Fabrizio Benedetti
The Journal of Neuroscience, 9 November 2005, 25(45): 10390-10402; doi: 10.1523/JNEUROSCI.3458-05.2005

Any medical treatment is surrounded by a psychosocial context that affects the therapeutic outcome. If we want to study this psychosocial context, we need to eliminate the specific action of a therapy and to simulate a context that is similar in all respects to that of a real treatment. To do this, a sham treatment (the placebo) is given, but the patient believes it is effective and expects a clinical improvement. The placebo effect, or response, is the outcome after the sham treatment. Therefore, it is important to emphasize that the study of the placebo effect is the study of the psychosocial context around the patient.

Full Text Article:  http://www.jneurosci.org/content/25/45/10390.full