Psychophysical responses in patients receiving a mock laser within context of an acupuncture clinical trial: an interoceptive perspective

BACKGROUND: The psychophysical responses induced by verum acupuncture are characterized by a constellation of unique subjective sensory responses commonly termed De Qi. Furthermore, a variety of sham interventions have been used as a control for acupuncture clinical trials. Indeed, one such control has been mock laser which has been used as control intervention in several acupuncture clinical controlled trials. The current study aim was to examine the De Qi sensory responses and its related characteristics elicited from acupuncture and compare them to those reported following sham laser in participants enrolled in a clinical trial. METHODS: The study was embedded in a multi-center, two-arm randomised clinical trial, which evaluated the effect of acupuncture on lateral elbow pain. De Qi was assessed using the Massachusetts General Hospital Acupuncture Sensation Scale (MASS). Ninety-six participants were randomly allocated to receive either acupuncture (n = 47) or mock laser (n = 49) at the acupoints LI 10 and LI 11. RESULTS: Participants in both intervention groups reported similar De Qi psychophysical characteristics; however, both intensity and frequency of the individually perceived De Qi characteristics were significantly higher in the acupuncture group. ‘Soreness’, ‘deep pressure’, and ‘fullness-distension’ in the acupuncture group and ‘tingling’, and ‘sharp pain’ in mock laser group, were identified as the leading characteristics. Similar level of MASS De Qi Index (MDI) scores were reported for ‘Hong Kong-China’ and ‘Australia-Italy’ with a significantly higher level of De Qi reported by ‘Hong Kong-China’. Furthermore, two distinct De Qi categories were identified, namely De Qi (in line with classical sensory responses of Suan, Ma, Zhang, and Zhong) and pain. CONCLUSIONS: Subjective ‘somatic or interoceptive awareness’ should be taken into account when De Qi psychophysical responses are examined. The study accentuates the necessity and the significance of further research into interoception phenomenon which may contribute to a better understanding of the placebo effect and De Qi psychophysical responses. TRIAL REGISTRATION: Australian and New Zealand Clinical Trial Registry reference: ACTRN12613001138774 on 11th of October 2013.