Clinical research on cognitive-behavioural hypnotherapy

Hypnotherapy probably has a stronger scientific evidence-base than most people realise. For example, a recent meta-analysis identified 57 good quality randomised controlled trials (RCTs), involving 1,829 participants, from a total of 444 studies examining the clinical efficacy of hypnosis, excluding “analogue” studies (Flammer & Bongartz, 2003). These researchers found that hypnosis had a “medium” (d=0.56) effect size overall, compared to control groups. The effect size was greatest (d=0.69) for those RCTs (n=8) that involved treatment of anxiety. The authors note that these calculations must be considered conservative because they included all reported measures, even those close inspection suggested were probably not very sensitive to the effects of treatment. The range of conditions treated by these studies was very broad and included the following:

Tinnitus Insomnia Duodenal ulceration Enuresis Asthma Warts Irritable bowel syndrome (IBS) Chronic and recurrent headaches Hypertension Smoking Test anxiety Posttraumatic Stress Disorder (PTSD) Anxiety Anxiety, quality of life and care following bypass surgery

Postoperative vomiting (following breast surgery) Blood loss/pressure in maxillofacial surgery Analgesia during labour Osteoarthritic pain Care of third molar surgery patients Healing process in bone fractures Local anaesthesia Postoperative recovery (open heart surgery) Analgesia/reducing unnecessary movement in ophthalmic surgery Improvement of postoperative course in children

Analgesia in interventional radiological procedures Analgesia for invasive medical procedures Distress/pain in breast biopsy patients Treatment of burn pain Procedural pain during burn care Chemotherapy-related nausea/vomiting in children Pain, distress, and anxiety in children undergoing bone marrow aspiration Pain/nausea during cancer treatment Chemotherapy distress in children with cancer

These researchers also found six studies reporting data on hypnotic susceptibility scale ratings, which together demonstrated a positive correlation (r=0.44) between the patient’s susceptibility to hypnotic suggestions in general and the outcome of treatment.

The precise nature of any interaction between hypnosis and specific cognitive-behavioural interventions, however, has not been extensively studied under controlled conditions. Nevertheless, modern research on hypnotherapy increasingly focuses upon integrating hypnotherapy and CBT since publication of Kirsch et al.’s influential meta-analysis which pooled data from eighteen separate controlled studies, including 577 participants, comparing the efficacy of “cognitive-behavioural hypnotherapy” to CBT alone. They concluded that for seventy per cent of patients (or ninety per cent if a possible statistical outlier is not excluded from the calculation) CBT was more effective when integrated with hypnosis, that is., that for the vast majority of clients cognitive-behavioural hypnotherapy is superior to CBT alone (Kirsch, Montgomery, & Sapirstein, 1995, p. 214). Put differently, this review of the research provided statistical evidence of a mean “additive” effect of hypnosis when combined with standard behaviour therapy or CBT, across a variety of issues.

More recent studies have continued to identify an additive effect of hypnosis when incorporated into conventional CBT. For example, one piece of research found that the addition of hypnosis made standard CBT using cognitive restructuring and in vivo exposure for public speaking anxiety more effective (Schoenberger, Kirsch, Gearan, Montgomery, & Pastyrnak, 1997). Likewise, a recent randomised controlled trial (RCT) comparing cognitive-behavioural hypnotherapy to standard CBT in the treatment of Acute Stress Disorder (ASD), involved eighty-nine civilian survivors of trauma (Bryant, Moulds, Guthrie, & Nixon, 2005). The researchers found both CBT and CBT+hypnosis to be equally effective, in terms of patients no longer meeting diagnostic criteria at six-month follow-up, and both cognitive-behavioural approaches to be about twice as effective as supportive counselling. However, CBT+hypnosis clients reported greater reduction of re-experiencing symptoms at post-treatment than the CBT group, which the researchers interpreted as evidence for their hypothesis that hypnosis was capable of enhancing the efficacy of imaginal exposure in the treatment of trauma, by increasing reliving, and thereby enhancing, emotional processing of traumatic memories. The approach adopted in this manual integrates hypnosis with standard CBT techniques such as coping skills training, exposure therapy, problem-solving and cognitive restructuring. The evidence from the studies above suggests that this may often be more effective than standard nonhypnotic CBT. For example, hypnotic induction and suggestions may enhance the use of imaginal exposure techniques of the kind discussed in later chapters.

Indeed, hypnotherapy may be particularly indicated in the treatment of anxiety symptoms. Although there has been some disagreement about this in the past, as Bryant observes, on the basis of a number of studies that report findings in this area, research increasingly suggests that anxious clients tend to be more responsive to hypnosis than average. Elevated levels of hypnotic responsiveness have been found in PTSD, acute stress disorder, phobias, and other disorders involving anxiety symptoms, and patients with multiple anxieties have been found more hypnotisable than those with single specific phobias (Bryant R. A., 2008, pp. 535-536).

There is no doubt that hypnosis can facilitate established means of treating anxiety disorders. Fear conditioning and extinction models have led to [cognitive-behavioural] treatments that involve new learning, and there is convergent evidence that this learning can be enhanced by hypnosis in numerous ways. The greater ability of hypnotized individuals to engage in imagery, focused attention, motivation to comply with instructions and imaginal rehearsal of mastery of fear all combines to potentiate the treatment gains for anxiety patients. (Bryant R. A., 2008, p. 545)

Moreover, hypnotherapy has typically performed well in the treatment of anxiety symptoms in controlled clinical outcome studies.

In addition to the treatment of anxiety, recent research has also supported the efficacy of hypnotherapy as a treatment for clinical depression. In particular, Assen Alladin, the author of a recent clinical manual for evidence-based Cognitive Hypnotherapy (Alladin, 2008) has employed hypnosis to induce positive imagery and feelings in depressed clients, in order, he postulates, to directly condition the formation of “anti-depressive pathways” in the brain. Good evidence in support of the efficacy of his cognitive hypnotherapy has already been produced by Alladin from a clinical trial, using eighty-four chronic depressives, in which cognitive hypnotherapy was compared head-to-head against the use of orthodox cognitive therapy in the treatment of depression. This study is particularly significant because it appears to meet the stringent research design criteria set down by the American Psychological Association for an empirically-supported treatment (EST) rated “probably efficacious” (Alladin & Alibhai, 2007).