The Efficacy, Safety and Applications of Medical Hypnosis: A Systematic Review of Meta-analyses

A systematic review of meta-analyses

Background: The efficacy and safety of hypnotic techniques in somatic medicine, known as medical hypnosis, have not been supported to date by adequate scientific evidence.

Methods: We systematically reviewed meta-analyses of randomized controlled trials (RCTs) of medical hypnosis. Relevant publications (January 2005 to June 2015) were sought in the Cochrane databases CDSR and DARE, and in PubMed. Meta-analyses involving at least 400 patients were included in the present analysis. Their methodological quality was assessed with AMSTAR (A Measurement Tool to Assess Systematic Reviews). An additional search was carried out in the CENTRAL and PubMed databases for RCTs of waking suggestion (therapeutic suggestion without formal trance induction) in somatic medicine.

Results: Out of the 391 publications retrieved, five were reports of meta-analyses that met our inclusion criteria. One of these meta-analyses was of high methodological quality; three were of moderate quality, and one was of poor quality. Hypnosis was superior to controls with respect to the reduction of pain and emotional stress during medical interventions (34 RCTs, 2597 patients) as well as the reduction of irritable bowel symptoms (8 RCTs, 464 patients). Two meta-analyses revealed no differences between hypnosis and control treatment with respect to the side effects and safety of treatment. The effect size of hypnosis on emotional stress during medical interventions was low in one meta-analysis, moderate in one, and high in one. The effect size on pain during medical interventions was low. Five RCTs indicated that waking suggestion is effective in medical procedures.

Conclusion: Medical hypnosis is a safe and effective complementary technique for use in medical procedures and in the treatment of irritable bowel syndrome. Waking suggestions can be a component of effective doctor–patient communication in routine clinical situations.

Hypnosis for purposes of medical treatment goes back a long way. The British Medical Association endorsed the use of hypnosis in somatic medicine in 1955, on the basis of case reports and series backed up by expert consensus, and the American Medical Association followed suit in 1958 (1, 2). Whether robust evidence exists for the efficacy and safety of hypnosis in somatic medicine in the era of evidence-based medicine (EBM) (3) remains to be clarified. Because systematic reviews with quantitative analysis (meta-analyses) of randomized controlled trials provide the highest level of evidence in EBM (3), we decided to carry out a systematic review of meta-analyses on medical hypnosis.

The aims of this article are as follows:

• To define the various forms of hypnosis
• To describe the requirements that have to be fulfilled before therapeutic hypnosis can be carried out
• To provide a historical overview of the use of hypnosis in medicine and the assessment of its efficacy
• To identify the indications for medical hypnosis supported by robust evidence
• To present the evidence for use of positive suggestions as a component of effective doctor– patient communication.

Definitions

The term “hypnosis” is used to mean both an altered state of consciousness (synonym: hypnotic trance) and the procedure by which this state is induced (4). During a hypnotic trance physiological, cognitive, and affective processes as well as behavior can be modified. A hypnotic state and hypnotic phenomena can be induced by another person (therapist) or alone (self-hypnosis). The subjective experience of hypnosis is characterized by a high degree of authenticity (experienced as real) and involuntariness (“it happens by itself”) (4).

Hypnosis can be distinguished from other states of consciousness such as normal wakefulness, sleep, deep relaxation, or meditation by means of electroencephalography (EEG) and imaging modalities (4). A hypnotic trance is characterized by a number of physiological and mental reactions, e.g., altered perception of time, selective amnesia, regression to a younger age (retrieval of memories or experiences from an earlier developmental stage), a marked inward focus, and heightened suggestibility, i.e., a stronger reaction to suggestions (4). In clinical situations associated with high affective participation of the patient, such as emergencies, diagnostic and therapeutic interventions, or communication of a serious diagnosis, hypnotic phenomena may occur spontaneously (e1, e2).

Suggestions work via verbal and nonverbal signals that correspond to internal expectations and have a powerful effect on mental and involuntary somatic processes. For example, cutaneous perfusion or the flow of saliva is not amenable to influence by a deliberate intellectual action, but can be affected by a suggestion, e.g., a picture or a story. In general use the word “suggestion” tends to imply manipulation, but in hypnosis it should be understood as meaning a proposal, an offer of options (“I suggest”). In contrast to the widespread preconceptions, hypnosis is not authoritarian, passive, and centered around the therapist, but a resource- and solution-oriented method in which the focus is on the patient's own potentials (4).

