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Hypnosis and Its Effectiveness as an Adjunct Therapy During Surgical Procedures

Libby Brandt

October 24, 2008



Until the twentieth century, medical procedures were performed without much regard for the patient’s emotional health before or after the procedure.  Today, alternative therapies are being used more frequently to aid in pre and postoperative pain and stress management.  Many therapies, such as hypnosis, are currently being studied for their benefits in decreasing patients’ anxiety levels, while simultaneously causing reductions in other symptoms such as pain, nausea, and recovery time.  How effective are these types of therapy in reducing these symptoms?  Are there dangers that a patient should be aware of when undergoing hypnotherapy?  What scientific research has been conducted to determine the benefits of hypnotherapy in the surgical setting?        


What is hypnotherapy and how does it work?

Hypnotherapy is the use of hypnosis to therapeutically alter a person’s attitudes towards an event or subject.  In many cases, hypnotherapy is used to create positive associations with an event that a person may feel anxious or worried about.  The type of hypnosis that is used most often in the clinical trials described below is suggestion therapy.  During these sessions, the patient becomes relaxed and deeply engaged in the process at hand.  Subsequently, the therapist makes suggestions to the patient of vitality, strength, and courage, which will prepare the patient mentally for the surgical procedure that will follow.  During hypnosis, patients exhibit a heightened state of concentration and relaxation, which leads to a greater ability to accept suggestions from the outside world. 

To better understand the process of hypnosis, it is appropriate to look at the function of a person’s conscious and subconscious mind.  The subconscious deals with all the things that a person does involuntarily and much of the brain’s processing occurs in the subconscious before it moves to the conscious mind.  Only then does a person form a recognizable thought.  During sleep, the conscious mind steps aside to allow the emergence of the subconscious, which is the site of a person’s impulses and imagination.  Through electroencephalography (EEG), scientists can determine the electrical brain function of a patient.  A person’s brain function looks very different during sleep and hypnosis. (

 However, hypnosis is similar to a combination of sleep and wakefulness, in that a person is completely aware of their surroundings, but the person’s conscious mind is put aside to allow the subconscious to move forward.  In this way, positive thoughts and suggestions sink deeper into the mind much more quickly.  It is important to note that for optimal retention of these suggestions, the process must be repeated to reinforce the images and ideas that were presented ( 

Many people wonder whether hypnosis is dangerous.  Hypnosis normally has no adverse effects on the patient.  Contrary to popular belief, a person under hypnosis cannot be made to do anything that he or she does not feel is right or is uncomfortable with.  The person’s mind is still very alert and he can still distinguish between right and wrong.  The main concern that psychologists address before performing hypnosis is the diagnosis of any psychiatric diseases.  Many times, hypnotic treatments can lead to exacerbated symptoms in patients with schizophrenia or other mental diseases (  The other potential error that may occur during hypnosis is the production of false memories.  The subconscious mind is very delicately penetrated during a hypnotic treatment and a psychologist must be careful not to make misleading suggestions to the patient that may lead to the production of these false memories.  This is especially important during forensic hypnosis and is not directly relevant to surgical hypnosis.    

The main application of hypnosis in the surgical setting is in the reduction of stress.  It has been shown that stress can lead to a dramatically increased period of healing for wounds.  For example, researchers in Columbus, Ohio recently showed that mice exposed to psychological stress due to confinement experienced a 40% increase in healing time.  This was attributed to the fact that the cells that normally produced the tissue for repair did not differentiate properly, leading to an increased healing time.  Thus, it is important to look into therapies that will reduce stress and simultaneously prevent these stress related difficulties in the healing process.  It is also important to note that hypnosis is most effectively used as an adjunct to other physiological or psychological treatments. 


What are people saying about hypnotherapy as an adjunct treatment for surgery?

