The Best Medicine
The placebo effect can improve almost any medical condition—yet doctors all too often ignore it. Here's what it can do for you—and how to take advantage of it.
By Walter A. Brown published September 1, 1997 - last reviewed on June 9, 2016
Finally, discouraged and now a little worried, I called my internist. And as soon as I picked up the phone, I began to feel better. My internist—I'll call him Dr. Stevens—was, as usual, thorough, upbeat, and authoritative. After asking about my symptoms, Dr. Stevens told me that persistent coughing was common following the recent flu strain and that in most cases it gradually cleared within six weeks. He prescribed a cough suppressant, told me I should feel much better within a week, and added that if I didn't I should call him back.
When I put down the phone, my cough was not yet better, but I was. Relief was a possibility; for the first time in a month I was in charge of my cough, not the other way around. For the rest of the day the cough seemed less troublesome, even though I probably coughed as often as I had for the past few weeks. Certainly I brooded about it less. That night I slept better than I had in a month. Within three days the cough was barely noticeable, and in a week it was gone.
The Powerful Placebo
I don't know if the suppressant helped heal my cough or if the cough would have healed just as quickly on its own. But as a psychiatrist, I do know that the mere fact of seeking and receiving medical care—the "treatment situation"—made me feel better: less disabled, less distressed, more hopeful.
The benefit I received from the treatment situation is called, often derisively, a placebo effect. Although the placebo effect is frequently disparaged by doctors, it is a powerful part of healing. In fact, the history of medicine is largely the history of placebos. When subjected to scientific scrutiny, the overwhelming majority of treatments, old and new, turn out to derive their benefits from the placebo effect.
It is easy for us to accept that the treatments of antiquity—potions, brews, and incantations—did not provide the benefits attributed to them. After all, truly effective treatments were in short supply; the healers of the past cannot be faulted for offering something they and their patients believed might be helpful. But it is less widely acknowledged that much of today's medicine—the treatments offered in technologically sophisticated hospitals and doctor's offices—continues to be an amalgam of faith, magic, and ritual. Yes, medical treatment is more scientific today. New treatments often undergo rigorous testing to prove their effectiveness. And both the healing professions and managed care providers are demanding that treatment be based on evidence. Even so, some experts estimate that as few as 20 percent of the treatments routinely used by physicians today have actually been proven effective in careful studies. Doctors and their patients continue to ascribe healing powers to pills, psychotherapies, and surgical procedures that may be essentially inert.
It isn't that these treatments don't work; most do. Patients benefit from them. The catch is, like most treatments of the past, the treatment itself is of no particular value. The healing comes from the placebo effect.
Unfortunately, placebos are all too often ignored by the healing professions. I say unfortunately because the placebo effect—a more accurate (though unwieldy) term is "response to the treatment situation"—contributes to the benefit of every treatment. And often it is the only benefit. But as you'll see, savvy patients can take steps to ensure that their doctor takes advantage of this remarkably effective healing tool.
Pills Are Just The Beginning
But what exactly are placebos? When many people hear the term, they think of a sugar pill, a pharmacologically inactive capsule. More broadly, though, a placebo can be thought of as those components of medical care that have no intrinsic therapeutic value for the condition being treated but that nonetheless make people feel better. This might include the act of getting a medical exam, receiving a diagnosis or an explanation for one's symptoms, being given a plausible treatment, and leaving the office expecting to feel better. Depending on a doctor's personal style, the treatment situation may also include the healer's enthusiasm and commitment, an opportunity for the patient to talk about the illness, and any encouragement and attention the patient receives. The placebo effect is simply the improvement that occurs as a result of these components of care.
Placebo treatment can be extraordinarily effective. For example, in the late 1950s thousands of patients with angina pectoris—chest pain caused by insufficient blood supply to the heart—underwent internal mammary artery ligation, a surgical procedure believed to increase the heart's blood supply. The results were impressive: As many as 90 percent of patients enjoyed relief from their symptoms. But some cardiac surgeons were skeptical and decided to take a closer look. As an experiment, they did internal mammary artery ligation in one group of patients and in another group performed a "sham" operation—they made a chest incision but did no further surgery. With the artery surgery 76 percent of patients improved; with the sham (placebo) surgery 100 percent improved. Internal mammary artery ligation turned out to be merely a rather effective placebo.
Most placebos aren't quite that powerful, and some afflictions are more responsive to placebo treatment than others. But it has been estimated that across a wide range of afflictions—pain, high blood pressure, rheumatoid arthritis, asthma, coughs, and many others—about 30 to 40 percent of patients experience significant relief with placebos alone. And in some cases an astonishing 60 to 70 percent of patients will improve from placebos.
