Ethical Overview of Placebo Control in Psychiatric Research - Concepts and Challenges.

Permissibility of placebo controls in psychiatric research is raising everlasting controversies. The main ethical issue remains: whether, when, under what conditions, and to what extent is it justifiable to disregard subject's present (best) interest for the presumably "greater" ones. In relation to this main ethical concern, two distinct arguments arose: proponents of placebo controls trials (placebo ortxodoxy) and proponents of active controls trials (active-control orthodoxy). More recently, in new ethical guidelines, Declaration of Helsinki and International Ethical Guidelines for Biomedical Research Involving Human Subjects, a "middle way" approach was formulated, acceptable to both sides of the argument, saying placebo controls can be justified under certain conditions: when and only when, they firstly present undisputed methodological reasoning, and secondly, fulfill certain ethical considerations - mainly regarding the permissibility of accompanied risks. These ethical evaluations are inevitably contextual and evoke the need for the principle of proportionality. In scope of recent findings of substantial and progressively increasing placebo response in psychiatric research, contextual factors are identified and both theoretical and practical challenges are discussed.