Evaluation of the clinical effects of acupuncture. A problem reassessed and a framework for future research

The authors reexamine the three areas that have encompassed the major part of clinical research within acupuncture: chronic pain, addiction (particularly smoking cessation), and the treatment of nausea and vomiting. Clarification of the findings, and of the different control conditions that have been used, suggests that point location is an important variable in the treatment of chronic pain and nausea, but not in addiction. These observations can be explained by postulating that different underlying mechanisms are involved in the treatment of different conditions: addictions may be purely mediated by opioid peptides, nausea by the autonomic system, and a combination of both may be involved in chronic pain, together with local trigger point action. A hypothesis is presented that suggests that the closer one gets to a purely endorphin-mediated effect, the less relevant it is to think in terms of point location and the more misleading a real versus sham acupuncture model is in the context of a clinical trial. The hypothesis is necessarily speculative, but it does provide a coherent theoretical framework that integrates neurophysiology, clinical trials, and some aspects of traditional Chinese medicine.