The nocebo effect
How Health Warnings Can Harm Health
A few years ago, a large-scale clinical trial of a new drug designed to alleviate the symptoms of prostatic hyperplasia was conducted, in which a large number of middle-aged men took part. However, the aim of the study was not only to assess the ability of the drug to help patients, but also to assess the ability of the power of their own mind to harm bodily health.
Before taking the drug, half of the men reported that there was a small risk of erectile dysfunction and other undesirable side effects of a sexual nature. None of the participants had a history of such problems, but they appeared in 44% of men who received a warning. Among the uninformed, this figure was only 15%.
This phenomenon is known as the nocebo effect. It lies in the fact that informing the patient about possible pain and other unpleasant side effects increases the likelihood of their occurrence. While the placebo effect, in which a patient's positive expectations can have a therapeutic effect, is relatively well known and studied, the nocebo effect is its little-known bad twin brother.
However, over the past two decades, experts have been receiving more and more evidence in favor of the existence of the nocebo effect. These evidences, as a rule, emerge when analyzing the side effects that develop during clinical trials in patients taking placebo, that is, not receiving any treatment. The aim of several recent studies has been to directly study the nocebo effect. Their results showed that negative expectations of patients are really able to aggravate their condition.
If the nocebo effect really works this way, then doctors can almost certainly reduce the suffering of their patients by downplaying or not mentioning some side effects at all. However, this drives them into an ethical trap, since in such cases, compliance with the principle of "do no harm" may conflict with the powerful doctrine of informed consent, which obliges doctors to inform patients about all the risks of potential treatment. Doctors and medical ethicists today are asking an unexpected question: if the pure truth can, in the literal sense of the word, harm, is it acceptable or even in the interests of patients in certain situations to withhold information from them about the possible side effects of prescribed drugs?
For most of medical history, doctors have been of the opinion that patients don't need to know much about their own treatment. This approach began to change at the beginning of the 20th century, after several doctors who performed surgery without the consent of patients were convicted of causing physical damage. After the end of World War II, the Nuremberg Trials were held and horrific facts about the activities of Nazi doctors who mutilated and often killed prisoners during their medical experiments were made public. In 1972, an investigation conducted by the American news agency Associated Press revealed the fact that there was no informed consent from participants in a 40-year study, during which poor black agricultural workers infected with syphilis were not informed of the diagnosis and were not provided with appropriate treatment.
In the 70s of the last century, "informed consent" – the patient's consent to treatment after receiving comprehensive information about possible risks and positive effects – became both a component of human rights compliance and a legal norm. Doctors were also convinced that clinical honesty contributed to the formation of trust, thanks to which patients were more willing to follow medical recommendations and report important symptoms. In the 80s, the federal health organizations of the United States and the American Medical Association officially approved the ethical standards of informed consent. The FDA has approved a requirement that information about potential adverse reactions should be printed on the labeling of the drug, as well as read out in television commercials.
However, as it turned out, the truth reported by doctors can have undesirable consequences. When conducting blind clinical trials, even placebo-receiving patients develop side effects listed in the instructions for the experimental drug.
There are very few empirical studies devoted to the study of the nocebo effect. This is partly due to the double ethical burden due to the fact that misleading the study participants can lead to their suffering. An analysis conducted in 2012 revealed only about 30 studies of the nocebo effect. However, during these early studies, scientists caused asthma attacks with the help of inhalers filled with a dummy drug, allegedly causing bronchospasm, and the pain experienced by postoperative patients who agreed to temporarily suspend the drip of morphine was twice as strong when the dropper was stopped openly than when this manipulation was carried out covertly.
Can doctors just hide or embellish the truth if they think it will help patients? From both an ethical and a legal point of view, this idea is unacceptable. However, some experts are trying to pave a more sophisticated way through this "minefield".
In the March issue of the American Journal of Bioethics, two researchers from Harvard University suggested using "contextual informed consent" as a possible way out of this situation. While standard informed consent obliges doctors to tell patients the whole truth about the risks associated with treatment, the authors argue in favor of the ambiguity of medical truth. In an interview, the first author of the article, Doctor of Neurology Rebecca Wells, states: "There is no "black-and-white" truth about the side effects of any drug. The words of [the doctor] do not just describe the probability of developing a side effect, in fact they are able to change this probability." In the article, Wells and her co-author, Ted Kaptchuk, a well-known placebo effect specialist, write that if doctors need to inform patients about the possibility of serious side effects, they should carefully choose words when describing minor side effects, especially if the patient has a history of similar symptoms or if there is a potential benefit from therapy very large.
What could this mean for healthcare ? Wells and Kapchuk mention several strategies that are already practiced by doctors to a certain extent.
According to Dr. Luana Colloca from the US National Institutes of Health, who studies the potential effects of placebo and nocebo in clinical practice, one of the ideas is that when describing the benefits and potential harm of therapy, emphasis should be placed on the positive effects. It is one thing to tell a patient that a negative side effect develops in 2% of cases, and quite another to tell him that in 98% of cases it does not develop. For example, during one of the studies, participants who were told about a low probability of developing fever and muscle pain after a flu shot developed these side effects much more often than participants who were told about a much higher probability of the absence of such troubles. The placement of accents did not affect people's decision about the expediency of vaccination, it only affected the frequency of side effects.
Another approach is for doctors to discuss the nocebo effect with patients and clarify their desire to receive information about minor side effects, while encouraging discussion of any problems that arise.
At the same time, from the point of view of patients, how many of us want to give up information about all potential side effects, even if it will get rid of unpleasant sensations? This would mean a partial loss of control over the situation and giving doctors the right to make decisions about what exactly we are supposed to know about the proposed therapy. For many of us, this idea does not look very attractive.
Kapchuk acknowledges that both the positive presentation of information and the process of obtaining informed consent of the patient should not go beyond certain limits.
There should be a clear line between preferential positivity and dishonesty. In particular, regarding "contextual informed consent", the article emphasizes that side effects develop even without the nocebo effect, and many of them are insignificant only if the patient observes bed rest. At the same time, even the minimal risk of treatment-induced drowsiness is extremely serious, for example, for the driver.
Moreover, providing patients with information about all possible side effects is safer from a legal point of view. There are other pragmatic aspects: making individual decisions about contextualizing informed consent requires much more time and attention to each patient than communicating a standard set of information to all patients. This question is quite important, since we live in an era of reducing the period of time allocated by a doctor for one patient.
Experts trying to draw public attention to the nocebo effect believe that moving forward depends on conducting new empirical studies examining the benefits and risks associated with this effect. They are agitating for the fact that doctors should be trained in a new type of communication with the patient, implying the awareness that spoken words can have a neurobiological effect.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on BostonGlobe: The nocebo effect: How health warnings cause health troubles.
The book "Mind Over Mind" dedicated to the nocebo effect, written by the author of the article, Boston journalist Chris Berdik, will be published in October this year.
Portal "Eternal youth" http://vechnayamolodost.ru26.09.2012