Franz Mesmer (1734–1815) believed that there is a magnetic force or "fluid" called "animal magnetism" within the universe that influences the health of the human body. He experimented with magnets to impact this field in order to produce healing. By around 1774, he had concluded that the same effect could be created by passing the hands in front of the subject's body, later referred to as making "Mesmeric passes". The word "mesmerize", formed from the last name of Franz Mesmer, was intentionally used to separate practitioners of mesmerism from the various "fluid" and "magnetic" theories included within the label "magnetism".
For several decades Braid's work became more influential abroad than in his own country, except for a handful of followers, most notably Dr. John Milne Bramwell. The eminent neurologist Dr. George Miller Beard took Braid's theories to America. Meanwhile, his works were translated into German by William Thierry Preyer, Professor of Physiology at Jena University. The psychiatrist Albert Moll subsequently continued German research, publishing Hypnotism in 1889. France became the focal point for the study of Braid's ideas after the eminent neurologist Dr. Étienne Eugène Azam translated Braid's last manuscript (On Hypnotism, 1860) into French and presented Braid's research to the French Academy of Sciences. At the request of Azam, Paul Broca, and others, the French Academy of Science, which had investigated Mesmerism in 1784, examined Braid's writings shortly after his death.
Barber, Spanos, and Chaves (1974) proposed a nonstate "cognitive-behavioural" theory of hypnosis, similar in some respects to Sarbin's social role-taking theory and building upon the earlier research of Barber. On this model, hypnosis is explained as an extension of ordinary psychological processes like imagination, relaxation, expectation, social compliance, etc. In particular, Barber argued that responses to hypnotic suggestions were mediated by a "positive cognitive set" consisting of positive expectations, attitudes, and motivation. Daniel Araoz subsequently coined the acronym "TEAM" to symbolise the subject's orientation to hypnosis in terms of "trust", "expectation", "attitude", and "motivation".
Pierre Janet originally developed the idea of dissociation of consciousness from his work with hysterical patients. He believed that hypnosis was an example of dissociation, whereby areas of an individual's behavioural control separate from ordinary awareness. Hypnosis would remove some control from the conscious mind, and the individual would respond with autonomic, reflexive behaviour. Weitzenhoffer describes hypnosis via this theory as "dissociation of awareness from the majority of sensory and even strictly neural events taking place."
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.)
Hypnosis is not a psychotherapeutic treatment or a form of psychotherapy, but rather a tool or procedure that helps facilitate various types of therapies and medical or psychological treatments. Only trained health care providers certified in clinical hypnosis can decide, with their patient, if hypnosis should be used along with other treatments. As with psychotherapy, the length of hypnosis treatment varies, depending on the complexity of the problem.