As my own research has confirmed, placebos can also be remarkably effective for certain psychiatric disorders. Although few patients with obsessive-compulsive symptoms or schizophrenia improve when given placebo treatment, about half of patients with depression or anxiety get significant relief with just placebo treatment.
In fact, we know a good deal about what placebos can do for people with depression, because over the past 40 years thousands of depressed patients have been given placebos in double-blind clinical trials—research studies in which a new drug is compared to a placebo, and both the patient and doctor are "blind" to which is being administered. In the most severe depression—the kind that makes it impossible to carry out the simplest tasks and requires hospitalization—placebo treatment is less effective than the standard treatments, antidepressant drugs and electroconvulsive therapy (ECT), or "shock treatment." About 20 to 30 percent of severely depressed people recover with placebo treatment, whereas 60 to 70 percent recover with antidepressants and 80 to 90 percent with ECT.
But in the most common type of depression—the milder version that affects almost 20 percent of people at some time in their lives but that doesn't require hospitalization—placebo pills are almost as effective as antidepressants. About 60 to 70 percent of such depressed patients recover with antidepressant medication, 30 to 70 percent with placebos. The less severe the depression, the more likely it is to improve with placebo treatment.
Placebos also stack up well next to another standard treatment for less severe depression, the various types of psychotherapy—interpersonal therapy, behavior therapy and, most prominently, cognitive therapy. Comparisons between these treatments and placebo pills have consistently shown that placebos are as effective as any of the psychotherapies, at least in the short term.
Why Do They Work?
Many diseases, such as the common cold, improve on their own. So some patients who get better with placebo treatment—and some who improve with standard treatment—would have gotten better if left to themselves. But placebo treatment is not simply the same as no treatment; it offers more than the passage of time. For example, although up to 70 percent of depressed patients improve when treated for a few weeks with a placebo, depressed patients awaiting treatment for a few weeks rarely improve. And when people experiencing pain are treated with a placebo they get maximum relief not at various times after treatment, as would be expected if "pain relief" was a result of spontaneous fluctuations, but one to two hours after treatment, just as they do with "real" pain medicine. Yet another example: A recent study in the European Journal of Psychiatry shows that people with schizophrenia who take placebo pills are less likely to relapse than those who receive no treatment.
So a placebo offers something therapeutic. What are its active ingredients? Jerome Frank, M.D., Ph.D., a psychotherapy scholar and author of Persuasion and Healing, pointed out that placebo treatment has the four features shared by all psychotherapies, features he believes are the curative elements: a person in distress; an expert; an explanation for the condition; and a healing ritual. According to Frank, these features reverse demoralization and promote the expectation of recovery.
Expectation undoubtedly makes an important contribution to the healing power of placebos. Across a wide range of illnesses, patients who expect to improve are more likely to improve. A recent British study, for example, examined the effects of both reassurance and expectation on patients with physical complaints but no identifiable disease. The doctor told some of these patients that no serious disease had been found and that they would soon be well. He told others only that the cause of their complaint was unclear. Two weeks later, 64 percent of the first group but only 39 percent of the second had recovered.
Expectation operates more specifically as well. For example, when people were given an alcohol-free drink but told that it contained alcohol, they often felt intoxicated, acted intoxicated, and showed some of the physical signs of intoxication. In another study, when people with asthma were given an inhaler containing only saltwater and told that they would be inhaling an irritant or allergen, they reported increased airway obstruction and had more difficulty breathing. But when told that the same inhaler had a medicine to help asthma, their airways opened up and they breathed more easily.
Yet another study reveals how expectations enhance the effects of "real" medicine. Patients with asthma were given a bronchodilator, a substance that opens airways and makes breathing easier. Its effect was twice as great when people were told that it would open up their airways and make it easier to breathe than when they were told it would tighten their airways and make breathing difficult.
Placebos that harm, as in the airway obstruction example above, are sometimes called "nocebos." Here, the expectation that one will get ill can actually produce illness, as with symptoms that are spread by being witnessed. Similarly, placebos can produce side effects; in a recent study of 303 men with enlarged prostates, more than 80 percent reported adverse effects while taking "inactive" pills.
Pills & Ills
In our culture, the pill is a symbol of healing. As such, the pill and the rituals surrounding it create powerful expectations of relief. And this expectation probably accounts for part of a pill's or capsule's therapeutic power.
As a result, placebos in pill form are remarkably effective. For example, propranolol is a drug often prescribed after a heart attack to regulate the heartbeat and prevent further damage. In a study headed by Ralph Horwitz, M.D., at the Yale University School of Medicine, patients who took propranolol regularly for a year had half the death rate of those who took it less regularly. But in the same study, those who took a placebo regularly also had half the death rate of those who took the placebo less regularly—even though the two groups of placebo users were similar medically and psychologically.
