Other causes that have been investigated are sarin, cyclosarin, and emissions from oil well fires, but their relationship to the illness is not as clear.Studies have consistently indicated that Gulf War syndrome is not the result of combat or other stressors and that Gulf War veterans have lower rates of post-traumatic stress disorder (PTSD) than veterans of other wars.According to a 2013 report by the Iraq and Afghanistan Veterans of America, veterans of the U.S. wars in Iraq and Afghanistan may also have Gulf War syndrome, though later findings identified causes that would not have been present in those wars.In 2022, researchers led by Robert Haley, MD at University of Texas Southwestern Medical Center found that exposure to sarin nerve gas in soldiers who had a particular genetic mutation that prevented them from breaking down the nerve gas is likely to be responsible for the syndrome. The findings and an editorial by two leading epidemiologists were published in Environmental Health Perspectives. Signs and symptoms
According to an April 2010 U.S. Department of Veterans Affairs (VA) sponsored study conducted by the Institute of Medicine (IOM), part of the U.S. National Academy of Sciences, 250,000 of the 696,842 U.S. servicemen and women in the 1991 Gulf War continue to be affected by chronic multi-symptom illness, which the IOM now refers to as Gulf War illness. The IOM found that it continued to affect these veterans nearly 20 years after the war.
The study did find a statistically significant elevation in the number of traffic accidents Gulf War veterans had. An April 1998 article in Emerging Infectious Diseases similarly found no increased rate of hospitalization and better health on average for veterans of the Persian Gulf War in comparison to those who stayed home.In contrast to those early studies, in January 2006, a study led by Melvin Blanchard published in the Journal of Epidemiology, part of the "National Health Survey of Gulf War-Era Veterans and Their Families", found that veterans deployed in the Persian Gulf War had nearly twice the prevalence of chronic multisymptom illness, a cluster of symptoms similar to a set of conditions often at that time called Gulf War Syndrome. On November 17, 2008, the Department of Veterans Affairs (VA) Research Advisory Committee on Gulf War Veterans Illnesses (RAC), a Congressionally mandated federal advisory committee composed of VA-appointed clinicians, researchers, and representative Gulf War veterans, issued a major report announcing scientific findings, in part, that "Gulf War illness is real", that GWI is a distinct physical condition, and that it is not psychological in nature. The 454 page report reviewed 1,840 published studies to form its conclusions identifying the high prevalence of Gulf War illness, suggesting likely causes rooted in toxic exposures while ruling out combat stress as a cause, and opining that treatments likely could be found.