                There are countless advertisements available on the internet that try to persuade consumers that hypnosis is an effective treatment for obesity, addiction, depression and other disorders.  Most relevantly, online sources claim that hypnosis can decrease a patient’s anxiety and pain during and after a surgical procedure.  Others claim that hypnotherapy can lessen the need for pain medications and analgesics, while significantly decreasing the recovery period after surgery.  Some examples are given here:

Sanna Carapellotti, MS, CCHT – Mental Performances – “Any behavior you want to change or improve!”

Post-Surgical Healing!

                It is difficult in most cases to know whether these individual promises of beneficial effects are truly believable.  Many of these assertions are supported solely by testimonials of “successful” interventions.  In most cases, the people who are advertising the therapy are looking to make a profit off of the consumer.  So, is the presented information necessarily true?  This is when scientific and clinical research must be consulted to decide whether the treatment is truly feasible.              

What does the clinical research say?

                A relatively small number of viable clinical trials have been conducted on the subject of hypnosis in alleviating pain and anxiety in patients during and after surgical procedures.  Of these, many are non-randomized leading to sampling biases and other sources of error. 

The first example is a randomized, controlled, and single-blinded trial conducted in a group of 76 patients.  The patients were assigned to separate treatment groups, which consisted of a hypnosis treatment group, a supportive attention group, and a standard of care group.  The patients’ blood pressures and heart rates were measured at baseline (significantly before treatment).   The patients were also given a baseline Visual Analog Scale (VAS) to rate their anxiety from 0-10 and a baseline State-Trait Anxiety Inventory (STAI) questionnaire prior to treatment and surgery.  These same measurements and questionnaires were obtained again after the intervention and upon their entry into the operating room.  First, the baseline STAI, VAS, BP, and HR levels did not differ significantly from group to group.  However, the second and third measurements of these conditions varied greatly, with the hypnosis group experiencing a 56% decrease in anxiety compared to the 10% increase in the patients given the standard of care.  The patients in the hypnosis group were also significantly less nervous upon entering the operating room than either of the other groups, showing the success of the intervention.

In the second clinical trial, a group of children undergoing a Voiding Cystourethography (VCUG) procedure were asked, along with their parents and medical staff, to rate their level of distress prior to the procedure in comparison to their prior experiences (each child had to have had at least one VCUG before).  Significantly less traumatic events were experienced by children in the hypnosis group, along with a reduced difficulty of performance for the medical professionals, and a significantly reduced procedure time.  It is interesting to note that the first variables could have been affected by the fact that all parties involved were aware of the purpose of the trial and could have unknowingly skewed the data in response.  However, an overall decrease in procedure time of 14 minutes was very promising. 

In a meta-analysis of available studies, 20 surgical studies were compared.  Through standardization of the data from all of the trials, they were evaluated     for the overall beneficial impact of the imposed hypnosis, the effect of hypnosis in decreasing other adverse effects, and the differences in effects between live hypnosis and cassette tape hypnosis.  All studies that were compared gave measured means, standard deviations, and other inferential statistics that allowed for the calculation of effect size over the sample.  These effect sizes were calculated as the mean effect for each group or trial, comparing 1624 individuals overall.  Investigators also eliminated the possibility of skewed data due to different population sizes in each study.  Hypnotized patients were given suggestions to reduce their pain and stress, and to increase their self-efficacy. 

There was a significant increase in effectivity for the hypnosis group, who had more favorable outcomes than 89% of their counterparts in the non-hypnosis groups.  It is important to note that the results of this meta-analysis included data from non-randomized trials, which could have led to skewed data., a “file-drawer” (Montgomery) problem may have occurred in choosing the sample to analyze.  This is due to the fact that many investigators may not have posted clinical trials in which significant results were not exhibited in the hypnosis treatment group.

