The newest healthy living trend: Sleep


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Insomnia is thought to affect one in 3 people in the UK, with sufferers finding it difficult to get to sleep, having interrupted sleep, waking early, and having difficulty concentrating and feeling tired and irritable during the day. With the … Continue reading

Hypnotherapy versus CBT: October Research Snippet

Hypnotherapy versus CBT: October Research Snippet

Donald Robertson, NCH Research Director

This month’s research snippet is about a very important treatment outcome study on public-speaking anxiety, a clinical trial comparing an established (evidence-based) CBT protocol for social phobia (social anxiety disorder) against the same protocol augmented by hypnosis, and a third (waiting list) control group.  The study was published in 1997 and has been frequently-cited since as providing evidence of the “additive” value of hypnosis as an adjunct to CBT and potentially other evidence-based treatments.  I’ve decided to summarise it this month because it’s probably one of the most important treatment outcome studies available in relation to hypnotherapy, and so NCH members should be familiar with its findings, and because the study was based on the doctoral dissertation of Nancy Schoenberger, the main author, who was supervised by Prof. Irving Kirsch, one of the speakers at this year’s NCH Extravaganza.  So if you’re lucky you may have the opportunity to ask Prof. Kirsch about this study yourselves!  In a nutshell, the authors conclude: “the addition of hypnosis to cognitive behavioural treatment enhanced the effects of treatment.”

The study involved 62 participants with severe public-speaking anxiety.  They were divided into three groups,

  1. Standard CBT (based on Heimberg’s protocol for social phobia)
  2. CBT+Hypnosis (Cognitive-behavioural hypnotherapy, CBH)
  3. Waiting list control, i.e., a group who received no treatment to control for the effect of spontaneous remission, etc.

The researchers emphasise the established finding that relaxation is not a necessary component of hypnosis (hypnosis is not a “state of relaxation”), although it featured as a treatment component in this study.  (This key misconception is virtually extinct among modern researchers but is still fairly widespread among hypnotherapists.) 

In sum, the hypnotic treatment included all components of the cognitive behavioural treatment.  It differed from the nonhypnotic treatment only in the following ways: (a) relaxation training was termed “hypnosis” and contained reference to entering hypnosis, (b) relaxation practice at home was termed “self-hypnosis”, (c) automatic thoughts were termed self-suggestions, and (d) suggestions for improvement were given following the hypnotic induction.

Participants in both treatment groups received five sessions, two-hours long, of CBT or CBH, based on Heimberg’s established protocol for the generalised subtype of social phobia.  This has already been applied to public-speaking, the most common fear among social phobics, and the authors adapted it to include relaxation skills training and tailored it for application to a specific fear (public speaking).

42 of the 62 participants completed the whole programme of treatment and assessment (= 68% completers).  Essentially, the study found that CBH subjects improved to a greater extent, because of the apparent additive value of hypnosis, across a battery of outcome measures, although the initial credibility rating of both treatments was virtually identical.  The mean effect size across all measures, calculated using a standard formula called Cohen’s d, was 0.80 for CBT, which increased to 1.25 in the group where hypnosis as incorporated.  This shows a substantial increase on average, apparently due to the inclusion of hypnosis in the standard CBT protocol.

The researchers also attempted to identify “moderators” of treatment, i.e., other factors which determined the response to therapy.  They measured hypnotic susceptibility and attitudes toward hypnosis for this purpose.  Suggestibility did not seem to correlate well with outcome measures except for pulse rate (which may have been problematic in this study anyway).  Positive attitudes to hypnosis appear to have moderated the benefits of hypnosis, and correlated with greater reduction in anxious behaviours.

Kirsch’s cognitive “response set” theory holds that the effects of hypnosis are largely mediated by changes in the client’s expectations of improvement.  (It’s generally been found by researchers that treatment expectations correlate with outcome, across the board.)  Although some hypnotists seem to dispute this, it was also central to Braid’s definition of hypnotism that it worked partly by means of expectation.  Statistical analysis in this study showed that hypnosis generated greated expectation for improvement in symptoms of public speaking anxiety than did CBT alone.

In sum, the addition of hypnosis to a cognitive behavioural treatment of anxiety enhances clients’ therapeutic outcome expectancies.  It also appears to promote greater improvement in both expected and experienced anxiety.  Behavioural improvement in hypnotic treatment is associated with positive initial attitudes toward hypnosis, and change in anxiety expectancy appears to be the central unifying characteristic among otherwise uncorrelated measures of change.  These data are consistent with [Kirsch’s] hypothesis that the benefits of adding hypnosis to treatment are mediated by expectancy.

This study followed on from an important meta-analysis by Kirsch and his colleagues which pooled data from different studies comparing different forms of CBT for different problems to the same treatment plus hypnosis and found that for between 70-90% of subjects, on average, hypnosis added to the effects of CBT.  This type of evidence is of particular importance to hypnotherapists as the future of hypnosis and hypnotherapy are likely to be bound up with the integration of hypnosis as a method with other empirically-supported treatments (ESTs).  Dr. Assen Alladin’s recent book Cognitive Hypnotherapy contains numerous integrative protocols which are carefully designed to enhance the effects of established evidence-based treatments for a range of conditions by the incorporation of hypnosis and we should hope that developments like this will continue to add to our understanding of how hypnosis interacts with other nonhypnotic treatments, as this will surely continue to define its role in the future. 


