Jeffrey L. Thomas

Mild Traumatic Brain Injury in U.S. Soldiers Returning from Iraq

BACKGROUND An important medical concern of the Iraq war is the potential long-term effect of mild traumatic brain injury, or concussion, particularly from blast explosions. However, the epidemiology of combat-related mild traumatic brain injury is poorly understood. METHODS We surveyed 2525 U.S. Army infantry soldiers 3 to 4 months after their return from a year-long deployment to Iraq. Validated clinical instruments were used to compare soldiers reporting mild traumatic brain injury, defined as an injury with loss of consciousness or altered mental status (e.g., dazed or confused), with soldiers who reported other injuries. RESULTS Of 2525 soldiers, 124 (4.9%) reported injuries with loss of consciousness, 260 (10.3%) reported injuries with altered mental status, and 435 (17.2%) reported other injuries during deployment. Of those reporting loss of consciousness, 43.9% met criteria for post-traumatic stress disorder (PTSD), as compared with 27.3% of those reporting altered mental status, 16.2% with other injuries, and 9.1% with no injury. Soldiers with mild traumatic brain injury, primarily those who had loss of consciousness, were significantly more likely to report poor general health, missed workdays, medical visits, and a high number of somatic and postconcussive symptoms than were soldiers with other injuries. However, after adjustment for PTSD and depression, mild traumatic brain injury was no longer significantly associated with these physical health outcomes or symptoms, except for headache. CONCLUSIONS Mild traumatic brain injury (i.e., concussion) occurring among soldiers deployed in Iraq is strongly associated with PTSD and physical health problems 3 to 4 months after the soldiers return home. PTSD and depression are important mediators of the relationship between mild traumatic brain injury and physical health problems.

Prevalence of Mental Health Problems and Functional Impairment Among Active Component and National Guard Soldiers 3 and 12 Months Following Combat in Iraq

CONTEXT A growing body of literature has demonstrated the association of combat in Iraq and Afghanistan with postdeployment mental health problems, particularly posttraumatic stress disorder (PTSD) and depression. However, studies have shown varying prevalence rates of these disorders based on different case definitions and have not assessed functional impairment, alcohol misuse, or aggressive behavior as comorbid factors occurring with PTSD and depression. OBJECTIVES To (1) examine the prevalence rates of depression and PTSD using several case definitions including functional impairment, (2) determine the comorbidity of alcohol misuse or aggressive behaviors with depression or PTSD, and (3) compare rates between Active Component and National Guard soldiers at the 3- and 12-month time points following their deployment to Iraq. DESIGN Population-based, cross-sectional study. SETTING United States Army posts and National Guard armories. PARTICIPANTS A total of 18 305 US Army soldiers from 4 Active Component and 2 National Guard infantry brigade combat teams. INTERVENTIONS Between 2004 and 2007, anonymous mental health surveys were collected at 3 and 12 months following deployment. MAIN OUTCOME MEASURES Current PTSD, depression, functional impairment, alcohol misuse, and aggressive behavior. RESULTS Prevalence rates for PTSD or depression with serious functional impairment ranged between 8.5% and 14.0%, with some impairment between 23.2% and 31.1%. Alcohol misuse or aggressive behavior comorbidity was present in approximately half of the cases. Rates remained stable for the Active Component soldiers but increased across all case definitions from the 3- to 12-month time point for National Guard soldiers. CONCLUSIONS The prevalence rates of PTSD and depression after returning from combat ranged from 9% to 31% depending on the level of functional impairment reported. The high comorbidity with alcohol misuse and aggression highlights the need for comprehensive postdeployment screening. Persistent or increased prevalence rates at 12 months compared with 3 months postdeployment illustrate the persistent effects of war zone service and provide important data to guide postdeployment care.

