will be examined under the first of the myths regarding the placebo effect. The problem is that much remains poorly understood concerning the placebo effect, and how it is defined. Such uncertainty leads to speculation, mistakes, and unfortunately the propagation of several myths concerning placebos. Some of these can be traced back to Beecher’s original article. In spite of its importance and many insights, it contains a number of statements about the placebo effect that have since been revised or overturned. Clarification of these points based on more recent analyses and studies will help to correct past mistakes and lay a better foundation for the practical applications that will be proposed at the end of this article. First, however, we must examine some ways in which the placebo effect has been defined.
Defining the Placebo Effect
Agreement over the definition of a "placebo" is much easier to find than agreement over a definition of the "placebo effect." Placebos are tablets, injections, surgeries, or procedures that in-and-of themselves would not be expected to directly influence a patient’s condition, symptoms, illness, or pain. And yet placebos do have these effects, which are sometimes viewed as placebo effects. For some, the causal connection is unimportant and all that matters is that the effects follow in time after administration of the placebo. However, the placebo effect is defined in at least two other ways.15 The first of these is as the effect of giving a placebo, or what is called the "treatment ritual." This is the idea that giving someone anything viewed as a remedy or therapy will lead to change. The third definition is that the placebo effect is the sum of all those psychological processes that occur during an interaction between a health care professional and a patient. This very broad view of the placebo effect raises the interesting implication that "a placebo effect does not require a placebo."10
The role of the placebo effect in the changes experienced by patients who receive any therapy is complicated by several factors. People’s symptoms and illnesses may improve due to a specific effect of the therapy on the illness. But improvements also may have more to do with the nature of the illness than the treatment.16 Some conditions, such as pain, anxiety, multiple sclerosis, and many others, normally fluctuate in their symptoms. Others spontaneously improve, such as the cold or flu.
Another complicating factor is the observation that when the intriguing results of an initial study are used to support fascinating conclusions, the results of later studies often do not support the initial conclusions. This finding underlies the importance of replicating measurements and studies. The phenomenon is called "regression towards the mean" and is a statistical axiom representing the tendency of extreme values to move closer to the average upon repeated measurement. For example, patients often come to doctors when their symptoms are the worst. Thus, no matter what happens during the visit, the symptoms of mild illness will naturally be somewhat better afterwards. Similar things can happen in clinical trials, with the improvements being ascribed to the placebo effect, when they are more likely due to natural fluctuations. Some have even gone so far as to claim that "most improvements attributed to the placebo effect are actually instances of statistical regression."17
All of this means that efforts must be taken to ensure that the placebo effect is not defined so broadly that it includes all improvements after a therapy except those physiologically caused by the therapy.18 This would portray the placebo effect as more powerful than it actually is. As we will see, this has important implications for the design of research studies. The differences between a placebo group and the test treatment group may not be due only to the placebo effect. The true placebo effect is the difference between those who are in a placebo group and those who do not receive any treatment. This can be difficult to measure, and may add additional costs to a study. A common way in which it can be added is by including a waiting list control.
Patients randomly assigned to a waiting list group are told that they will be admitted to one of the study groups later. Pre-test clinical measurements are taken when they are placed on a waiting list at the beginning of the study, and then again when they are moved to either the placebo or active treatment group. These measurements allow changes due to natural variation and other factors to be measured, and allow the placebo effect to be calculated.
Because of these complications and disagreements over definitions, a controversy is growing concerning whether the placebo effect is real. Some would rather refer to the improvements experienced and observed by many as "non-specific effects."16 Others continue to call them placebo effects, but limit them to those changes that occur due to the interpersonal interactions between health care professionals and patients. In contrast with the physiological or pharmacological effects of a treatment, the placebo effects are those resulting from psychological and symbolic factors.10 "These include physician attention, interest, and concern in a healing setting; patient and physician expectations of treatment effects; the reputation, expense, and impressiveness of the treatment; and characteristics of the setting that influence patients to report improvement."19 As such, they constitute an important aspect of clinical practice, conventional or alternative, with the potential for significantly influencing people’s responses to any therapy. Many of these factors are integral to how alternative therapies are practiced. Yet if these benefits are to be maximized, the myths surrounding the placebo effect must be corrected.
