Various forms of hypnosis, trance, and altered states of consciousness have been documented in a number of cultures throughout history. Hypnosis-like practices can be traced to ancient Egypt, Babylon, Greece, Persia, Britain, Scandinavia, America, Africa, India, and China. Wong Tai, a father of Chinese medicine, made an early written reference to hypnosis in 2600 BC. Hypnotic practices have played roles in religion and religious ceremonies. Mention is made in the Bible, Talmud, and Hindu Vedas, and trance-states are included in some Native American and African ceremonies.
Sleep temples (also known as dream temples or Egyptian sleep temples) are regarded by some as an early instance of hypnosis over 4000 years ago, under the influence of Imhotep. Imhotep served as Chancellor, and High Priest of the sun god Ra at Heliopolis. He was said to be a son of Ptah, his mother being a mortal named Khredu-ankh.
Sleep temples were hospitals of sorts, healing a variety of ailments, perhaps many of them psychological in nature. The treatment involved chanting, placing the patient into a trance-like or hypnotic state, and analysing their dreams in order to determine treatment. Meditation, fasting, baths and sacrifices to the patron deity or other spirits were often involved as well.
Sleep temples also existed in the Middle East and Ancient Greece. In Greece, they were built in honour of Asclepios, the Greek God of Medicine and were called Asclepieion. The Greek treatment was referred to as incubation, and focused on prayers to Asclepios for healing. A similar Hebrew treatment was referred to as Kavanah, and involved focusing on letters of the Hebrew alphabet spelling the name of the Hebrew God. Sir Mortimer Wheeler unearthed a Roman Sleep temple at Lydney Park, Gloucestershire in 1928, with the assistance of a young J.R.R. Tolkien.
The term hypnosis is derived from the Greek word hypnos, meaning sleep. The origin of modern Western hypnotherapy is often traced to the Austrian physician Franz Anton Mesmer (1734-1815). Mesmer believed that illness is caused by an imbalance of magnetic fluids in the body that can be corrected through "animal magnetism." He asserted that the hypnotist's own personal magnetism can be transferred to a patient. The term "mesmerize" is derived from Mesmer's name.
In the mid 20th Century, the British and American Medical Associations and the American Psychological Association endorsed hypnosis as a medical procedure. In 1995, the U.S. National Institutes of Health (NIH) issued a consensus statement noting the scientific evidence in favor of the use of hypnosis for chronic pain, particularly pain associated with cancer