Deception and the ethics of placebo.

The placebo effect in many areas of neurological therapeutics is common and prominent. The importance of the response means that any new treatment must account for the placebo effect, but this in turn raises major challenges as to how to conduct scientifically meaningful research in an ethically acceptable fashion. Basic principles that may be in tension with one another are those of beneficence and respect for autonomy. It may be challenging to respect autonomy if the scientific design of a study depends upon the use of deception, but this is often mitigated by the information provided to trial participants as part of the informed consent process. Deception is a particular challenge if placebos are to be used in a clinical/therapeutic setting, outside the context of a clinical trial. While practice-based placebo use may on occasion be both beneficial and ethically acceptable, close attention must then be paid to ensuring that basic ethical principles are respected and that placebos are either prescribed in an open and honest fashion, or that any deception is authorized.