e4-10: Hypnosis

Hypnosis is a procedure that induces an altered state of consciousness in which the patient's mind is more accepting of suggestion. It is believed that during hypnosis the usual evaluative, critical function of the conscious mind is bypassed and more direct communication with the subconscious mind occurs.

Hypnotic phenomena, including trancelike states for medical purposes, have been practiced around the world throughout human history. It was the Scottish surgeon, James Braid, in 1843, however, who coined the term "hypnosis" and laid the foundation for the use of hypnosis in modern medicine. Braid believed the effects of hypnosis were mediated by the mind of the patient. Important early research was conducted in the 1930s by Dr. Clark Hull and his student, Dr. Milton Erickson. In the mid-1950s, the British and American Medical Associations suggested that hypnosis be incorporated into the medical curriculum. In 1960, the American Psychological Association endorsed hypnosis as a branch of psychology. In 1996, an NIH Technology Assessment Panel judged hypnosis to be an effective intervention for alleviating pain.

The mechanism of action of hypnosis has not been fully elucidated, but its effects are seen at multiple levels, including somatosensory cortex, anterior cingulate cortex (modulation of pain affect via limbic system), spinal cord, and autonomic nervous system (eg, reduction of colonic motility in irritable bowel syndrome). Additional evidence regarding the mechanism includes upregulation of immune-related gene expression (eg, effects on tumor necrosis factor) and reduction of mucosal inflammatory response (in ulcerative colitis). Hypnotic trance is a state distinct from sleep or relaxation, and hypnotic analgesia is distinct from placebo analgesia.

Certification for hypnosis, granted through the American Society of Clinical Hypnosis, has these requirements: (1) health professional degree, (2) 40 hours of workshop training, (3) 20 hours of supervised clinical training, and (4) 2 years of independent practice using clinical hypnosis.

Other certification programs exist. Patients and clinicians should inquire about the training and certification of any practitioner of hypnosis because there are no restrictions limiting its use to licensed health care practitioners.

The procedure of hypnosis can be divided into three phases: induction (or pre-suggestion), suggestion, and post-suggestion. The induction of a trance is accomplished in a variety of ways with the intention of developing relaxation and focused attention. Once the trance is induced, therapeutic suggestions are offered. In the post-suggestion phase, the patient returns to their usual state of consciousness and the suggestions may be discussed and reinforced. Self-hypnosis may be taught to further reinforce the therapeutic suggestions between sessions.

Although most people can respond to hypnosis, there is great variability in hypnotic susceptibility (suggestibility) in the population. This can be measured with standard instruments such as the Harvard Group Scale of Hypnotic Susceptibility and the Stanford Hypnotic Susceptibility Scale. Studies have shown a positive correlation between hypnotic susceptibility and its efficacy.

The ideal candidate for hypnosis is a patient with high suggestibility and motivation, with a condition for which hypnosis has proven benefit. Course of treatment can vary from a single session to several. Sessions are usually 45–60 minutes, with the first session typically lasting 90–120 minutes. It is helpful when referring patients to dispel common myths about hypnosis. For example, it is not true that one loses consciousness in trance or that one cedes control to the hypnotist. Trance state may best be described as a voluntary state of mind like the one experienced when absorbed in reading a book or when daydreaming. It may be useful to explain to patients that the purpose of referral to hypnosis is to learn skills to use the mind-body connection.

Adverse events from hypnosis have not been well studied. As with any psychological therapy, distressing emotions or thoughts may occur. These can manifest as somatic symptoms, such as dizziness, headache, or nausea. Occasionally, uncovering repressed psychic content can evoke strong emotional response, known as abreaction. A minority of hypnosis practitioners believe abreaction is therapeutic. Also, as with other mind-body medicine modalities that include deliberate relaxation, paradoxical anxiety reactions can rarely occur.

There is no consensus on contraindications to hypnosis; however, the use of hypnosis in patients with severe psychiatric disease is controversial. Also, patients with very low scores on hypnotic susceptibility scales are less likely to derive therapeutic benefit.

A. Pain

There are over 40 controlled studies of variable methodologic quality on the use of hypnosis for treating acute pain in adult and pediatric populations. Hypnosis has been shown to be promising for periprocedural and perioperative pain in patients undergoing breast lumpectomy, excisional and core breast biopsy, bone marrow aspiration, pectus excavatum repair (Nuss procedure), percutaneous transluminal coronary angioplasty and other percutaneous vascular and renal procedures, burn wound care, dental procedures, and plastic surgery. Many studies also report less procedure-related anxiety and lower analgesic medication requirement. According to a 2013 meta-analysis, additional documented benefits include reduced recovery and surgical procedure times. A 2021 meta-analysis looked at the efficacy of hypnosis in 50 studies involving 4269 patients undergoing surgical procedures. The analysis found small to medium effects in favor of hypnosis on various surgery relevant outcomes, including mental distress, pain, medication consumption, recovery, and surgical procedure time; however, study heterogeneity limited the reliability of the findings.

For chronic pain, individual studies have shown efficacy for headache, orofacial pain, dyspepsia, low back pain, vulvodynia, sickle cell crisis, fibromyalgia, multiple sclerosis, and spinal cord injury. A 2021 meta-analysis of 45 trials found that hypnosis had moderate benefit for the treatment of chronic pain.

B. Cancer-Related Symptoms

There are at least 15 RCTs that have evaluated the efficacy of hypnosis for cancer-related pain, distress, fatigue, nausea, and hot flashes in adults. All trials showed benefit compared with no treatment or usual care. Three of four trials showed significant benefit of hypnosis for reducing anticipatory nausea and vomiting from chemotherapy. Other RCTs concluded that: (1) hypnosis decreased hot flash scores by 68% in breast cancer survivors; (2) self-hypnosis plus empathic attention was superior to empathic attention alone for reducing pain, anxiety, and medication usage patients undergoing percutaneous tumor treatment; (3) preoperative hypnosis reduced institutional costs for breast cancer patients; (4) hypnosis reduced the anesthesia medication requirements and reduced pain, fatigue, nausea, and emotional upset in breast cancer patients; and (5) a combined intervention of hypnosis with CBT reduced fatigue in one study of breast cancer patients undergoing radiation therapy and, in another study in a similar patient population, reduced negative affect and increased positive affect.

C. Irritable Bowel Syndrome

There are more than 20 studies of hypnosis for irritable bowel syndrome in adults, seven of which are controlled (placebo pill, CBT, or waitlist control). All seven controlled studies showed reduction in pain and bowel symptoms, and some showed improved quality of life and reduced anxiety. Five follow-up studies have found maintenance of benefits for 1–7 years. Two large studies (one RCT and one retrospective trial) found efficacy of hypnosis for patients with refractory irritable bowel syndrome. The American College of Gastroenterology includes hypnosis among its recommended behavioral therapies for the treatment of irritable bowel syndrome.

D. Smoking Cessation

A 2012 Cochrane review of 11 trials that compared hypnosis to other interventions or no treatment in patients attempting smoking cessation could reach no definitive conclusions due to conflicting results and statistical weaknesses in head-to-head trials. Another 2012 meta-analysis found hypnosis may possibly aid smoking cessation, but a large CI in the final statistical analysis prevented the authors from stating any definitive conclusion. A 2016 three-arm RCT involving 164 hospitalized patients concluded that hypnotherapy was superior to nicotine replacement therapy for promoting smoking cessation, as measured by abstinence rates at 12 and 26 weeks, however, the statistical significance of this conclusion was questionable. A 2017 randomized controlled study of 140 veterans did not find significant improvements when hypnosis was used for smoking relapse prevention.