Findings on many other major cohorts of Gulf War veterans support what has been found in primary studies (Gray et al., 2002; McCauley et al., 2002). The most important limitation was their reliance on self-reports of “physician-diagnosed disorders” rather than measurement of symptoms with validated questionnaires or face-to-face interviews. In the UK cohort studied by Unwin et al. (1999), investigators asked some questions taken from the Mississippi Scale for Combat-Related PTSD but did not administer the entire questionnaire. They found that some symptoms were about 2-3 times more likely in deployed than in two nondeployed groups. The magnitude of the increase is consistent with that seen in the primary studies. Several other secondary studies have found an association between serving in the Gulf War and psychiatric disorders (Holmes et al., 1998; Magruder et al., 2005; Simmons et al., 2004; Steele, 2000; Stretch et al., 1996a,b; Sutker et al., 1995).
Goss Gilroy (1998) assessed all 3113 Canadian Gulf War veterans deployed to the war zone and a comparison group of nondeployed veterans with a mail questionnaire. Using the PCL-M, the investigators found that symptoms of PTSD were 2.5 times more prevalent in the deployed than in the nondeployed veterans (OR 2.69, 95% CI 1.7-4.2). Using the PRIME-MD, the investigators found that the deployed had higher prevalences of major depression (OR 3.67, 95% CI 3.0-4.4), chronic dysphoria, and anxiety. Anxiety and depression were more severe in lower-income veterans.
The studies of psychological outcomes in Australian Gulf War veterans were distinguished by inclusion of the entire deployed population (unclear what is meant by “direct assessment”). The instruments described below are self-administered screening questionnaires. McKenzie et al. (2004) used the SF-12, the PCL-M, and the GHQ-12 (12-item version of the General Health Questionnaire) to assess 1424 male Gulf War veterans (86.5% Navy) and 1548 male Australian Defence Force members who were not deployed to the Gulf War. On those self-rating instruments, the Gulf War-deployed had overall poorer psychological health (OR 1.4, 95% CI 1.2-1.6) and more PTSD-like symptoms (OR 2.0, 95% CI 1.5-2.9) than control veterans. The psychological distress increased with age in the comparison group but decreased with age in the Gulf War veterans (that is, the youngest Gulf War veterans had the worst psychological ill health). Moreover, the perceived level of exposure to war stress was associated with both psychological ill health and PTSD-like symptoms, although very few experienced direct combat.
The Update committee identified four new primary studies (Fiedler et al., 2006; Ismail et al., 2002; Kang et al., 2009; Toomey et al., 2007) and five new secondary studies (Al-Turkait and Ohaeri, 2008; Axelrod et al., 2005; Black et al., 2006; Kang et al., 2005; Rona et al., 2007).
Using a standardized clinician interview, Ismail and colleagues (2002) assessed mental health of random samples of UK Gulf War veterans who reported disability (n = 111) and those who did not (n = 98) and compared them to random samples of era veterans and Bosnia veterans reporting disability (n = 54 and 79, respectively). Individuals who had a known disease or serious medical condition were excluded from the study. One-month prevalences of DSM-IV disorders were assessed using the WHO schedule of clinical assessment in neuropsychiatry, a clinician-administered interview on which they achieved good inter-rater reliability. This is the