There is no single cause for Gulf War illness, researchers have concluded.
The row about the effects of serving in the 1991 conflict continues
The journal Philosophical Transactions of the Royal Society has published 16 papers outlining research into possible causes, such as exposure to chemicals.
Researchers say effects on servicemen's health have been seen, but there is no direct scientific link between serving in the 1991 Gulf War and a syndrome.
But the National Gulf War Veterans and Family Association said a series of medical disasters had caused illness.
In a commentary in the journal, Professor Simon Wessely, co-director of Kings College Centre for Military Health Research and guest editor of the special issue of the journal, said one of the papers it included showed the term Gulf War Syndrome was a "misnomer".
"No new illness or symptom cluster unique to Gulf War veterans has been identified."
One paper in the journal looks at exposure to depleted uranium - which has been singled out by veterans' groups as a potential cause of ill-health.
The research looks at soldiers directly exposed to DU in "friendly fire" incidents.
But despite this exposure, there was no evidence of kidney damage, which the journal states would be the most likely effect.
Papers also suggest there is no "credible evidence" linking exposure to pesticides or nerve agents such as sarin, directly to ill health.
But the researchers do suggest the health concerns related to the Gulf War could improve the way soldiers are monitored before, during and after future conflicts to minimise the impact of war on health.
Professor Wessely said: "An enormous amount of money and effort have been expended on understanding Gulf War Illnesses worldwide.
"These reviews make it clear that there is no single cause, rather there are a range of factors likely to be responsible.
"There is little value in conducting further research into the causes.
"We should now focus our resources on rehabilitating those people who are ill as a result of service in the Gulf War."
But Shaun Rusling, of the National Gulf Veterans and Families Association, said: "We, the ill veterans, have never claimed a single cause to our ill health but a number of serious medical disasters starting with a secret vaccine regime and multiple vaccinations, with childhood whooping cough given with each anthrax vaccine to boost the immune system causing autoimmune type diseases."
Veterans Minister Don Touhig said: "This publication is a significant landmark in the field of research into Gulf War illnesses and is welcomed by the Ministry of Defence.
"It confirms that there is no straightforward explanation of ill-health experienced by some Gulf veterans and that it cannot be solely attributed to toxic chemicals, depleted uranium, organophosphates or medical counter-measures."
"Professor Wessely is absolutely correct when he says we should now look to the future and focus our resources on rehabilitating Gulf War veterans who are ill."