Affiliations: Universität Duisburg-Essen, Alfried Krupp von
Bohlen und Halbach – Stiftungsprofessur für Naturheilkunde, Innere Medizin
V: Naturheilkunde und Integrative Medizin, Kliniken Essen-Mitte,
Knappschafts-Krankenhaus, Essen | Medizinische Universitätsklinik VI,
Psychosomatische Medizin und Psychotherapie, Forschungsbereich,
Universitätsklinikum Tübingen, Tübingen
Note: [] Korrespondenzadresse: Dipl.-Psych. Kyung-Eun Choi,
Universität Duisburg- Essen, Alfried Krupp von Bohlen und Halbach
?Stiftungsprofessur für Naturheilkunde, Innere Medizin V: Naturheilkunde
und Integrative Medizin, Kliniken Essen-Mitte, Knappschafts-Krankenhaus, Am
Deimelsberg 34a, 45276 Essen. E-mail: [email protected]
Abstract: Background: In its classical definition a placebo is considered to
be a substrate free medication surrogate that induces positive effects on a
disease when given to a patient. The effect is then not attributable to a
specific active agent of the placebo. This placebo concept has always been
associated with a negative connotation and was interpreted as deception and
withholding of an effectice treatment. Due to enhanced research on placebo
effects and the assumption that some aspects of verum treatment effects are as
well attributable to a so-called placebo effect, the actual discussion on
placebo turns towards the utilization of placebo effects in clinical practice. Placebo effects are common in gastrointestinal disorders, while the size of
these placebo effects is not related to the functional aspects of the disease.
Placebo effects in functional dyspepsia and irritable bowel syndrome are as
high as in organic gastrointestinal diseases such as duodenal ulcer or inflammatory bowel disease. Conclusion: In many aspects, placebo effects are not distinguishable from the effects of other interventions including
pharmacological treatments. Thus, a strengthening of a verum treatment by
placebo induced factors has the potential to optimize a treatment. However,
especially in the older placebo literature the effect sizes of placebo effects
were overestimated. This was mainly due to methodological deficiencies of
former studies. The presented article gives an overview about criticism on
methodologies of these studies, with a focus on research results of
gastroenterology.
Keywords: Placebo, expectancy, verum treatment, ethics
