When the Allies were fighting to liberate Europe from Nazi rule during World War II, the demand for morphine in field hospitals was great, and it was in short supply when fighting caused heavy casualties. Sometimes it was even necessary to operate without anesthesia . On one such occasion, Henry K. Beecher, an American anesthetist, was about to operate without morphine on a seriously injured soldier. Then something incredible happened: one of the nurses injected him with a saline solution and, to Beecher’s surprise, the soldier immediately calmed down. Not only did he feel almost no pain during the operation , but he also had no cardiovascular problems. Apparently the salt water was a powerful anesthetic.
Beecher used this new trick every time he ran out of morphine, and it worked. After the war and back in the United States, Bleecher devoted himself to research on the placebo effect. The result of this work was “The Powerful Placebo” which he published in 1955 and which was destined to become a classic because, among other things, it pointed out the importance of the placebo in medical research.
Bleecher was not the first to use the term ‘placebo’. The first was TC Graves in an article in The Lancet in 1920. What made Bleecher’s contribution essential is that he called attention to the need for double-blind, placebo-controlled clinical trials. . Today it is the standard protocol when checking the efficacy of a medicine or a vaccine: the group of patients is divided into two, and one is administered the medicine and the other the placebo. The fundamental thing -and where Bleecher was brilliant- is that neither the patient knows what he is taking, nor the doctor knows what he is supplying.
How far does the placebo effect go?
Researchers are currently divided when it comes to assessing the placebo effect. For some it is almost all-powerful and can be applied to practically any ailment. Others, however, set certain limits. Certainly it is observed that giving a placebo can make the patient improve from a certain ailment, but is the improvement really due to that effect? Shouldn’t it be possible to eliminate other possible causes, such as spontaneous remission, the natural fluctuation of symptoms…? For these researchers, the only way to determine the true efficacy of placebos -it is generally accepted that it is 30%- is to do it against non-treatments. But, of course, carrying out this type of trial poses a serious ethical problem: you cannot stop caring for a patient.
It is generally accepted that where the efficacy of placebo is proven is in the treatment of pain . Numerous studies show that when you have three groups, one receiving a drug, another a placebo while a third is left without receiving anything, the first two have a more favorable evolution than the last.
All the questions raised by the placebo effect could be answered if the triggers that set it off were known. Unfortunately, they remain a mystery. It seems that the main mechanisms involved in the placebo response, such as the release of opiates within the body , act as a result of the interruption of a complex biological phenomenon known as the acute phase response, better known as inflammation.
The mechanism of action
For centuries medicine has called the four signs of inflammation tumor, redness, heat and pain . If we add to this the psychological changes that occur in the patient, such as lethargy, apathy, loss of appetite or increased sensitivity to pain, we have the acute phase response. Now, what are the mechanisms that interrupt it? And in response to what? Mystery.
The causes that can trigger the placebo effect are as diverse as the medical conditions on which it is said to act. However, it is believed that there must be ‘something’ in common to all of this, a kind of hidden component that drives the placebo response and that without its help, the placebo does not work. Saying that it is the release of endorphins does not solve anything, because for that to happen ‘something’ must give the order. Moreover, the release of endorphins in the body is surely the last link in a very long chain that begins in the brain. So far all researchers agree; where the discussion begins is when they are asked what the brain process is.
Reference:
Evans, D (2014) Placebo: Mind over Matter in Modern Medicine, HarperCollins
