People have been pondering and arguing over hypnosis for more than 200 years, but science has yet to fully explain how it actually happens. We see what a person does under hypnosis, but it isn't clear why he or she does it. This puzzle is really a small piece in a much bigger puzzle: how the human mind works. It's unlikely that scientists will arrive at a definitive explanation of the mind in the foreseeable future, so it's a good bet hypnosis will remain something of a mystery as well.
Adverse events resulting from relaxation techniques are uncommon. Rare reports describe basilar or vertebral artery occlusion after yoga postures that put particular strain on the neck. People with poorly controlled cardiovascular disease should avoid progressive muscle relaxation because abdominal tensing can cause the Valsalva response. Patients with a history of psychosis or epilepsy have reportedly had further acute episodes after deep and prolonged meditation.
But for the comparison between PHA and functional amnesia to be most meaningful, we need to know that they share underlying processes. One way to test this is to identify the brain activity patterns associated with PHA. In a groundbreaking study published in Neuron, neuroscientist Avi Mendelsohn and colleagues at the Weizmann Institute in Israel did just that using functional magnetic resonance imaging (fMRI). They carefully selected 25 people to participate in their experiment. Although all were susceptible to hypnosis, earlier testing had shown that half could respond to a PHA suggestion (labelled “the PHA group”) and half could not (the “non-PHA group”). In the Study session of their experiment, participants watched a 45-minute movie. One week later, in the Test session, participants returned to the laboratory and were hypnotized while they lay within the fMRI scanner. During hypnosis, people in both the PHA and non-PHA groups received a suggestion to forget the movie until they heard a specific cancellation cue.
The LAP BAND® procedure was approved by my insurance, but I just did not want to go through with it. I needed to do something to reduce my weight and the virtual gastric band hypnosis sounded more like something I could live with. I am eating much smaller portions and feeling so much better. My only problem is my clothes are too big so I need to go shopping.
The main theorist who pioneered the influential role-taking theory of hypnotism was Theodore Sarbin. Sarbin argued that hypnotic responses were motivated attempts to fulfill the socially constructed roles of hypnotic subjects. This has led to the misconception that hypnotic subjects are simply "faking". However, Sarbin emphasised the difference between faking, in which there is little subjective identification with the role in question, and role-taking, in which the subject not only acts externally in accord with the role but also subjectively identifies with it to some degree, acting, thinking, and feeling "as if" they are hypnotised. Sarbin drew analogies between role-taking in hypnosis and role-taking in other areas such as method acting, mental illness, and shamanic possession, etc. This interpretation of hypnosis is particularly relevant to understanding stage hypnosis, in which there is clearly strong peer pressure to comply with a socially constructed role by performing accordingly on a theatrical stage.
Charcot operated a clinic at the Pitié-Salpêtrière Hospital (thus, known as the "Paris School" or the "Salpêtrière School"), while Bernheim had a clinic in Nancy (known as the "Nancy School"). Charcot, who was influenced more by the Mesmerists, argued that hypnotism was an abnormal state of nervous functioning found only in certain hysterical women. He claimed that it manifested in a series of physical reactions that could be divided into distinct stages. Bernheim argued that anyone could be hypnotised, that it was an extension of normal psychological functioning, and that its effects were due to suggestion. After decades of debate, Bernheim's view dominated. Charcot's theory is now just a historical curiosity.[59]
Findings from randomized controlled trials support the use of various relaxation techniques for treating both acute and chronic pain, although 2 recent systematic reviews suggest that methodologic flaws may compromise the reliability of these findings. Randomized trials have shown hypnosis is valuable for patients with asthma and irritable bowel syndrome, yoga is helpful for patients with asthma, and tai chi helps to reduce falls and fear of falling in elderly people. Evidence from systematic reviews shows hypnosis and relaxation techniques are probably not of general benefit in stopping smoking or substance misuse or in treating hypertension.​hypertension.,​,
At first, Freud was an enthusiastic proponent of hypnotherapy. He "initially hypnotised patients and pressed on their foreheads to help them concentrate while attempting to recover (supposedly) repressed memories",[61] and he soon began to emphasise hypnotic regression and ab reaction (catharsis) as therapeutic methods. He wrote a favorable encyclopedia article on hypnotism, translated one of Bernheim's works into German, and published an influential series of case studies with his colleague Joseph Breuer entitled Studies on Hysteria (1895). This became the founding text of the subsequent tradition known as "hypno-analysis" or "regression hypnotherapy".

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.