Gut-directed hypnotherapy delivered by psychologists appears as effective in group or individual sessions, potentially offering a new treatment option for irritable bowel syndrome in primary and secondary care.
Hypnotherapy might help relieve irritable bowel syndrome (IBS) complaints for some patients for as long as 9 months after the end of treatment, according to a randomised controlled trial of 354 adults with IBS in primary and secondary care published in The Lancet Gastroenterology & Hepatology journal.
After 3 months of treatment, adequate relief of IBS symptoms was reported by more patients who received individual (40%; 41/102 for whom data were available) and group hypnotherapy (33%; 31/91) than those given education and supportive care (17%; 6/35), and these benefits persisted at 9 months follow-up (42% [38/91], 50% [40/80], and 22% [7/31]).
Importantly, the findings suggest that group hypnotherapy is as effective as individual sessions, which could enable many more patients with IBS to be treated at reduced cost.
The study is the largest randomised trial of hypnotherapy for IBS to date, and one of the first conducted in primary care, where the vast majority of IBS patients are treated.
The study found that IBS patients undergoing hypnotherapy reported a greater overall improvement in their condition and were more able to cope with, and were less troubled by, their symptoms compared with those who received educational supportive therapy. However, hypnotherapy did not appear to reduce the severity of symptoms.
While the findings are promising, the authors conclude that more research will be needed to test the optimum number of hypnotherapy sessions, the effect that patient expectations may have on treatment outcome, and the extent to which hypnotherapy outcomes are influenced by the magnitude of the psychological complaints of the patient.
"Our study indicates that hypnotherapy could be considered as a treatment option for patients with IBS, irrespective of symptom severity and IBS subtype," says Dr Carla Flik from the University Medical Center Utrecht, Netherlands, who led the research. "It is also promising to see that group hypnotherapy is as effective as individual sessions, which may mean that more people could be treated with it at lower cost, should it be confirmed in further studies." 
"What's striking about these findings is the extent to which patient's perception of their illness has an effect on their suffering, and that their perception of symptoms appears to be as important as actual symptom severity." 
IBS affects around 1 in 5 people worldwide and is a persistent and difficult-to-treat condition, with symptoms that can seriously affect quality of life including abdominal pain, bloating, diarrhoea, and constipation. For many sufferers, drug and dietary treatments are not successful.
Psychological interventions have proven effective, but their use is limited by a shortage of trained therapists. Hypnotherapy has previously shown promising results for IBS, but the majority of studies have been done in highly specialised centres, and more research is needed into whether hypnotherapy is beneficial in primary and secondary care where most patients are treated.
The IMAGINE study recruited 354 adults (aged 18-65 years) with IBS who were referred by primary care physicians and hospital specialists to 11 hospitals across the Netherlands between May 2011 and April 2016. Participants were randomly assigned to receive either 45-minute individual sessions (150 patients) or group sessions (150) of hypnotherapy twice weekly for 6 weeks, or education and supportive care (54).
Hypnotherapy treatment was provided by psychologists who were trained as hypnotherapists and involved a technique of positive visualisation during which patients were given suggestions about how they could gain control over their digestive system to reduce feelings of pain and discomfort. Patients were also given a CD so they could practice self-hypnosis exercises at home for 15-20 minutes every day.
Participants completed assessments on their level of symptom severity, quality of life, psychological symptoms, health-care costs, and work absence at the start of the trial and immediately after treatment (3 months) and again 9 months later, as well as symptom relief immediately after treatment and 9 months later.
Results showed that immediately after treatment, participants in the two hypnotherapy groups reported satisfactory relief at substantially higher rates than those who received educational supportive care, and these benefits persisted for 9 months after the treatment ended (table 2).
Nevertheless, satisfactory relief of symptoms was not accompanied by a significant improvement in symptom severity.
As Dr Flik explains: "We do not know exactly how gut-directed hypnotherapy works, but it may change patients' mindset and internal coping mechanisms, enabling them to increase their control over autonomic body processes, such as how they process pain and modulate gut activity." 
Improvements in quality of life, psychological complaints, cognitions and reductions in medical costs and IBS-related work absence were similar between groups.
Overall, hypnotherapy was well tolerated. Eight serious unexpected adverse reactions (six in the individual hypnotherapy group and two in the group hypnotherapy group) were reported, mostly cancer and inflammatory bowel disease, but were not related to hypnotherapy.
The authors note some limitations--for instance, that 22 (15%) patients in the individual hypnotherapy group, 22 (15%) in the group hypnotherapy group, and 11 (20%) in the control group dropped out before or during therapy, and a substantial number of participants did not complete questionnaires at 3 months and 9 months after treatment, which might have biased the results (figure 1). They also point out that the inexperience of therapists in dealing with IBS, and the low number (six) of hypnotherapy sessions provided (half the usual number), might have led to underestimations of the effects of hypnotherapy.
Writing in a linked Comment, Professor Olafur Palsson, University of North Carolina at Chapel Hill, USA discusses factors that may have contributed to the "modest" therapeutic impact of hypnosis in the study.
He writes: "The hypnotherapy tested in this study might have been suboptimal in amount or implementation. However, as the authors note, the smaller therapeutic effect in this trial compared with most hypnotherapy trials in tertiary care might have been because IBS in primary and secondary care is different to that in tertiary care--perhaps simpler in nature and with less involvement of psychological factors. Therefore, despite this impressive investigative effort by Flik and colleagues, it remains unclear whether gut-directed hypnotherapy is well suited for the treatment of patients with IBS in primary and secondary care, and future trials are needed to provide definitive answers."
NOTES TO EDITORS:
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