Myths About the Placebo Effect
1. One-Third of Patients Respond Well to Placebos
A common myth is the claim that about one-third of patients will respond positively to any intervention because of the placebo effect. This claim can be traced back to Beecher’s paper, which remains the most frequently cited article in discussions about the placebo effect.13 Beecher randomly chose 15 studies involving more than 1,000 patients and estimated the average percentage of subjects who were relieved satisfactorily by a placebo to be 35.2 ± 2.2%. However, even within Beecher’s study, the effectiveness of the placebos ranged from 15% to 58%. An even wider range has been found in other studies. Roberts reviewed a number of treatments that were once believed to be effective, but were subsequently shown to work via the placebo effect.20 An average effectiveness of 70% was found in these, with some studies finding the placebo effective in 100% of those to whom it was given. Other studies reported no one benefiting from the placebo.
A recent re-analysis of Beecher’s data found serious problems.16 Two researchers obtained the original 15 studies used by Beecher and found that many of the improvements that Beecher classified as resulting from placebo effects were caused by other factors. For example, one of the studies Beecher analyzed found that 35% of patients with the common cold reported improvements after six days of taking a placebo. Beecher classified these improvements as resulting from the placebo effect. However, these could have been due to the normal improvements experienced by people after six days with a cold. Even more problematic were mistakes in the presentation of data from the original studies. In a study of a cough medication, Beecher stated that two groups of 22 patients each were given lactose (the placebo), and that 36% of one group and 43% of the other group reported improvements due to the placebo effect. However, the original study reported no groups as large as 22 and no significant improvements with any placebo.16 Mistakes were found in data Beecher took from 10 of the 15 studies.
The re-analysis reported that 14 of the 15 studies did not clearly demonstrate any placebo effect. The fifteenth study reported no information on its design so that Beecher’s claims about it could not be assessed. The authors concluded: "Many factors and phenomena have been summed up under the terms placebo’ and placebo effect,’ without being placebos or effects of placebo administration. ... Thus, The Powerful Placebo turns out to be a fiction."16
A subsequent review examined the results of randomized controlled trials that had included both a placebo and a no-treatment group.14 The aim was to determine if placebos had a role in the clinic as a form of treatment, and they concluded against such use. They found no significant effect from placebos as compared with no treatment. However, among sub-groups examined, there was a significant difference between placebo and no-treatment with subjective outcomes and in the treatment of pain, but not with objective outcomes or treatment of any other condition. This review also found larger placebo effects in trials with smaller numbers of subjects. The authors argued that reports of large placebo effects arise because of methodological problems that make it impossible to distinguish the effect of placebo from the natural course of the disease, regression to the mean, or patient-provider interactions.
Clearly, then, it is overly simplistic to claim that the placebo effect will lead to any treatment being effective for any particular proportion of its recipients. Some therapies for some conditions do appear to involve significant placebo effects. Much of the debate over whether the placebo is powerful or powerless can be traced to disagreements over terminology and the cause of resulting changes. Clinicians and patients have noted real changes after administration of inactive agents. Attributing the changes to the placebo itself commits the post hoc fallacy of assigning cause to the action most recently taken.1 Several causes may have been involved and possibly interacted with one another.
Clinicians using placebos as clinical treatments must therefore grapple with the premise that "there is no evidence of a general and clinically important effect of placebo interventions."15 Yet even those who reviewed Beecher’s data and found no evidence of placebo effects did acknowledge that "non-specific effects" occur, which they viewed as primarily "psychosomatic" and arising out of interactions between patients and providers.16 Promoting these effects may improve patient outcomes. But there is enough variation in results to conclude that claims that any therapy will bring improvements in one-third of patients are groundless. Different therapies vary in their placebo effects.
2. Certain Types of Patients Respond Well to Placebos
Beecher believed some people were "reactors" to placebos and others were non-reactors. He hoped to use placebos most beneficially by identifying characteristics of reactors. Earlier authors believed intelligence was one of those characteristics: "for some unintelligent or inadequate patients life is made easier by a bottle of medicine to comfort their ego ... to decline to humour an elderly chronic’ brought up on the bottle is hardly within the bounds of possibility."8 Beecher dismissed some of these ideas, showing that the placebo effect was not influenced by gender or intelligence, but held that: "There are however significant differences in attitudes, habits, educational background, and personality structure between consistent reactors and non-reactors."13
Attempts to identify these personality traits have proved unfruitful. Beecher himself noted that 55% of his patients could not be consistently classified as either reactors or non-reactors. This has since been verified in numerous studies. If someone responds positively to a placebo, that should not be viewed as a negative evaluation of the patient’s intelligence or any other characteristic. However, what has been demonstrated is that the extent of the placebo effect is influenced by certain factors in patients, such as their attitudes towards their health, their doctor, or their treatment, and how suggestible they are. All of these again point to the importance of the patient-therapist interaction.
