[Effect of placebo response on results of antidepressant clinical trials].

Provocative data have been published regarding the results of clinical trials executed in order to assess the efficacy of antidepressants (AD) during the past years. Beside the continuously increasing placebo response the efficacy of ADs could not be differentiated from the effect of placebo in more than half of the studies. Several factors have been identified in the background of this phenomenon, researchers have proposed numerous possible solutions for this issue, including systematic re-evaluation of data, reconsideration of tools used for assessment of efficacy, of study design and of statistical methods. Multiple different possible interpretations, problem definitions and explication models can be found in the literature providing an overview which can be useful for clinicians and researchers as well. The following review summarizes the data and results which help in drawing a more detailed picture about the relationship between AD and placebo effect. The way this specific problem is addressed points beyond the actual topic, as it challenges the dilemmas of evidence-based medicine. As a conclusion it can be stated that despite the fact that the degree and relevance of placebo effect is the subject of continuous debate, the use of placebo is still unavoidable in clinical trials and deepening the knowledge on this topic is required.