Dr Graham Wagstaff, a researcher and member of the British Society of Experimental and Clinical Hypnosis, will tell its annual conference in Birmingham on Saturday that there is no proof that hypnosis can cause severe mental illness such as schizophrenia.

Stage hypnotist Paul McKenna was recently cleared of causing a man to become schizophrenic after he appeared in his show.

Dr Wagstaff told News Online: "If people have an underlying mental health problem, a whole variety of things could make it worse, such as an accident.

"But that is not a peculiar characteristic of hypnosis.

"It depends what the hypnotist does. Hypnotists should take the normal safeguards that any good therapists does."

There are currently few regulations regarding hypnotherapy.

Anyone can advertise as a hypnotherapist in the Yellow Pages and they may have only the most minimum of knowledge of the subject.

Some hypnotherapists are calling for the regulations to be tightened, but Dr Wagstaff says this should apply to other therapies as well, such as counselling, where there are also few regulations.

"There is nothing particularly unusual about hypnotherapy," he said. "Bad therapy is bad therapy wherever it is found."

He added: "A lot of the fears over hypnosis are due to an outdated concept of hypnosis related to entertainment.

"A lot of people think it makes you enter a strange state where you lose control and are controlled by the hypnotist who can cause strange neurological effects."

Education

He said there was a great need for education about what hypnosis involved.

"Most people who have been hypnotised say it is a situation where they imagine and relax and go along with suggestions made to them unless they are violently opposed.

"They do not zonk out and lose consciousness."

He believes people do stupid things when hypnotised on stage because of social pressure rather than as a result of hypnosis.

"It would be embarrassing if they did not join in. That is not hypnosis," he said.

He added that there were great differences between stage and clinical hypnosis.

"Stage show hypnosis is for entertainment. There is no preparation, no relaxation and no case history is taken."