Applications of hypnosis

Depending on the goals, various applications of hypnotic techniques can be distinguished (4):

• Medical hypnosis

– Alleviation of somatic symptoms

– Reduction of mental stress during medical treatment

– Amelioration of disordered physiological/biochemical parameters

– Facilitation of physiological/biochemical healing processes

• Hypnotic communication

– Waking suggestions (suggestions without trance induction)

– Suggestions with the patient under general anesthesia

– Use of findings from hypnotherapy for effective doctor–patient communication

• Hypnotherapy (psychotherapy with the patient in a trance)

– Improvement of problem management by giving the patient access to their own resources

– Facilitation of changes in behavior

– Restructuring (minimization, reinforcement, new conditioning) of cognitive–affective patterns

– Restructuring of emotionally stressful events and sensations

– Reintegration of non-accessible (dissociated) feelings

• Experimental hypnosis

– Basic research on somatic sensations (e.g., pain), emotions, and states of consciousness

• Stage hypnosis

– Demonstration of hypnotic phenomena to entertain an audience

The perception of hypnosis as an authoritarian, manipulative technique, nourished particularly by its use in stage shows, represents the greatest barrier to the (re)integration of hypnosis into medical treatment.

Phases of medical hypnosis

A session of medical hypnosis generally lasts between 20 and 50 min and can be divided into various phases (4):

• Verification of the indication; explanation (correction of inappropriate anxiety or false expectations); definition of goal(s)
• Induction
• Consolidation
• Therapeutic suggestions
• Reorientation, posthypnotic suggestions
• Discussion
• Integration into daily routine: use of an audio file at home; behavioral exercises (e.g., exposure training); possibly learning of self-hypnosis techniques.

A selection of broadcasts (mostly in German) publicly available on the internet can be found in eBox 1.

eBox 1

Selection of German-language videos and podcasts from public broadcasters on medical hypnosis

Formal re quirements

In Israel and Sweden, hypnosis may be carried out only by physicians and psychologists who have received appropriate training. In Germany, from the legal point of view, anyone can offer hypnosis for non-medical reasons. Treatment of illness by means of hypnosis requires a license to perform procedures for the purpose of healing (medical and psychological psychotherapists, child and adolescent psychotherapists, naturopaths) (e3). Medical hypnosis can be carried out by physicians of all patient-related specialties in the framework of basic psychosomatic care. An invoice for relaxation hypnosis according to the official German schedules for physicians’ fees (Uniform Value Scale, Einheitlicher Bewertungsmaßstab) can be submitted only by persons who possess a qualification in basic psychosomatic care and have successfully completed a course in hypnosis comprising two units of 16 hours each (e4). Most medical and psychological psychotherapists and child and adolescent psychotherapists learn the techniques of hypnotherapy as a supplementary qualification. As a rule hypnotherapists are also trained in other methods of psychotherapy.

Details of the history of hypnosis and assessment of its efficacy prior to the introduction of evidence-based medicine (EBM) are provided in eBox 2.

eBox 2

The history of hypnosis and assessment of its efficacy before the advent of evidence-based medicine (EBM)

Evidence for efficacy and safety

Methods

This review was conducted according to the recommendations of the Cochrane Collaboration for systematic reviews of previously published reviews and the recommendations of the Joanna Briggs Institute for umbrella reviews (6).

Systematic survey of the literature

The Cochrane databases CDSR and DARE and PubMed were searched for systematic reviews (SRs) published in the period January 2005 to June 2015. The following search terms were used: “review,” “meta-analysis,” and “hypnosis”. We searched PubMed with “((“hypnosis”[MeSH] OR “hypnosis, dental”[MeSH]) AND (“meta-Analysis” [Publication Type] OR “review” [Publication Type])) OR ((hypnosis OR hypnotherap*) AND (meta-analy* OR metaanaly*))”. Moreover, the reference lists of the SRs identified were inspected for further SRs. With regard to waking suggestions we searched the databases Central and PubMed for randomized controlled trials (RCTs) using the terms “suggestion” [MeSH] and “hypnotic suggestion”. Finally, for all topics we asked experts in medical hypnosis about SRs.

