ObjectiveControversy exists concerning unexplained illness in Persian Gulf War veterans, especially regarding the contribution of psychological trauma. We sought to determine if war zone trauma or posttraumatic stress symptomatology (PTSS) are associated with illnesses reported by Gulf War veterans that were documented by medical examination but not attributable to a medical diagnosis.MethodsA total of 1119 (55% response rate) of 2022 randomly sampled veterans of the United States Persian Gulf War were screened and 237 cases and 113 controls were identified by medical examination for a case-control study comparing Persian Gulf War military veterans with or without medically documented, but unexplained, symptoms. Multivariate logistic regression and cross-validation analyses examined self-report measures of demographics, subjective physical symptoms and functioning, psychiatric symptoms, stressors, war zone trauma, and PTSS, to identify correlates of case-control status.ResultsPosttraumatic stress symptomatology and somatic complaints were independently associated with case status, as were (although less consistently) war zone trauma and depression. Age, education, and self-reported health, stress-related somatization, pain, energy/fatigue, illness-related functional impairment, recent stressors, and anxiety were univariate (but not multivariate) correlates of case status.ConclusionsPTSS related to war zone trauma warrants additional prospective research study and attention in clinical screening and assessment as a potential contributor to the often debilitating physical health problems experienced by Persian Gulf War veterans.