Placebo pills may also get their therapeutic power from the learning process known as conditioning. Just as Pavlov's dogs learned to salivate upon hearing a bell because the sound of a bell had accompanied food, a medically neutral substance or procedure associated with drug administration may eventually elicit the same response as the drug. For example, after a rat has been given several injections of amphetamine, an injection of saltwater alone produces a temporarily hyperactive rodent, just as the amphetamine had.
A similar process may well occur in humans. People who have experienced relief after taking a pill may unconsciously learn through conditioning that various characteristics of the pill—for example, its shape or color—and the context in which the pill is given, bring relief. A careful study by Eugene Laska, Ph.D., and Abraham Sunshine, M.D., has shown that the degree to which a placebo relieves pain is directly related to the potency of the pain medication taken the previous day. In other words, a placebo will relieve your headache more effectively if you took two codeine tablets yesterday than if you took a single children's aspirin. Clearly, previous experiences with treatment influence the response to placebo treatment, and a placebo is most effective when it follows active treatment.
All of this raises a provocative question: Might doctors someday openly use placebos as part of everyday treatment? Robert Ader, Ph.D., a psychologist at the University of Rochester and an expert on conditioned drug responses, suggests that in some treatment regimens placebo pills could be periodically substituted for drug-containing pills without losing the desired response to the drug. For example, someone taking codeine for a chronic pain problem could substitute placebo pills half or more of the time and as a result of conditioning get adequate pain relief. This approach would reduce the dose of "real" medicine, reduce the cost of treatment, and probably reduce toxicity and side effects as well. Like other research findings on placebo treatment, however, this approach has yet to be thoroughly tested and applied.
In considering how placebos may work, the distinction between disease and illness is worth noting. Disease can be defined as an abnormal state of the body—a broken leg, cancer, a lung infection—whereas illness is the suffering that accompanies disease. More succinctly, disease is what a physician sees; illness is what the patient feels. The misery of illness is a mixture of unpleasant symptoms, fear, and demoralization. Often people who are ill don't know what's wrong or what will happen to them. They feel at the mercy of the body that has betrayed them.
Placebo treatment may or may not benefit disease, but it always benefits illness. The decision to seek treatment restores some sense of control. The symbols and rituals of healing—the doctor's office, stethoscope, physical exam—offer reassurance; the prognosis, when favorable, reduces fear and uncertainty, and even when unfavorable reduces the distress of uncertainty; and a plausible treatment mobilizes hope and creates the expectation of improvement.
Since placebos may work in part by reducing the distress of illness, it comes as little surprise that placebo treatment seems most effective for afflictions in which distress directly affects the symptoms. In certain forms of depression and anxiety, for example, distress is the illness, and placebos are remarkably effective. Pain often improves with placebo treatment, as do asthma and moderate high blood pressure; in these conditions distress is one of the symptoms, or contributes directly to the symptoms.
There is no direct evidence that placebo treatment influences the course of diseases like cancer or bacterial infection. But distress does reduce the efficiency of the immune system, and it affects the secretion of hormones important in disease resistance. It is conceivable that by reducing distress, placebo treatment could influence countless diseases, including some we don't usually think of as subject to psychological influence.
Neglected and Rejected
Given its effectiveness, why is the placebo response ignored and often disparaged by the medical community? Some of the negativity surrounding the placebo comes from the term itself. Placebo is Latin for "I shall please." Because it is the first word of the Catholic vespers for the dead, these vespers were commonly referred to in the 12th century as "placebos." By the 14th century, placebo had become a secular and pejorative term; it meant flatterer, today. This usage probably stemmed from the derision felt toward professional mourners, who were paid to sing placebos. When placebo entered medical terminology, the pejorative connotation stuck: It was defined as a medicine given to please patients rather than to benefit them. In the 20th century the word took on its current definition, referring to a lack of pharmacologic activity.
Thus, placebo brings with it connotations of deception and inauthenticity. And some of the myths about placebos reflect this stigma. If a condition improves with placebo treatment, according to one myth, the condition is not real but all in the patient's head. Not true. Consider that placebo treatment is arguably the most consistently effective treatment for angina pectoris, an indisputably "real" heart condition. Placebo treatment not only relieves the pain of angina pectoris, it increases the victim's ability to exercise and in some cases produces improvements in the electrocardiogram.
