In a nested case-comparison study, Black et al. (2004a) conducted face-to-face interviews with 602 veterans in 1999-2002. They used the SCID with a random group of veterans drawn from strata of the PRIME-MD-interviewed group who reported one or more of the following symptom-based conditions during their previous interview: depression (major or minor depression), widespread chronic pain (established criteria for generalized, severe, and chronic pain), and cognitive dysfunction (amnesia or cognitive impairment of a moderate and prolonged intensity). Veterans were stratified by each symptom combination (one, two, or all) and by deployed or nondeployed status. Controls had not met screening criteria for any of these conditions and might have been deployed or not deployed. The veterans were selected randomly for interview from each stratum to optimize the match between cases and controls.
Personality disorders were screened for with the Schedule for Nonadaptive and Adaptive Personality (SNAP). Level of functioning was assessed using the SF-36. The Whiteley Index was used to determine hypochondriasis. The study found that 32% of the veterans met the criteria for a lifetime depression diagnosis (all types), and that rate was the same in deployed and nondeployed veterans (36.6% vs 30.3%, not significant). There were few diagnostic differences between the depressed deployed and the depressed nondeployed veterans, except for lifetime and current PTSD (OR 4.50, 95% CI 1.80-11.27 and OR 7.13, 95% CI 2.10-24.20, respectively), any lifetime and current anxiety disorders (OR 2.89, 95% CI 1.52-5.47 and OR 3.19, 95% CI 1.62-6.27, respectively), and any current psychiatric disorder (OR 2.00, 95% CI 1.0-3.74). The deployed depressed veterans were also more likely to have a diagnosis of any lifetime, but not current, substance-use disorder (OR 2.15, 95% CI 1.15-4.03), particularly lifetime alcohol-use disorder (OR 2.0, 95% CI 1.07-3.74). What was most surprising about the direct interview analysis was that there was little difference between the deployed and the nondeployed veterans in aspects of depression; the largest difference was found in the prevalence of any anxiety disorder (51.5% for deployed vs 25.0% for nondeployed).
Kang et al. (2003) conducted a population-based stratified random sample of 15,000 US Gulf War troops compared to a similar sample of nondeployed troops. Phase 1 was a mail survey and phase 2 was a telephone-based survey of PTSD symptoms using the PCL-M and chronic fatigue symptoms. In the interview cohort, 12.1% of Gulf War veterans and 4.3% of other veterans had symptoms of PTSD, with an adjusted OR of 3.1 (95% CI 2.7-3.4) for PTSD in the Gulf War group; 5.6% of the Gulf War veterans, and 1.2% of the other veterans (OR 4.8, 95% CI 3.9-5.9) had chronic fatigue symptoms. It was interesting to note that PTSD symptoms showed a dose-response relationship to intensity of war stress, whereas the chronic fatigue symptoms did not show any relationship to war stress. Estimates of PTSD as determined by a cutoff score of 50 or above tracked rates of stressors closely. Deployment, but not war stress, was associated with chronic fatigue symptoms.
Wolfe et al. (1999a,b) and Proctor et al. (1998) examined cohorts of veterans randomly sampled and stratified from the Fort Devens, Massachusetts, and New Orleans Gulf War veterans, as well as a cohort deployed to Germany. The Gulf War deployed veterans from Fort Devens were followed longitudinally from the day of their arrival home from the gulf (time 1) to about 2 years later (time 2) with a 78% participation rate. The Fort Devens cohort was mainly male, caucasian, and National Guard; rates of PTSD measured at time 1 were 3%. From those cohorts, stratified random samples were selected for closer study with direct interview (220 of the Fort Devens cohort, 73 of the New Orleans cohort, and 48 of the Germany deployed). The researchers used questionnaires (the 52-item expanded Health Symptoms Checklist [HSC] and the Expanded Combat Exposure Scale), a neuropsychologic test battery, an environmental