“Hypnosis, in and of itself, isn’t dangerous,” says psychologist Bruce N. Eimer. It can be a therapeutic tool; but like all tools, he says, in the hands of someone incompetent or who uses it inappropriately, it can cause harm. “Would a massage therapist perform acupressure on an 84-year-old with osteoporosis?” Eimer asks. Probably not. Similarly, it would be unwise for a clinician to use hypnosis without first assessing if a patient is too psychologically fragile.