Still, doctors and other healers are troubled by the placebo response. As noted earlier, much of both conventional and alternative medicine consists of treatments that are frequently prescribed, highly cherished—and scientifically unproven. The placebo's effectiveness challenges the value of these treatments. Further adding to doctors' discomfort is the lack of a complete understanding of how placebos work.
A Place For Placebos
Perhaps, though, the time has come to accept and harness this important part of healing. The treatment situation can be seen—like many conventional drugs—as a broadly effective treatment whose means of action is not entirely understood, and which is more effective in some conditions than others. How can patients take advantage of the placebo's power? Research offers some guidance as to how to enhance this component of healing:
- In order to boost your expectations of recovery, choose a healer in whom you have confidence. This idea is not new. In the second century, Galen, the Greek physician, observed: "He cures most successfully in whom the people have the most confidence." Even if the clinician you consult has been highly recommended and has impeccable credentials, if you don't have confidence in him or her you're better off with someone else.
- Choose a healer who is optimistic and upbeat.
- Look for a doctor who treats you as a collaborator, solicits your opinions, and involves you in treatment decisions.
- If you have a condition for which there are several equally effective treatments, ask for the treatment you believe will work best.
- If you have a recurrent condition that has responded well to a certain treatment in the past, use the same regimen again unless there is a very good reason not to, such as the availability of a clearly more effective or safer alternative.
- If you have reservations about a treatment your doctor suggests, express your concern. Other treatments more acceptable to you may be available. Should there be no other options, get more information regarding whatever concerns you. Hidden worries have more power than those in the open. Airing your fears makes it less likely that they will undermine the treatment's effectiveness.
The characteristics I've just mentioned may seem like nothing more than good medical practice, but they're all too often neglected. A patient's confidence is frequently enhanced when a physician listens attentively and conducts a thorough physical examination. The clinicians of the past seemed to know this intuitively. They didn't have antibiotics or insulin, but they did have a bag full of tonics and elixirs—all placebos—for any ailment and, more important, they wove healing rituals and symbols into a reassuring mosaic.
This personal style of medical care, of course, can require more than a five-minute visit. It is no small irony that at the same time the importance of placebos is being more widely recognized by professionals, changes in medical practice—such as the emergence of managed care—are restricting the activities of doctors, reducing the time they can spend with patients to an extent that threatens to eliminate important components of the healing situation. Managed care aims to make health care more efficient and inexpensive, but the erosion of doctors' freedom to give the attentive and thorough treatment that is crucial for the placebo response may make these goals harder to reach.
Another irony is that as conventional medicine becomes more sophisticated and scientifically based, Americans are seeking more and more of their health care elsewhere. Although new and indisputably effective treatments are developed every month, including diagnostic instruments and procedures that can achieve a level of accuracy unheard of just a decade ago, people are flocking to alternative treatments—herbs, megavitamins, acupuncture, spinal manipulation—even when there's little or no evidence these regimens provide specific, measurable benefits. But people get better from such remedies because, if nothing else, they boost expectations of healing. Perhaps now that we understand the molecular mechanisms by which many medical treatments work, physicians will feel more comfortable incorporating the powerful elements of healing that we don't fully understand.
The Placebo Phenomenon
- Placebo injections are more potent than placebo pills, and capsules more potent than tablets.
- A patient's response to placebos is not related to his or her personality, sex, or even suggestibility.
- Placebo effects are dose related. Two placebo pills have a greater effect than one, and large pills are more powerful than smaller ones.
- In a study of medical students, blue placebo capsules were more likely to produce sedation than pink capsules.
- The most common "side effects" from placebos: drowsiness, headaches, nervousness, insomnia, nausea, and constipation.
"Nocebos," or negative placebos, can also be quite powerful. Researchers at UCLA told psychology students who had volunteered for a study that a mild electric current would be passed through their skulls, and that they might experience a headache. Although there was in fact no such current, more than two-thirds of the students reported that they felt pain.
Placebos At Home
Many minor illnesses and injuries don't require a trip to the doctor's office. But around the home, family members can still take advantage of the placebo effect when caring for sick children, spouses, or parents. (Most parents, in fact, routinely treat their kids' ills with placebos without realizing it.) Here are some ways to make placebos part of your family's medical kit:
- For children, provide simple healing rituals—anything from a bandage of the traditional: "Let mommy kiss it and make it better."
- Be reassuring and optimistic to enhance the child's or other family member's expectations of healing. Tell him that he will feel better and explain when he will feel better.
- Remind the patient of previous positive experiences: "Remember how quickly it healed last time?"
- If professional medical care is required, emphasize the positive effects of treatment rather than focusing on negatives like pain or side effects. Tell the child (or adult) what positive changes to expect: "This medicine will take away the pain in your ear."