Evidence from Systematic Reviews:-

In 1892, the British Medical Association, (BMA), commissioned a team of doctors to undertake an extensive evaluation of the nature and effects of hypnotherapy, they reported:

“The Committee, having completed such investigation of hypnotism as time permitted, have to report that they have satisfied themselves of the genuineness of the hypnotic state.” (British Medical Journal, 1892)  Adding, “The Committee are of opinion that as a therapeutic agent hypnotism is frequently effective in relieving pain, procuring sleep, and alleviating many functional ailments.” [i.e., psycho-somatic complaints and anxiety disorders]. (Ibid.) This report was approved by the general council of the BMA, thereby forming BMA policy and rendering hypnotherapy a form of "orthodox" as opposed to complementary or alternative, medicine. Subsequent research on hypnotherapy has tended to highlight three main areas in which its efficacy as a treatment has been demonstrated,  Anxiety.. Insomnia..  Pain management..  Psycho-somatic disorders, i.e., stress-related illness. Hypnotherapy has many other applications but efficacy research has tended to focus upon these issues. More mixed results have been obtained for its efficacy in relation to the treatment of addictions, an area where high relapse is common with most treatments.

In 1955, the Psychological Medicine Group of the BMA commissioned a Subcommittee, led by Prof. T. Ferguson Rodger, to deliver a second, and more comprehensive, report on hypnosis. The Subcommittee consulted several experts on hypnosis from various fields, including the eminent neurologist Prof. W. Russell Brain, and the psychoanalyst Wilfred Bion. After two years of study and research, its final report was published in the British Medical Journal, (BMJ), under the title, “Medical use of Hypnotism”. 

The terms of reference were:

“To consider the uses of hypnotism, its relation to medical practice in the present day, the advisability of giving encouragement to research into its nature and application, and the lines upon which such research might be organized.” (BMA, 1955). This is a much more thorough and extensive report, and constitutes one of the most significant documents in the history of hypnotherapy research. With regard to efficacy, it concludes from a systematic review of available research that:

“The Subcommittee is satisfied after consideration of the available evidence that hypnotism is of value and may be the treatment of choice in some cases of so-called psycho-somatic disorder and Psychoneurosis. It may also be of value for revealing unrecognized motives and conflicts in such conditions. As a treatment, in the opinion of the Subcommittee it has proved its ability to remove symptoms and to alter morbid habits of thought and behavior.  In addition to the treatment of psychiatric disabilities, there is a place for hypnotism in the production of anesthesia or analgesia for surgical and dental operations, and in suitable subjects it is an effective method of relieving pain in childbirth without altering the normal course of labor.” ("Medical use of hypnosis." BMJ, April, 1955)

According to a statement of proceedings published elsewhere in the same edition of the BMJ, the report was officially, “approved at last week’s Council meeting of the British Medical Association.” (BMA Council Proceedings, BMJ, April 23, 1955:1019). In other words, it was approved as official BMA policy. This statement goes on to say that:

“For the past hundred years there has been an abundance of evidence that psychological and physiological changes could be produced by hypnotism which were worth study on their own account, and also that such changes might be of great service in the treatment of  patients.”  (Loc. cit.)  Soon afterwards, in 1958, the American Medical Association, (AMA), commissioned a similar (though more terse) report which endorses the 1955 BMA report and concludes:

“That the use of hypnosis has a recognized place in the medical armamentarium and is a useful technique in the treatment of certain illnesses when employed by qualified medical and dental personnel.” ("Medical use of hypnosis." JAMA, 1958).

Again, the AMA council approved this report rendering hypnotherapy an orthodox treatment. The Reference Committee on Hygiene, Public Health, and Industrial Health approved the report and commended the Council on Mental Health for its work. The House of Delegates adopted the Reference Committee report. (AMA Proceedings, JAMA, September 1958: 57.)  In 1995, the National Institute for Health, (NIH), in the US, established a Technology Assessment Conference that compiled an official statement entitled, “Integration of Behavioral & Relaxation Approaches into the Treatment of Chronic Pain & Insomnia.” This is an extensive report that includes a statement on the existing research in relation to hypnotherapy for chronic pain. It concludes that:

“The evidence supporting the effectiveness of hypnosis in alleviating chronic pain associated with cancer seems strong. In addition, the panel was presented with other data suggesting the effectiveness of hypnosis in other chronic pain conditions, which include irritable bowel syndrome, oral mucositis, [pain and swelling of the mucus membrane], temporomandibular disorders [jaw pain], and tension headaches.” (NIH, 1995).