Inclusion criteria

The following conditions regarding study type, indications, setting, and study population had to be fulfilled:

Study type: We included SRs with meta-analysis of (quasi-)RCTs on hypnosis as intervention for somatic medical indications. In the event of serial publications by the same group of authors we used the most recent publication. We selected inclusion of at least 400 patients in quantitative analysis (meta-analysis) of the study results as a quantitative criterion of robust evidence (7).

Indications: The endpoints of the meta-analysis had to be somatic symptoms (e.g., pain or nausea) or physiological findings (e.g., bleeding time or airway resistance) and/or mental stress during medical treatments and/or cost-related data (e.g., operating time, legth of hospital stay, or drug consumption). We excluded meta-analyses of RCTs on psychiatric and psychotherapeutic indications (e.g., anxiety disorders, depressive disorders, addiction/abuse, or behavioral disorders) and meta-analyses of RCTs on various diseases (e.g., psychosomatic illnesses) in which no subgroup analyses were conducted for individual diseases.

Setting and study population: No restrictions were imposed with regard to setting, age, or country.

Methodological quality

The methodological quality of the meta-analyses was verified using AMSTAR (A Measurement Tool to Assess Systematic Reviews) (8). AMSTAR scores of 0–4 were classified as low, 5–8 as intermediate, and 9–11 as high methodological quality (9).

Data extraction

The following characteristics of the meta-analyses were extracted independently by two of the authors (WH, MH) and discrepancies were resolved by consensus:

• The medical indication
• The number of RCTs/patients included
• The age and sex of the patients
• The type and duration of hypnosis
• The nature of the control group
• The instrument for and results of measurement of methodological quality of the included RCTs
• The databases searched and the period covered
• The findings regarding efficacy, tolerance, and safety
• The authors' conclusions
• The AMSTAR rating.

Given the heterogeneity of diseases and outcome variables, no quantitative data synthesis was planned from the outset.

Results: survey and inclusion

The database survey and the hand search identified 391 publications in total. Seventy-seven full texts were examined in detail (Figure). Fourteen meta-analyses (on topics such as chemotherapy-induced nausea and vomiting, fibromyalgia syndrome, and temporomandibular disorder) were excluded from analysis because they included fewer than 400 patients in their calculations (eTable 1) (e11–e24). Five meta-analyses were included in our qualitative review (10–14). The methodological quality was high in one meta-analysis, intermediate in three, and low in one (eTable 2). The characteristics of the original articles investigated in these five meta-analyses are outlined in Table 1.

Figure

Results of the lit erature survey

Table 1

Characteristics of the randomized controlled studies of medical hypnosis included in the meta-analyses*

eTable 1

List of excluded systematic reviews with meta-analysis*

eTable 2

Assessment of the methodological quality of the meta-analyses of controlled trials of medical hypnosis by means of AMSTAR (8)

Results: efficacy and safety

Hypnosis was superior to standard treatment or attention control (controls) in reduction of emotional stress, (10, 13, 14), pain (10, 14), duration of convalescence, and drug consumption (10) in interventional procedures and operations. The effect size on emotional stress varied: it was slight in one meta-analysis (10), intermediate in another (14), and high in a third (13). The effect size on pain reduction was low (10, 14). The effect sizes of hypnosis in medical interventions were dependent on the methodological quality of the original studies (10, 14).

Gut-directed hypnosis was superior to the treatments used in the control groups with regard to the number of patients with an appropriate reduction of symptoms at the end of treatment (number needed to treat [NNT] 5) and at follow-up 6 months later (NNT 3) (12). Hypnosis was not more effective than standard treatment or attention control for pain during labor and childbirth (11).

Evaluation of the data on safety of hypnosis in two meta-analyses (pain during labor and childbirth, irritable bowel syndrome) (11, 12) revealed no signs of a higher rate of adverse effects than in controls (Table 2).

Table 2

Results of the meta-analyses of randomized controlled trials on medical hypnosis*

Discussion of the results can be found in eBox 3.

eBox 3

Discussion of the findings concerning the evidence of the efficacy of medical hypnosis

Applications of hypnosis in daily clinical practice

Preparation and performance of interventions

Anesthesia and surgery: The use of hypnosis instead of local anesthesia in dental surgery (e25) and in place of anesthesia for more extensive surgery (cholecystectomy, aortocoronary bypass operation) has been described in case reports (e26). However, hypnosis is being routinely used as a complement rather than an alternative to modern, safe techniques of anesthesia, primarily to minimize anxiety and stress. Hypnosis has been shown to reduce pain, anxiety, and the consumption of analgesics and sedatives to a statistically significant extent in patients undergoing operations under local or regional anesthesia (e27, e28).

