So long as the therapist is trained and follows basic ethical norms, hypnotherapy is safe. Some people may feel dizzy or nauseous during or after being hypnotized. People who discuss traumatic memories may be subject to feelings of panic, flashbacks, or general feelings of anxiety, and the clinician or client may elect to discontinue treatment when symptoms are severe.
The experience of hypnosis can vary dramatically from one person to another. Some hypnotized individuals report feeling a sense of detachment or extreme relaxation during the hypnotic state while others even feel that their actions seem to occur outside of their conscious volition. Other individuals may remain fully aware and able to carry out conversations while under hypnosis.
Experiments by researcher Ernest Hilgard demonstrated how hypnosis can be used to dramatically alter perceptions. After instructing a hypnotized individual not to feel pain in his or her arm, the participant's arm was then placed in ice water. While non-hypnotized individuals had to remove their arm from the water after a few seconds due to the pain, the hypnotized individuals were able to leave their arms in the icy water for several minutes without experiencing pain.
Hypnosis is not a dangerous procedure. It is not mind control or brainwashing. A therapist cannot make a person do something embarrassing or that the person doesn't want to do. The greatest risk, as discussed above, is that false memories can potentially be created and that it may be less effective than pursuing other, more established and traditional psychiatric treatments.
This finding—that PHA temporarily disrupted some people’s ability to recall the past—echoes decades of hypnosis research. What is entirely new in Mendelsohn et al.’s study is their demonstration that PHA was associated with a specific pattern of brain activation. Consistent with what normally occurs in remembering, when people in the non-PHA group performed the recognition task and successfully remembered what happened in the movie, fMRI showed high levels of activity in areas responsible for visualizing scenes (the occipital lobes) and for analyzing verbally presented scenarios (the left temporal lobe). In stark contrast, when people in the PHA group performed the recognition task and failed to remember the content of the movie, fMRI showed little or no activity in these areas. Also, fMRI showed enhanced activity in another area (the prefrontal cortex) responsible for regulating activity in other brain areas.
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", 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".
The British Psychological Society commissioned a working group to survey the evidence and write a formal report on hypnotherapy in 2001. They found, “Enough studies have now accumulated to suggest that the inclusion of hypnotic procedures may be beneficial in the management and treatment of a wide range of conditions and problems encountered in the practice of medicine, psychiatry and psychotherapy.”
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.