Schoenberger, N. E., Kirsch, I., Gearan, P., Montgomery, G., & Pastyrnak, S. L. (1997). Hypnotic Enhancement of a Cognitive Behavioral Treatment for Public Speaking Anxiety. Behavior Therapy (28), 127-140.

Review of Evidence-Based Hypnotherapy: May 2010 Mega-Research-Snippet

Which Forms of Hypnotherapy are Evidence-Based?

Hypnotherapy as Empirically-Supported Treatment (EST)

Ratings using Chambless & Hollon (1998) criteria reviewed by David M. Wark (2008)

Copyright © Donald Robertson, 2009  Reprinted from The Hypnotherapy Journal Spring 2009

I beg farther to remark, if my theory and pretensions, as to the nature, cause, and extent of the phenomena of [hypnotism] have none of the fascinations of the transcendental to captivate the lovers of the marvellous, the credulous and enthusiastic, which the pretensions and alleged occult agency of the mesmerists have, still I hope my views will not be the less acceptable to honest and sober-minded men, because they are all level to our comprehension, and reconcilable with well-known physiological and psychological principles.  – James Braid, Hypnotic Therapeutics, 1853

One of the most useful articles to be published recently was arguably Wark’s review of those studies on hypnotherapy that were rated as meeting the Chambless & Hollon (1998) criteria for “empirically-supported treatments” in the field of psychology, known as ESTs for short.  It may not surprise many NCH members to know that when the research literature on psychotherapy was previously reviewed by a task force of nineteen psychologists led by Prof. Dianne Chambless most of the psychological therapies identified as “empirically-supported” (formerly termed “empirically-validated”) tended to be specific forms of cognitive and/or behaviour therapy (CBT).  Most forms of psychotherapy, ranging from the more controversial and pseudoscientific ones to some of the more “respectable” and mainstream approaches, do not meet these strict criteria for empirical support.  However, one study was identified which demonstrated that cognitive-behavioural hypnotherapy (CBH) was “probably efficacious” for weight loss in obese clients.  In this respect, hypnotherapy might (tentatively) be said to have garnered more compelling evidence for its efficacy than many other modalities of psychological therapy, apart from the cognitive and/or behavioural treatments and some brief psychodynamic approaches. 

            However, over the past decade, many additional studies of a high quality have been published which provide support for the efficacy of hypnotherapy, including meta-analyses and systematic reviews which collate data from multiple studies to form a more general picture of the research findings in this area.  David Wark’s review entitled ‘What we can do with hypnosis: a brief note’ identifies  over thirty additional studies on hypnotherapy which he rates using the revised Chambless & Hollon (1998) criteria for either “possible”, “probable”, or “specific” empirically-supported treatments, depending upon the nature of the evidence available (see the explanations below).  I have compiled this information into a new table which you will find underneath.  Of course, these are not all the possible applications of hypnotherapy, simply the ones which currently have the strongest empirical support, based on Wark’s rating using established criteria for research quality.  More studies are published every year which potentially meet these criteria and might be included on a future list.

            I think it might be observed that certain hypnotherapy treatments for certain types of pain, anxiety, and weight loss are supported by the strongest evidence at present, by this standard.  In total, three studies (anxiety due to asthma, public speaking, and taking a test) provide good evidence for the efficacy of hypnotherapy as a treatment for anxiety.  Assen Alladin’s recent study which provides support for the use of hypnosis in the treatment of depression is rated as meeting the “possibly” efficacious criteria.  Most of the other studies provide evidence relating to the treatment of acute or chronic pain, and certain stress-related or psychosomatic medical conditions such as insomnia, migraine and IBS.  Wark even finds one study on hypnotherapy for smoking cessation which meets the criteria for “possibly efficacious”, an area where well-designed research has previously been lacking. 

            This overview is consistent with a general trend in the literature, since the Victorian era, which tends to point toward hypnotherapy showing most promise in the treatment of anxiety, insomnia, pain management, and several stress-related medical conditions, with mixed findings in relation to its use for the treatment of habits and addictions such as over-eating, smoking, and alcohol abuse.  For example, a committee of experts commissioned by the British Medical Association concluded in 1892 that,

The Committee are of opinion that as a therapeutic agent hypnotism is frequently effective in relieving pain, procuring sleep, and alleviating many functional [i.e., psycho-somatic] ailments.

However, we can now go beyond those early clinical observations and primitive experiments and provide an overview of the therapeutic usefulness of hypnotherapy based on modern research design meeting the highest standards of quality. 

