Implications of placebos and nocebos in clinical research

While studies on physiological bases of placebo and nocebo effects have contributed to elucidating their underlying mechanisms, little progress has been made in translating placebo and nocebo knowledge into improved clinical research. Here, we discuss the importance of considering specific mechanisms of placebo and nocebo effects to improve clinical research and outcomes. In order to apply this knowledge to clinical research, it must be coupled with a person-level assessment of patients’ expectations, understanding of genetic variations among patients, and consideration of both framing effects and treatment history. We suggest some elements for how, when, and why to apply knowledge of placebo and nocebo effects to clinical research.