Two ME patients have lost a High Court appeal against what they claimed was an "unfair and irrational" approach by the NHS to their condition.
The judicial review was brought by Kevin Short, from Norwich, and London-based Douglas Fraser.
They argued the NHS was wrong to place so much emphasis on psychological rather than medical therapies.
But a judge dismissed their allegations that current therapies were harmful to some with myalgic encephalomyelitis.
Lawyers for the two men had argued that guidance issued by the National Institute for Health and Clinical Excellence (NICE), restricted the range of treatment available.
Professor Peter Littlejohn, NICE's public health director of the National Institute for Health and Clinical Excellence welcomed the decision.
He said: "We are pleased to have won convincingly on all counts in this case – this judgment is a welcome endorsement of the rigorous methods we use to produce our guidelines.
"This result is very good news for the thousands of people with ME, who can continue to benefit from evidence-based diagnosis, management and care for this disabling condition."
The guidance issued in August 2007 related to ME and chronic fatigue syndrome, which affect over 200,000 across the country.
Experts are divided over the severity and best way to treat the conditions – and whether they are indeed two separate illnesses.
NICE recommends cognitive behavioural therapy (CBT), a form of counselling, and planned activity programme known as graded exercise therapy (GET) as front-line treatments.
But the two men told the High Court that such therapies can actually be harmful to people with ME in particular.
They said there should be more emphasis placed on drug treatments, arguing ME can lead to cardio-vascular problems and severe joint pain.
Professor Littlejohns said: "The judgment acknowledges the robust procedures that NICE follows in ensuring that its guidance is independent, evidence-based and fit for purpose.
"We're delighted that this issue is now closed."