Many experts point out that recent brain-imaging studies purporting to prove the existence of a placebo response are suggestive but far from conclusive. Howard Brody, whose chapter on the placebo effect appears in Callahan’s book, warns against reading too much into brightly colored brain scans that seem to show how certain regions of the brain “light up” when the placebo effect is induced. Brody, who is a family physician and researcher at Michigan State University, says, “I support the idea that PET [positron emission tomography] scanning data are helpful because they suggest which brain centers are involved in placebo effects and thereby suggest possible neural mechanisms that can be explored in future studies.” But, Brody adds, “I don’t agree with the notion that the placebo effect can now be proven to be real [just] because we can see it on a PET scan.”
To pinpoint the mechanisms responsible for the physiological changes associated with placebos, defenders of the effect will have to work more closely with their skeptical peers. Proponents have made much scientific progress and picked up some key endorsements. But they need to work harder to identify the type of research that will fully explain the phenomenon. In turn, the medical community needs to be more open to the potential benefits offered by placebos.
The most obvious common ground between the two camps is the economic imperatives they both face. If enthusiasts of the placebo effect want more notice and respect, they must prove the financial advantages of promoting the effect as a way to boost and supplement mainstream treatments. They must show that higher expectations will mean faster healing and better quality of care and will save money. That’s a message that will surely carry weight in the economically stressed health-care industry. As Groopman’s book illustrates, the practice of medicine ultimately comes down to what happens at the bedsides of patients. And there, Groopman reminds us, it’s worth keeping in mind the value of hope as a powerful and very real medicine.
Stephan Herrera is a contributing writer for Technology Review who often writes about the business and politics of health care.