LONDON, U.K.: A significant new study from the University of Edinburgh has found genetic differences in people with chronic fatigue syndrome, offering the strongest evidence yet that the condition has a biological basis.

The research, part of the DecodeME project, identified eight regions of the genome that differ between individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and those without. The team says the findings help counter long-standing misconceptions that ME/CFS is psychological or caused by laziness.

The results offer "the first robust evidence that genes contribute to a person's chance of developing the disease," the researchers said in a statement.

ME/CFS affects an estimated 67 million people globally and is characterized by extreme fatigue, cognitive impairment ("brain fog"), and worsening symptoms after even mild physical or mental exertion. There is currently no diagnostic test or cure.

The study analyzed DNA samples from 15,579 people who self-reported ME/CFS symptoms and 259,909 people without, all of European ancestry. Researchers found that several gene variants were more common in the ME/CFS group, particularly those linked to the immune and nervous systems.

At least two of the regions are tied to the body's response to infection—supporting reports that ME/CFS symptoms often follow an infectious illness. Another region has been linked to chronic pain, which is also common among people with the condition.

"These results will not mean that a test or cure will be developed straight away, but they will lead to a greater understanding," said researcher Andy Devereux-Cooke. "They should prove game-changing in the ME/CFS research field."

While the study has not yet been peer-reviewed, it has been hailed as a milestone by patients and scientists alike. Some experts noted limitations, particularly the reliance on self-reported cases rather than formal clinical diagnoses. They called for larger follow-up studies to confirm the findings.

"This will take considerable investment in academia and by industry," said Dr. Jackie Cliff, an ME/CFS researcher at Brunel University of London, adding that more work is needed to turn the findings into treatments.