title: Is there a Gulf War Syndrome? Searching for syndromes by factor analysis of symptoms.
abstract: OBJECTIVE
  To search for syndromes in Persian Gulf War veterans.
  
  
  METHODS
  Two hundred forty-nine (41%) of the 606 Gulf War veterans of the Twenty-fourth Reserve Naval Mobile Construction Battalion living in 5 southeastern states participated; 145 (58%) had retired from service, and the rest were still serving in the battalion.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Epidemiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, 75235-8874, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Haley
authors.forename: T L
authors.initials: TL
authors.lastname: Kurt
authors.forename: J
authors.initials: J
authors.lastname: Hom
mesh_terms: D000328:Adult; D001072:Apraxias; D001259:Ataxia; D003072:Cognition Disorders; D005163:Factor Analysis, Statistical; D005334:Fever; D006304:Health Status; D006801:Humans; D008206:Lymphatic Diseases; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases; D018923:Persian Gulf Syndrome / Q000175:diagnosis / Q000453:epidemiology; D010698:Phobic Disorders; D011581:Psychological Tests; D014728:Veterans / Q000523:psychology