There may be hope for the 4 million Americans suffering from the baffling ailment known as chronic fatigue syndrome: A new study firms up the theory that it's caused by a virus, raising the prospect of the first effective treatment. Researchers say they've identified a mouse-related retrovirus in the vast majority of patients, and they think that drugs currently used to treat HIV (an unrelated retrovirus) might help, reports the Wall Street Journal.
The study is anything but a slam dunk, notes the Los Angeles Times, and a co-author says the results "raise as many questions as they answer." But a spate of government studies already underway could settle many of those questions within the year—including whether it might someday be possible to develop a standard test for the ailment.
(Read more chronic fatigue syndrome stories.)