In his later works, Braid reserved the term "hypnotism" for cases in which subjects entered a state of amnesia resembling sleep. For other cases, he spoke of a "mono-ideodynamic" principle to emphasise that the eye-fixation induction technique worked by narrowing the subject's attention to a single idea or train of thought ("monoideism"), which amplified the effect of the consequent "dominant idea" upon the subject's body by means of the ideo-dynamic principle.
Hypnosis or deep relaxation can sometimes exacerbate psychological problems—for example, by retraumatizing those with post-traumatic disorders or by inducing “false memories” in psychologically susceptible individuals. Evidence, although inconclusive, has raised concerns that the dissociation necessary to participate in relaxation or hypnosis can lead to the manifestation of the symptoms of psychosis. Only appropriately trained and experienced practitioners should undertake hypnosis. Its use should be avoided in patients with borderline personality disorder, dissociative disorders, or with patients who have histories of profound abuse. Competent hypnotherapists are skilled in recognizing and referring patients with these conditions.
Although there are different techniques, clinical hypnotherapy is generally performed in a calm, therapeutic environment. The therapist will guide you into a relaxed, focused state and ask you to think about experiences and situations in positive ways that can help you change the way you think and behave. Unlike some dramatic portrayals of hypnosis in movies, books, or on stage, you will not be unconscious, asleep, or in any way out of control of yourself. You will hear the therapist’s suggestions, but it is up to you to decide whether or not to act on them.