An example of the efficacy of hypnotic communication—even without formal trance induction—is its application in waking craniotomies, as performed for instance for removal of a brain tumor close to the speech area or for deep brain stimulation. In these procedures the patient receives regional anesthesia of the head and remains awake for the whole duration of the brain surgery for purposes of neurological testing, with no need for sedation and additional analgesia. Dissociation to an inner place of tranquility away from the operating room plays an important part, as does the reinterpretation of sensory perceptions (e29).

Some German hospitals offer live or audio file–aided hypnosis as a complement to general and regional anesthesia.

Gastroenterology: With the aid of hypnosis—e.g., self-hypnosis or hypnosis by means of audio files— diagnostic esophagogastroduodenoscopy procedures can be carried out without sedation (e30). The use of audio files is also efficacious in irritable bowel syndrome (e31). These files can be given to patients with irritable bowel syndrome by their primary care physician or internist, and the progress with regard to symptom control can be discussed with the patients in the framework of basic psychosomatic care (e32). This aproach can greatly facilitate the clinical application of hypnosis. Gastroenterology departments in Great Britain (e33), Austria (e34), and the USA (e35) have integrated psychosocial services that offer live and audio file–aided hypnosis to patients with functional gastrointestinal disorders who do not respond well to conventional medicinal treatment (see eBox 1 for more on gut-directed hypnosis). Some office-based gastroenterologists in Germany offer hypnosis as an alternative to sedation in esophagogastroduodenoscopy.

Dentistry: The German Dental Hypnosis Society (Deutsche Gesellschaft für Zahnärztliche Hypnose) has trained around 3000 dentists in hypnosis. The society's website lists over 600 dentists who offer this service to their patients. The indications for which hypnosis is available are pronounced fear of dental treatment, gag reflex, intolerance of local anesthetics, and craniomandibular dysfunction. Hypnosis in the following forms is offered (e25):

• The use of CDs developed specially for dental treatment (e.g. “Beim Zahnarzt ohne Spritze [Dental surgery without injection]”). At the beginning of the treatment session track 1 is played repeatedly over headphones, and at the end of treatment the patient is woken by track 2.
• Delegation of the hypnosis to a trained member of staff (hypnosis assistant). In this case the dentist must also be trained in hypnosis, because he/she is responsible for the patient's welfare and must be able to deal with the rare cases of adverse reaction to hypnosis.
• Induction of hypnosis by the dentist him-/herself. This takes 2 to 5 min for relaxation prior to an injection, about 10 min for treatment without local anesthesia.
• It is advantageous to combine nitrous oxide and hypnosis, because the gas has an anxiolytic effect and increases suggestibility.
• Some dentists who concentrate on treatment of patients with anxiety or craniomandibular dysfunction draw on the services of an external hypnotist.

Live hypnosis versus audio file–aided hypnosis

A meta-analysis of hypnosis in medical interventions demonstrated no significant differences in efficacy between live hypnosis and suggestion by means of audio files (14). Another meta-analysis by a different group of authors concluded that only live hypnosis, which is more apt to provide the context of a personal relationship, significantly reduced postoperative anxiety and pain. Both live and audio file–aided hypnosis significantly decreased postoperative nausea and consumption of analgesics (10).

Waking suggestions in doctor–patient communication

The German Medical Assembly 2015 spoke out in favor of strengthening physicians’ communicative competence (15). In our opinion, together with authentic and empathetic interaction (16), effective doctor–patient communication has to include avoidance of negative suggestions (16–19) and targeted use of positive waking suggestions (18). In this context, communication could be improved by applying basic principles of hypnotherapy such as employment of indirect suggestions and the establishment of a trusting doctor–patient relationship (rapport). Three RCTs on invasive radiological procedures found that positive suggestions and empathy, with and without techniques of self-hypnosis, were superior to the standard treatment in reducing pain and anxiety and in decreasing consumption of analgesics (20–22). In two RCTs, neutral or positive instructions before blood sampling (“I'm going to start taking the blood sample now”) or induction of local anesthesia led to lower levels of pain than (unintended) negative suggestions (“this may hurt a bit”) (23, 24). A RCT in a hospital emergency room found that the pain-relieving effect of intramuscular diclofenac was not reinforced by a waking suggestion (“this is a powerful painkiller”) in patients with acute headache (25) (eTable 3). Therapeutic waking suggestions can be used by all physicians in a medical context (see Table 3 for examples).

