Hypnosis has been a controversial topic in many circles since the 18th century. What it is and how it works have been misunderstood and sometimes hotly debated for centuries. Hypnotists are often portrayed on movies and TV as mind-control masters who can compel their subjects to do bizarre or horrible things against their own will.

In the 20th century, though, hypnosis gradually came into its own as a technique for psychotherapists to help patients recall traumatic incidents that were continuing to affect their lives. Often, recalling the origin of a mental problem helped the patient deal with the issues involved.

Physicians and dentists learned that hypnosis could be used to ease pain and even allow patients to endure otherwise painful procedures without the use of anesthetics.

Then law enforcement officials jumped into the act, using hypnosis to coax testimony from forgetful witnesses. That led to still more controversy when it was discovered that witnesses could easily, even accidentally, be led to “remember” things that never happened. That meant hypnosis was not a reliable tool for coaching witnesses for court testimony.

With all that going on, there were still those in the medical establishment who did not believe hypnosis was useful, or perhaps even real. Now, after all these years, the verdict of medical research is in: “Hypnosis works. We don’t know why.”