The Placebo Effect

placebo effectWhen visiting the doctors, we often end up hanging around in the waiting room reading a couple of old magazines before answering a series of questions and being examined, so after this rather lengthy experience we expect something in return, a drug, prescription or injection. This is where the use of a placebo can come into play, something reassuring for the patient so they feel that they are being treated effectively, whilst leaving the body to manage the problem which didn’t require any medical treatment.

The placebo effect is a beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient’s belief in that treatment. There are several different types of placebo, the most common being a pill containing no active ingredients, so it is pharmacologically inert and instead contains basic ingredients such as sugar, hence the term ‘sugar pill’.

Several studies point to a biological basis for the placebo effect, with the latest research focused on a region of the brain known as the mid-frontal gyrus, which runs along the frontal lobes just above the eyes. These studies conclude that this region of the brain seems to be quite separate from another region of the brain, known to be involved in responding to the effects of real painkilling drugs, and positive effects of placebos have been seen with heart problems, asthma and severe pain.

Other researchers, meanwhile, have focused on identifying the genetic basis of the placebo effect. This is based on the idea that certain signalling pathways in the brain, especially those involved in the ‘reward’ network, help to mediate the placebo effect. The idea is that these signalling pathways are under genetic control and that some people may have a certain combination of genes that make them more or less responsive to a placebo effect. Scientists have found that when people experience a decrease in pain from a placebo, certain compounds, called endorphins, are released in their brains. It has also been noted that particular colours, shapes and marks on these fake drugs make the placebo even more effective, an example being yellow capsules which are the most effective antidepressants.

Clinical trials teams often use placebo-controlled drug studies to determine whether their newly-designed drug is having the desired effect, or instead whether it is due to the power of positive thinking, believing that the drug is working. If patients on the new drug fare significantly better than those taking the placebo, the study helps to support the conclusion that the medicine is effective. However, using a placebo is less common nowadays due to ethical reasons, so instead they will compare new and old drugs during clinical trials, occasionally using a placebo so that the effects of the drugs used in the trial can be directly compared.

Ultimately, although using a placebo with the hope of patient belief is not going to a cure serious illnesses, such as inoperable tumours, studies have suggested that healing may not always lie in the treatment, but rather in the patients’ emotional and cognitive processes of feeling cared for.

Harriet LVI


Photo Credit: Mikkel Juul Jensen / Bonnier Publications / Science Photo Library / Universal Images Group

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