Mesmer developed a general theory of disease he called “animal magnetism,” which held that every living thing carries within it an internal magnetic force, in liquid form. Illness arises when this fluid becomes blocked, and can be cured if it can be coaxed to flow again, or so Mesmer’s thinking went. To get that fluid flowing, as science journalist Jo Marchant describes in her recent book, Cure, Mesmer “simply waved his hands to direct it through his patients’ bodies” — the origin of those melodramatic hand motions that stage hypnotists use today.”
There are numerous applications for hypnosis across multiple fields of interest, including medical/psychotherapeutic uses, military uses, self-improvement, and entertainment. The American Medical Association currently has no official stance on the medical use of hypnosis. However, a study published in 1958 by the Council on Mental Health of the American Medical Association documented the efficacy of hypnosis in clinical settings.[76]
Research on the effectiveness of hypnotherapy on a variety of medical conditions is extensive. In one study, the use of hypnotherapy did not seem to alter the core symptoms in the treatment of attention-deficit hyperactivity disorder (ADHD); however, it did seem to be useful in managing the associated symptoms including sleep disturbances and tics.
Some therapists use hypnosis to recover possibly repressed memories they believe are linked to the person's mental disorder. However, the quality and reliability of information recalled by the patient under hypnosis is not always reliable. Additionally, hypnosis can pose a risk of creating false memories -- usually as a result of unintended suggestions or the asking of leading questions by the therapist. For these reasons, hypnosis is no longer considered a common or mainstream part of most forms of psychotherapy. Also, the use of hypnosis for certain mental disorders in which patients may be highly susceptible to suggestion, such as dissociative disorders, remains especially controversial.
Changes in brain activity have been found in some studies of highly responsive hypnotic subjects. These changes vary depending upon the type of suggestions being given.[168][169] The state of light to medium hypnosis, where the body undergoes physical and mental relaxation, is associated with a pattern mostly of alpha waves[170] However, what these results indicate is unclear. They may indicate that suggestions genuinely produce changes in perception or experience that are not simply a result of imagination. However, in normal circumstances without hypnosis, the brain regions associated with motion detection are activated both when motion is seen and when motion is imagined, without any changes in the subjects' perception or experience.[171] This may therefore indicate that highly suggestible hypnotic subjects are simply activating to a greater extent the areas of the brain used in imagination, without real perceptual changes. It is, however, premature to claim that hypnosis and meditation are mediated by similar brain systems and neural mechanisms.[172]
Hypnosis or deep relaxation can sometimes exacerbate psychological problems—for example, by retraumatizing those with post-traumatic disorders or by inducing “false memories” in psychologically susceptible individuals. Evidence, although inconclusive, has raised concerns that the dissociation necessary to participate in relaxation or hypnosis can lead to the manifestation of the symptoms of psychosis. Only appropriately trained and experienced practitioners should undertake hypnosis. Its use should be avoided in patients with borderline personality disorder, dissociative disorders, or with patients who have histories of profound abuse. Competent hypnotherapists are skilled in recognizing and referring patients with these conditions.
Abnormal results can occur in instances where amateurs, who know the fundamentals of hypnosis, entice friends to become their experimental subjects. Their lack of full understanding can lead to immediate consequences, which can linger for some time after the event. If, for example, the amateur plants the suggestion that the subject is being bitten by mosquitoes, the subject would naturally scratch where the bites were perceived. When awakened from the trance, if the amateur forgets to remove the suggestion, the subject will continue the behavior. Left unchecked, the behavior could land the subject in a physician's office in an attempt to stop the itching and scratching cycle. If the physician is astute enough to question the genesis of the behavior and hypnosis is used to remove the suggestion, the subject may experience long-term negative emotional distress and anger upon understanding exactly what happened. The lack of full understanding, complete training, and supervised experience on the part of the amateur places the subject at risk.