Table 3

Examples of positive waking suggestions at premedication and before induction of anesthesia (modified from [18, 19])

eTable 3

Overview of randomized controlled trials on the effect of waking suggestions in medical treatment procedures*

Psychosomatic medicine

Examples of the application of medical hypnosis by psychotherapists in somatic medicine are given in the Box.

Box

Potential applications of medical hypnosis in daily clinical practice (case reports and/or case series)

Conclusion

Hypnosis techniques have long been used—and their efficacy assessed—in somatic medicine. The modern evidence-based indications (emotional stress associated with medical interventions, functional disorders such as irritable bowel syndrome) correspond with the applications of mesmerism in medicine in the middle of the 19^th century (e5). Learning techniques of self-hypnosis empowers patients to participate in their own treatment and grants them independence. Hypnosis techniques such as the building of a trusting relationship with the patient and therapeutic waking suggestions can considerably reinforce the communicative competence of physicians (15).

Conflict of interest statement

Dr. Häuser receives royalties from the sale of CDs on medical hypnosis in irritable bowel syndrome and fibromyalgia syndrome from Hypnos Verlag. He is an instructor for hypnosis of the German Society for Medical Hypnosis and Autogenous Training (Deutsche Gesellschaft für Ärztliche Hypnose und Autogenes Training).

Dr. phil. Dipl.-Psych. Hagl has received honoraria for authorship or co-authorship of yearly reviews of hypnosis research from the Milton H. Erickson Society for Clinical Hypnosis (Milton H. Erickson Gesellschaft für Klinische Hypnose).

Dr. Schmierer has received an honorarium for authorship or co-authorship from Quintessenzverlag (dental hypnosis).

Prof. Hansen is a member of the scientific advisory board of the Milton H. Erickson Society for Clinical Hypnosis (Milton H. Erickson Gesellschaft für klinische Hypnose).

Manuscript submitted on 28 September 2015, revised version accepted on 7 January 2016

Translated from the original German by David Roseveare

Corresponding author
PD Dr. med. Winfried Häuser
Klinik Innere Medizin I
Klinikum Saarbrücken
Winterberg 1, 66119 Saarbrücken, Germany

@Supplementary material
For eReferences please refer to:
www.aerzteblatt-international.de/ref1716

eBoxes und eTables:
www.aerzteblatt-international.de/16m0289

References

1. British Medical Association. Medical use of hypnotism: report of a subcommittee appointed by the Psychological Medicine Group Committee of the British Medical Association. BMJ Suppl 1955; 23: 190–3.

2. Council on Mental Health: Medical use of hypnosis. JAMA 1958; 168: 186–9

3. Baethge C: Evidenzbasierte Medizin. In der Versorgung angekommen, aber noch nicht heimisch. Dtsch Arztebl 2014; 111: 163

4. Peter B: Hypnosis. In: Wright DE: International encyclopedia of the social and behavioral sciences. 2 nd edition, Volume 11. Oxford: Elsevier 2015; 458–64

5. Higgins JPT, Green S (eds.): Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. www.cochrane-handbook.org (last accessed on 1 August 2015).

6. Aromataris E, Fernandez R, Godfrey C, et al.: Methodology for jbi umbrella reviews. The Joanna Briggs Institute Reviewers Manual 2014. http://arrow.monash.edu. au/hdl/1959.1/1131560 (last accessed on 1 June 2015).

7. Andrew Moore R, Eccleston C, Derry S, et al.: ACTINPAIN Writing Group of the IASP Special Interest Group on Systematic Reviews in Pain Relief; Cochrane Pain, Palliative and Supportive Care Systematic Review Group Editors: „Evidence“ in chronic pain-establishing best practice in the reporting of systematic reviews. Pain 2010; 15: 386–9.

