Presentation summary

After decades of steady growth of scientific research on acupuncture mechanisms of action and controlledclinical trials, demand for scientific evidence published in indexed periodicals has increased among patients, medical community, and private and public health systems. However, experimental controls in clinical research on acupuncture are still troubled by many particularities, when compared to current Western biomedicine.

A pivotal issue regards experimental controls for placebo and the less mentioned nocebo effects, generally seen as driven by positive and negative expectancy, respectively. Given experimental controls are critical in defining how much we can trust data, stressing the importance of both placebo and nocebo effects is never enough.

Unlike placebo effect, which has been extensively studied under different models (including, for example, the Streitberger, Park and Takakura sham devices), nocebo effect in acupuncture remains a largely unexplored issue. Even though generally rendered as the opposite of placebo effect, nocebo effect is more complex thanthat, and is truly indissociable from the former.

If placebo effect in acupuncture can be defined as the difference between sham control and no treatment control, nocebo effect can be more accurately described in terms of that difference in relation to adverse effects (e.g., worsening of pain, tiredness, drowsiness etc.).

We analyze advances in the methodological study of nocebo effect by critically addressing the research literature, andfocusing on how that can affect our conclusions.

Such reasoning will be an important asset in shaping future research on clinical acupuncture in order to generate reliable and useful data.