That may seem like putting a thumb on the scale for drugs, but under the logic of the drug-approval regime, to eliminate placebo effects is not to cheat; it merely reduces the noise in order for the drug’s signal to be heard more clearly. That simple logic, however, may not hold up as Hall continues her research into the genetic basis of the placebo. Indeed, that research may have deeper implications for clinical drug trials, and for the drugs themselves, than pharma companies might expect.
Since 2013, Hall has been involved with the Women’s Health Study, which has tracked the cardiovascular health of nearly 40,000 women over more than 20 years. The subjects were randomly divided into four groups, following standard clinical-trial protocol, and received a daily dose of either vitamin E, aspirin, vitamin E with aspirin or a placebo. A subset also had their DNA sampled — which, Hall realized, offered her a vastly larger genetic database to plumb for markers correlated to placebo response. Analyzing the data amassed during the first 10 years of the study, Hall found that the women with the low-COMT gene variant had significantly higher rates of heart disease than women with the high-COMT variant, and that the risk was reduced for those low-COMT women who received the active treatments but not in those given placebos. Among high-COMT people, the results were the inverse: Women taking placebos had the lowest rates of disease; people in the treatment arms had an increased risk.
These findings in some ways seem to confound the results of the I.B.S. study, in which it was the low-COMT patients who benefited most from the placebo. But, Hall argues, what’s important isn’t the direction of the effect, but rather that there is an effect, one that varies depending on genotype — and that the same gene variant also seems to determine the relative effectiveness of the drug. This outcome contradicts the logic underlying clinical trials. It suggests that placebo and drug do not involve separate processes, one psychological and the other physical, that add up to the overall effectiveness of the treatment; rather, they may both operate on the same biochemical pathway — the one governed in part by the COMT gene.
Hall has begun to think that the placebome will wind up essentially being a chemical pathway along which healing signals travel — and not only to the mind, as an experience of feeling better, but also to the body. This pathway may be where the brain translates the act of caring into physical healing, turning on the biological processes that relieve pain, reduce inflammation and promote health, especially in chronic and stress-related illnesses — like irritable bowel syndrome and some heart diseases. If the brain employs this same pathway in response to drugs and placebos, then of course it is possible that they might work together, like convoys of drafting trucks, to traverse the territory. But it is also possible that they will encroach on one another, that there will be traffic jams in the pathway.
What if, Hall wonders, a treatment fails to work not because the drug and the individual are biochemically incompatible, but rather because in some people the drug interferes with the placebo response, which if properly used might reduce disease? Or conversely, what if the placebo response is, in people with a different variant, working against drug treatments, which would mean that a change in the psychosocial context could make the drug more effective? Everyone may respond to the clinical setting, but there is no reason to think that the response is always positive. According to Hall’s new way of thinking, the placebo effect is not just some constant to be subtracted from the drug effect but an intrinsic part of a complex interaction among genes, drugs and mind. And if she’s right, then one of the cornerstones of modern medicine — the placebo-controlled clinical trial — is deeply flawed.
When Kathryn Hall told Ted Kaptchuk what she was finding as she explored the relationship of COMT to the placebo response, he was galvanized. “Get this molecule on the map!” he urged her. It’s not hard to understand his excitement. More than two centuries after d’Eslon suggested that scientists turn their attention directly to the placebo effect, she did exactly that and came up with a finding that might have persuaded even Ben Franklin.
But Kaptchuk also has a deeper unease about Hall’s discovery. The placebo effect can’t be totally reduced to its molecules, he feels certain — and while research like Hall’s will surely enhance its credibility, he also sees a risk in playing his game on scientific turf. “Once you start measuring the placebo effect in a quantitative way,” he says, “you’re transforming it to be something other than what it is. You suck out what was previously there and turn it into science.” Reduced to its molecules, he fears, the placebo effect may become “yet another thing on the conveyor belt of routinized care.”