Guided Imagery Reduces Non-Cancer Pain, but How Remains a Mystery
Researchers from the College of Nursing, Kent State University conducted a pilot study to determine the effect of a guided imagery (GI) intervention over an 8-week period on pain and pain disability in a sample of patients with chronic, non-cancer pain (CNCP); and to then analyze the mediating effects of neuroendocrine and neuroimmune functioning on outcome variables.
A simple interrupted time-series design (12-week period) was used. Guided imagery was introduced at Week 4 and used daily by 25 participants for the remaining 8 weeks.
Measures of pain and pain disability were obtained at the beginning of the study period and at six repeated 2-week intervals.
Measures of hypothalamic-pituitary-adrenal (HPA) axis activation (plasma, cortisol), immune-mediated analgesia (lymphocyte subset counts and proliferation), and immune-mediated hyperalgesia (interleukin-1β) were obtained at the beginning of the study and at Week 11.
Findings showed that usual pain levels were lower after the introduction of GI at Week 4 (Wilks' λ = 52.31; df = 2, 22; p = .000).
Pain disability levels were lower after the introduction of GI at Week 4 (Wilks' λ = 5.98; df = 6, 18; p = .001).
The investigators concluded that guided imagery was effective in reducing pain intensity and pain disability over an 8-week period.
Surprisingly, however, the findings did not show the expected effects of decreased HPA axis activation, improved immune-mediated analgesia, nor reduced immune-mediated hyperalgesia in driving these outcomes.
They suggest that these results may be related to procedural and theoretical issues and/or limitations related to the study design.
[Ed. Note: How about these findings may be related to the fact that pain is a matter of perception in the brain, and guided imagery shifts perception?]
Citation: Lewandowski W, Jacobson A, Palmieri PA, Alexander T, Zeller R. Biological Mechanisms Related to the Effectiveness of Guided Imagery for Chronic Pain. Biological Research in Nursing. 2010 Nov 26. [Epub ahead of print]