what is the placebo effect

A Phony Cure? All About The Placebo Effect

Often when your primary care doctors and specialists at The Medical Group of South Florida discuss the relative merits of a new drug or treatment, you’ll hear us explain how well it performed vs. a placebo in clinical trials.

But what is a placebo? The popular definition is a “sugar pill,” but it’s more than that. When researchers are conducting a new drug trial, they will divide their subjects into one of two or three groups: those receiving the drug to be tested, those receiving a placebo such as sugar or distilled water, and often, depending on the type of trial, a control group that receives nothing. Placebos have been used not only in testing drugs but in such widely varied procedures as acupuncture and knee surgery.

The problem with testing new treatments against placebos is that, in any trial, up to 40% of those receiving the procedure will experience some benefit. For example, in the knee surgery mentioned above, a famous 2002 study looked at the effect of arthroscopic surgery in the knee, and found that sham surgery (in which incisions were made in the knee but nothing else was done) yielded results equal to those receiving the actual surgery (in which either loose or worn cartilage was cut away or flushed out). All participants reported comparable and lasting reductions in pain.

“Placebo” is Latin for “I shall please,” and reflects the supposition that those who experience the placebo effect (or response) are trying to please the researcher or doctor by reporting that they feel better than they actually do, or even by triggering endorphins in the brain that can temporarily mask pain.

But a 2015 article from the Harvard Medical School insisted that recent research confirmed the placebo effect is real, and that measurable physiological changes can be observed in those taking a placebo, similar to those observed with subjects taking the real drug. Relief of such symptoms as itching, tremors, nausea, constipation, and depression call into question the endorphin explanation, not to mention the “I shall please” concept.

Others have observed that the placebo effect is an example of our brain’s powers of self-healing, and theorize that the belief that the drug will be effective releases natural healing chemicals within the body. One study, for example, showed a placebo effect in subjects with Parkinson’s disease; further testing revealed that their brains had responded to the placebo by manufacturing more of the chemical that was in the real drug given other study subjects.

Another similarly mysterious aspect of placebos was highlighted in a 2015 University of Colorado study in which subjects were told the drug they were receiving was the real thing, then several sessions later, were told they were actually receiving the placebo. Mysteriously, they continued to experience pain relief with the fake drug even after the revelation.

Tor Wager, one of the co-authors of the study said, “We’re still learning a lot about the critical ingredients of placebo effects. What we think now is that they require both belief in the power of the treatment and experiences that are consistent with those beliefs. Those experiences make the brain learn to respond to the treatment as a real event. After the learning has occurred, your brain can still respond to the placebo even if you no longer believe in it.”

Of all the factors advanced as possibly being responsible for the placebo effect, perhaps the most important is the doctor-patient relationship. There is strong evidence that at least some of the placebo effect can be attributed to attentive, empathetic interaction from the physician. “People are wired to feel better when doctors listen to them, explain the cause of their problem and convey that they care,” said Dr. Howard Brody of the Institute for Medical Humanities in Galveston, TX.

This is why your primary care physicians and specialists at The Medical Group of South Florida devote so much time to interacting with our patients—we know that a caring physician can make all the difference.