Post-combat invincibility : Violent combat experiences are associated with increased risk-taking propensity following deployment

Combat exposure is associated with increased rates of mental health problems such as post-traumatic stress disorder, depression, and anxiety when Soldiers return home. Another important health consequence of combat exposure involves the potential for increased risk-taking propensity and unsafe behavior among returning service members. Survey responses regarding 37 different combat experiences were collected from 1252 US Army Soldiers immediately upon return home from combat deployment during Operation Iraqi Freedom. A second survey that included the Evaluation of Risks Scale (EVAR) and questions about recent risky behavior was administered to these same Soldiers 3 months after the initial post-deployment survey. Combat experiences were reduced to seven factors using principal components analysis and used to predict post-deployment risk-propensity scores. Although effect sizes were small, specific combat experiences, including greater exposure to violent combat, killing another person, and contact with high levels of human trauma, were predictive of greater risk-taking propensity after homecoming. Greater exposure to these combat experiences was also predictive of actual risk-related behaviors in the preceding month, including more frequent and greater quantities of alcohol use and increased verbal and physical aggression toward others. Exposure to violent combat, human trauma, and having direct responsibility for taking the life of another person may alter an individuals perceived threshold of invincibility and slightly increase the propensity to engage in risky behavior upon returning home after wartime deployment. Findings highlight the importance of education and counseling for returning service members to mitigate the public health consequences of elevated risk-propensity associated with combat exposure.

Relationship of combat experiences to alcohol misuse among U.S. soldiers returning from the Iraq war

OBJECTIVE Studies have shown a relationship between combat experiences and alcohol misuse in military personnel; it is not known if there are specific combat experiences that confer a greater risk. The current study examined the association of specific types of combat experiences with a positive screen for alcohol misuse. METHODS 1120 U.S. soldiers who were members of brigade combat infantry teams were surveyed anonymously 3-4 months after returning from deployment to Iraq regarding their experiences in combat and their physical and mental health. Combat items were independently rated and placed into the following categories: (1) Fighting; (2) Killing; (3) Threat to oneself; (4) Death/injury of others; (5) Atrocities; and, (6) Positive experiences. Alcohol misuse was measured using a 2-item alcohol screen combined with alcohol-related behavioral items. RESULTS Of the soldiers sampled, 25% (N=275) screened positive for alcohol misuse 3-4 months post-deployment; 12% (N=125) screened positive and exhibited alcohol-related behavioral problems. Most combat exposure factors were significantly related to alcohol misuse individually. When factors were analyzed simultaneously, soldiers who had higher rates of exposure to the threat of death/injury were significantly more likely to screen positive for alcohol misuse; exposure to atrocities predicted misuse of alcohol with alcohol-related behavioral problems. CONCLUSIONS High exposure to threatening situations and atrocities was associated with a positive screen for alcohol misuse. Clinicians treating combat veterans should be aware of the potential association of alcohol misuse with specific types of experiences and closely follow those soldiers upon their return home.

Timing of postcombat mental health assessments.

509 Army Soldiers (who had returned within the previous week from a 12-month deployment to Iraq) participated in a study to examine changes in psychological symptoms between homecoming and 120 days later. Rates of psychological symptoms were significantly higher at 120 days postdeployment than at immediate reintegration largely due to an increase in Soldiers who were initially nonsymptomatic but became symptomatic later.

Mild traumatic brain injury (concussion) during combat: lack of association of blast mechanism with persistent postconcussive symptoms.

ObjectiveTo determine whether screening for a blast mechanism of concussion identifies individuals at higher risk of persistent postconcussive symptoms (PCS). SettingUnited States Army post. Participants3952 US Army infantry soldiers were administered anonymous surveys 3 to 6 months after returning from a yearlong deployment to Iraq. Main Outcome MeasuresSelf-reported concussion (defined as an injury that resulted in being “dazed, confused, or ‘seeing stars’”; “not remembering the injury”; or “losing consciousness [knocked out]): Patient Health Questionnaire 15-item scale for physical symptoms and PCS; Posttraumatic Stress Disorder Checklist; and Patient Health Questionnaire depression module. ResultsOf the 587 soldiers (14.9% of the total sample) who met criteria for concussion, 201 (34.2%) reported loss of consciousness, and 373 (63.5%) reported only an alteration of consciousness without loss of consciousness; 424 (72.2%) reported a blast mechanism, and 150 (25.6%) reported a nonblast mechanism. Among soldiers who lost consciousness, blast mechanism was significantly associated with headaches and tinnitus 3 to 6 months postdeployment compared with a nonblast mechanism. However, among the larger group of soldiers reporting concussions without loss of consciousness, blast was not associated with adverse health outcomes. ConclusionsBlast mechanism of concussion was inconsistently associated with PCS, depending on the definition of concussion utilized. A self-reported history of blast mechanism was not associated with persistent PCS for the majority of US soldiers with concussions.

