Control conditions in hypnotic-analgesia clinical trials: challenges and recommendations.

Case studies and controlled clinical trials indicate that hypnotic analgesia can effectively reduce pain in patients with a number of different chronic pain conditions. However, because none of the studies published to date have included a credible control condition that adequately controls for expectancy effects, at this point we cannot conclude that hypnotic-analgesia treatment has a specific effect on chronic pain beyond that that might be produced by a credible placebo intervention. This paper (a) describes the types of control conditions that have been, or might be, used in clinical trials of hypnotic analgesia for chronic pain; (b) reviews their strengths and weaknesses; and (c) concludes with specific recommendations that investigators should consider when designing clinical trials of hypnotic analgesia.