In 1999, the British Medical Journal (BMJ) published a Clinical Review of current medical research on hypnotherapy and relaxation therapies, it concludes, “There is good evidence from randomized controlled trials that both hypnosis and relaxation techniques can reduce anxiety, particularly that related to stressful situations such as receiving chemotherapy. They are also effective for panic disorders and insomnia, particularly when integrated into a package of cognitive therapy (including, for example, sleep hygiene). A systematic review has found that hypnosis enhances the effects of cognitive behavioural therapy for conditions such as phobia, obesity, and anxiety. Randomized controlled trials support the use of various relaxation techniques for treating both acute and chronic pain. Randomized trials have shown hypnosis to be of value in asthma and in irritable bowel syndrome. Relaxation and hypnosis are often used in cancer patients. There is strong evidence from randomized trials of the effectiveness of hypnosis and relaxation for cancer related anxiety, pain, nausea, and vomiting, particularly in children.” (Vickers & Zollman, “Clinical Review: Hypnosis & Relaxation Therapies.” BMJ, 1999).

In 2001, the Professional Affairs Board of the British Psychological Society, (BPS), commissioned a working party of expert psychologists to publish a report entitled “The Nature of Hypnosis.” Its remit was “to provide a considered statement about hypnosis and important issues concerning its application and practice in a range of contexts, notably for clinical purposes, forensic investigation, academic research, entertainment and training.” The report provides a concise, (20 pages), summary of the current scientific research on hypnosis. It opens with the following introductory remark:

“Hypnosis is a valid subject for scientific study and research and a proven therapeutic medium.” (BPS, 2001). With regard to the therapeutic uses of hypnosis, the BPS arrive at much more positive conclusions.

“Enough studies have now accumulated to suggest that the inclusion of hypnotic procedures may be beneficial in the management and treatment of a wide range of conditions and problems encountered in the practice of medicine, psychiatry and psychotherapy.” (BPS, 2001).

The working party then provided an overview of some of the most important contemporary research on the efficacy of clinical hypnotherapy, which is summarized as follows, (omitting their detailed references).

“There is convincing evidence that hypnotic procedures are effective in the management and relief of both acute and chronic pain and in assisting in the alleviation of pain, discomfort and distress due to medical and dental procedures and childbirth.  Hypnosis and the practice of self-hypnosis may significantly reduce general anxiety, tension and stress in a manner similar to other relaxation and self-regulation procedures. Likewise, hypnotic treatment may assist in insomnia in the same way as other relaxation methods.  There is encouraging evidence demonstrating the beneficial effects of hypnotherapeutic procedures in alleviating the symptoms of a range of complaints that fall under the heading 'psychosomatic illness.' These include tension headaches and migraine; asthma; gastro-intestinal complaints such as irritable bowel syndrome; warts; and possibly other skin complaints such as eczema, psoriasis and urticaria [hives]. There is evidence from several studies that its [hypnosis'] inclusion in a weight reduction program may significantly enhance outcome.” (BPS, "The Nature of Hypnosis", 2001).

“Meta-analysis of Success Rates In 2003.” perhaps the most recent meta-analysis of the efficacy of hypnotherapy was published by two researchers from the university of Konstanze in Germany (Flammer & Bongartz). The study examined data on the efficacy of hypnotherapy across the board, though studies included mainly related to psycho-somatic illness, test anxiety, smoking cessation and pain control during orthodox medical treatment. Most of the better research studies used traditional-style hypnosis, only a minority (19%) employed Ericksonian hypnosis.

The authors considered a total of 444 studies on hypnotherapy published prior to 2002. By selecting the best quality and most suitable research designs for meta-analysis they narrowed their focus down to 57 controlled trials. These showed that on average hypno-therapy achieved at least 64% success compared to 37% improvement among untreated control groups.