It’s a plot device that’s been used over and over in movies, television, and books. The main character is convinced that he or she is going to fail, until a friend offers some sort of token – a potion, a lucky coin, a magic feather. Suddenly the main character is confident, and he or she wins, certain that it’s all thanks to the special token, only to find out that the magic feather wasn’t really magic at all. This, in a nutshell, is the placebo effect.

Placebos are treatments that have no active ingredients.

Placebos, also called sugar pills or dummy pills, are commonly used in clinical trials for medications. One group of trial participants is given the real medication, while the other group is given placebos. Then the medical professionals leading the trial can compare the two groups’ results and see what effects the real medication has.

Also, placebos aren’t limited solely to pills. Injections can be placebos, too, as can almost any sort of treatment that can potentially be faked. When a procedure or therapy is faked or a placebo, it’s usually referred to as sham therapy or sham treatment.

However, it’s been noted time and again that simply taking a placebo can yield positive results. This is how placebos got their name. The word “placebo” is Latin for “I shall please.”

When measurable results occur as a result of placebos, it’s referred to as the placebo effect.

WebMD explains the placebo effect, stating:

“Sometimes a person can have a response to a placebo. The response can be positive or negative. For instance, the person’s symptoms may improve. Or the person may have what appears to be side effects from the treatment. These responses are known as the ‘placebo effect.’“

The placebo effect can’t cure an illness. For instance, if a person has cancer-related pain or stomach ulcers, placebos won’t make everything better. The placebo effect may, however, ease the symptoms. One study looked at depressed individuals who took placebos that looked exactly like antidepressant medications. In study participants who had previously taken and benefitted from the real antidepressant medication, researchers were able to see changes in brain activity that were indistinguishable from the changes produced by the real medication.

The opposite effect is also possible with placebos. In one study, researchers gave participants a steady unchanging dose of opioid medication via an intravenous line. They applied heat to participants’ legs so that, on a scale of 1 to 100, participants rated their pain at about 70. The pain medication was administered before the study participants were aware, and participants noted a reduction in pain from a rating of 66 to 55. Once the researchers informed them that the pain medication had been delivered, the participants reported a reduction in pain rating to 39.

Then, however, the participants were informed that the IV pain medication had been stopped, even though it actually hadn’t. Pain ratings climbed back up to 66, the same as they’d been before the application of pain medication. This shows that, just as the expectation that a medication might help can produce positive results, expecting poor results can produce negative results.

When expectations of negative symptoms produce those same negative symptoms, it’s referred to as the nocebo effect.

The most common instance of the nocebo effect is when a person is warned about potential side effects of a medication. For example, if someone starting a new medication is warned that it may cause nausea, he or she might begin experiencing nausea. This holds true even when the medication is actually a placebo, incapable of producing nausea or any other side effect.

The nocebo effect can sometimes put physicians in an awkward position. Physicians may feel compelled to discuss potential side effects with patients for the sake of honesty and safety. However, simply by discussing potential side effects, it can increase the likelihood that an individual will experience them.

Another example of the nocebo effect can be found in people who are exposed to the media regularly. Specifically, researchers have found that when the media reports that certain substances may be hazardous to the health, some people actually develop the symptoms of a disease, even if there’s no cause or reason for it.

For instance, the participants in one study watched a documentary on the hazards of exposure to electromagnetic fields (EMFs) produced by cell phones, wi-fi, and other electronics. They were then exposed to sham wi-fi signals, which they believed to be real. More than half of the participants reported feeling agitation, anxiety, loss of concentration, or tingling in the extremities. Two of the participants even left the study early, because their symptoms were severe enough that they didn’t want to be exposed to the (sham) wi-fi signals any more.

Scientists are slowly gaining an understanding as to why placebos can produce such significant results.

One group of researchers designed a study that considered how important cognitive awareness is to the placebo effect. In their first experiment, they applied painful heat stimulation to people while showing them an image of a face. When shown a “low pain” face, participants reported a lower pain rating. When shown a “high pain” face, participants reported a higher pain rating, even though the amount of heat stimulation being applied hadn’t changed.

The next experiment was almost the same, except that the faces shown to the participants flashed by quickly enough that the participants couldn’t consciously recognize them. Despite this, the results were the same. After being shown the low pain face, a lower pain rating was reported, while a higher pain rating was reported after being shown the high pain face.

This suggests that the placebo and nocebo effects don’t depend on conscious expectation. Rather, the nonconscious mind automatically and quickly determines what to expect. The too-fast-to-recognize exposure to the faces in the experiment were still long enough for the nonconscious mind to recognize, so the nonconscious mind produced a placebo effect. There’s even emerging evidence that placebos can even work when the person taking them is aware that the medication is a placebo.

Therefore, the placebo effect is tied to the signals and rituals that the nonconscious mind associates with specific results. Medications are associated with alleviation of symptoms, so taking a pill – even a placebo – can ease symptoms. Even symbols like a medical diploma on the wall, the writing on a bottle of prescription medication, or an interaction with a physician may produce a placebo effect.

In fact, even cost can impact the placebo effect. Studies have shown that, even when two medications are identical, patients respond more strongly to the one they believe to be more expensive.

How would you respond if your doctor suggested placebos as treatment?

Image by Patrik Nygren via Flickr


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