The use of hypnotism to treat medical problems is increasing, but how it works still baffles scientists
by Sally Appleton, 8 September 2004, The Telegraph

Some doctors use it to treat insomnia, asthma and eczema. Others to calm migraines and irritable bowels, and to reduce anxiety. Yet, even though the use of hypnosis is on the increase across the medical profession, no one understands how it works. Some experts even believe the "trance" induced by hypnosis can happen to us all when we are daydreaming, engrossed in a bestseller or commuting to work.

The ways that doctors are willing to use hypnosis are expanding in number and range. Some use it to relieve the chronic pain of arthritis, the acute pain of dental surgery, reduce the side effects of cancer treatments and help people stop smoking or lose weight. It is even used to make food taste better for cancer patients whose taste buds have been damaged by radiotherapy.

Hypnosis is now one of the most commonly used complementary therapies, with an estimated 353,000 consumers every year in England. To meet this demand, more and more health professionals are being trained in its use. General practices in 12 per cent of primary care groups in England offer hypnosis to patients. This results in nearly one-and-a-half million private and NHS appointments with hypnotherapists every year, at a cost to private users of £34 million and to the NHS of more than £5 million.

Despite this increase in medical use and a boom in hypnosis research, experts still don't agree how it works and such understanding could make it even more effective. Scientists at the British Association's Festival of Science in Exeter will continue the long-running debate on the subject tomorrow.
Hypnosis attempts to direct a person's thoughts, feelings and behaviour by "suggestions" that instruct him or her to concentrate on particular images or ideas. This can be achieved with the help of a hypnotist or through self-hypnosis. For example, a "suggestion" to reduce the pain of having a tooth extracted might invoke an image of pain being controlled like the volume on a television set. So if the dial is turned down, the pain can be reduced. Likewise, the image of lying on a beach in the sun can help some people to experience less pain.

People usually need a series of hypnosis sessions, starting with a "hypnotic induction", which increases relaxation and allows people to become absorbed in their inner thoughts. During hypnosis, subjects are usually aware of their environment, can remember most of what happens and cannot be made to do things against their will.

Scientists agree that there is a pattern or "orchestra" of brain activity during hypnosis that some refer to as a trance. A trance can be described as a state of mind in which a person's attention is focused, he or she is absorbed in a specific activity and is switched off from what is going on around them. This brain activity depends on the type of "suggestion" that the patient is given and can occur in a number of parts of the brain, including the cortex that controls the "higher" brain functions such as perception, sensation, thought and memory and the lower parts that control unconscious processes such as breathing, heart rate and muscle movement.

One view suggests that the brain achieves an altered state of consciousness, a unique trance, during hypnosis.

Prof Helen Crawford, of Virginia Polytechnic Institute and State University in Blacksburg, Virginia, an expert in the neurophysiology of pain relief through hypnosis, says she has concrete physiological evidence to show that the brain achieves a state of focused attention during hypnosis. She says there is something "dramatically different" about the brain activity in people during hypnosis, for pain relief, compared with when they are not hypnotised.

She describes a change in the pattern of brain activity during hypnosis, characterised by a significant increase in theta waves of about 5-7Hz recorded by electroencephalograph (EEG) monitors.

However, support among experts for an alternative explanation appears to be growing. Although proponents of this rival theory do not dispute that research has reliably shown physiological changes in the brain during hypnosis, they do not believe these changes are confined to hypnosis.

They propose that the pattern of brain activity seen during hypnosis can be found during everyday experiences when attention is focused: for example, being absorbed in a piece of music or driving a long distance. This explanation makes the brain activity seen during hypnosis seem less special, since it suggests this can happen to us all.

One of the authors of a British Psychological Society report on hypnosis, Dr Graham Wagstaff of the University of Liverpool, believes the physiological evidence cited by some scientists to support the idea that the brain is in a unique "trance" during hypnosis has been over-interpreted. "If you give anybody an instruction, you will get physiological changes in the brain," he says. "To establish that hypnosis invokes a special physiological state of the brain, you have to show that the person is not capable of doing that when not hypnotised."

He says current research methods are typically not able to answer that question, despite the conclusions of the scientists involved, because they do not enable us to separate the effect on the brain of the "suggestion" itself from being in a hypnotic state of mind. "I have yet to come across an experiment where they look for physiological differences between a group of people who are given a suggestion under hypnosis, and a different group of people, who share similar psychological characteristics, but who receive exactly the same suggestion without hypnosis." One reason for this lack of good controlled research, he says, is that scientists searching for the physiological basis of hypnosis are usually trying to show that it is something special. They might not be as successful at securing funding for this expensive and time-consuming work if the aim was to show that there was nothing unique about brain activity during hypnosis.

"There are question marks," acknowledges another author of the report, Dr Michael Heap of Wathwood Hospital, Rotherham, who has frequently used hypnosis to treat psychological conditions. Dr Heap says the traditional idea that you are in some special state of consciousness, a unique trance, during all forms of hypnosis is very unlikely.

He disagrees that there is a "biological marker" to show that brain activity during hypnosis is "uniquely hypnotic".
We may not know how it works, but it certainly seems to. Phyllis Alden, of Derbyshire Royal Infirmary, is a clinical psychologist who has used hypnosis to treat patients for the past 20 years. She says hypnosis can be so effective in reducing pain that patients can even stop using
conventional painkillers. She believes the hypnotic state is simply capitalising on our natural capacity to focus our attention.

"Hypnosis involves the focusing of attention to the point where you can make what you imagine feel real at the same time as being able to switch off from what is real," she says. "That is what makes hypnosis work. I don't think it is a lot more complicated than that. You don't have to formally induce this state called hypnosis to get some of these things to happen."

Despite the mystery, experts seem to agree that hypnosis is not dangerous, if it is carried out with a trained hypnotherapist who has a good understanding of the patient's condition.

People who do not have vivid imaginations and those who are sceptical about its value may not benefit from hypnosis, as imagination and expectation are important in determining its effectiveness. Hypnosis is not regarded as the treatment of choice for people with severe mental health problems, such as schizophrenia.

As the debate continues, it highlights how little is known about the closely related and fundamental scientific question of human consciousness. These complex questions are likely to continue to baffle scientists for many more years.

In the meantime, millions of people will continue to benefit from hypnosis, even though this lack of understanding seems to be at odds with the health service drive for evidence-based medicine.