3. Placebos are Just Sugar Pills
Another common misconception is that placebos only come in the form of sugar pills or saline injections. Placebo effects have been observed with tablets, capsules, injections, ointments, medical instruments, surgery, and a host of other interventions. Some would even go so far as to suggest that inadvertent statements, or an unwary raising of the eyebrows, can cause a placebo effect—usually of the negative type in these situations. Basically, any medical intervention or health care interaction can involve placebo effects. Some evidence exists that more invasive procedures lead to larger placebo effects. For example, in studies of migraine medications, placebos given by subcutaneous injection had significantly greater effectiveness than placebos given orally.21 These point to both the prevalence of these effects, and the importance of understanding them more fully.
4. Placebos Effects are Short-Lasting
Another myth is the idea that placebos have only short-lasting effects. This often is tied into the idea that placebo effects arise from a positive environment surrounding the interaction between patient and practitioner. The myth is that once the patient leaves the office, the good feelings disappear as the placebo effect quickly wears off. However, this assumes that the placebo effect is a purely subjective psychological one. In fact, profound physiological changes can occur after a placebo. For example, ultrasound therapy after the extraction of molar teeth resulted in reduced pain, swelling, and facial muscle spasms.22 These objective changes were due to the placebo effect since the results were the same whether the ultrasound instrument was turned on or off.
The long-term nature of the placebo effect was shown in studies of a surgical procedure called the internal mammary artery ligation. This surgery, used during the 1950s to treat angina, was believed to increase blood flow to arteries supplying the heart. In a double-blind study, a small number of patients received this surgery while another group believed they were receiving the surgery, but were given only a skin incision.23 Six months after surgery, more than half the patients in each group reported significant improvements overall, and significant reduction in nitroglycerine use. A replication of this study monitored patients one year after surgery.24 Two-thirds of those in the group receiving the true surgery reported greater than 50% improvement in angina symptoms, while 100% of those who received the placebo surgery reported the same improvement. Clearly, placebo effects can be long-lasting.
5. Placebos Cure Imaginary Illnesses
One of the most painful myths about placebos is the allegation that relief from a placebo demonstrates that the symptoms must have been imaginary. In other words, the illness or pain must have been "all in the patient’s head." Subjective measurements, such as people’s perceptions of pain, have been the focus of much placebo research.7 Pain is one of the conditions upon which placebos have a relatively large impact. It also has been noticed that conditions that are strongly influenced by stress are most amenable to the placebo effect. "Placebos seem to be most effective for highly anxious subjects, and placebo effects are often attributed to anxiety reduction and associated stress reduction."19 Studies also suggest that people pursuing alternative medicine tend to be more anxious than the general population.5 Does this mean that alternative medicine providers are also more adept at providing stress reduction?
Regardless of how any therapy works, relief of stress or anxiety does not imply that the symptoms were imaginary. These could be as real as those caused by a microorganism or a trauma. Recent studies have demonstrated that placebos cause changes in numerous objective outcomes. Positron emission tomography (PET) has demonstrated increased dopamine release after placebo administration to people with Parkinson’s disease.25 PET scans also showed activation of the same area of the brain by both opioid analgesics and placebos, although the analgesic did provide greater pain relief.26 Previous studies had demonstrated that the opioid antagonist naloxone can abolish placebo effects.
Another study used an electromagnetic device alleged to bring pain relief.27 The researcher rigged the instrument so that its lights and dials would give the appearance it was working, when in fact no magnetic field was being emitted. Of those who completed the study, 13% noted improvements in range of motion and existence of muscle spasm immediately after receiving the sham procedure. These outcomes were objectively measured by blinded physicians. Numerous other types of objective changes have been produced by placebos, raising serious questions about the value of some of the elaborate and expensive devices used by some practitioners.