In 2007, a meta-analysis from the Cochrane Collaboration found that the therapeutic effect of hypnotherapy was "superior to that of a waiting list control or usual medical management, for abdominal pain and composite primary IBS symptoms, in the short term in patients who fail standard medical therapy", with no harmful side-effects. However the authors noted that the quality of data available was inadequate to draw any firm conclusions.[2]
This method of hypnotherapy is commonly beneficial to hypnotherapists in discovering the psychological root of a problem or symptom, such as social anxiety, depression, or past trauma. These types of trauma are often hidden in unconscious memory and forgotten on a conscious level. Using hypnotherapy for analysis has proven particularly effective at digging into the subconscious memory to attempt to retrieve suppressed memories or early developmental trauma that could result in a wide range of psychological conditions or problematic behavior.
Hypnotherapy has been used to stop self-destructive and addictive habits like smoking. It has also been used to curb the urge to eat for overeaters, to stem the disruptive actions of tics, cure insomnia , stop bed-wetting, and minimize anxiety. Excessive stress can be generated from any number of sources and can be the springboard for anxiety. Some of the more prominent sources of anxiety and stress for which people seek hypnotherapy are: public speaking, test taking, and job stress. Hypnotherapy also works well for other anxiety disorders such as phobias and has proven to be an effective treatment for mild to moderate depression. In one study, hypnotherapy was used in conjunction with traditional cognitive therapy, to assist persons who had severe aversion to needles. The treatment was necessary, because it was essential that each participant receive periodic medical injections. However, the participants would have become non-compliant without the adjunct intervention of hypnotherapy. In another case, involving care for terminally ill cancer patients, it was concluded that hypnotherapy was more effective at enhancing quality of life and relieving anxiety and depressive symptoms, when compared to others who received traditional care.
Speech, on account of the whole preceding life of the adult, is connected up with all the internal and external stimuli which can reach the cortex, signaling all of them and replacing all of them, and therefore it can call forth all those reactions of the organism which are normally determined by the actual stimuli themselves. We can, therefore, regard "suggestion" as the most simple form of a typical reflex in man.[165]
In as much as patients can throw themselves into the nervous sleep, and manifest all the usual phenomena of Mesmerism, through their own unaided efforts, as I have so repeatedly proved by causing them to maintain a steady fixed gaze at any point, concentrating their whole mental energies on the idea of the object looked at; or that the same may arise by the patient looking at the point of his own finger, or as the Magi of Persia and Yogi of India have practised for the last 2,400 years, for religious purposes, throwing themselves into their ecstatic trances by each maintaining a steady fixed gaze at the tip of his own nose; it is obvious that there is no need for an exoteric influence to produce the phenomena of Mesmerism. […] The great object in all these processes is to induce a habit of abstraction or concentration of attention, in which the subject is entirely absorbed with one idea, or train of ideas, whilst he is unconscious of, or indifferently conscious to, every other object, purpose, or action.[52]

Hypnosis -- or hypnotherapy -- uses guided relaxation, intense concentration, and focused attention to achieve a heightened state of awareness that is sometimes called a trance. The person's attention is so focused while in this state that anything going on around the person is temporarily blocked out or ignored. In this naturally occurring state, a person may focus his or her attention -- with the help of a trained therapist -- on specific thoughts or tasks.
In this state, you are also highly suggestible. That is, when the hypnotist tells you do something, you'll probably embrace the idea completely. This is what makes stage hypnotist shows so entertaining. Normally reserved, sensible adults are suddenly walking around the stage clucking like chickens or singing at the top of their lungs. Fear of embarrassment seems to fly out the window. The subject's sense of safety and morality remain entrenched throughout the experience, however. A hypnotist can't get you to do anything you don't want to do.
