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Spontaneous Remission and the Placebo Effect

Stephen Barrett, M.D.

When someone feels better after using a product or procedure, it is natural to credit whatever was done. However, this is unwise. Most ailments are self-limiting, and even incurable conditions can have sufficient day-to-day variation to enable quack methods to gain large followings. Taking action often produces temporary relief of symptoms (a placebo effect). In addition, many products and services exert physical or psychologic effects that users misinterpret as evidence that their problem is being cured. These "Dr. Feelgood" modalities include pharmacologically active herbal products, quack formulas adulterated with prescription drugs, colonic irrigations (which some people enjoy), bodywork, and meditation. Scientific experimentation is almost always necessary to establish whether health methods are really effective. Thus it is extremely important for consumers to understand the concepts of spontaneous remission and the placebo effect.

Spontaneous Remission

Recovery from illness, whether it follows self-medication, treatment by a scientific practitioner, or treatment by an unscientific practitioner, may lead individuals to conclude that the treatment received was the cause of the return to good health. As noted by Medical historian James Harvey Young, Ph.D.:

John Doe does not usually realize that most ailments are self-limiting and improve with time regardless of treatment. When a symptom goes away after he doses himself with a remedy, he is likely to credit the remedy with curing him. He does not realize that he would have gotten better just as quickly if he had done nothing! Thousands of well-meaning John and Jane Does have boosted the fame of folk remedies and have signed sincere testimonials for patent medicines, crediting them instead of the body's recuperative power for a return to well-being. . . .

The unscientific healer does not need to observe the restraints of reputable medicine. Where true medical science is complex, the quack can oversimplify. . . . Where ailments are self-limiting, the quack makes nature his secret ally [1].

It is commonly said that if you treat a cold it will disappear in a week, but if you leave it alone it will last for seven days. Even many serious diseases have ups and downs. Rheumatoid arthritis and multiple sclerosis are prime examples. On rare occasions, even cancer can inexplicably disappear (although most testimonials for quack cancer remedies are based on faulty original diagnosis or simultaneous administration of effective treatment).

Quackery's victims are not the only ones who can be fooled by the placebo effect, spontaneous remissions, and other coincidental events. The gratitude and adulation of people who think they have been helped can even persuade charlatans that their methods are effective!

The Placebo Effect

The power of suggestion has been demonstrated by many investigators in a variety of settings. In a classroom, for example, a professor sprayed plain water about the room and asked the students to raise their hands as soon as they detected an odor. Seventy-three percent managed to smell a nonexistent odor.

Persons with a dominant or persuasive personality often have considerable impact on others through their ability to create confidence, which enhances suggestibility. Many individuals who are taken in by a charlatan later tell their doctors, "But he talked to me; he explained things; he was so nice."

Individuals who are psychologically susceptible to suggestion often feel better under the influence of counseling or reassurance. Several years ago, an airline flight attendant told me, "I take a multivitamin pill that Consumer Reports says is useless. But I don't care. It makes me happy."

Gullibility and wishful thinking are common human characteristics. People are willing to believe in untrue things in varying ways and to varying degrees. Even scientifically sophisticated people may respond to the power of suggestion.

In medicine the effect of suggestion is referred to as the "placebo effect." The Latin word placebo means "I shall please." A placebo effect is a beneficial response to a substance, device, or procedure that cannot be accounted for on the basis of pharmacologic or other direct physical action. Feeling better when the physician walks into the room is a common example.

A placebo may be used in medicine to satisfy a patient that something is being done. By lessening anxiety, placebo action may alleviate symptoms caused by the body's reaction to tension (psychosomatic symptoms). In certain circumstances, a lactose tablet (sugar pill) may relieve not only anxiety but also pain, nausea, vomiting, palpitations, shortness of breath, and other symptoms. The patient expects the "medication" to cause improvement, and sometimes it does.

Many studies suggest that placebos can relieve a broad range of symptoms. In many disorders, one third or more of patients will get relief from a placebo. Temporary relief has been demonstrated, for example, in arthritis, hay fever, headache, cough, high blood pressure, premenstrual tension, peptic ulcer, and even cancer. The psychologic aspects of many disorders also work to the healer's advantage. A large percentage of symptoms either have a psychologic component or do not arise from organic disease. Hence, treatment offering some lessening of tension can often help. A sympathetic ear or reassurance that no serious disease is involved may prove therapeutic by itself. Psychologist Barry Beyerstein, Ph.D., has observed:

Pain is partly a sensation . . . and partly an emotion. . . . Anything that can allay anxiety, redirect attention, reduce arousal, foster a sense of control, or lead to . . . reinterpretation of symptoms can alleviate the agony component of pain. Modern pain clinics put these strategies to use every day. Successful quacks and faith healers typically have charismatic personalities that make them adept at influencing these psychological variables that can modulate pain. . . . But we must be careful that purely symptomatic relief does not divert people from proven remedies until it is too late for them to be effective [2].