6. Placebos Are the Same as Doing Nothing
With the increased attention given to placebos in clinical research, an unfortunate assumption has become prevalent among researchers. A search of MEDLINE from 1987 to 1993 found 130 studies that referred to either a placebo control or an untreated control. In 52 of these (40%), the terms were used synonymously, which is incorrect. "These data show that many researchers are confused as to what constitutes a placebo response."28 The problem arises when a placebo is viewed as the same as no treatment. As noted earlier, changes after administration of a placebo could be due to several non-specific factors other than the placebo effect.
During the 1950s, there was some debate over whether a placebo was the same as a "dummy" tablet. One authority distinguished a dummy tablet as "a form of treatment which is intended to have no effect. ... A placebo is something which is intended to act through a psychological mechanism. It is an aid to therapeutic suggestion, but the effect which it produces may be either psychological or physical."11 This distinction has been lost in the intervening years with the assumption that a placebo is the same as "doing nothing." But there often can be a big difference.
For this reason, the best clinical trials will include a placebo group and a no-treatment group.18 The placebo group captures the impact of the interactions between the researchers and subjects, and the effects of being involved in the research. Comparison with the test treatment group will allow determination of the presence of specific therapeutic benefit of the treatment above the placebo effect. Comparison between the no-treatment group and the placebo group will allow the natural course of the illness to be captured. This helps ensure that natural fluctuations in the course of the illness are not attributed to either the treatment or the placebo. Knowing that a placebo is not the same as doing nothing also can alleviate some of the anxiety felt about using placebos. In fact, some have wondered if the placebo effect occurs because placebos can stand as symbols for a physician saying, in effect, "I will take care of you."13
7. Placebos Can’t Do Any Harm
Another serious misunderstanding about placebos is that they can’t do any harm. This idea probably arose on the basis of the other myths that placebos only resolve imaginary problems and are the same as doing nothing. Sometimes therapies are promoted with the naïve disclaimer that if it’s just a placebo then at least it can’t do any harm. Such is not the case.
Negative effects can occur after placebos are administered and are called nocebo effects. A review of 109 research studies found that 19% of healthy volunteers given placebos in clinical studies had adverse nocebo reactions.29 Beecher’s seminal article included a section on toxic side effects. He had observed 35 different side effects, the most frequent of which were drowsiness, headache, fatigue, sensation of heaviness, and nausea.13 In some of these studies, up to 50% of the placebo recipients had side effects. However, whether these effects are the direct result of the placebo administered, or indirect, non-specific effects, remains unclear.16
Such nocebo effects point to the importance of how practitioners present information about a therapy. For example, the developer of Therapeutic Touch, a biofield energy therapy, cautions that recipients "can overdose on human energies" leading to "increasing restlessness, irritability, and anxiety that may be expressed as hostility or felt as pain."30
Studies on the nocebo effect demonstrate that just telling patients that an energy will be directed towards them that can cause adverse effects often will elicit the same consequences. For example, subjects were told that a very mild electric current would be passed through their heads to determine whether it would cause mild headaches.31 The subjects were told the focus of the research was to examine natural means of relieving headaches. One group of subjects was told that the electric current had produced mild headaches in the past, and a second group was told the (non-existent) current might cause a mild headache. The researchers explained that the current would be too mild to feel. For the research they actually used no current at all. Regardless of which group the subjects were in, almost three-quarters of the subjects got headaches. This study demonstrated the role of negative suggestion in nocebo effects.
Like placebo effects, nocebo effects can be severe and long-lasting. In a double-blind study, the impact of an electromagnetic device on pain was studied in 58 patients.31 Each subject received two treatments with the magnet turned on, and one with it turned off (sham treatment). In all cases, the instrument was rigged to appear as if it were working, whether or not it actually did work. Overall, after receiving sham treatment, 17% of the patients had worsened pain, 10% had definitive improvement, and 73% had no change. Five subjects dropped out of the study after receiving only the sham therapy, reporting increased pain. Three of these people stated six months later that the treatment (a placebo) had made their pain permanently worse.
Placebos can carry certain risks. Whatever the power of the placebo to do good, it also can do harm. The nocebo effect shows that suggestion can be the source of significant negative effects, and raises questions about how many side effects may occur because of nocebo effects. The nocebo effect should caution any person against promoting and providing therapies based on the belief that "at least it can’t cause any harm."
