Placebo use in medical practice

Monika Merkes sq 

Dr Monika Merkes

First published on The Conversation on 17 July 2013.






Placebos that involve deception: an ethical conundrum

Social entrepreneur Daniel Jacobs raised US$50,000 to develop a ‘placebo’ iPhone app that he says will help people make positive changes in their lives for health, joy and love.

No deception is involved. And the user will get to choose their type of placebo, such as (an image of) a pill, a magic wand, or a communion wafer.

But how much deception is involved in more conventional forms of placebo used in medical practice?

The effect

The placebo effect is caused by an expectation (people taking a placebo may experience something that they expect to happen, such as pain relief) or through classical conditioning, or both.

Classical conditioning is based on the idea that we form an association between a stimulus and a response. In Ivan Pavlov’s famous experiment, dogs were conditioned to salivate when a bell was rung because they had been taught to associate the bell with food.

This kind of conditioning or expectation leads to biochemical reactions in the brain, so placebos involve the same mechanisms and biochemical pathways as drugs, such as activating different neurotransmitters.

Studies show that placebos can alleviate symptoms of illnesses that involve pain, fatigue, nausea, and anxiety and functional disorders in the digestive, pulmonary and urinary systems, among other illnesses.

Many medical doctors use placebos regularly. A UK survey of primary care practitioners published earlier this year, for instance, found that three out of four use placebos at least once a week.

In particular, the use of impure placebos appears to be common. Impure placebos involve substances with pharmacological effect but not on the condition being treated, such as antibiotics for viral infections or vitamins.

Using deception is often considered necessary for a placebo to be effective. Indeed, the use of placebos in clinical practice usually involves deception. But research shows that placebos can be used without deception and still work.

Using deception for the placebo effect violates the ethical principles of respect for patient autonomy and informed consent. It can also undermine trust and damage the patient-physician relationship.

There are arguments both for and against the deceptive use of placebos in peer-reviewed medical literature as well as advice from professional organisations.

An argument for placebo with deception

One of the arguments for the deceptive use of placebos is that, in some situations, they are the best available treatment. In these instances, the principle of beneficence takes priority over patient autonomy, and deception is justified when it serves the patient’s welfare.

From this viewpoint, paternalism is justified.

Medical ethicist Daniel Sokol suggests such deception is justified when:

’the reasons include the prevention of great physical or psychological harm (including death), the exercise of kindness or compassion, the emotional or cognitive incapacity of the patient, and the reliable belief that the patient wishes to be deceived.’

To help practitioners decide when deception is appropriate, Sokol has published a deception flow chart in the British Medical Journal. He restricts the use of deception to rare occasions when ‘benignly deceiving patients can be morally acceptable’.

Arguments against placebo with deception

Medical practitioners use placebos sometimes to calm people when they can’t make a firm diagnosis but the patient expects a tangible treatment. In these situations, the American Medical Association cautions against the use of placebo.

It advises:

’placebo must not be given merely to mollify a difficult patient, because doing so serves the convenience of the physician more than it promotes the patient’s welfare.’

Another reason against the use of placebos is that it amounts to disease mongering [PDF 118KB] where healthy people are seen as requiring treatment and thus converted into patients.

Impure placebos can be unsafe; antibiotics, sedatives and analgesics can cause serious adverse reactions. And although the risk of adverse reactions might be low, the use of impure placebos without informed consent is problematic.

The unnecessary prescription of antibiotics also carries the risk of leading to antibiotic resistance, affecting not just the person who takes the drugs, but a much broader group of seriously ill people.

Even pure placebos can be unsafe; the sugar in sugar pills is often lactose, for instance, and some people are intolerant to it.

The guidance of medical associations

Some medical associations provide advice on the ethical use of placebos, such as the advice of the American Medical Association mentioned above. It generally guides its members against the use of placebos.

But others, such the Australian Medical Association, are quiet on the topic.

The German medical association, the Bundesärztekammer, advises that placebo treatments outside of clinical trials are ethically justified [PDF 290KB]:

    •    if there is no current proven (drug) intervention for that particular medical condition;
    •    for minor conditions in circumstances where the patient expresses a wish for treatment; and
    •    if it seems likely that a placebo treatment will be successful.

The chairman of the British Medical Association’s Ethics Committee expressed disappointment on learning of the extensive use of placebos by British GPs. He is quoted in a British newspaper as saying, ‘[P]rescribing something that you know is of no value is not ethical.’

How do patients perceive placebo use?

A recent survey from the United States confirmed what previous surveys (for example, from Switzerland and Hungary) discovered: most people found the use of placebo acceptable and valued honesty and transparency with such treatment.

Medical practitioners may be underestimating the openness of their patients toward the use of placebos.

The clinical use of placebos appears to be fairly well accepted and established by medical practitioners, given the extent of placebo use reported in several surveys. A systematic review of empirical studies found that between 41% and 99% of physicians and nurses had used pure or impure placebos, or both.

But without consensus on ethical use and without international guidelines, the use of placebos that involve deception continues to be an ethical conundrum.

Perhaps we can take guidance from the surveys and the placebo app. If the app proves to be effective and popular with users, it would confirm the open attitudes found by the surveys.

Medical practitioners should feel encouraged to explore their patients' views on placebo treatments as part of clinical decision making, and be open and transparent about their use of placebo treatments.

Dr Monika Merkes is an Honorary Associate at the Australian Institute for Primary Care & Ageing at La Trobe University.