Confidence in the treatment -- on the part of the patient and the practitioner -- makes it more likely that a placebo effect will occur. But the power of suggestion may cause even a nonbeliever to respond favorably. The only requirement for a placebo effect is the awareness that something has been done. It is not possible to predict accurately or easily a particular patient's reaction to a placebo at a particular moment. However, the psychologic predisposition to respond positively to placebos is present to some extent in most people. Some are very likely to obtain relief from placebos in a wide variety of situations, whereas others are very unlikely to do so. Most people's response lies somewhere inbetween.

Another factor that can mislead people is selective affirmation -- a tendency to look for positive responses when improvement is expected. As former National Council Aghainst Health Fraud president William T. Jarvis, Ph.D., has noted:

A culturally significant setting can also produce a potent effect, as folk healers know well. Effective settings can be as divergent as the trappings of an oriental herb shop to Asians, a circle of witchcraft paraphernalia to a primitive tribesman, or the atmosphere of a modern clinic to a modern urban American. Social expectations can also play a role, as occurs in stoic cultures where people are taught to endure pain and suffering without complaining. . . .

Operant conditioning can occur . . . when behavior is rewarded. . . . Thus, people with a history of favorable responses to treatment are more apt to react well to the act of treatment [3].

Moreover, says Dr. Jarvis:

People suffering from chronic symptoms are often depressed, and depression often produces symptoms that the patient attributes to the underlying disease. If the quack's promises make the patient feel hopeful, the depressive symptoms may resolve, leading the patient to conclude -- at least temporarily -- that the quack's approach has been effective against the disease [4].

Responses to the treatment setting can also be negative ("nocebo effects"). In one experiment, for example, some subjects who were warned of possible side effects of a drug were given injections of a placebo instead. Many of them reported dizziness, nausea, vomiting, and even mental depression. A recent review of 109 double-blind drug trials found that the overall incidence of adverse events in healthy volunteers during placebo administration was 19% [5].

Placebo responses, such as feeling less pain or more energy, do not affect the actual course of the disease. Thus placebo responses can obscure real disease, which can lead to delay in obtaining appropriate diagnosis or treatment.

The placebo effect is not limited to drugs but may also result from procedures [6]. Devices and physical techniques often have a significant psychologic impact. Chiropractors, naturopaths, and various other nonmedical practitioners use heat, light, diathermy, hydrotherapy, manipulation, massage, and a variety of gadgets. In addition to any physiologic effects, their use can exert a psychologic force that may be reinforced by the relationship between the patient and the practitioner. Of course, devices and procedures used by scientific practitioners can also have placebo effects.

Ethical Considerations

Doctors are confronted by many people who complain of tiredness or a variety of vague symptoms that are reactions to nervous tension. Far too often, instead of finding out what is bothering them, doctors tell them to take a tonic, a vitamin, or some other type of placebo.

A recent study has challenged the widely held view that the placebo effect is a major factor in the outcome of clinical trials. Most placebo-controlled trials compare the active treatment with a placebo, not with no treatment. This design cannot distinguish an effect of placebo from the natural course of the disease, regression to the mean (the tendency for random increases or decreases to be followed by observations closer to the average), or the effects of other factors. After analyzing 114 randomized trials that had a "no-treatment" group in addition to active treatment and placebo groups, the authors concluded:

An accompanying editorial stated that placebo use should be sharply reduced but may still be justified in carefully selected situations where pain relief is needed [8]. The study also casts doubt on the widely promoted notion that "alternative methods" may work by stimulating a placebo effect

Quacks who rely on the placebo effect pretend that (a) they know what they are doing, (b) they can tell what is wrong with you, and (c) their treatment is effective for just about everything. Many of their patients play the equivalent of Russian roulette. Medical doctors who use vitamins as placebos may not be as dangerous, but they encourage people to habitually use products they don't need. Because most people who use placebos do not get relief from them, their use is also a financial rip-off.


  1. Young JH. Why quackery persists. In Barrett S, Jarvis WT, editors. The Health Robbers: A Close Look at Quackery in America. Amherst, N.Y., 1993, Prometheus Books.
  2. Beyerstein BL. Testing claims of therapeutic efficacy. Rational Enquirer 7(4):1-2, 8, 1995.
  3. Jarvis WT. Arthritis: Folk remedies and quackery. Nutrition Forum 7:1-3, 1990.
  4. Jarvis WT. Personal communication to Dr. Stephen Barrett, Dec 18, 2001.
  5. Rosensweig P and others. The placebo effect in healthy volunteers: Influence of experimental conditions on the adverse events profile during phase I studies. Clinical Pharmacology and Therapeutics 54:578-583, 1993.
  6. Turner JA and others. The importance of placebo effects in pain treatment and research. JAMA 271:1609-1614, 1994.
  7. Hrobjartsson A, Gotzsche PC. Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment. NEJM 344:1594-1602, 2001.
  8. Bailar JC III. The powerful placebo and the Wizard of Oz. NEJM 344:1630-1632, 2001.

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This article was posted on December 18, 2001.