If anyone had any doubts that Chronic Fatigue Syndrome is essentially just a medical term for a confirmed habit of whining and malingering, this news item from Britain’s Guardian describing activists’ attacks on doctors questioning or investigating CFS demonstrates the existence of the sort of political constituency which genuine illnesses just do not have.

The full extent of the campaign of intimidation, attacks and death threats made against scientists by activists who claim researchers are suppressing the real cause of chronic fatigue syndrome is revealed today by the Observer. According to the police, the militants are now considered to be as dangerous and uncompromising as animal rights extremists.

One researcher told the Observer that a woman protester who had turned up at one of his lectures was found to be carrying a knife. Another scientist had to abandon a collaboration with American doctors after being told she risked being shot, while another was punched in the street. All said they had received death threats and vitriolic abuse.

In addition, activists – who attack scientists who suggest the syndrome has any kind of psychological association – have bombarded researchers with freedom of information requests, made rounds of complaints to university ethical committees about scientists’ behaviour, and sent letters falsely alleging that individual scientists are in the pay of drug and insurance companies.

“I published a study which these extremists did not like and was subjected to a staggering volley of horrible abuse,” said Professor Myra McClure, head of infectious diseases at Imperial College London. “One man wrote he was having pleasure imagining that he was watching me drown. He sent that every day for months.”

Chronic fatigue syndrome – also known as myalgic encephalomyelitis (ME) – is common and debilitating. A recent BMJ (formerly the British Medical Journal) feature suggested that as many as one in 250 people in the UK suffers from it. Patients are sometimes unable to move and become bedridden, occasionally having to be fed through a tube. For more than 20 years, scientists have struggled to find the cause, with some pointing to physiological reasons, in particular viral infections, while others have argued that psychological problems are involved.

It is the latter group that has become the subject of extremists’ attacks. The antagonists hate any suggestion of a psychological component and insist it is due to external causes, in particular viruses. In the case of McClure, her “crime” was to publish a paper indicating that early studies linking the syndrome to the virus XMRV were wrong and the result of laboratory contamination. So furious was the reaction that she had to withdraw from a US collaboration because she was warned she might be shot.

A similar hate campaign was triggered by a study published in the Lancet earlier this year. It suggested that a psychological technique known as cognitive behavioural therapy could help some sufferers. This produced furious attacks on the scientists involved, including Michael Sharpe, professor of psychological medicine at Oxford University. He had already been stalked by one woman who was subsequently found to be carrying a knife at one of his lectures.

“The tragedy is that this tiny group of activists are driving young scientists from working in the field,” said Sharpe. “In the end, these campaigns are only going to harm patients.”