The final source was a simple comparison and analysis of techniques and results of many hypnosis clinical trials.  This article compares studies with hypnosis or suggestion groups and control groups, which used hypnotherapy prior to and during surgical procedures.  The authors point out discrepancies that are found in many of the available studies.  The lack of standard hypnosis techniques makes it quite complicated to accurately compare the studies in a meta-analysis.  Many of the studies have small populations, bad statistical evaluation methods, and no control groups, leading to results that are biased in many ways.  Also, most of the studies employed volunteer patients throughout their study, which could have affected their results.  The authors found that many of the non-randomized clinical trials reported statistically significant results due to selection bias.  This article also points out that many of the studies, such as van der Laan et al, showed no significant reductions in post-operative pain and nausea in patients treated preoperatively with hypnosis.  Other studies showed small, questionable reductions in hypnosis patients.  Finally, the authors pointed out that many of the trials had confounding variables due to the lack of stratification.  For example, some trials measured the data over a variety of surgical procedures.  This means that the degree of difficulty of the operation, and the time spent in the operating room are also confounding variables within the clinical trial.  However, since the authors of this article did not standardize their data numerically, it is impossible to tell whether the data from the trials in question is significant or not when pooled together.            


Conclusion:  What is the verdict?

                At this point, it is difficult to determine the direct benefits of hypnosis therapy based on the scant amount of available research.  It is impossible to create double-blind experiments when dealing with hypnotherapy, because the patients must be active participants in their hypnosis in order to get the expected results.  This means that every trial will introduce bias into the measurements from the start.  In many cases, it is difficult to accurately determine whether the patient is benefitting from the increased attention or from the actual hypnosis.  However, many other randomized, clinical trials do exist, detailing the benefits of hypnosis in the reduction of anxiety, pain, pain medication requirements, nausea and other side effects in surgical patients.  Overall, the field of research needs to expand in order to definitively prove the beneficial nature of hypnotherapy in the surgical setting.  If hypnosis proves effective in the near future, it could potentially improve the compliance of patients and families with follow-up procedures by significantly reducing their anxiety levels associated with the procedure.         


Other Sources:



Butler, L. D., Symons, B. K., Henderson, S. L., Shortliffe, L. D., Spiegel, D. (2005). Hypnosis Reduces

        Distress and Duration of an Invasive Medical Procedure for Children. Pediatrics, 114(1), 77-85.


Flory, N., Salazar, G. M., Lang, E. V. (2007). Hypnosis for Acute Distress Management During Medical

Procedures. International Journal of Clinical and Experimental Hypnosis, 55(3), 303-317.

Ginandes, C., Brooks, P., Sando, W., Jones, C., Aker, J. (2003). Can Medical Hypnosis Accelerate

Post-Surgical Wound Healing?  A Clinical Trial. American Journal of Clinical Hypnosis, 45(4), 333-351.

Montgomery, G. H., Bovbjerg, D. H., Schnur, J. B., David, D., Goldfarb, A., Weltz, C. R., et al. (2007). A

        Randomized Clinical Trial of a Brief Hypnosis Intervention to Control Side Effects in Breast Surgery

        Patients. Journal of the National Cancer Institute, 99(17), 1280-1281.


Montgomery, G. H., David, D., Winkel, G., Silverstein, J. H., Bovbjerg, D. H. (2002). The Effectiveness of

        Adjunctive Hypnosis with Surgical Patients:  A Meta-Analysis. Anesthesia and Analgesia, 94(6), 1639-



Sadaat, H., Drummond-Lewis, J., Maranets, I., Kaplan, D., Sadaat, A., Wang, S. M., et al.  (2006). 

Hypnosis Reduces Preoperative Anxiety in Adult Patients.  Anesthesia and Analgesia, 102(5), 1394-1396.


Van der Laan, W. H., van Leeuwen, B. L., Sebel, P. S., Winograd, E., Baumann, P., Bonke, B. (1996).

        Therapeutic Suggestion Has No Effect on Postoperative Morphine Requirements.  Anesthesia and

        Analgesia, 82(1), 148-152.


Wobst, A. H.  (2007). Hypnosis and Surgery:  Past, Present, and Future.  Anesthesia and Analgesia,

        104(5), 1199-1208.





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