In 1985, The AMA convened a commission that warned against using hypnotherapy to aid in recollection of events. The commission cited studies that showed the possibility of hypnotic recall resulting on confabulation or an artificial sense of certainty about the course of events. As a result, many states limit or prohibit testimony of hypnotized witnesses or victims.
Therefore, Braid defined hypnotism as a state of mental concentration that often leads to a form of progressive relaxation, termed "nervous sleep". Later, in his The Physiology of Fascination (1855), Braid conceded that his original terminology was misleading, and argued that the term "hypnotism" or "nervous sleep" should be reserved for the minority (10%) of subjects who exhibit amnesia, substituting the term "monoideism", meaning concentration upon a single idea, as a description for the more alert state experienced by the others.[23]
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]
Hypnotherapy, while thought of by some as something non-scientific, is a regulated, legitimate form of therapy that can both explore and use a person’s subconscious to better help them through psychotherapy, and also act as a method of therapy that helps relieve a person of symptoms and problems they are afflicted with. Hypnotherapy has proven to be extremely effective in cases with patients suffering from pain and addiction.

For some psychologists who uphold the altered state theory of hypnosis, pain relief in response to hypnosis is said to be the result of the brain's dual-processing functionality. This effect is obtained either through the process of selective attention or dissociation, in which both theories involve the presence of activity in pain receptive regions of the brain, and a difference in the processing of the stimuli by the hypnotised subject.[137]
The central theoretical disagreement regarding hypnosis is known as the "state versus nonstate" debate. When Braid introduced the concept of hypnotism, he equivocated over the nature of the "state", sometimes describing it as a specific sleep-like neurological state comparable to animal hibernation or yogic meditation, while at other times he emphasised that hypnotism encompasses a number of different stages or states that are an extension of ordinary psychological and physiological processes. Overall, Braid appears to have moved from a more "special state" understanding of hypnotism toward a more complex "nonstate" orientation.[citation needed]

We know it is hard to sort out all the different claims made by some so-called “hypnosis schools and boards.” Stay away from “distance learning” or correspondence courses that claim to certify you as a clinical hypnotherapist. Hypnosis and hypnotherapy is a healing art based on scientific methods. Only basic hypnotherapy theory can be obtained from the right books or videos. Effectiveness is unlikely without live demonstrations, in-depth and advanced discussion, question and answer opportunities and supervised clinical practice.  Just as correspondence courses are inappropriate for counselors, medical doctors and massage therapists, they are wrong for people who want to be effective and successful clinical hypnotherapists.

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.