Mysterious Placebo Power Is Underappreciated

Are you taking a placebo? This may be a shocking idea. A placebo, after all, is a pill, potion or patch that is not expected to have any particular therapeutic effect on your condition. So, surely, your doctor would never prescribe one.

Actually, your doctor might, and with good reason. According to a study published last month, about half of the rheumatologists and internists who responded to a survey said they sometimes prescribe a placebo (BMJ, online Oct. 23, 2008).

Now, these doctors were not writing prescriptions for sugar pills. Most were recommending vitamins or over-the-counter pain relievers such as aspirin or acetaminophen. About two-thirds of the respondents thought there was nothing unethical about this. After all, the treatments were meant to make the patient feel better without creating complications.

This research made headlines, perhaps because the placebo response is fascinating and mysterious. Astute observers have known for centuries that the expectation of getting benefit can have a powerful healing impact.

One of the most dramatic examples in the medical literature comes from the middle of the 20th century. A man with lymphoma had large tumors throughout his body and was expected to die within a few weeks. As a last resort, his physician injected a dose of an experimental treatment called Krebiozen. The response was dramatic: “The tumor masses had melted like snow balls on a hot stove, and in only these few days they were half their original size! This is, of course, far more rapid regression than the most radiosensitive tumor could display under heavy x-ray given every day…” (quoted by Larry Dossey in the  book, The Extraordinary Healing Power of Ordinary Things).

The patient’s response to the treatment was amazing, but even more amazing was what happened when, months later, news media reported that Krebiozen was useless. At that point, his health deteriorated rapidly, but his doctor gave him a second injection. He told the patient that it was a new, far more powerful form of Krebiozen, but it was in fact sterile water. Nonetheless, the patient had another dramatic recovery and enjoyed two more apparently healthy months. Then the American Medical Association announced its findings that Krebiozen was without any merit. Within a few days, the patient was admitted to the hospital and died shortly thereafter.

Medical research on new treatments relies on placebo. Without a randomized, placebo-controlled trial, scientists don’t know how well the drug or device really works. In fact, the FDA requires that new medicines be proven more effective than placebo—and that can be harder than you might imagine. In most studies of conditions such as pain, depression or even heartburn, one- to two-thirds of patients respond to the inert pill. The drug being tested has to provide benefit to significantly more subjects.

All this points up a few quirks in current medical practice. Most doctors like to think of themselves as practicing “evidence-based medicine.” They look down their noses at unproven approaches like herbs, homeopathy or home remedies. Yet a majority is willing to utilize unproven treatments when they have nothing better to offer a patient.