Pierre Janet (1859–1947) reported studies on a hypnotic subject in 1882. Charcot subsequently appointed him director of the psychological laboratory at the Salpêtrière in 1889, after Janet had completed his PhD, which dealt with psychological automatism. In 1898, Janet was appointed psychology lecturer at the Sorbonne, and in 1902 he became chair of experimental and comparative psychology at the Collège de France. Janet reconciled elements of his views with those of Bernheim and his followers, developing his own sophisticated hypnotic psychotherapy based upon the concept of psychological dissociation, which, at the turn of the century, rivalled Freud's attempt to provide a more comprehensive theory of psychotherapy.
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.
But how does the suppression mechanism decide what to suppress? In this study, movie content but not movie context was influenced by PHA. Memories involve the “what,” “how,” “when” and “where” of an event interwoven together, such that distinctions between content and context may be blurred (for example, “Was the movie shot with a hand-held camera?”). To make such fine discriminations, the brain’s suppressor module presumably needs to process information at a sufficiently high level. Yet this module needs to act quickly, preconsciously suppressing activation of the information before it even enters awareness. Brain imaging technologies with superior temporal resolution to fMRI, such as magnetoencephalography (MEG), might help to resolve this seeming paradox of sophisticated, yet rapid, operations.
Evidence from randomized controlled trials indicates that hypnosis, relaxation, and meditation techniques can reduce anxiety, particularly that related to stressful situations, such as receiving chemotherapy (see box). They are also effective for insomnia, particularly when the techniques are integrated into a package of cognitive therapy (including, for example, sleep hygiene). A systematic review showed that hypnosis enhances the effects of cognitive behavioral therapy for conditions such as phobia, obesity, and anxiety.
Since hypnotherapy is an adjunct form of therapy, used along with other forms of psychological or medical treatment, there are many applications. Hypnotherapy can be used to treat anxiety, phobias, substance abuse including tobacco, sexual dysfunction, undesirable spontaneous behaviors, and bad habits. It can be used to help improve sleep, learning disorders, communication, and relationship issues. Hypnotherapy can aid in pain management and help resolve medical conditions such as digestive disorders, skin issues, and gastrointestinal side effects of pregnancy and chemotherapy. It can also be used by dentists to help patients control their fears or to treat teeth grinding and other oral conditions.