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]

It is far easier to describe what hypnosis is not rather than to describe what it is. For example, it is not one person controlling the mind of another. The patient is not unconscious and does not lose control of his or her faculties. People will not do things under hypnosis that they would be unwilling to do otherwise. The person being hypnotized is always in control. The hypnotized person decides how deep the trance will be, what suggestions will be accepted, and when to awaken. Therefore, a hypnotyized person cannot be forever "lost" if the therapist should fall dead during an induction or while the patient is deep in trance.
At the outset of cognitive behavioural therapy during the 1950s, hypnosis was used by early behaviour therapists such as Joseph Wolpe[71] and also by early cognitive therapists such as Albert Ellis.[72] Barber, Spanos, and Chaves introduced the term "cognitive-behavioural" to describe their "nonstate" theory of hypnosis in Hypnosis, imagination, and human potentialities.[35] However, Clark L. Hull had introduced a behavioural psychology as far back as 1933, which in turn was preceded by Ivan Pavlov.[73] Indeed, the earliest theories and practices of hypnotism, even those of Braid, resemble the cognitive-behavioural orientation in some respects.[69][74]
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.
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]
Hypnotherapy expert, Dr Peter Marshall, former Principal of the London School of Hypnotherapy and Psychotherapy Ltd. and author of A Handbook of Hypnotherapy, devised the Trance Theory of Mental Illness, which provides that people suffering from depression, or certain other kinds of neurosis, are already living in a trance and so the hypnotherapist does not need to induce them, but rather to make them understand this and help lead them out of it.[24]
Barber et al. noted that similar factors appeared to mediate the response both to hypnotism and to cognitive behavioural therapy, in particular systematic desensitization.[35] Hence, research and clinical practice inspired by their interpretation has led to growing interest in the relationship between hypnotherapy and cognitive behavioural therapy.[70]:105[113]

He also believed that hypnosis was a "partial sleep", meaning that a generalised inhibition of cortical functioning could be encouraged to spread throughout regions of the brain. He observed that the various degrees of hypnosis did not significantly differ physiologically from the waking state and hypnosis depended on insignificant changes of environmental stimuli. Pavlov also suggested that lower-brain-stem mechanisms were involved in hypnotic conditioning.[166][167]
Gruzelier and his colleagues studied brain activity using an fMRI while subjects completed a standard cognitive exercise, called the Stroop task. The team screened subjects before the study and chose 12 that were highly susceptible to hypnosis and 12 with low susceptibility. They all completed the task in the fMRI under normal conditions and then again under hypnosis. Throughout the study, both groups were consistent in their task results, achieving similar scores regardless of their mental state. During their first task session, before hypnosis, there were no significant differences in brain activity between the groups. But under hypnosis, Gruzelier found that the highly susceptible subjects showed significantly more brain activity in the anterior cingulate gyrus than the weakly susceptible subjects. This area of the brain has been shown to respond to errors and evaluate emotional outcomes. The highly susceptible group also showed much greater brain activity on the left side of the prefrontal cortex than the weakly susceptible group. This is an area involved with higher level cognitive processing and behaviour.[178][179]
Look for a hypnotherapist who is a member of the American Society of Clinical Hypnosis (ASCH) or the Society for Clinical and Experimental Hypnosis. To be a member of either of these organizations, a hypnotherapist must have a doctorate level degree in medicine, dentistry, or psychology, or a master’s degree in nursing, social work, psychology, or marital/family therapy plus a specific number of hours of approved training in hypnotherapy. In some cases, accredited, doctoral-level practitioners of alternative health care, such traditional Chinese medicine, may also be approved for membership. Of course, in addition to looking at qualifications, you should also find a hypnotherapist with whom you feel confident and comfortable in a therapeutic relationship.