It is used for a wide variety of applications, and studies into its efficacy are often of poor quality[2] which makes it difficult to determine efficacy. Several recent meta-analyses and systematic reviews of the literature on various conditions have concluded that the efficacy of hypnotherapy is "not verified",[3] that there is no evidence[4][5] or insufficient evidence[6][7] for efficacy.
A person with depression experiences a wide variety of emotions. According to the University of New Hampshire, hypnotherapy can help a person learn to reduce and/or better control feelings of anxiety, stress, and sadness. Hypnotherapy is also used to treat negative behaviors that could be worsening a person’s depression. These behaviors may include smoking and poor eating and sleeping habits.
Last May [1843], a gentleman residing in Edinburgh, personally unknown to me, who had long resided in India, favored me with a letter expressing his approbation of the views which I had published on the nature and causes of hypnotic and mesmeric phenomena. In corroboration of my views, he referred to what he had previously witnessed in oriental regions, and recommended me to look into the Dabistan, a book lately published, for additional proof to the same effect. On much recommendation I immediately sent for a copy of the Dabistan, in which I found many statements corroborative of the fact, that the eastern saints are all self-hypnotisers, adopting means essentially the same as those which I had recommended for similar purposes.[51]
The patient must be made to understand that he is to keep the eyes steadily fixed on the object, and the mind riveted on the idea of that one object. It will be observed, that owing to the consensual adjustment of the eyes, the pupils will be at first contracted: They will shortly begin to dilate, and, after they have done so to a considerable extent, and have assumed a wavy motion, if the fore and middle fingers of the right hand, extended and a little separated, are carried from the object toward the eyes, most probably the eyelids will close involuntarily, with a vibratory motion. If this is not the case, or the patient allows the eyeballs to move, desire him to begin anew, giving him to understand that he is to allow the eyelids to close when the fingers are again carried towards the eyes, but that the eyeballs must be kept fixed, in the same position, and the mind riveted to the one idea of the object held above the eyes. In general, it will be found, that the eyelids close with a vibratory motion, or become spasmodically closed.[34]
In this special mental state, people feel uninhibited and relaxed. Presumably, this is because they tune out the worries and doubts that normally keep their actions in check. You might experience the same feeling while watching a movie: As you get engrossed in the plot, worries about your job, family, etc. fade away, until all you're thinking about is what's up on the screen.

In his later works, Braid reserved the term "hypnotism" for cases in which subjects entered a state of amnesia resembling sleep. For other cases, he spoke of a "mono-ideodynamic" principle to emphasise that the eye-fixation induction technique worked by narrowing the subject's attention to a single idea or train of thought ("monoideism"), which amplified the effect of the consequent "dominant idea" upon the subject's body by means of the ideo-dynamic principle.[57]
Hypnosis is not a unitary state and therefore should show different patterns of EEG activity depending upon the task being experienced. In our evaluation of the literature, enhanced theta is observed during hypnosis when there is task performance or concentrative hypnosis, but not when the highly hypnotizable individuals are passively relaxed, somewhat sleepy and/or more diffuse in their attention.[174]
Mesmer performed his technique by passing his hands up and down the patient's body. The technique was supposed to transmit magnetic fluid from his hands to the bodies of his patients. During this time period, there was no clear delineation between health conditions that were physical or psychological in nature. Although Mesmer did not realize it at that time, his treatments were most effective for those conditions that were primarily psychosomatic.
Hypnosis has been used as a supplemental approach to cognitive behavioral therapy since as early as 1949. Hypnosis was defined in relation to classical conditioning; where the words of the therapist were the stimuli and the hypnosis would be the conditioned response. Some traditional cognitive behavioral therapy methods were based in classical conditioning. It would include inducing a relaxed state and introducing a feared stimuli. One way of inducing the relaxed state was through hypnosis.[77]

It appears that hypnosis, under other names, has been used since the beginning of time. In fact, it has been insinuated that the earliest description of hypnosis may be portrayed in the Old Testament and in the Talmud. There is also evidence of hypnosis in ancient Egypt, some 3,000 years ago. However, the man credited with the development of what has become modern hypnosis is Friedrich Anton Mesmer, an Austrian physician. One day, Mesmer watched a magician on a street in Paris demonstrate that he could have spectators do his bidding by touching them with magnets. Fascinated by the demonstration, Mesmer believed the magnets had power of their own and from this belief developed his theory of "animal magnetism." He also believed that good health depended on having correct magnetic flow and that the direction of one's magnetic flow could be reversed easily. He further believed that he could direct this magnetic flow into inanimate objects, that could then be used for the good health of others. The term "mesmerism" came to be applied to his mystical workings. He experienced much success in helping the people of Paris as well as visitors who came from other countries, upon hearing of his powers. Later he was completely discredited by a special commission of the French Academy appointed by the King of France, causing him to leave the country. Two of the more famous members of the French Academy at the time were chairman of the commission Benjamin Franklin, American ambassador to France, and Dr. Guillotine, the inventor of the execution device.
In 1974, Theodore X. Barber and his colleagues published a review of the research which argued, following the earlier social psychology of Theodore R. Sarbin, that hypnotism was better understood not as a "special state" but as the result of normal psychological variables, such as active imagination, expectation, appropriate attitudes, and motivation.[16] Barber introduced the term "cognitive-behavioral" to describe the nonstate theory of hypnotism, and discussed its application to behavior therapy.