The Placebo Effect
Many clinical trials are designed to show what effects a drug has. It is important to demonstrate all of the effects of the drug - the good ones as well as the bad ones. In order to do this, participants are often divided into two groups (or "arms"): an experimental group and a control group. Participants in the experimental group receive a dose of the drug, while participants in the control group are given something that looks like the drug, but actually contains no drug at all. This fake or empty dose is necessary because people often react when they think they are being given a drug even though there is really no drug in the dose. The effects they experience may be positive or negative. They may be similar to what the drug is supposed to do or they may take the form of unwanted side effects. These effects, caused by the fake doses, are known as "placebo effects" and the fake doses themselves are called "placebos."
The placebo effect has been known for many years. Occasionally, the placebo effects are every bit as powerful or effective as the drug itself. In fact, before governments began regulating drugs, many medications actually contained no active compounds. But they were cleverly advertised, they were strong smelling or tasting, and they were administered with much care. As a result, patients believed they would in fact be affected by the medications and they showed signs of improvement in whatever the particular condition. Sometimes they showed side effects as well. We didn't know exactly what caused the placebo effect other than to assume it was mental and not physical. But, for the purposes of conducting clinical trials, it really didn't matter. All that mattered was that there were two arms to drug studies so that the effects of placebos were compared with those of the actual test drug in order to show what the real, physical effects of the drug were.
What this means, however, is that any particular participant would be put into either the experimental or the control arm of the study. If they were put in the experimental arm, they received drug; if they were put in the control arm, they received placebo. Of course, they couldn't be told which arm they were being put into because then the true effects of the placebo would not be known. There are ways of designing studies such that participants are put into one arm of the study and then crossed-over onto the other arm, but this is not always possible.
Recent research has shed some light on how the placebo effect is actually caused in the brain. And that information might well change the way clinical trials are designed. More on this next time.
-Joe
Related Topics: Can You Think Pain Away?, Placebo Effect in Multiple Sclerosis
The placebo effect has been known for many years. Occasionally, the placebo effects are every bit as powerful or effective as the drug itself. In fact, before governments began regulating drugs, many medications actually contained no active compounds. But they were cleverly advertised, they were strong smelling or tasting, and they were administered with much care. As a result, patients believed they would in fact be affected by the medications and they showed signs of improvement in whatever the particular condition. Sometimes they showed side effects as well. We didn't know exactly what caused the placebo effect other than to assume it was mental and not physical. But, for the purposes of conducting clinical trials, it really didn't matter. All that mattered was that there were two arms to drug studies so that the effects of placebos were compared with those of the actual test drug in order to show what the real, physical effects of the drug were.
What this means, however, is that any particular participant would be put into either the experimental or the control arm of the study. If they were put in the experimental arm, they received drug; if they were put in the control arm, they received placebo. Of course, they couldn't be told which arm they were being put into because then the true effects of the placebo would not be known. There are ways of designing studies such that participants are put into one arm of the study and then crossed-over onto the other arm, but this is not always possible.
Recent research has shed some light on how the placebo effect is actually caused in the brain. And that information might well change the way clinical trials are designed. More on this next time.
-Joe
Related Topics: Can You Think Pain Away?, Placebo Effect in Multiple Sclerosis
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