LONDON, March 13 (Reuters) - The emails, tweets and blog posts in the "abuse" folder that Michael Sharpe keeps on his computer continue to pile up. Eight years after he published results of a clinical trial that found some patients with chronic fatigue syndrome can get a little better with the right talking and exercise therapies, the Oxford University professor is subjected to almost daily, often anonymous, intimidation.

A Twitter user who identifies himself as a patient called Paul Watton (@thegodofpleasur) wrote: "I really am looking forward to his professional demise and his much-deserved public humiliation." Another, Anton Mayer (@MECFSNews), likened Sharpe's behaviour to "that of an abuser."

Watton and Mayer have never been treated by Sharpe for their chronic fatigue syndrome, a little-understood condition that can bring crushing tiredness and pain. Nor have they met him, they told Reuters. They object to his work, they said, because they think it suggests their illness is psychological. Sharpe, a professor of psychological medicine, says that isn't the case. He believes that chronic fatigue syndrome is a biological condition that can be perpetuated by social and psychological factors.

Sharpe is one of around a dozen researchers in this field worldwide who are on the receiving end of a campaign to discredit their work. For many scientists, it's a new normal: From climate change to vaccines, activism and science are fighting it out online. Social media platforms are supercharging the battle.

Reuters contacted a dozen professors, doctors and researchers with experience of analysing or testing potential treatments for chronic fatigue syndrome. All said they had been the target of online harassment because activists objected to their findings. Only two had definite plans to continue researching treatments. With as many as 17 million people worldwide suffering this disabling illness, scientific research into possible therapies should be growing, these experts said, not dwindling. What concerns them most, they said, is that patients could lose out if treatment research stalls.

A spokesperson for Twitter said the platform "exists to serve the public conversation. Its strength lies in providing people with a diversity of perspectives into critical issues – all in real-time." Where someone used anonymity for bad purposes, Twitter would take immediate action, the spokesperson added.

Chronic fatigue syndrome, also known as myalgic encephalomyelitis, or CFS/ME, is described by specialists as a "complex, multisystem, and often devastating disorder." Symptoms include overwhelming fatigue, joint pain, headaches, sleep problems and isolation. It can render patients bed- or house-bound for years. The Centers for Disease Control and Prevention, or CDC, estimates the illness costs the U.S. economy $17 billion to $24 billion annually in medical bills and lost incomes. It is thought to affect as many as 2.5 million people in the United States.