The Placebo Effect
“What’s effective is not the placebo, but the meaning of the treatment,” writes the doctor Harriet Hall in Skeptic Magazine. “We enter into a human relationship with a caring person who offers to help us.”
Hall is talking about placebos, those pills used by doctors and scientists that don’t contain any medicine, but often seem to help patients get better anyway. I say “seem” because the exact nature of the improvement, and the way that placebos effect it, is one of the most famously controversial topics in 20th-century medicine.
The article mentions that patients who know they’ve been given a placebo (commonly a sugar pill or just water) often request to continue the treatment. If you’re the type doctor who only believes in a physically measurable improvement — and most doctors are — then this request seems hardly justified. On the other hand, even if the patient is “imagining” their improvement, it seems presumptuous to claim that they are also “imagining” the sense of subjective comfort they are obviously getting.
The answer, says Hall, is to widen the medical definition of “betterment” beyond the rigid and often unsympathetic limits imposed on it by the tradition of empirical science. Consider another example from the article:
One study supposedly showed that patients recovered faster if their window looked out on trees rather than a brick wall; even if they didn’t recover faster, wasn’t it nice to give them a view? Even if we can’t document a quantifiable effect on patient outcome, the quality of life is important.
According to Dr. Hall, this implies that:
We may have a conditioned response to expect improvement because we have been helped in the past. We get a story, a narrative that explains why we feel sick and what we can do to get better. We get hope, support, human warmth, touch. All these factors might lead to an actual physiological response in which our pulse rate drops, we relax, our stress hormones decrease, and other changes facilitate healing, or at least comfort.
I’d suggest another conclusion from these examples — that what confounds most doctors about the effects of placebos, and which has basically fueled a century-long debate over nothing, is an outdated ontology of human ailment. The distinction between an “imagined” response to a drug and a “physical” response simply doesn’t exist in any fundamental sense.
As already hinted at in Dr. Hall’s article, anything that happens to us ultimately will have a “real” or “physical” effect. A painkiller might inhibit an enzyme in an inflamed knee, or an anti-depressant might target another enzyme in your brain. But something as simple as seeing a smile on someone’s face, or getting verbal reassurance from your doctor, will also release a cascade of chemicals in all different, complicated ways throughout your body. So would the complicated series of psychological and social (but ultimately, always physical) factors that are inherent in taking a placebo.
This doesn’t mean that the distinction between a drug and a smile isn’t useful. If anything, recognizing the complexity of human disease, even if deep down it’s nothing but a system of stimuli and response, provides even stronger justification for the quest to find simple, modular components of that system (i.e. drug pathways) and use them to our advantage. The thing is, we also shouldn’t forget the large, complex, and frustratingly non-modular components of the system either — a smile, an emotion, or a random perturbation in your chemistry that suddenly and inexplicably cures a discomforting ailment. This last point, the role that bewildering complexity–and with it, sheer chance–often plays in disease, makes for some of the most frustrating and inspiring moments in medicine, as told, for example, in “The Itch” by Atul Gawande.
A smile may well be the most powerful cure for an individual’s sickness, but a small molecule might be the simplest one to give to an entire population. And in between all of this, a placebo is still an important experimental method to control for all those complexities of the human system that we may or may not ever see directly.