Specificity of expectancy effects for acupuncture, sham acupuncture/R.Gollub

Massachusetts General Hospital, Boston MA

Investigators

Linked publications & trials

Abstract

A growing body of evidence substantiates that acupuncture treatment significantly improves clinical outcomes for patients with chronic pain disorders, and specifically for patients with chronic Low Back Pain (cLBP). Major stakeholders recommend acupuncture as one possible treatment option, despite the fact that in most cases, especially in large trials, sham (placebo) treatment is equally efficacious to real acupuncture, because both treatments are superior to optimal mainstream care or no-treatment. To more fully understand acupuncture treatment and how to best incorporate it into clinical practice, understanding placebo effects is urgent. Further, extensive research from our own group suggests that sham acupuncture has enhanced placebo effects compared to placebos for conventional treatments (e.g. pills or creams). Mechanistic work using a conditioning expectancy manipulation in healthy subjects to investigate the neural basis for analgesia after treatment with real acupuncture or placebo acupuncture suggests that this difference is not because of differential expectations. A critical question is, do different routes of administration configure unique neural mechanisms of placebo analgesia? Published fMRI data from our team demonstrates distinctly different mechanisms for real and placebo acupuncture, despite comparable levels of pain relief. Comparing our fMRI data with published studies from other laboratories suggests different mechanisms between sham acupuncture and placebo creams. Importantly, levels of expectation of pain relief were experimentally enhanced by the same conditioning mechanism. Notably, very little work has been done to investigate the neural mechanism underlying placebo effects in chronic pain patients. In this study, we will directly compare cohorts of cLBP patients and matched healthy control subjects to investigate the impact that living with significant, chronic pain has on the neural mechanisms underlying the expectation component of analgesic response to real acupuncture and placebo acupuncture. This study will expand our understanding of acupuncture's potential role in the management of cLBP and clarify the nature of placebo responses.