July 2010
Reviewer: Jeff C. Huffman, MD
Prevalence of mental health problems and functional impairment among active component and National Guard soldiers 3 and 12 months following combat in Iraq
Thomas JL, Wilk JE, Riviere LA, McGurk D, Castro CA, Hoge CW
Arch Gen Psychiatry 2010; 67(6):614-623
Background: The prevalence of depression and post-traumatic stress disorder (PTSD) appear to be substantially elevated among returning veterans who served in active duty in Iraq. However, prior studies widely varied in the definition of these conditions, functional impairment was not assessed, and important comorbidities (e.g., alcohol use) were not always addressed. This study aimed to address these limitations and more accurately assess the prevalence of clinically-significant PTSD and depression in this important cohort.
Methods: The authors collected anonymous surveys from returning active duty soldiers from Iraq, from both active component soldiers (who expect to go into combat) and National Guard soldiers (who may not have expected combat upon enlisting). Surveys were collected at 3 months and 12 months post-deployment. Survey measures included the PTSD checklist (PCL) and the Patient Health Questionnaire-9 (PHQ-9); for both measures, the authors used several different case definitions for PTSD and depression, which most often differed in the degree to which they required functional impairment. Other measures included a measure of alcohol misuse and aggressive behavior.
Results: In total, 18,305 (62%) of 29,460 possible soldiers in the surveyed units responded to survey questions (active: n=4933 at 3 months, 4024 at 12 months; National Guard: 2684 at 3 months, 1585 at 12 months). The soldiers had high rates of exposure to potentially traumatic events (e.g., ~88% being attacked or ambushed, ~45% handling or uncovering human remains, ~38% being responsible for death of an enemy combatant, ~27% having a buddy shot or hit who was near you, ~11% being responsible for the death of a noncombatant). Overall, approximately 11% of subjects met the most stringent criteria for PTSD or depression (requiring serious functional impairment) and one-quarter met criteria for PTSD or depression and had some associated functional impairment. Rates of PTSD/depression were higher at 12 months than at 3 months in all cases; this was especially true for National Guard soldiers, who had an approximately 50% increase in prevalence in these disorders by 12 months vs. 3 months. Alcohol misuse or aggressive behavior were comorbid with PTSD/depression in one-half of cases; aggressive behavior significantly increased by 12 months in the National Guard cohort.
Discussion: These results clearly underscore the high rates of PTSD and depression among soldiers undergoing ground combat operations in Iraq. The soldiers had high rates of difficult wartime experiences, and one-quarter met criteria for PTSD or depression—with at least some functional impairment—after returning home. Given that rates of these illnesses were not less (but in fact higher) at 12 months than at 3 months, it seems that despite serious attempts by the military to systematically assess soldiers upon return and to encourage treatment and increase access to care, it seems that most soldiers are not psychologically recovering by one year. National Guard soldiers in particular—who may have less access to care after 6 months for a variety of reasons—had substantially greater increases in PTSD/depression and aggression by 12 months.
This study did have some important limitations: the units surveyed were ground combat units—those most likely to experience serious and repeated combat during deployment—and may well have higher rates of psychiatric sequelae than other personnel. The surveys were self-report, anonymous, cross-sectional, and not completed by 38% of the units’ soldiers. Overall, however, the study was carefully designed, had a very large number of subjects, and the results—at least for ground combat units—seem accurate.
The implications in medical psychiatry are that we should be aware of the high prevalence and substantial persistence of PTSD and clinical depression in soldiers returning from Iraq, and that we should be assessing these patients for these disorders as a matter of course. It is also important to ask about comorbid alcohol use and about aggressive behaviors as part of—or separate from—these syndromes.