disorder, mostly depressive and anxiety disorders; and this comorbidity was associated with significant impairment of health-related quality of life in this population of veterans.
O’Toole et al. (1996a) studied a random sample of 641 Australian Army Vietnam veterans using a battery of self-reporting instruments to assess psychologic status. Vietnam-related PTSD was assessed by the PTSD module of the SCID and the DIS. The most prevalent lifetime psychiatric conditions in Australian Vietnam veterans were alcohol abuse or dependence (42.6%), PTSD (18.7%), somatoform pain disorder (16.5%), social phobias (14.8%), and simple phobias (10.2%); somatoform pain disorder emerged as one of the most prevalent and enduring disorders. The most prevalent 6-month psychiatric conditions were also alcohol abuse or dependence (20.1%), somatoform pain disorder (12.6%), social phobias (11.3%), and simple phobias (7.8%); PTSD was not diagnosed. Furthermore, PTSD, alcohol abuse or dependence, and phobias were all related to combat exposure (a combat self-report scale was contained in the SCID) but not to being posted to a combat unit. The risk of a diagnosis of each of those and other psychiatric disorders increased with increasing combat exposure. When the prevalence of lifetime or current PTSD was compared with responses to a 21-item combat index, there was a linear dose-response relationship with increasing combat exposure. The OR for each combat-score quartile for lifetime PTSD was 1.00, 3.03, 5.36, and 9.18; for current PTSD, the ORs were 1.00, 2.11, 6.97, and 10.33 for each quartile increase in combat exposure. For lifetime alcohol abuse or dependence, the ORs were 1.00, 1.07, 1.56, and 1.86 (p = 0.002); for GAD, the ORs were 1.00, 0.91, 1.81, and 3.14 (p = 0.003); for social phobia, the ORs were 1.00, 1.24, 1.80, and 2.18 (p = 0.012); for panic disorder, the ORs were 1.00, 3.20, 3.27, and 10.10 (p = 0.001); and for dysthemia, the ORs were 1.00, 0.98, 1.67, and 2.58 (p = 0.009).
A number of secondary studies were cross-sectional surveys of diverse populations of veterans, including two of veterans returning from deployments to OEF and OIF (Hoge et al. 2004, 2006). In January 2003, Hoge et al. (2004) surveyed 2530 soldiers from one Army infantry brigade for mental-health problems before a year-long deployment to Iraq. In 2003, they also surveyed 1962 soldiers returning from a 6-month deployment in Afghanistan, 894 soldiers returning from an 8-month deployment to Iraq, and 815 Marines returning from a 6-month deployment to Iraq; the second group of soldiers and the Marines had been in the forefront of ground-combat operations in Iraq. PTSD was assessed with the 17-item PTSD Checklist from VA; MDD and GAD were assessed with a questionnaire that included questions about functional impairment. Compared with the prevalence of mental-health problems in the Army group before deployment, MDD was significantly increased in the Army groups after deployment to Afghanistan (OR 1.33, 95% CI 1.03-1.71, p < 0.05) or to Iraq (OR 1.53, 95% CI 1.12-2.08, p < 0.01), but not in the Marines. PTSD was not significantly increased in the soldiers deployed to Afghanistan but was in those deployed to Iraq (OR 2.84, 95% CI 2.17-3.72, p < 0.01) and in the Marines (OR 2.66, 95% CI 2.01-3.51, p < 0.01). GAD was not increased in any of the groups after deployment. This study is limited because different groups of soldiers were surveyed before and after deployment, no Marines were surveyed before deployment, and the mental-health assessments were based on screening instruments.
Similar results were seen in a later study by Hoge et al. (2006), who surveyed 303,905 Army soldiers and Marines returning from deployments mainly in Iraq and Afghanistan. All returning veterans were required to complete a brief postdeployment health assessment (PDHA). The PDHA includes two questions for depression modified from the two-item patient health questionnaire and the four-item screen for PTSD developed by the National Center for PTSD, both of which are intended for use in primary care settings; and four questions related to suicide,