Understanding the Placebo Effect    


 This blog post talks about the placebo effect; what it is, its historical roots and how no one really understands how it works.

The Placebo Effect     

The placebo effect is one of the most fascinating aspects of modern medical research. Although there are many theories, in reality we don’t really understand how it works.


What Is A Placebo ?

The word placebo is usually translated from Latin as ‘I shall please. ’ DE Moerman, the Godfather of research in this field, gives a definition from 1811 where a placebo is described as ‘an epithet given to any medicine adopted more to please than benefit the patient.’ (Reading medical papers from the 1800s is the best, you get to see words like epithet being used in an actual sentence).

Today, a placebo usually refers to a substance or treatment which has no known medical affect effects. The placebo effect describes the phenomenon whereby some people experience a benefit after the administration of the placebo.

That’s right, even though there is no medical reason why someone should experience a benefit, they do.


Placebo Pills

Examples of placebos include sugar pills, sterile water or a saline solution. However, placebos are not just restricted to drugs, they can include treatments as well.   There have been experiments where subjects have had ‘fake surgeries’* and the outcomes compared to patients who’ve had an actual operation.

*As an aside, these studies make my head explode. Sham surgeries often involve fake blood and sound effects, really highlighting a surgeon’s propensity for the dramatic.


The History of the Placebo Effect

What’s particularly fascinating is that no one really understands how the placebo effect works. It is just an accepted part of medical research.  

Randomized controlled trials (RCTs) are experiments which aim to test a new treatment in an unbiased way. In order to do so, people participating in the trial are randomly allocated to either a group receiving the treatment or a ‘control’ group where the subjects don’t receive the treatment.

When RCTs were first widely in the 1950s,  several trials used a placebo as a control group. In other words, some of the patients received treatment whilst others received a sugar pill or something similar.  What took most people by surprise was that a certain percentage of the patients in the placebo group also displayed benefits.


The Placebo Effect in Medical Research

In 1955, a physician called Henry Beecher published a paper where he observed that nearly 30% of patients with severe pain received satisfactory pain relief from a placebo.

Other researchers found this to be such a widespread finding that trials had to adjust for the placebo effect. In other words, a treatment could only be described as truly effective if its benefits were greater than that of a placebo. This was a radical change - before this, treatments were deemed effective when their benefits were greater than no treatment at all.

These days, medical ethics often stop us using placebos in clinical trials. The Declaration of Helsinki tells us to do no harm in medical research. We can’t design studies for cancer treatment and have half the patients receive no treatment at all. Instead, most modern trials will compare a new treatment to that of current standard of care.


There is no general consensus within the medical community as to the cause of the placebo effects. But the most obvious question to answer is whether the power of belief actually helps the body heal from symptoms ?

We’re going to look at some of the data on this in our future blog posts.


Keep upto date by subscribing.