The Relationship Between “Rapid Induction” and Placebo Analgesia, Hypnotic Susceptibility, and Chronic Pain Intensity

The effects of Rapid (hypnotic) Induction Analgesia (RIA) and an oral placebo on clinical and experimental pain were compared in 30 volunteer male paraplegic veterans with chronic pain syndrome. Scores of hypnotic susceptibility and chronic pain experience were also correlated with the effects of RIA on clinical and experimental pain. Self-ratings of S’s clinical pain on a 0-100 scale were obtained before and after RIA and placebo treatments. Threshold and tolerance for ischemic muscle pain (experimental pain) was measured during baseline control, RIA, and placebo sessions. The general linear hypothesis was used to analyse the data. The results indicate that RIA is not significantly more effective than an oral placebo in (a) reducing clinical pain and (b) increasing experimental pain tolerance (when the effect of hypnotic susceptibility is controlled). The effect of treatment (RIA or placebo) is not related to either chronic pain experience or pre-treatment 0-100 pain ratings (when the effect of hypnotic susceptibility is controlled). The effect of RIA is not significantly related to hypnotic susceptibility for clinical or experimental pain (when the effect of chronic pain experience is controlled). In conclusion, the effectiveness of a single RIA session for the control of clinical and experimental pain in chronic pain patients is more limited than might be anticipated from previous studies using RIA for the control of acute/experimental dental pain. Nevertheless, the technique may be promising for the control of chronic pain, because its applicability is not restricted by hypnotic susceptibility.