What Is the Placebo Effect?

Is it all in your mind? Or, is it all in your brain? Does the placebo effect show that the mind controls the body, that the mind can heal? Or does it reduce to a biochemical process-- provoked by a caring and attentive physician?

It’s an interesting question, one that Gary Greenberg addressed at length in a New York Times article. (via Maggie’s Farm)

In large part, it’s all in the context. A placebo works best when it is administered by a professional in a medical context:

Give people a sugar pill ... and those patients — especially if they have one of the chronic, stress-related conditions that register the strongest placebo effects and if the treatment is delivered by someone in whom they have confidence — will improve. Tell someone a normal milkshake is a diet beverage, and his gut will respond as if the drink were low fat. Take athletes to the top of the Alps, put them on exercise machines and hook them to an oxygen tank, and they will perform better than when they are breathing room air — even if room air is all that’s in the tank. Wake a patient from surgery and tell him you’ve done an arthroscopic repair, and his knee gets better even if all you did was knock him out and put a couple of incisions in his skin. Give a drug a fancy name, and it works better than if you don’t.

It works even if the patient knows that she is taking a sugar pill. What matters is that she is told, by a medical authority, that the pill will cure her illness:

You don’t even have to deceive the patients. You can hand a patient with irritable bowel syndrome a sugar pill, identify it as such and tell her that sugar pills are known to be effective when used as placebos, and she will get better, especially if you take the time to deliver that message with warmth and close attention. Depression, back pain, chemotherapy-related malaise, migraine, post-traumatic stress disorder: The list of conditions that respond to placebos — as well as they do to drugs, with some patients — is long and growing.

Is it about the mind taking control of the body? Some hold to this belief:

But most of these have traditionally been psychological in nature, focusing on mechanisms like expectancy — the set of beliefs that a person brings into treatment — and the kind of conditioning that Ivan Pavlov first described more than a century ago. These theories, which posit that the mind acts upon the body to bring about physical responses, tend to strike doctors and researchers steeped in the scientific tradition as insufficiently scientific to lend credibility to the placebo effect. “What makes our research believable to doctors?” asks Ted Kaptchuk, head of Harvard Medical School’s Program in Placebo Studies and the Therapeutic Encounter. “It’s the molecules. They love that stuff.” As of now, there are no molecules for conditioning or expectancy — or, indeed, for Kaptchuk’s own pet theory, which holds that the placebo effect is a result of the complex conscious and nonconscious processes embedded in the practitioner-patient relationship — and without them, placebo researchers are hard-pressed to gain purchase in mainstream medicine.

If it’s not the molecules, it’s the relationship. Of course, defining the nature of the relationship is more difficult than you might expect. Is it about caring and empathy? Or is it about ritual and drama?

Kaptchuk, who before joining Harvard had been an acupuncturist in private practice, wasn’t particularly disturbed by the finding that his own profession worked even when needles were not actually inserted; he’d never thought that placebo treatments were fake medicine. He was more interested in how the strength of the treatment varied with the quality and quantity of interaction between the healer and the patient — the drama, in other words. Hall reached out to him shortly after she read the paper.

To be clearer than Greenberg is, the interaction between healer and patient is not a drama. It is not taking place on a stage in front of an audience. It is a ritualized exchange that also affirms the patient as a member of society. True, enough, it’s an act of caring, but it is much more than that.

Naturally, researchers compare it to primitive rituals… which is not news. Claude Levi-Strauss did the same decades ago in his book, Structural Anthropology. He argued that recounting a myth that explained labor pains in terms of a struggle between spirits made more sense to a pregnant woman than would a scientific explanation. And thus, that it was as effective as medicine.

Greenberg continues:

that the placebo effect is a biological response to an act of caring; that somehow the encounter itself calls forth healing and that the more intense and focused it is, the more healing it evokes. He elaborated on this idea in a comparative study of conventional medicine, acupuncture and Navajo “chantway rituals,” in which healers lead storytelling ceremonies for the sick. He argued that all three approaches unfold in a space set aside for the purpose and proceed as if according to a script, with prescribed roles for every participant. Each modality, in other words, is its own kind of ritual, and Kaptchuk suggested that the ritual itself is part of what makes the procedure effective, as if the combined experiences of the healer and the patient, reinforced by the special-but-familiar surroundings, evoke a healing response that operates independently of the treatment’s specifics. “Rituals trigger specific neurobiological pathways that specifically modulate bodily sensations, symptoms and emotions,” he wrote. “It seems that if the mind can be persuaded, the body can sometimes act accordingly.” He ended that paper with a call for further scientific study of the nexus between ritual and healing.

Dare we mention it, but if a woman is giving birth she would do better to be in a modern hospital than in a primitive village where no medical care is available. If in the latter, she is doing the best under less than optimal circumstances. The issue is not so much the drama as the exchange itself, and especially the rituals that affirm her as a member of a community. Being connected is therapeutic. Feeling isolated and detached is not.

Now, however, physicians have discovered that the placebo effect produces an enzyme that correlated with a placebo response:

… a colleague presented evidence that an enzyme called COMT affected people’s response to pain and painkillers. Levels of that enzyme, Hall already knew, were also correlated with Parkinson’s disease, depression and schizophrenia, and in clinical trials people with those conditions had shown a strong placebo response. When they heard that COMT was also correlated with pain response — another area with significant placebo effects — Hall recalls, “Ted and I looked at each other and were like: ‘That’s it! That’s it!’ ”

Can you produce the same response by isolating and injecting the enzyme. Researchers are skeptical, rightly so. What if there is more to the biochemistry of human connection than an enzyme?

Some thoughts well worth pondering.