In a startling experiment, 40 asthmatics inhaled a harmless saline mist that they were told contained allergens and irritants. Almost half suffered airway constriction, and 12 had full-blown asthma attacks. Those 12 were treated with the same saline mist, only this time they were told it was medicine. Their symptoms abated.
Behold the power of the placebo. It can cause or cure illness, even though it has no inherent physiological effect. And that makes it embarrassing to Western medicine. Science, with its focus on the body half of the mind-body duality, hasn’t been able to explain how placebos work, so it resorts to derision: placebo is roughly synonymous with sham medicine or hocus-pocus. From dummy pills to hypnosis, any remedy that isn’t physical is supposedly “just in your head.”
But what about the bodily response of the asthmatics? And they’re hardly an exception. Thirteen patients with hypersensitive skin were touched on one arm with harmless, placebo leaves that they were told came from the wax tree (Japanese poison ivy). On the other arm they were touched with the actual irritant leaves, but told that those leaves were harmless. All 13 subjects developed physical skin reactions to the placebo foliage, and only two to the real leaves.
Placebos have ameliorated such physical problems as angina pectoris and high blood pressure. Simply imagining healing has sped the disappearance of warts. And placebo alcohol has triggered changes in skin temperature, heart rate, and even penile erections. Using a cuff to measure arousal, researchers found that men who thought they’d drunk alcohol got stiffer stiffies while watching erotic videos than knowingly sober porn oglers.
Intrigued by such hard evidence, a growing number of researchers are devoting serious research to the placebo effect. How does it work? Can its power be harnessed for better healing? And what does it say about the mind-body problem?
Brown University psychiatrist Walter Brown has been studying placebos for about a decade, and earlier this year he wrote a fascinating Scientific American article about the subject. The first thing to understand, he says, is that the placebo effect is “not just a response to a sugar pill, but to the entire treatment situation.”
Indeed, actively doing something to get healthy is itself restorative. In a study of patients with heart disease, the death rate was halved among those who took placebo pills exactly as prescribed, compared to those who took the pills only intermittently. (It turned out that the placebo worked as well as the “medicine” being tested.) But patients also want clear signals from their doctors. In a British study of 200 patients who had general symptoms but no clear-cut illness, half were told they did not have a serious disease and would get better soon; the others were told that the doctor was not sure what was wrong. Two weeks later, 64 per cent of the first group had recovered, but only 39 per cent of the second group.
Of course, it’s a thin line between reassurance and paternalism. It’s also a thin line between placebos and snake oil. Early in the AIDS epidemic, Louise Hay made a fortune telling gullible gay men that they could heal themselves if only they would just love themselves more.
Still, as the ancient Greek physician Galen noted, “He cures most successfully in whom the people have the most confidence.” If placebos have an active ingredient, it’s probably belief. That’s almost certainly why placebo injections work better than placebo pills, and big pills work better than small ones.
“What physicians do nowadays is equivalent in many ways to what shamans and medicine men did for centuries,” says Brown. “Going to experts who have all the paraphernalia of healing is a very powerful experience.” He advises doctors to play up the symbols of medicine by wearing a white coat, hanging medical certificates on the walls, and giving patients a full exam even if the ailment is immediately obvious. In short: take time to make the patient feel cared for.
Of course, that’s anathema to HMOs, which pressure doctors to hustle patients through as fast as possible. Managed care, says Brown, “is threatening to remove the mask and feathers and snakeskin” from modern medicine, and so diminish its healing power.
The Placebo Effect, a marvelous book published last year, ends with the transcript of a symposium that ranges from voodoo death (in which people die from hexes), to the nature of faith and hope, to the power of the calendar. Why, as one study shows, are Orthodox Jews less likely to die during Jewish holidays than Chinese holidays, and vice versa for traditional Chinese? And why do many workaholics wait until vacation to get sick?
To study placebos is, finally, to study the influence of the mind on the body. No one has the foggiest idea how this works. But it’s a good thing that it does, because it’s estimated that only about 20 per cent of medicines in use today have been proven to work. Many of the rest are probably placebos.
Research assistance: Sam Bruchey, Andrew Robertson