Placebo controls have often been used in standard clinical studies in order to minimize the effects of psychological interference.However

no ideal placebo(including false needle technique)has been designed for the purpose of acupuncture research.As a result

many of the clinical studies of acupuncture do not follow proper criteria for designing a conventional clinical trial.Understanding the differences of the placebo effect in acupuncture and pharmaceutical drug research is the key to answering this challenge.To do this

the concept of placebo

sham point

acupuncture point specificity and meridian all need to be properly considered in order to avoid a failure in clinical design.The sham points control in the previous acupuncture studies often obeyed the definition of the placebo.Being different from drugs which act upon pre-designed specific receptors

acupuncture may have various effects on multiple systems

organs and a lot of cells and receptors

multiple transmitters

hormones

etc..For this reason

the results of acupuncture treatment

such as pain relief and relaxation

have been criticized as a "placebo" effect.However

evidence from fMRI and other studies strongly suggest that acupuncture affects multiple psychological and emotional control centers of the brain

such as the limbic system and the prefrontal cortex.This may result in a series of functional modulations

which involves pain and stress management.The results suggest that the placebo effect could be induced by non-specific physical stimulation of acupuncture and may favor the patient's health recovery to a certain degree.From this point of view

acupuncture may be a unique remedy for "mind-body" disorders.The current placebo control design in clinical trials of acupuncture needs to be reevaluated.