Placebo Effect: Why People Believe ‘It Works’ [Video]

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placebo effectFrom drug testing to faith healing, many people believe that certain treatments can “cure” or ameliorate the symptoms of their disease or injury, even if there is no evidence that the treatment actually works. This phenomenon is known as the placebo effect, which can make people believe something works in spite of evidence proving that it does not work or no evidence proving that it does.

Harvard psychologist Ellen Langer shared a study with NPR that she did in 2008 of the placebo effect on hotel maids and weight loss. Langer observed that most of the hotel maids performed the level of physical activity that far exceeded U.S. surgeon general’s recommendations for daily exercise. However, they do not look like fitness models or reflect the appearance like they “exercised” regularly. When questioned, 67 percent of the maids reported that they do not exercise. Most do not see themselves as being “active,” even though they haul heavy objects, walk and do manual labor all day long for several days a week.

Langer thought that this was odd. She then split the 84 maids into two groups. One group received explanations on how many calories were burned from doing the work and was told that the women had met the surgeon general’s requirement. The other group received no information at all. A month later, Langer and her colleagues returned to take the maids’ body measurements and compared them to the measurements they did before the study started. The educated group had an average decrease of two pounds , a decreased waist-to-hip ratio, and had lowered their blood pressure by about 10 percent. The study was published in Psychological Science in February 2007.

However, both groups’ activity level, diet or lifestyle did not change during the study, according to their reports, which perplexed Langer. She and her colleagues speculated that it is possible that the “room attendants actually did change their behavior” by cutting back on calories, improving the food quality that they ate or working more vigorously. They just did not report these changes.

The placebo effect is no magic or miracle, and scientists are not sure why people are affected by it. Basically, the placebo effect is any type of treatment that acts like a “real” treatment and provides no active substance to affect health, according to WebMD. In other words, the “fake” treatment can come in different forms -a shot, pill, manual therapy, food, etc. – that mimics the actual treatment. Researchers use placebos to help them compare different treatment effects and understand if a new treatment can have specific effects on a condition. For example, researchers would give one group of test subjects in a study a drug to treat type II diabetes mellitus and a placebo. The subjects do not know whether they received the drug or the placebo. By comparing both groups, researchers can determine the drug’s effectiveness. But why do some people seem to feel better when they take a placebo treatment?

Clinical neurologist Steven Novella, M.D., who is the founder and current executive editor of Science-Based Medicine, wrote that the “placebo effect is a misnomer and contributes to confusion” because it stems from multiple factors, not just one. The factors that contribute to the placebo effect’s outcome depends on the situation, such as “symptoms or outcomes are being observed.” Personal perception of outcomes that can be misinterpreted among subjects and can vary are influenced by many psychological factors.

For instance, if subjects in a study have cancer and they want to get better, they could believe that they are receiving the test drug that is supposed to “cure” the type of cancer that they have. They may want to perceive that the time and effort they had put into the study was worthwhile, and they may want to please the researchers. Thus, this may lead to a bias in the subjects’ reports as well as those from the researchers who may be also biased to the study’s outcome. This is just one among many explanations to why some people are susceptible to the placebo effect.

Sometimes people do not have to be deceived into getting a placebo. A year-long Harvard study that was published in the December 2010 issue of PLoS One showed that patients with irritable bowel syndrome (IBS) may benefit from a placebo treatment even when they were told that they were getting a placebo. This indicates that belief, even if it is false, could skew a person’s perception of what really works.

Science writer Paul Ingraham, who is the assistant editor for Science-Based Medicine, wrote that people say things that do not “accurately represent their internal experience. Simply “being better” is not the same as actually “feeling better,” and  “feeling better is not the same as saying you feel better.”

Even if a placebo effect makes some people feel better and believe that the treatment works, it may not be always be an ethical thing to do. Novella does not feel that intentionally prescribing a placebo treatment is effective or ethical. However, he thinks that the placebo effect teaches something for clinicians and other health professionals. This is the lesson that therapy and treatments go beyond the physiological and physical aspects of treating people. The mind and perhaps even the lifestyle and environment can affect the treatment’s outcome. Valid scientific treatments can help people without the deception of a placebo effect


By Nick Ng
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