nonwar zone (for example, Germany). To diagnose psychiatric disorders, primary studies also included an in-person standardized diagnostic interview. Some studies used clinician interviews such as the Structured Clinical Interview for DSM-III-R (SCID); the Schedule for Clinical Assessment and Diagnosis (SCAN); or for PTSD, the Clinician Administered PTSD Scale (CAPS). Others used interviews administered by trained lay interviewers, such as the Composite International Diagnostic Interview (CIDI), a comprehensive and standardized diagnostic interview that is very widely used. The CIDI has been adapted to many forms that limit the diagnoses covered and the length of interview, and these alternative forms often produce less precise diagnoses. Studies of Gulf War veterans often used versions of the CIDI that were abbreviated from the full standard CIDI. Secondary studies typically failed to use diagnostic interviews to diagnose mental health disorders and often screened for mental health disorders using symptom checklists such as the PTSD Checklist developed by the VA.
Many of the large epidemiologic studies of Gulf War veterans’ health included items pertaining to mental health. Moreover, there was often a nested case-control study of mental health characteristics in the primary epidemiologic cohort studies that used direct-interview techniques. In Volume 4, eight primary studies were reviewed that used direct-interviews of the large Gulf War cohorts described in Chapter 3. These studies often used validated instruments, such as the CIDI, SCID, and CAPS, to complement the interview. Black et al. (2004b) reanalyzed the population-based, telephone interviews from the Iowa cohort of 4886 randomly selected veterans (military and reserve), deployed and nondeployed (Iowa Persian Gulf Study Group, 1997). The initial cohort study had uncovered higher than anticipated levels of anxiety; therefore, this analysis of the interview data looked more carefully into the features of anxiety in that population. The original cohort was interviewed by telephone using the Primary Care Evaluation of Mental Disorders (PRIME-MD), the Post Traumatic Stress Disorder Checklist-Military (PCL-M), and the CAGE2 to estimate alcoholism. Additional structured questions identified medical conditions and military preparedness. Compared with nondeployed veterans, deployed veterans had a twofold increase in the prevalence of generalized anxiety disorder, panic disorder, PTSD, and any anxiety disorder (OR 2.3, 95% CI 1.5-3.5). Participation in combat increased the likelihood of the development of anxiety disorders, particularly PTSD (OR 2.1, 95% CI 1.7-4.2). Anxious Gulf War veterans were more likely to have had a pre-existing psychiatric condition, to have taken psychotropic medications, or to have had a psychiatric hospitalization prior to deployment. Anxiety conditions were comorbid with several psychiatric and medical conditions, particularly symptoms of cognitive dysfunction, any depression, major depression, and symptoms of fibromyalgia.
Barrett et al. (2002) analyzed the same data as Black et al. (2004b) to assess PTSD. A score of 50 or more on the PCL-M defined PTSD. PTSD-positive veterans had a mean score of 58.7, whereas those without PTSD had a mean score of 19.7; the prevalence of PTSD was 1.09%. The PTSD score was significantly associated with decreased functioning and quality of life, as well as increased reporting of symptoms and medical conditions.