8. Shea BJ, Hamel C, Wells GA, et al.: AMSTAR is a reliable and valid measurement tool to assess the methodological quality of systematic reviews. J Clin Epidemiol 2009; 62: 1013–20

9. Seo HJ, Kim KU: Quality assessment of systematic reviews or meta-analyses of nursing interventions conducted by Korean reviewers. BMC Med Res Methodol 2012; 12: 129

10. Kekecs Z, Nagy T, Varga K: The effectiveness of suggestive techniques in reducing postoperative side effects: a meta-analysis of randomized controlled trials. Anesth Analg 2014; 119: 1407–19

11. Madden K, Middleton P, Cyna AM, Matthewson M, Jones L: Hypnosis for pain management during labour and childbirth. Cochrane Database Syst Rev 2012; 11: CD009356

12. Schaefert R, Klose P, Moser G, Häuser W: Efficacy, tolerability, and safety of hypnosis in adult irritable bowel syndrome: systematic review and meta-analysis. Psychosom Med 2014; 76: 389–98

13. Schnur JB, Kafer I, Marcus C, Montgomery GH: Hypnosis to manage distress related to medical procedures: a meta-analysis. Contemp Hypn 2008; 25: 114–28

14. Tefikow S, Barth J, Maichrowitz S, Beelmann A, Strauss B, Rosendahl J: Efficacy of hypnosis in adults undergoing surgery or medical procedures: a meta-analysis of randomized controlled trials. Clin Psychol Rev 2013; 33: 623–36

15. Klinkhammer G: Förderung der ärztlichen Kommunikationskompetenz gefordert. Dtsch Arztebl 2015; http://www.aerzteblatt.de/nachrichten/62808/Aerztetag-Foerderung-%20der-aerztlichen-Kommunikationskompetenz-gefordert

16. Bingel U, Placebo Competence Team: Avoiding nocebo effects to optimize treatment outcome. JAMA 2014; 312: 693–4

17. Häuser W, Hansen E, Enck P: Nocebo phenomena in medicine: their relevance in everyday clinical practice. Dtsch Arztebl Int 2012; 109: 459–65

18. Hansen E, Bejenke C: [Negative and positive suggestions in anaesthesia: Improved communication with anxious surgical patients]. Anaesthesist 2010; 59: 199–202, 204–6, 208–9

19. Seemann M, Zech N, Graf BM, Hansen E: [The premedication visit—suggestions for a patient-friendly design]. Anasthesiol Intensivmed Notfallmed Schmerzther 2015; 50: 142–6

20. Lang EV, Benotsch EG, Fick LJ, et al.: Adjunctive non-pharmacological analgesia for invasive medical procedures: a randomised trial. Lancet 2000; 355: 1486–90

21. Lang EV, Berbaum KS, Faintuch S, et al.: Adjunctive self-hypnotic relaxation for outpatient medical procedures: a prospective randomized trial with women undergoing large core breast biopsy. Pain 2006; 126: 155–64

22. Lang EV, Berbaum KS, Pauker SG, et al.: Beneficial effects of hypnosis and adverse effects of empathic attention during percutaneous tumor treatment: when being nice does not suffice. J Vasc Interv Radiol 2008; 19: 897–905

23. Ott J, Aust S, Nouri K, Promberger R: An everyday phrase may harm your patients. Clin J Pain 2012; 28: 324–8

24. Varelmann D, Pancaro C, Cappiello EC, Camann WR: Nocebo-induced hyperalgesia during local anesthetic injection. Anesth Analg 2010; 110: 868–70

25. Oktay C, Eken C, Goksu E, Dora B: Contribution of verbal suggestion to the therapeutic efficacy of an analgesic agent for acute primary headache. Cephalalgia 2015; 35: 579–84

e1. Barabasz AF: Whither spontaneous hypnosis: a critical issue for practitioners and researchers. Am J Clin Hypn 2005; 48: 91–7

e2. Cheek DB: Importance of recognizing that surgical patients behave as though hypnotized. Am J Clin Hypn 1962; 4: 227–31

e3. Revenstorf D: Expertise zur Beurteilung der wissenschaftlichen Evidenz des Psychotherapieverfahrens Hypnotherapie entsprechend den Kriterien des Wissenschaftlichen Beirats Psychotherapie. Hypnose-ZHH 2006; 1; 7–164.

e4. Fritzsche K, Geigges W, Richter H, Wirsching M (eds.): Psychosomatische Grundversorgung. 1 st edition. Heidelberg: Springer, 2003.

