Abstract
The placebo effect is a psychological reaction induced by a therapeutic ritual, regardless of the therapy is effective, probably effective, or obviously inert. Despite expectations, main pathogenesis appears not to be affected by the placebo, placebo acts only at the level of subjective experience of given disease.
Therefore, main pathology remains usually unaffected. It was revealed in the case of pain treatment that the response to placebo therapy is connected with functional changes in the structures involved in the processing of pain-related pathways.
Therefore, placebo acts not only at the level of subjective experience, but also at the level of lower structures involved in processing of pain. a number of neurobiological mechanisms involved in placebo effect have been described, particularly the endogeneous opioid system. The nocebo is the effect which is the opposite.
For example, the placebo induces placebo analgesia whereas the nocebo induces nocebo hyperalgesia. While from the psychological point of view, both effects can be considered as two sides of the same coin, from the neurobiological point of view, there are some differences between these processes.
For example, both processes can be turned off by drugs. While the placebo is sensitive to the blockade of receptors for endogeneous opioids by naloxone, the nocebo is sensitive to the blockade of receptors for cholecystokinine by proglutamid. of importance for clinical practice is the fact that the response to the placebo depends on many factors, including physicians' personality, patient's psychical state, patient's personality, patient's life-history, and also genetics.