Clinical relevance and ethical aspects of placebos

In recent years, the topic of placebo has gained momentum. Basic scientists started elucidating the neurophysiological and neuropharmacological processes that mediate the placebo response. At the same time, questions arose about the purported power of placebos. In addition, the debate on the ethics of the use of placebos heated up after the publication of some recent surgical trials using invasive placebo surgery procedures. In this article, we discuss the clinical relevance and the ethical problems associated with the use of placebos. Although a recent meta-analysis questioned the power of placebo, good evidence exists that placebos can lead to important improvement in many clinical conditions. A part of the conflict on the ethics of the use of placebos in randomized clinical trials can be solved by distinguishing between ethical guidelines for good clinical practice and for clinical research. We will also discuss some of the difficulties in finding proper placebo controls in clinical trials involving neurosurgical procedures.