Practical Application
After correcting for these myths, the placebo effect remains an important way in which patient outcomes can be improved. When placebos are believed to be merely inert tools for use in clinical research, important ways by which health care professionals can help their patients can be missed. Bedside manner and caring presence have been promoted as part of what is traditionally important in health care, or as part of providing health care ethically. Many within alternative medicine assign primacy to the healing relationship between patient and provider and use that relationship to support patient belief in therapeutic interventions, hoping to promote efficacy and patient benefit. Recent research on the placebo effect is revealing that these practitioner-patient interactions are important factors in influencing objective patient outcomes.
An interesting study was conducted with 200 patients with a variety of relatively minor symptoms, but for whom a thorough examination led to no firm diagnosis.32 The patients were randomly divided into four groups. Two of the groups received a "positive" interaction with the physician, with one of these groups getting a prescription for a placebo and the other receiving no treatment. The two other groups received a "negative" interaction, and then got either a placebo or no treatment. The "positive" interaction was one in which the patients were given a firm diagnosis and confidently told that they would be better in a few days. The "negative" interaction was one in which no firm assurance was given, including the statement, "I cannot be certain what is the matter with you." If these patients were to receive the placebo they also were told, "I am not sure that the treatment I am going to give you will have an effect."
Two weeks after this office visit, all patients were mailed a survey asking about their recovery. Of those who received the positive interaction, 64% said they had recovered. There was no difference between those who were treated and those who were not. Of those who received the negative interaction, 39% had recovered, again with no differences between those treated and not treated. However, given the natural progression of the relatively minor illnesses that these patient had, 61% would have been expected to recover without medical help. Yet as a result of the negative interaction with the physician, many of these people remained ill. This study demonstrates very clearly the importance of being positive and generating hope in patients.32
Yet the problem is that "a favorable therapeutic style requires the therapist’s effort. ... The therapist must do the work of listening, perceiving, communicating, and giving of one’s self in an appropriate manner."1 Recent studies reveal that poorly understood non-specific effects do play a significant role in health. Much of the controversy surrounds which of these effects should be called placebo effects. Regardless of how a placebo is defined, recent studies show that the interaction between patients and physicians or therapists can significantly influence patient outcomes. Therefore, time should be taken to maximize these interactions, not only because they are pragmatically useful, but also because they are central to the ethical practice of medicine.
Conclusion
The placebo effect remains a mysterious phenomenon in human behavior. Some knowledge has been added recently regarding its importance and usefulness, but much remains unknown about how it works or why. Its existence is a reminder of the intimate mind-body connection, and the role of belief in healing. The beliefs and expectations of both patients and health care professionals, and the nature of their interactions, make a significant contribution to patient outcomes.
Placebos are central to high-quality clinical research to elucidate the effectiveness and safety of therapies and remedies. Groups must be compared to one another, and the placebo group is vital. However, changes in the placebo group are determined by more than just the placebo effect. To tease the placebo effect out from all these changes, a no-treatment group is needed in many studies. Comparing the placebo and no-treatment groups reveals more about the role of those non-specific, intangible factors also known by some as the placebo effect.
Practically speaking, health care professionals can increase the contribution of the placebo effect by promoting the art of medicine, in addition to the science of medicine. This also has been called the doctor’s bedside manner, or the nurse’s caring presence. There are numerous practical ways in which this can be learned and promoted.6 Availability to patients is important, as is giving them the time they need. Being approachable, listening to patients’ concerns, and empathizing with them make real contributions. This will serve to build trust, provide realistic hope, and bring reassurance that no matter what happens, someone they know will remain with them in their hour of need.
There also is a delicate art to using suggestion to influence patients’ expectations and therefore the outcomes. This has to be done ethically so that unrealistic hopes are not built. In many ways, these are communication skills, which are of vital importance in health care. Obviously, these are complicated issues, and the task is daunting. This is probably at least part of the reason why health care has drifted away from holistic care. But this is the essence of what medicine, nursing, and health care are all about.
The following statement about the role of physicians as healers is equally applicable to any health care professional. "The sheer difficulty of this role makes it all the more exciting, challenging, and important. ... Not surprisingly, it has been said that some of the best brains should be in general practice because it is, of all the branches of medicine, the most difficult to do well.’"6
Learning to maximize the placebo effect would go a long way to promoting care of patients.
Dr. O’Mathúna is Professor of Bioethics and Chemistry at Mount Carmel College of Nursing, Columbus, OH.
References
1. Feinstein AR. Post-therapeutic response and therapeutic style’: Re-formulating the placebo effect.’ J Clin Epidemiol 2002;55:427-429.
