nondeployed veterans, all from Kansas. Deployed veterans reported not feeling rested after sleep and problems in falling or staying asleep significantly more often than nondeployed veterans (OR 2.69, 95% CI 2.04-3.54 and OR 2.98, 95% CI 2.18-4.08, respectively).
A similar pattern was observed among Gulf War veterans from other countries. Unwin et al. (1999) conducted a cross-sectional mailed survey of a random sample of UK veterans: 3284 Gulf War-deployed, 1815 deployed to the Bosnia conflict, and 2408 era veterans. The Gulf War veterans reported a higher frequency of sleeping difficulties than the Bosnia cohort (OR 1.7, 95% CI 1.5-2.0) or the era cohort (OR 1.9, 95% CI 1.7-2.2) adjusted for age, smoking, alcohol consumption, marital status, educational attainment, rank, employment status, civilian or military status on followup, and score on a general health questionnaire. More UK veterans deployed to the Gulf War than nondeployed veterans reported waking up feeling tired and worn out, losing sleep because of worry, and having nightmares (Cherry et al. 2001a). Australian Gulf War veterans also reported more sleep problems than their nondeployed counterparts (Kelsall et al. 2004a). The most frequently reported symptom among the deployed veterans was feeling unrefreshed after sleep (OR 1.7, 95% CI 1.4-2.1). More deployed veterans also reported sleep difficulties (OR 1.8, 95% CI 1.5-2.2). ORs were adjusted for service type, rank, age, education, and marital status. Ishoy et al. (1999) compared the frequency of self-reported sleep difficulties in Danish veterans who had been deployed to the Persian Gulf during 1990-1997 as peacekeepers and age- and sex-matched controls. They found a higher frequency of sleep problems in the deployed subjects. For example, 19.4% of the deployed and 9.1% of the nondeployed controls reported problems in falling asleep.
Because difficulty in falling asleep or staying asleep and nightmares are two of the diagnostic criteria for PTSD, it is difficult to distinguish between PTSD and comorbid psychiatric disorders, such as MDD and GAD, many of which are also characterized by sleep disturbances. Nevertheless, several studies have looked at sleep disturbances in veterans with and without PTSD. Using questionnaire data from the NVVRS, Neylan et al. (1998) obtained self-reported information on five items in the Mississippi Scale for Combat-Related PTSD that assess sleep. Three domains of sleep were addressed: difficulties in sleep onset, nightmares, and sleep maintenance disturbance. Subjects were asked about the frequency with which the sleep problems occurred. Vietnam-theater veterans who met the case definition of PTSD at the time of the survey reported more disturbances in all three domains. For example, difficulties in falling asleep at least sometimes were reported by 44.0% of combat veterans with PTSD, 5.5% of combat veterans without PTSD, 9.4% of era veterans, and 5.0% of civilian comparison subjects (p < 0.0001). Difficulties in staying asleep occurred in 90.7% of combat veterans with PTSD, 62.5% of combat veterans without PTSD, and 63.1% of era veterans (p < 0.0001). Nightmares were reported by 52.4% of the combat veterans with PTSD, 4.8% of those without PTSD, and 5.7% of era veterans. Frequent or very frequent nightmares and difficulties in falling asleep were reported only by subjects with PTSD. Using hierarchic multiple regression, the investigators found that 48% of the variance in frequency of nightmares was accounted for by non-sleep-related PTSD symptoms. Combat exposure accounted for an additional 9% of the variance for nightmares. The weighted Pearson correlation of combat exposure and nightmares was 0.63 (p < 0.001). Limitations of this study include its retrospective assessment of combat exposure and that sleep measures were subjective and not standardized.