 “Specific” empirically supported treatments
1. Anxiety about asthma attack   Brown, 2007
2. Headaches and migraine Relaxation + image modification > wait list control Hammond, 2007
“Effective” empirically-supported treatments
3. Cancer pain   Syrjala et al., 1992
4. Distress during surgery Hypnosis reduces distress and pain > controls Lang et al., 2006
5. Surgery pain (adult) Self-hypnosis reduces drug use > attention control Lang et al., 1996
6. Surgery pain (child) Hypnosis reduces pain + hospital time > control Lambert, 1996
7. Weight reduction Hypnosis + CBT > CBT, differences increase over time Kirsch, 1996
“Possible” empirically-supported treatments
8. Acute pain (adult)   Patterson & Jensen, 2003
9. Acute pain (children) Hypnosis > distraction for bone marrow aspiration Zeltzer & LaBaron, 1982
10. Anorexia Staged treatment with hypnosis > same without hypnosis Baker & Nash, 1987
11. Anxiety about public speaking Hypnosis > CBT Schoenberger et al., 1997
12. Anxiety about taking a test Self-hypnosis>discussion control Stanton, 1994
13. Asthma Hypnosis>attention control Ewer & Stewart, 1986
14. Bed wetting Suggestion with or without hypnosis > wait list control Edwards & Van der Spuy, 1986
15. Bulimia Hypnosis = CBT > wait list Griffiths et al., 1996
16. Chemotherapy distress Hypnosis>conversation + antiemetic medication Jacknow et al., 1994
17. Cystic fibrosis Self-hypnosis>wait list control Belsky & Khanna, 1994
18. Depression Hypnosis enhances CBT Alladin & Alibhai, 2007
19. Duodenal ulcer relapse Hypnosis + medication > medication only Colgan et al., 1988
20. Fibromyalgia Hypnosis > physical therapy for subjective symptoms Haanen et al., 1991
21. Haemorrhage Preoperative suggestion reduces blood flow Enqvist et al., 1995
22. High blood-pressure Hypnosis > wait list in reducing BP long-term Gay, 2007
23. Hip or knee osteoarthritis pain Hypnosis = relaxation > wait list control Gay et al., 2002
24. Insomnia (primary) Hypnosis + CBT > medication long-term Graci & Hardie, 2007
25. Irritable bowel syndrome (IBS) Hypnosis > psychotherapy Whorwell et al., 1984
26. Nausea & hyperemesis Hypnotic-like relaxation > control Lyles et al., 1982
27. Obstetrics Apgar score Hypnosis associated with higher Apgar score Harmon et al., 1990
28. Obstetrics pain Hypnosis shortens labour and reduces analgesic use Jenkins & Prichard, 1983
29. Smoking cessation Hypnosis or relaxation > wait list controls for good subjects Schubert, 1983
30. Trauma recovery Desensitisation = hypnosis = psychodynamic therapy > control Brom et al., 1989
31. Wart removal Suggestion with or without hypnosis > control or medication Spanos et al., 1990

These ratings are derived from the review published by Wark (2008), in which the references and criteria are given in full.  In brief, the main criteria for the ratings are those set by Chambless & Hollon (1998), which they define roughly as follows but see their article for a more specific and detailed account of the criteria.


A treatment is “possibly” empirically-supported if peer-reviewed studies meet the following minimum criteria.  Studies should normally contain samples of at least 25 subjects who are randomly assigned to treatment and control groups, i.e., the study is a randomised control trial (RCT).  There is a treatment manual or equivalent (such as a hypnosis script) so that the treatment can be replicated in other studies.  Treatment must be conducted upon a specific condition which has been adequately assessed, and adequate outcome measures must be used which are subject to suitable statistical analysis.  The outcome must essentially show the treatment to be significantly more effective than a placebo or no-treatment control group, or equivalent to another empirically-supported treatment.


A treatment is termed empirically-supported as being “effective” if statistically significant superiority to control group measures have been replicated with completely independent samples or by independent research teams, and data supporting the treatment in question must be shown to predominate if there are conflicting data from other studies.


A treatment can be considered empirically-supported as “specific” (i.e., better than “non-specific” treatment) if it has shown statistically significant superiority to a placebo (“sham”) therapy or another psychological therapy in at least two independent studies.


Bolocofsky, D.N., Spinler, D., & Coulthard-Morris, L. (1985).  ‘Effectiveness of hypnosis as an adjunct to behavioral weight management’,  Journal of Clinical Psychology, 41.

Chambless, D.L., & Hollon, S.  ‘Defining empirically supported therapies’, Journal of Consulting and Clinical Psychology, 66.

Task Force on Promotion and Dissemination of Psychological Procedures. ‘Training in and dissemination of empirically validated psychologist treatments: report and recommendations.’ Clin Psychol 1995;48:3–23.

Chambless DL, Sanderson WC, Shoham V, Bennett Johnson S, Pope KS, Crits-Christoph P, et al. ‘An update on empirically validated therapies.’ Clin Psychol 1996;49:5–18.

Chambless DL, Baker MJ, Baucom DH, Beutler LE, Calhoun KS, Crits-Christoph P, et al. ‘Update on empirically validated therapies, II.’ Clin Psychol 1998;51:3–16.

Wark, David M.  (2008). ‘What we can do with hypnosis: a brief note’, American Journal of Clinical Hypnosis, July 2008