I developed an acute interest in the placebo effect -- where a person improves on a fake drug because they believe they are taking an actual drug -- while working in drug development for a multinational pharmaceutical company.
We all experience placebo effects from time to time. Believing in a drug or in a physician who prescribed it can help it to work better. Reams of research now paint a picture that what we believe with regards to medication can have measurable effects on the body.
The same placebo can do opposite things, for instance, depending on what the person believes it is for. If patients are given a placebo and told it will relax their muscles then it will, but the same placebo can cause muscular tension if the person believes that's what it does. Similarly, believing that it is a stimulant will increase heart rate and blood pressure, but thinking that it is a depressant gives it the opposite effect: reducing heart rate and blood pressure.
Some people who are given alcohol placebos, thinking they are drinking real alcoholic beverages, even get drunk.
And placebos can enhance athletic performance. In a 2007 study, non-professional athletes had been given morphine during a pre-competition training phase. On the day of a competition the morphine was secretly swapped for a placebo but the athletes still experienced an increase in pain endurance and physical performance that would be expected from taking morphine.
In another study, 40 asthmatics were given an inhaler containing a placebo, which was water vapor, but were told that it contained allergens that would restrict their airways. Nineteen of them then suffered considerable constriction of their airways and 12 of them actually experienced a full-blown asthma attack. When they were given a different inhaler and told it would relieve their symptoms, it did, even though it was also a placebo. One person in the study developed symptoms of hay fever too after being told that the inhaler also contained pollen.
Color can matter with placebos
Where you live also affects the power of placebos. In a U.S. study of migraine treatments, placebo injections were 1.5 times more powerful than placebo pills. But a European trial found that placebo pills were marginally better than placebo injections. The reason for the difference is in our cultural language. U.S. patients tend to speak of 'getting a shot,' but Europeans talk of 'popping pills,' or at least they do in the UK.
Similarly, in trials of the anti-ulcer drug, Tagamet, which was popular in the 80s, the placebo was 59 percent effective in France but the drug itself was 60 percent effective in Brazil -- a difference of 1 percent.
Some of the variation comes down to communication between medical staff and patient. For relatively common ailments at least, a physician who shows optimism about the patient's recovery is more likely to see the patient recovering than one who is more unsure or pessimistic.
Perception of a medicine or placebo matters too. In a UK study, 835 women were given one of four different pills for headaches. One group received a well-known branded aspirin tablet. A second group received a simple tablet labelled 'analgesic,' which was typical of a cheaper mass-market brand. A third group received a branded placebo, while the last group received a basic placebo labeled 'analgesic.'
It turned out that the branded aspirin worked better than the unbranded one, but amazingly the branded placebo worked better than the unbranded placebo -- even though they were both inert.
The placebo effect might even lift the power of Viagra beyond its basic pharmacological effect, at least according to psychiatrist Aaron K. Vallance, who suggested in a 2006 paper that the medicine might be enhanced because the name 'Viagra' is similar-sounding to the words, 'vigour' and 'Niagara,' which might create a perception of vigorousness and power.
I wonder if it would work so well if it was called 'Flopsy!'
Of course, the drug works extremely well. Drugs are built to carry out biological functions in the body.
But research into the placebo effect is beginning to paint a picture of a strong interaction between the mind and the body such that what you think or believe about a drug or a physician really matters.
For the opposite effects of placebos, see, I. Kirsch, "Specifying non-specifics: Psychological mechanism of the placebo effect". In Harrington A. The Placebo Effect: An Interdisciplinary Exploration. (Harvard University Press, Cambridge, 1997, pp. 166-86)
For the Tagamet data, see D. Moerman, "Meaning, Medicine and the 'Placebo Effect'" (Cambridge University Press, 2002, pp. 80)