2. Russo E. The biological basis of the placebo effect. Scientist 2002;16:30-31.
3. Shapiro AK, Shapiro E. The Powerful Placebo: From Ancient Priest to Modern Physician. Baltimore and London: Johns Hopkins University Press; 1997.
4. Evans D. Placebo—The Belief Effect. London: HarperCollins; 2003.
5. Astin JA. Why patients use alternative medicine: Results of a national study. JAMA 1998;279:1548-1553.
6. Dixon DM, et al. The physician healer: Ancient magic or modern science? Br J Gen Pract 1999;49:309-312.
7. Wall PD. The placebo and the placebo response. In: Wall PD, Melzack R, eds. Textbook of Pain. New York: Churchill Livingstone; 1994:1297-1308.
8. Anonymous. The humble humbug. Lancet 1954;ii:321.
9. Jefferson T. The Writings of Thomas Jefferson. Version 9, Ford PL, ed. New York: G. P. Putnam’s; 1898. Cited in: Kaptchuk TJ. Powerful placebo: The dark side of the randomized controlled trial. Lancet 1998;351:1722-1725.
10. de Craen AJM, et al. Placebos and placebo effects in medicine: Historical overview. J R Soc Med 1999;92:511-515.
11. Gaddum JH. Clinical pharmacology. Proc R Soc Med 1954; 47:195-204.
12. Kaptchuk TJ. Powerful placebo: The dark side of the randomized controlled trial. Lancet 1998;351:1722-1725.
13. Beecher HK. The powerful placebo. JAMA 1955;159: 1602-1606.
14. Hróbjartsson A, Gøtzsche P. Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment. N Engl J Med 2001;344:1594-1602.
15. Hróbjartsson A. What are the main methodological problems in the estimation of placebo effects? J Clin Epidemiol 2002; 55:430-435.
16. Kienle GS, Kiene H. The powerful placebo effect: Fact or fiction. J Clin Epidemiol 1997;50:1311-1318.
17. McDonald C, et al. How much of the placebo effect’ is really statistical regression? Stat Med 1983;2:417-427.
18. Ernst E, Resch KL. Concept of true and perceived placebo effects. BMJ 1995;311:551-553.
19. Turner JA, et al. The importance of placebo effects in pain treatment and research. JAMA 1994;271:1609-1614.
20. Roberts AH, et al. The power of nonspecific effects in healing: Implications for psychosocial and biological treatments. Clin Psychol Rev 1993;13:375-391.
21. de Craen AJM, et al. Placebo effect in the acute treatment of migraine: Subcutaneous placebos are better than oral placebos. J Neurol 247;2000:183-188.
22. Hashish I, et al. Reduction of postoperative pain and swelling by ultrasound: A placebo effect. Pain 1988;83:303-311.
23. Cobb LA, et al. An evaluation of internal-mammary-artery ligation by a double-blind technic. N Engl J Med 1959;260: 1115-1118.
24. Dimond EG, et al. Comparison of internal mammary ligation and sham operation for angina pectoris. Am J Cardiol 1960; 5:483-486.
25. de la Fuente-Fernández R, et al. Expectation and dopamine release: Mechanism of the placebo effect in Parkinson’s disease. Science 2001;293:1164-1166.
26. Petrovic P, et al. Placebo and opioid analgesia— imaging a shared neuronal network. Science 2002;295:1737-1740.
27. Long DM, et al. Placebo responses to medical device therapy for pain. Stereotactic Functional Neurosurg 1989;53:149-156.
28. Ernst E, Resch KL. The importance of placebo effects [letter]. JAMA 1995;273:283.
29. Rosenzweig P, et al. The placebo effect in healthy volunteers: Influence of experimental conditions on the adverse events profile during phase I studies. Clin Pharmacol Ther 1993;54: 578-583.
30. Krieger D. Accepting Your Power to Heal: The Personal Practice of Therapeutic Touch. Santa Fe, NM: Bear & Company; 1993.
31. Schweiger A, Parducci A. Nocebo: The psychologic induction of pain. Pavlovian J Biol Sci 1981;16:140-143.
32. Thomas KB. General practice consultations: Is there any point in being positive? BMJ 1994;294:1200-1202.
O'Mathuna DP. The placebo affect and alternative therapies. Altern Med Alert 2003;6(6):61-69.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content