The Placebo Effect
A placebo is an inert substance that does not contain an active drug ingredient. The placebo effect is a psychosomatic phenomenon where we observe a beneficial change in the individual due to placebo manipulation. The nocebo effect is the opposite of the placebo effect, when a negative expectation or attitude leads to harmful or undesirable outcomes. For example, a patient taking a placebo drug may report having headaches, nausea or dizziness. Most of the history of medicine until fairly recently has been a result of the placebo effect, given the fairly limited and inaccurate knowledge about human anatomy and infectious diseases. One explanation for the placebo effect is that expectation may lead to changes in behavior. Anxiety becomes reduced with positive expectation (placebo effect). Anxiety increases with negative expectation (nocebo effect). This phenomenon might be explained on the basis of Pavlovian conditioning: When we expect to feel better after being treated, and we are highly motivated to believe that a treatment will work, therefore we are more likely to experience a placebo effect. This is why symbols of hope and the power of suggestion play a large role in providing relief from stress. The evolutionary perspective on the placebo effect also takes the stance that social mechanisms of support such as altruism, rituals, and empathy may trigger placebo responses by enhancing the individual’s resilience. According to the FDA (Food and Drug Administration), every clinical drug trial must include a control group for comparison purposes, in which participants are randomly assigned to either the active substance group or the placebo group, and neither the researchers nor the subjects know which group receives the treatment (double blind). There may be high occurrences of adverse side effects in patients receiving the placebo in double blind drug trials. According to a study by Mondaini et al. (2007), patients who were informed about...
Cited: Kaptchuk, T. J., Kelley, J. M., Conboy, L. A., Davis, R. B., Kerr, C. E., Jacobson, E. E., Kirsch, I., Schyner, R.N., Nam, B.H., Nyugen, L.T., Park, M., Rivers, A. L., McManus, C., Kokkotou, E., Drossman, D.A., Goldman, P., & Lembo, A. J. (2008). Components of placebo effect: randomised controlled trial in patients with irritable bowel syndrome. Bmj,336(7651), 999-1003.
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Mondaini, N., Gontero, P., Giubilei, G. et al. (2007) Finasteride 5mg and Sexual Side Effects: How Many of these are Related to a Nocebo Phenomenon? Journal of Sexual Medicine, 4: 1708-1712
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