Health expectations influence the result

Andrés Fontalba
 

In search of the perfect woman, Pygmalion fell in love with his Galatea statue. Such was his wish, according to Ovid's account in The Metamorphoses, that the statue became human. When the Pygmalion effect occurs, the expectations we have influence our behaviour and our way of acting is precisely what causes the expected result. Our own beliefs also influence other people and thus we seek that our expectations become true with behaviours that tend to confirm them. This effect is also known as "self-fulfilling prophecy" and it means that we will do everything possible to make what we believe will happen finally come true.

A recent review in The New England Journal of Medicine reflects the effect of positive (placebo effect) and negative (nocebo effect) expectations on health outcomes. These effects occur in all contexts, both in clinical and research settings as well as inactive treatments and with placebos, in the informed consent process and public health campaigns. The placebo effect causes positive results and nocebo harmful results. The relationship between the patient and the healthcare professional greatly influences the likelihood that the placebo effect will appear or that side effects will be reported. Trust in the clinician and a positive relationship, with open communication, between the patient and the professional have shown the reduction of adverse effects.

Patients with common colds who perceive their doctors as empathic report symptoms that are less severe and of shorter duration than those who define them as distant people; in turn, when this relationship is good, there are reduced levels of inflammatory markers such as interleukin-8 and the neutrophil count. Therefore, one way to take advantage of the placebo effect in a non-paternalistic way would be to explain the results of treatment realistically and positively. Positive expectations increase response to treatments such as topical lidocaine, diazepam, deep brain stimulation, acupuncture, or even surgery. Concerning the expectations of clinicians, a study compared the effect of analgesic treatment with that of placebo after tooth extraction, showing that the knowledge, on the part of the doctor, that the patient was receiving the analgesic and not the placebo it was associated with his expressing greater pain relief.

On the contrary, information expressed worryingly or accompanied by social alarm, erroneous beliefs, pessimistic expectations, previous negative experiences or pressure from the environment can cause side effects or reduce the benefits of any type of treatment, as well as increase the risk that nonspecific side effects appear (intermittent, idiosyncratic, not dose-dependent and not reproducible). These side effects lead to non-adherence to treatment or its abandonment and lead the patient to seek alternatives in other fields. All these consequences could be attributed to the nocebo effect. If, when explaining the expected result of treatment, the proportion of patients who don’t have side effects is mentioned instead of the proportion that does, the incidence of such effects is diminished.

Finally, we ought to consider other serious consequences that the aforementioned effects can produce in a patient who receives treatment or undergoes a diagnostic test or intervention he doesn’t need, in both cases due to excessive and unrealistic expectations about its results. In this way, the belief about the potential benefits of said treatments or tests is maximized and the negative consequences thereof are minimized. The placebo and nocebo effects exist, they have a strong neurobiological and social basis, and their knowledge and management must be taken into account in any healthcare setting