Placebo

 What else helps placebos to work?

Some other things that help the placebo effect to work include:

The characteristics of the placebo – if the pill looks real, the person taking it is more likely to believe that it contains an active medicine. Research shows that larger sized pills suggest a stronger dose than smaller pills, and taking 2 pills appears to be more potent than swallowing just one. Generally, injections have a more powerful placebo effect than pills.

The person's attitude – if the person expects the treatment to work, the chances of a placebo effect are higher, but placebos can still work even if the person is sceptical of success. The power of suggestion is at work here.

Doctor–patient relationship – if the person trusts their health care practitioner, they are more likely to believe that the placebo will work.

Placebos and clinical trials

Placebos have been used in clinical trials for a long time, and are an essential part of research into new treatments. They are used to help test the effectiveness of a new health care treatment, such as a medication. For ethical (moral) reasons, people participating in clinical trials are told that they may be given a 'dummy' treatment.

Usually, one group of people takes the medication while another group (the ‘control group’) takes the placebo. The placebo may be a sugar pill. In some cases, none of the participants know whether they are taking the active or inactive (placebo) substance. Sometimes, not even the researchers know (this is called a double-blind test).

Comparing the results from both groups should show the effects of the medication.

Around one third of people taking placebos for health complaints (including pain, headache and seasickness will experience relief from symptoms. To show that a new treatment is more effective than can just be explained by the placebo effect, the results from the people taking the new treatment are compared with the results from the people taking a placebo.

The placebo effect does not imply an 'imaginary' illness

If a person's symptoms are relieved by taking a placebo or undergoing a ‘dummy procedure’, it may seem logical to assume that their illness must have been imaginary. This is not the case.

Medical research has shown that state of mind plays an important role in the development of disease. For example, stress is known to increase blood pressure, which in turn is a risk factor for heart disease. So, just as the mind can contribute to a physical disorder, it can also contribute to its cure.

The argument against placebos

Arguments against the use of placebos, include:

Placebos have the power to cause unwanted side effects. Nausea, drowsiness and allergic reactions, such as skin rashes, have been reported as negative placebo effects – also known as nocebo effects (see below).

Deceiving people is wrong, even if it helps someone’s symptoms to go away.

The ‘nocebo’ effect

The nocebo effect describes negative outcomes (such as pain or nausea) that occur because a person was expecting to experience them. A nocebo effect can occur if a person takes a real or active medicine, and can also occur if they are given a placebo.

This expectation of negative effects may be triggered when a patient is told which adverse effects they might experience before starting treatment.

Open-label placebos

Sometimes open-label placebos are used in clinical studies. This means that people are openly and knowingly prescribed placebo medication for a condition so that doctors can’t be said to have been deceptive or dishonest.

Despite being told that the medication they are taking is a placebo, the placebo effect can still occur for people using open-label placebos. It is thought that this could be due to:

feeling hopeful because of participating in a study

expectations of relief

the physical effect of pill-taking (such as opening a pill bottle, or swallowing)

natural fluctuations in pain levels (for example, pain coincidentally decreases when a placebo is taken).