Is there a gulf war syndrome? Searching for syndromes by factor analysis of symptoms

Objective.-To search for syndromes in Persian Gulf War veterans. Participants.-Two hundred forty-nine (41%) of the 606 Gulf War veterans of the Twenty-fourth Reserve Naval Mobile Construction Battalion living in 5 south-eastern states participated; 145 (58%) had retired from service, and the rest were still serving in the battalion. Design.-Participants completed a standardized survey booklet measuring the anatomical distributions or characteristics of each symptom, a booklet measuring wartime exposures, and a standard psychological personality assessment inventory. Two-stage factor analysis was used to disentangle ambiguous symptoms and identify syndromes. Main Outcome Measures.-Factor analysis-derived syndromes, Results.-Of 249 participants, 175 (70%) reported having had serious health problems that most attributed to the war, and 74 (30%) reported no serious health problems. Principal factor analysis yielded 6 syndrome factors, explaining 71% of the variance. Dichotomized syndrome indicators identified the syndromes in 63 veterans (25%). Syndromes 1 (''impaired cognition,'' characterized by problems with attention, memory, and reasoning, as well as insomnia, depression, daytime sleepiness, and headaches), 2 (''confusion-ataxia,'' characterized by problems with thinking, disorientation, balance disturbances, vertigo, and impotence), and 3 (''arthro-myo-neuropathy,'' characterized by joint and muscle pains, muscle fatigue, difficulty lifting, and extremity paresthesias) represented strongly clustered symptoms; whereas, syndromes 4 (''phobia-apraxia''), 5 (''fever-adenopathy''), and 6 (''weakness-incontinence'') involved weaker clustering and mostly overlapped syndromes 2 and 3. Veterans with syndrome 2 were 12.5 times (95% confidence interval, 3.5-44.8) more likely to be unemployed than those with no health problems. A psychological profile, found in 48.4% of those with the syndromes, differed from posttraumatic stress disorder, depression, somatoform disorder, and malingering. Conclusion.-These findings support the hypothesis that clusters of symptoms of many Gulf War, veterans represent discrete factor analysis-derived syndromes that appear to reflect a spectrum of neurologic injury involving the central, peripheral, and autonomic nervous systems.