Hypnosis

Hypnosis is a state of consciousness characterized by focused attention, reduced peripheral awareness, and heightened responsiveness to suggestion. The American Psychological Association (APA) defines it as a procedure during which a health professional suggests changes in sensations, perceptions, thoughts, or behavior. The experience involves an absorption in imagery or ideas, a suspension of critical judgment, and an enhanced ability to alter perception and memory. Hypnotic induction typically uses verbal cues and relaxation, but not all individuals respond equally; susceptibility varies widely, with about 10–15% of people being highly hypnotizable. The state is not sleep; brain imaging shows distinct patterns of activity, including altered connectivity in the default mode network and prefrontal cortex.¹

Modern hypnosis traces to Franz Mesmer's 18th-century theory of animal magnetism, which was discredited by a royal commission in 1784.² In 1841, Scottish surgeon James Braid coined the term 'hypnosis' from the Greek 'hypnos' (sleep), emphasizing a psychological rather than magnetic explanation. Later, French neurologist Jean-Martin Charcot studied hypnosis in hysterical patients, while Hippolyte Bernheim argued it was a normal suggestibility phenomenon. In the 20th century, Milton Erickson developed a permissive, indirect style of induction, and Ernest Hilgard introduced the concept of the 'hidden observer' to explain divided consciousness.³ Hypnosis gained medical recognition when the British Medical Association endorsed it in 1955 and the APA followed in 1960.

Hypnotherapy is used for pain management, anxiety, phobias, irritable bowel syndrome, and habit modification such as smoking cessation. A meta-analysis of 18 studies found that hypnosis reduced pain in 75% of surgical patients compared to controls. It is also effective for treating chronic pain, with evidence from randomized controlled trials. Hypnosis can enhance the effectiveness of cognitive-behavioral therapy for anxiety and depression. However, its use for memory recovery is controversial; hypnotically refreshed memories are often unreliable and can lead to false memories.⁴ The British Psychological Society acknowledges hypnosis as a valid therapeutic tool but cautions against its use for age regression or past-life therapy.

Hypnosis has niche applications beyond therapy: it is used in forensic settings to aid witness recall, though many jurisdictions restrict its admissibility due to memory distortion risks.⁴ In sports psychology, hypnosis helps athletes improve focus and performance. Stage hypnosis exploits social compliance and suggestibility, but participants are not actually under the hypnotist's control; they retain the ability to resist suggestions. Research on hypnotic analgesia has revealed that suggestions can modulate pain perception through descending inhibitory pathways, independent of placebo. A rare phenomenon, 'hypnotic coma,' involves deep absorption with apparent unresponsiveness, but it is not a true coma. Also, self-hypnosis is a learnable skill that can be used for stress reduction and habit control, with apps and audio guides available.

Hypnotic induction

The procedure used to initiate a hypnotic state, typically involving relaxation and focused attention.

Suggestibility

The tendency to accept and act on suggestions, which is heightened during hypnosis.

Hidden observer

A concept proposed by Ernest Hilgard describing a part of the mind that remains aware during hypnosis.

Hypnotic analgesia

The reduction of pain through hypnotic suggestion, often used in medical settings.