In recent years debate has spurred over the potential conflict between two emerging paradigms in biomedicine: Personalized Medicine (PM) and Person-Centered Medicine (PCM). Though both P-Med and PCM aim at tailoring therapies to the individual level, they do so by resorting to different conceptual frameworks and techniques. The promise of PM is that of taking advantage of genomic and molecular data to improve the diagnosis, therapy and prevention of diseases. The core idea of PCM, instead, is that of promoting health and recovery by considering the patient’s individual beliefs, values, past experiences, and narratives as an integral part of the healing process. If PM is associated with the use of genetic tests and therapies targeted at the molecular level, the hallmark of PCM is instead the patient-physician relationship and the stress on the importance of creating an optimal healing environment. Accordingly, PM and PCM are often presented in contrasting terms. Contrary to this dichotomous view, recent studies on the genetic biomarkers of placebo responses indicates that PM and PCM should not be understood as two mutually exclusive approaches, but rather as two sets of strategies that can and eventually ought to be integrated to maximize the patient’s benefit.

As for placebo responses, physicians and healers have always been aware of the curious fact that sometimes even a “fake” medicine may have a real effect if the patients have high expectations about its efficacy. Only in the last thirty years, however, a converging series of clinical trials, laboratory experiments and neurocognitive studies have begun to elucidate some of the underlying mechanisms of placebo responses. Today we know that such responses are primarily mediated by our neurocognitive systems and activate specific brain areas; that they may modulate symptoms across a broad spectrum of highly prevalent conditions such as pain, chronic pain, anxiety, depression, nausea, and Parkinson’s disease; and that to trigger clinically relevant placebo responses a “warm” or “emphatic” physician-patient relationship is one of the most robust and powerful components. Furthermore, it has been demonstrated that placebo responses are to some extend “individual”. Not everyone is a good placebo responder: some people have stronger placebo responses than others, just like some people respond better (or worse) to the same pharmacological therapy [1].

Naturally, a key-question in the field of placebo studies is thus whether there exists a reliable way of identifying placebo responders and non-responders. While previous attempts at answering this question have been inconclusive, a recent study targeting a specific genetic polymorphism (called COMTval158met) may have shed new light on this crucial issue [2]. People carrying such polymorphism on one or both of their chromosomes produce functional but less efficient forms of an enzyme that regulates the depletion of dopamine in brain areas. Since dopamine is known to play a key-role in many placebo responses, this study hypothesized a correlation between the presence of this genetic variance and the magnitude of individual placebo response. Testing this hypothesis on patients from a previous clinical trial [3], this study found a significant correlation between the number of variant alleles that people had (0, 1, or 2), and the magnitude of their responses to a more or less “emphatic” patient-physician relationship. The general conclusion of this study, thus, is that genetic data could to some extend predict who will benefit from a more patient-centered interaction with a physician, and who will instead receive no significant clinical improvements from it.

Though this result ought to be considered just as a first “proof of principle” awaiting further empirical confirmation, it nonetheless points at a series of new and intriguing implications for the future of personalized and person-centered medicine. First, rather than being two radically different ways of conceiving the medicine of the future, personalized genomic medicine and person-centered medicine may instead represent two different sides of the same coin. As this study on the genetic biomarker of placebo response demonstrates, it is now possible to combine a technique typical of PM –i.e. screening for a specific genetic polymorphism– with a protocol typical of PCM –i.e. an enhanced patient-physician relationship– in order to generate new empirical data. This approach opens the way to a new kind of experimental studies aimed at assessing the role that our genome plays not only with respect to traditional drug response, but also with respect to other variables that are characteristically embedded in clinical contexts, such as the patient-physician relationship. Second, the possibility to use genetic data to tailor-made non-pharmacological aspects of the clinical experience raises a new series of complex ethical issues. Should people be assigned to a more or less empathic patient-physician relationship on the basis of their genomic profile? Should doctors inform the patients about their status as placebo-responders? And how should this genetic information be obtained, disclosed, and protected as to respect patients’ privacy? While we may be still a couple of years away from the moment in which these interrogatives will surface in everyday care settings, what is already clear is that the future integration of personalized and person-centered medicine will depend much on the development of new experimental approaches as well as on our ability to anticipate and properly address its ethical and societal implications.

[1] Benedetti F, (2009) Placebo Effects: understanding mechanism in health and diseases, Oxford University Press.

[2] Kaptchuk T, et. al. (2008) Components of placebo effect: randomised controlled trial in patients with irritable bowel syndrome. BMJ. 3; 336(7651): 999–1003.

[3] Hall K, (2012) Catechol-O-Methyltransferase val158met Polymorphism Predicts Placebo Effect in Irritable Bowel Syndrome. PLoS One.; 7(10): e48135.