During almost all clinical drug trials, a certain percentage of volunteers receive an identical looking but chemically neutral pill or injection called a placebo. The group of volunteers who receive this placebo may be used as a control group, meaning their reactions during the trial will be compared to those volunteers who actually received the real medication. There is also the possibility that the volunteers or the testers themselves would have no idea which volunteers took a placebo and which received the real drug. In this scenario, a controversial phenomenon known as the placebo effect has been known to occur.
The placebo effect occurs whenever a volunteer's strong belief in the treatment actually triggers an improvement in his or her health. Even if the patient or volunteer is given a completely harmless sugar pill or an injection of sterilized water, the possibility of receiving a benefit from the real drug creates a placebo effect. According to some researchers, a certain percentage of those patients who unknowingly receive a placebo report some signs of improvement, especially in the areas of pain management and overall energy level.
Most experts consider the placebo effect to be psychosomatic in nature, since there are no active compounds present in the placebos. It has been speculated that the researchers themselves help to create this effect by telling volunteers they may or may not have received the active form of the drug. If a motivated volunteer chooses to believe he has indeed received the real drug, then he may become overly sensitive to any and all changes in his condition. Interestingly enough, many who have experienced the placebo effect only report minor to moderate changes in their conditions, not complete cures or remissions.
The placebo effect could also be related to the body's release of natural pain killers called endorphins, as well as other chemicals designed to combat depression or raise energy levels. While a placebo itself may have no discernible effect on a volunteer's body chemistry, some patients may experience a sense of calm or peace of mind after receiving what could be a beneficial treatment. This effect may be similar to the psychological benefits many people experience after a physician's exam. The apparent improvement of symptoms caused by the placebo effect could be the result of the volunteer receiving a professional's personal attention and reassurance.
The placebo effect is not universally recognized by researchers, however. Almost all of the benefits reported are of the non-quantifiable variety, such as pain reduction or improved mental focus, which means they cannot be verified easily through standard medical testing. The volunteer who received a placebo may be subconsciously supplying answers he or she believes the researchers would want to hear, specifically how effective the trial medication appears to be.