Many medical conditions are claimed to benefit when hypnosis is incorporated into their treatment. For some conditions, the claims are largely anecdotal, but the treatment of pain stands out in two ways. First, there is a strong body of evidence that hypnosis can produce clinically useful analgesic effects. Second, since innocuous pain can be induced in the laboratory, the process can be explored rigorously. This idea assumes that experimentally induced pain and clinical pain behave identically. We describe using experimentally induced pain in patients already suffering from temporomandibular disorders. Scanning results indicate that the pain and its amelioration are the same in the two circumstances. Moreover, the absence of any impact upon a nociceptive trigemino-facial reflex implies that the impact of hypnosis is purely cortical. Finally, we address the observation that clinical success correlates poorly with hypnotic susceptibility scores. It is proposed that a painful experimental situation induces anxiety. This, like hypnosis, has been associated with an emphasis on right hemisphere activity. Thus, clinical anxiety may render a person more responsive to hypnosis than would be indicated by a susceptibility test delivered in stress-free circumstances.
Keywords: Chronic pain; hypnotic analgesia; hypnotic susceptibility; right hemisphere; temporomandibular disorders pain.