No one completely understands how hypnosis works on pain, but brain-imaging studies have shown that people have a distinctly different pattern of brain activity when they are hypnotized. Activity is reduced in areas of the pain network, including the primary sensory cortex, which is responsible for the perception of pain. "These changes suggest that hypnosis blocks the pain signal from getting to the parts of the brain that perceive pain," says Sebastian Schulz-Stubner, M.D., Ph.D., an assistant professor in the University of Iowa Department of Anesthesia.
Hypnosis is slowing gaining favor as a way to ease the pain of childbirth. According to Grantly Dick-Read, M.D., the English obstetrician who wrote Childbirth Without Fear in 1933, hypnosis during labor helped women break the "fear-tension-pain syndrome." In a 2006 study, Australian researchers compared childbirth experiences of 77 women who were taught self-hypnosis in preparation for childbirth to those of 3,249 controls. The women who used hypnosis were less likely than others to need an epidural.
In a 1999 study at Harvard Medical School, health psychologist Carol Ginandes, Ph.D., divided 12 people with ankle fractures into two groups. Everyone received casts and standard orthopedic care, but six also underwent a series of hypnotherapy sessions, which included suggestions meant to target their particular stage of healing. Researchers reinforced the sessions by sending patients home with hypnotherapy audiotapes. Six weeks after they broke their ankles, the hypnotized patients had healed to an extent that would normally take eight and a half weeks.
Ginandes and colleague Patricia Brooks followed up with a study in 2003 on incision healing. They divided 18 women who underwent breast-reduction surgery into three groups of six. One received only standard postoperative care. The second group had eight sessions with a psychologist who offered emotional support but no hypnosis. The third group received eight hypnotherapy sessions. Nurses who examined the surgical wounds for seven weeks after the surgery found that the group receiving hypnosis healed fastest, followed by those who had had psychological support; the standard-care group healed most slowly.