This review identified 13 published controlled articles that evaluated the efficacy of hypnosis for chronic pain. With the exception of two articles (Appel & Bleiberg, 2005–2006
; Melzack & Perry, 1975
), the studies reviewed included a control condition for comparison. In each of the studies, the hypnosis intervention was demonstrated to be significantly more effective than a no-treatment condition in reducing pain in chronic-pain patients. Moreover, the efficacy of hypnosis in reducing pain was consistently confirmed for a wide variety of different chronic-pain conditions (e.g., cancer, low-back pain, arthritis pain, sickle cell disease, temporomandibular pain, disability-related pain).
However, there have been a relatively small number of studies conducted for each of the different chronic-pain conditions (in some cases only one study). Although it is encouraging that 13 controlled studies have reported on the use of hypnosis with chronic pain, there are a number of basic research design weaknesses that tend to run throughout most of these reports. The number of patients enrolled in the studies tends to be low, bringing up issues of power to detect group differences. Control conditions used usually have lacked credible controls for placebo and/or expectation. Multiple measures of outcomes are seldom employed as are follow-up assessment of sufficient duration (i.e., long-term follow-up). Thus, although the findings provide support for the general applicability of hypnosis in the treatment of chronic pain, considerably more research will be needed to fully determine the effects of hypnosis for different chronic-pain conditions (e.g., neuropathic, sickle cell disease, arthritis, etc.).
Studies of hypnosis in the treatment of chronic pain have often included instructing patients in self-hypnosis as a way of coping with pain and gaining greater self-control over pain (e.g., Dinges et al., 1997
; Elkins et al., 2004
; Gay et al., 2002
; Haanen et al., 1991
; Jensen et al., 2005
; McCauley et al., 1983
; Simon & Lewis, 2000
; Spiegel & Bloom, 1983
; Spinhoven & Linssen, 1989
; Winocur et al., 2002
). This usually includes providing patients with tape recordings of hypnosis sessions and instructions in home practice of self-hypnosis. However, research has yet to determine the importance of and the best ways to provide instruction in self-hypnosis practice. For example, it is unknown whether standard tapes are as effective as individualized recordings. Also, the necessary frequency of practice has not been determined or even if home practice is as effective as “live” sessions. Our clinical experience suggests that patients who are more actively involved in self-hypnosis practice benefit more and may have more long-lasting gains (see Elkins et al., 2004
; Jensen & Barber, 2000
). In clinical practice, we recommend to patients that they practice at least once a day. To facilitate this, we provide them with tape recordings of the sessions. We also give them instructions for practicing self-hypnosis without the use of a recording. Some patients choose to practice by listening to a tape, and some choose to practice self-hypnosis without a tape; many do both.
Chronic pain is a complex phenomenon that may be affected by emotional, cognitive, behavioral, and physiological responses and a multimodal treatment approach may be important for some chronic-pain patients. However, there have been few studies that have evaluated the effect of hypnosis as an adjunct to other treatment modalities for chronic pain, including, for example, treatment programs designed to increase activity and to reduce the negative effects of pain on function (Patterson & Jensen, 2003
). One study compared CBT to CBT combined with a hypnotic induction. In that study (Edelson & Fitzpatrick, 1989
), only the CBT treatment alone resulted in significantly lower pain-rating scores in comparison to an attention-control condition. This finding is somewhat puzzling, because some aspects of the CBT treatment used in this study appeared to be very similar to a hypnotic intervention (i.e., the CBT intervention included instructions to reinterpret pain sensations as “numbness” through the use of imagery). However, this study suggests the possibility that the addition of a hypnosis induction may have detracted from an intervention focused on altering maladaptive cognitions. Further research is needed to determine the best methods of integrating hypnosis with CBT and other multimodal interventions for chronic-pain management.
The present review also reveals that there is a lack of standardization in hypnotic induction and interventions. There is a need to more clearly identify the components of a hypnotic intervention to better allow comparison across studies and to differentiate hypnosis from other “hypnotic-like” interventions such as relaxation training. For example, in the present review, treatments such as progressive muscle relaxation and mental imagery appeared to be approximately as effective as interventions that were labeled as “hypnosis.” It may be that these treatments are similar in regard to mechanism of action and effect. Research is needed to determine the efficacy of hypnosis and specific hypnotic suggestions and interventions. Jensen and Patterson (2006)
proposed a basic chronic-pain hypnotic-analgesia intervention that consists of the following: (a) a standard hypnotic induction that includes a focus of attention and relaxation; (b) suggestions for alteration in subjective experience of pain; (c) hypnotic suggestion lasting at least 20 minutes; (d) four to seven sessions indicating “brief hypnosis treatment” and eight or more sessions to indicate “hypnosis treatment;” and (e) instruction in daily home practice of self-hypnosis. Greater standardization in hypnosis research protocols for chronic pain would allow for greater specificity of treatment and clearer identification of innovations in the development of particularly effective hypnotic interventions.
The current review indicates that hypnotic interventions for chronic pain results in significant reductions in perceived pain that, in some cases, may be maintained for several months. Further, in a few studies, hypnotic treatment was found to be more effective, on average, than some other treatments, such as physical therapy or education, for some types of chronic pain. These findings are encouraging for an initial wave of studies, but a more sophisticated body of research including larger sample sizes and more rigorous controls would be far more convincing. Further, most studies have focused on how hypnotic suggestion may be used to achieve analgesic effect, but hypnosis may also have other benefits for chronic-pain patients such as reduced anxiety, improved sleep, and enhanced quality of life (Jensen, McArthur, et al., 2006
). These targets for hypnosis intervention with chronic-pain patients warrant further investigation. Research to date has been very promising and continued research is needed to fully evaluate the effects and mechanisms of hypnosis interventions for chronic pain in randomized trials and clinical practice.