e5. Peter B: Zur Geschichte der Hypnose in Deutschland. Hypnose und Kognition 2000; 17: 47–106.

e6. Bailly JS: Exposé zu den Erfahrungen, die zur Untersuchung des animalischen Magnetismus gesammelt worden sind. HyKog 1784/2000; 17: 107–14.

e7. Esdaile J: Mesmerism in India, and its practical application in surgery and medicine. London: Longman, Borwon, Green and Longmans, 1846.

e8. Robertson D: BMA Report on Hypnosis. www.rebhp.org/articles/1892.pdf (last accessed on 1 July 2015).

e9. Bongartz W, Flammer E, Schwonke R: Die Effektivität der Hypnose. Eine meta-analytische Studie. Psychotherapeut 2002; 47: 67–76

e10. Wissenschaftliche Beirat Psychotherapie. Gutachten zur wissenschaftlichen Anerkennung der Hypnotherapie. Wissenschaftlicher Beirat Psychotherapie 2006. www.wbpsychotherapie.de/page.asp?his=0.113.122.123 (last accessed on 1 July 2015).

e11. Adachi T, Fujino H, Nakae A, Mashimo T, Sasaki J: A meta-analysis of hypnosis for chronic pain problems: a comparison between hypnosis, standard care, and other psychological interventions. Int J Clin Exp Hypn 2014; 62: 1–28

e12. Bernardy K, Füber N, Klose P, Häuser W: Efficacy of hypnosis/guided imagery in fibromyalgia syndrome-a systematic review and meta-analysis of controlled trials. BMC Musculoskelet Disord 2011; 12: 133

e13. Birnie KA, Noel M, Parker JA, et al.: Systematic review and meta-analysis of distraction and hypnosis for needle-related pain and distress in children and adolescents. J Pediatr Psychol 2014; 39: 783–808

e14. Bowker E, Dorstyn D: Hypnotherapy for disability-related pain: A meta-analysis. J Health Psychol 2014 (epub ahead of print).

e15. Enck P, Junne F, Klosterhalfen S, Zipfel S, Martens U: Therapy options in irritable bowel syndrome. Eur J Gastroenterol Hepatol 2010; 22: 1402–11

e16. Flammer E, Alladin A: The efficacy of hypnotherapy in the treatment of psychosomatic disorders: meta-analytical evidence. Int J Clin Exp Hypn 2007; 55: 251–74

e17. Ford AC, Quigley EM, Lacy BE, et al.: Effect of antidepressants and psychological therapies, including hypnotherapy, in irritable bowel syndrome: systematic review and meta-analysis. Am J Gastroenterol 2014; 109: 1350–65 .

e18. Glazener CM, Evans JH, Cheuk DK: Complementary and miscellaneous interventions for nocturnal enuresis in children. Cochrane Database Syst Rev 2005 18: CD005230.

e19. Huang T, Shu X, Huang YS, Cheuk DK: Complementary and miscellaneous interventions for nocturnal enuresis in children. Cochrane Database Syst Rev 2011; 12: CD005230

e20. Köllner V, Häuser W, Klimczyk K, et al.: Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften: [Psychotherapy for patients with fibromyalgia syndrome. Systematic review, meta-analysis and guideline]. Schmerz 2012; 26: 291–6

e21. Lee HH, Choi YY, Choi MG: The efficacy of hypnotherapy in the treatment of irritable bowel syndrome: A systematic review and meta-analysis. J Neurogastroenterol Motil 2014; 20: 152–62

e22. Richardson J, Smith JE, McCall G, Richardson A, Pilkington K, Kirsch I: Hypnosis for nausea and vomiting in cancer chemotherapy: a systematic review of the research evidence. Eur J Cancer Care 2007; 16: 402–12

e23. Smith CA, Collins CT, Cyna AM, Crowther CA: Complementary and alternative therapies for pain management in labour. Cochrane Database Syst Rev 2006 18: CD003521.

e24. Zhang Y, Montoya L, Ebrahim S, et al.: Hypnosis/relaxation therapy for temporomandibular disorders: a systematic review and meta-analysis of randomized controlled trials. J Oral Facial Pain Headache 2015; 29: 115–25

e25. Schmierer A: Hypnose in der Zahnheilkunde: Geschichte, Organisation, Methoden, Praxis. Hypnose-ZHH 2010; 5: 69–94.

