The July/August 2011 issue of the Clinical Journal of Pain includes a German randomized-control study investigating potential patient characteristics that could predict positive outcomes to acupuncture for the treatment of chronic pain. Nearly 10,000 individuals were included in the study, all of whom received routine standard therapies with half receiving acupuncture over a three-month period. Although not statistically significant, the acupuncture group showed greater pain relief than the routine treatment only group. Potential predictors of positive outcomes include living in a multi-person household, former positive experience with acupuncture, female gender, and failure of other therapies.
These results support the contention that acupuncture, like many other therapies, is a helpful modality that may work better in some people than in others, Naturally, more studies are necessary to further investigate potential effect modifiers, however there is no strong evidence that you have to believe in acupuncture for it to work or that a practitioner can tell acupuncture is going to work for an individual based solely on their demographics and health history.