Posttraumatic stress disorder associated with combat service in Iraq or Afghanistan: reconciling prevalence differences between studies.

Abstract Studies of posttraumatic stress disorder (PTSD) prevalence associated with deployment to Iraq or Afghanistan report wide variability, making interpretation and projection for research and public health purposes difficult. This article placed this literature within a military context. Studies were categorized according to deployment time-frame, screening case definition, and study group (operational infantry units exposed to direct combat versus population samples with a high proportion of support personnel). Precision weighted averages were calculated using a fixed-effects meta-analysis. Using a specific case definition, the weighted postdeployment PTSD prevalence was 5.5% (95% CI, 5.4–5.6) in population samples and 13.2% (12.8–13.7) in operational infantry units. Both population-level and unit-specific studies provided valuable and unique information for public health purposes; understanding the military context is essential for interpreting prevalence studies.

Unit-Level OCB and Unit Effectiveness: Examining the Incremental Effect of Helping Behavior

Recent research has begun to address the study of OCB at the unit level of analysis (Ehrhart, 2004; Ehrhart & Naumann, 2004; Podsakoff & MacKenzie, 1997; Schnake & Dumler, 2003) and to establish the impact of unit-level organizational citizenship behavior (OCB) on unit outcomes (e.g., Koys, 2001; Podsakoff, Ahearne, & MacKenzie, 1997; Walz & Niehoff, 2000). In this study, we examined outcomes that have not been considered in past unit-level OCB research and tested for the incremental contribution of one type of unit-level OCB in predicting these outcomes beyond the effects of other important group processes. Specifically, we tested the relationship between unit-level helping behavior and four indicators of military unit effectiveness, and the incremental contribution of helping behavior beyond cohesion, conflict, and leader effectiveness. Data from 31 military units supported the hypothesis that unit-level helping behavior is related to unit effectiveness, and for three of the outcomes, that unit-level helping behavior explains incremental variance beyond other group process variables.

A group randomized trial of critical incident stress debriefing provided to U.S. peacekeepers

In a group randomized trial of critical incident stress debriefing (CISD) with platoons of 952 peacekeepers, CISD was compared with a stress management class (SMC) and survey-only (SO) condition. Multilevel growth curve modeling found that CISD did not differentially hasten recovery compared to the other two conditions. For those soldiers reporting the highest degree of exposure to mission stressors, CISD was minimally associated with lower reports of posttraumatic stress and aggression (vs. SMC), higher perceived organizational support (vs. SO), and more alcohol problems than SMC and SO. Soldiers reported that they liked CISD more than the SMC, and CISD did not cause undue distress.

Mental health outcomes in US and UK military personnel returning from Iraq

BACKGROUND Research of military personnel who deployed to the conflicts in Iraq or Afghanistan has suggested that there are differences in mental health outcomes between UK and US military personnel. AIMS To compare the prevalence of post-traumatic stress disorder (PTSD), hazardous alcohol consumption, aggressive behaviour and multiple physical symptoms in US and UK military personnel deployed to Iraq. METHOD Data were from one US (n = 1560) and one UK (n = 313) study of post-deployment military health of army personnel who had deployed to Iraq during 2007-2008. Analyses were stratified by high- and low-combat exposure. RESULTS Significant differences in combat exposure and sociodemographics were observed between US and UK personnel; controlling for these variables accounted for the difference in prevalence of PTSD, but not in the total symptom level scores. Levels of hazardous alcohol consumption (low-combat exposure: odds ratio (OR) = 0.13, 95% CI 0.07-0.21; high-combat exposure: OR = 0.23, 95% CI 0.14-0.39) and aggression (low-combat exposure: OR = 0.36, 95% CI 0.19-0.68) were significantly lower in US compared with UK personnel. There was no difference in multiple physical symptoms. CONCLUSIONS Differences in self-reported combat exposures explain most of the differences in reported prevalence of PTSD. Adjusting for self-reported combat exposures and sociodemographics did not explain differences in hazardous alcohol consumption or aggression.