Confusion can occur when one seeks a hypnotherapist, as a result of the various titles, certifications, and licenses in the field. Many states do not regulate the title "hypnotist" or "hypnotherapist," so care must be exercised when selecting someone to see. As a rule, it is best to consult a professional in the field of mental health or medicine, although alternative sources for hypnosis are available. Care must be taken also by the therapist to ensure adequate training and sufficient experience for rendering this specialized service. The therapist must be well grounded in a psychotherapeutic approach before undertaking the use of hypnotherapy. Professionals should not attempt hypnotherapy with any disorder for which they would not use traditional therapeutic approaches. The patient seeking hypnotherapy is reminded that unskilled or amateur hypnotists can cause harm and should not be consulted for the purpose of implementing positive change in an individual's life. The detrimental effects of being subjected to amateur or inadequately trained persons can be severe and long lasting. (See abnormal results below.)
Poor regulation of hypnosis and deeper relaxation techniques is more serious. Although several professional organizations exist, these groups do not regulate or certify practitioners in hypnotherapy or relaxation. Hypnotherapists with a conventional health care background (such as psychologists, physicians, dentists, and nurses) are regulated by their professional regulatory bodies. Psychotherapists who use hypnotherapy as an adjunctive treatment modality require appropriate training. Individuals who have received a master's degree in counseling or social work or a doctorate in clinical or counseling psychology will be likely to have received appropriate training and supervision.
Hypnotic music became an important part in the development of a ‘physiological psychology’ that regarded the hypnotic state as an ‘automatic’ phenomenon that links to physical reflex. In their experiments with sound hypnosis, Jean-Martin Charcot used gongs and tuning forks, and Ivan Pavlov used bells. The intention behind their experiments was to prove that physiological response to sound could be automatic, bypassing the conscious mind.[155]
Jump up ^ Michel Weber is working on a Whiteheadian interpretation of hypnotic phenomena: see his « Hypnosis: Panpsychism in Action », in Michel Weber and William Desmond, Jr. (eds.), Handbook of Whiteheadian Process Thought, Frankfurt / Lancaster, ontos verlag, Process Thought X1 & X2, 2008, I, pp. 15-38, 395-414 ; cf. « Syntonie ou agencement ethnopsychiatrique ? », Michel Weber et Vincent Berne (sous la direction de), Chromatikon IX. Annales de la philosophie en procès — Yearbook of Philosophy in Process, Les Editions Chromatika, 2013, pp. 55-68.
State theorists interpret the effects of hypnotism as due primarily to a specific, abnormal, and uniform psychological or physiological state of some description, often referred to as "hypnotic trance" or an "altered state of consciousness". Nonstate theorists rejected the idea of hypnotic trance and interpret the effects of hypnotism as due to a combination of multiple task-specific factors derived from normal cognitive, behavioural, and social psychology, such as social role-perception and favorable motivation (Sarbin), active imagination and positive cognitive set (Barber), response expectancy (Kirsch), and the active use of task-specific subjective strategies (Spanos). The personality psychologist Robert White is often cited as providing one of the first nonstate definitions of hypnosis in a 1941 article:
This popular representation bears little resemblance to actual hypnotism, of course. In fact, modern understanding of hypnosis contradicts this conception on several key points. Subjects in a hypnotic trance are not slaves to their "masters" -- they have absolute free will. And they're not really in a semi-sleep state -- they're actually hyperattentive.
A hypnotherapist can work with you to find the technique that can work best for what you're trying to accomplish. Although it's important to begin by working with a hypnotherapist, the hypnotherapist can then teach you self-hypnosis so you can practice at home. Once you have a firm grip on an issue like pain or fatigue with the therapist, you can continue on your own with self-hypnosis.

In 2007, a meta-analysis from the Cochrane Collaboration found that the therapeutic effect of hypnotherapy was "superior to that of a waiting list control or usual medical management, for abdominal pain and composite primary IBS symptoms, in the short term in patients who fail standard medical therapy", with no harmful side-effects. However the authors noted that the quality of data available was inadequate to draw any firm conclusions.[2]