e26. Faymonville ME: Hypnose in der Anästhesie. Hypnose-ZHH 2010; 5: 111–20.

e27. Faymonville ME, Mambourg PH, Joris J, et al.: Psychological approaches during conscious sedation. Hypnosis versus stress reducing strategies: a prospective randomized study. Pain 1997; 7: 361–7

e28. Faymonville ME, Fissette J, Mambourg PH, Roediger L, Joris J, Lamy M: Hypnosis as adjunct therapy in conscious sedation for plastic surgery. Reg Anesth 1995; 20: 145–51

e29. Hansen E, Seemann M, Zech N, Doenitz C, Luerding R, Brawanski A: Awake craniotomies without any sedation: the awake-awake-awake technique. Acta Neurochir (Wien) 2013; 155: 1417–24

e30. Häuser W: Hypnose in der Gastroenterologie. Hypnose und Kognition 1997; 14: 25–32.

e31. Rutten JM, Vlieger AM, Frankenhuis C, et al.: Gut-directed hypnotherapy in children with irritable bowel syndrome or functional abdominal pain (syndrome): a randomized controlled trial on self exercises at home using CD versus individual therapy by qualified therapists. BMC Pediatr 2014; 14: 140

e32. Häuser W: Hypnose in der Therapie des Reizdarmsyndroms. Psychomed 2002; 14: 227–32.

e33. Gonsalkorale WM, Houghton LA, Whorwell PJ: Hypnotherapy in irritable bowel syndrome: a large-scale audit of a clinical service with examination of factors influencing responsiveness. Am J Gastroenterol 2002; 97: 954–61

e34. Moser G, Trägner S, Gajowniczek EE, et al.: Long-term success of GUT-directed group hypnosis for patients with refractory irritable bowel syndrome: a randomized controlled trial. Am J Gastroenterol 2013; 108: 602–9

e35. Kinsinger SW, Ballou S, Keefer L: Snapshot of an integrated psychosocial gastroenterology service. World J Gastroenterol 2015; 21: 1893–9

e36. Colloca L, Finniss D: Nocebo effects, patient-clinician communication, and therapeutic outcomes. JAMA 2012; 307: 567–8

e37. Iserson KV: An hypnotic suggestion: review of hypnosis for clinical emergency care. J Emerg Med 2014; 46: 588–96

e38. Zech N, Seemann M, Signer-Fischer S, Hansen E: [Communication with children: practical hints and tools for the anesthesiology routine]. Anaesthesist 2015; 64: 197–207

e39. Seemann M, Zech N, Graf B, Hansen E: [Anesthesiological management of awake craniotomy: Asleep-awake-asleep technique or without sedation]. Anaesthesist 2015; 64: 128–36

e40. Eitner S, Sokol B, Wichmann M, Bauer J, Engels D: Clinical use of a novel audio pillow with recorded hypnotherapy instructions and music for anxiolysis during dental implant surgery: a prospective study. Int J Clin Exp Hypn 2011; 59: 180–97

e41. Hermes D, Truebger D, Hakim SG, Sieg P: Tape recorded hypnosis in oral and maxillofacial surgery-basics and first clinical experience. J Craniomaxillofac Surg 2005; 33: 123–9

e42. Ebell H, Beyer A: Die Schmerzbehandlung von Tumorpatienten. Stuttgart, New York: Thieme 2001.

e43. Ebell H: Hypnose und Selbsthypnose in der Behandlung von Patienten, die an chronischen Schmerzen leiden. Hypnose und Kognition 2002; 19: 27–38.

e44. Tschugguel W, Tschuguell S: Hypnose bei Patientinnen mit gynäkologischen Symptomen. Hypnose-ZHH 2010; 5: 121–44.

e45. Schulze W: Hypnose in der Palliativmedizin. Hypnose-ZHH 2010; 5: 145–61.

e46. Tigges-Limmer K, Gummert J: Hypnotherapeutische Interventionen in der Herztransplantation. Hypnose-ZHH 2010; 5: 179–97.

e47. Schmierer A, Schmierer G: Hypnose in der Zahnarztpraxis – eine sichere und schnelle Möglichkeit zum Angstabbau. DZzH 2004; 3: 31–51.