Unit cohesion during deployment and post-deployment mental health: is cohesion an individual- or unit-level buffer for combat-exposed soldiers?

BACKGROUND: Unit cohesion may protect service member mental health by mitigating effects of combat exposure; however, questions remain about the origins of potential stress-buffering effects. We examined buffering effects associated with two forms of unit cohesion (peer-oriented horizontal cohesion and subordinate-leader vertical cohesion) defined as either individual-level or aggregated unit-level variables. METHODS: Longitudinal survey data from US Army soldiers who deployed to Afghanistan in 2012 were analyzed using mixed-effects regression. Models evaluated individual- and unit-level interaction effects of combat exposure and cohesion during deployment on symptoms of post-traumatic stress disorder (PTSD), depression, and suicidal ideation reported at 3 months post-deployment (model n's = 6684 to 6826). Given the small effective sample size (k = 89), the significance of unit-level interactions was evaluated at a 90% confidence level. RESULTS: At the individual-level, buffering effects of horizontal cohesion were found for PTSD symptoms [B = -0.11, 95% CI (-0.18 to -0.04), p < 0.01] and depressive symptoms [B = -0.06, 95% CI (-0.10 to -0.01), p < 0.05]; while a buffering effect of vertical cohesion was observed for PTSD symptoms only [B = -0.03, 95% CI (-0.06 to -0.0001), p < 0.05]. At the unit-level, buffering effects of horizontal (but not vertical) cohesion were observed for PTSD symptoms [B = -0.91, 90% CI (-1.70 to -0.11), p = 0.06], depressive symptoms [B = -0.83, 90% CI (-1.24 to -0.41), p < 0.01], and suicidal ideation [B = -0.32, 90% CI (-0.62 to -0.01), p = 0.08]. CONCLUSIONS: Policies and interventions that enhance horizontal cohesion may protect combat-exposed units against post-deployment mental health problems. Efforts to support individual soldiers who report low levels of horizontal or vertical cohesion may also yield mental health benefits.

Risk for suicidal behaviors associated with alcohol and energy drink use in the US Army.

PURPOSE: Suicidal behaviors have increased in the US Army since 2005. To identify potential interventions for suicide risk, we examined the relationship between alcohol and energy drink use, independently and in combination, and rates of seriously considering and/or attempting suicide in US Army soldiers. METHODS: This study used the DoD Survey of Health Related Behaviors Among Active Duty Military Personnel (DoD HRB), which sampled 10,400 Army soldiers, with 5,927 responses representing 508,088 soldiers. Use of energy drinks in combination with alcohol (A/ED) and average daily amount of alcohol consumption over the past 30 days and history of seriously considering and/or attempting suicide in the past year were assessed via self-report questions. RESULTS: Six percent of Army service members reported either seriously considering and/or attempting suicide in the past year. Twenty-six percent of soldiers reported A/ED. Those who reported the highest level of alcohol use were more likely to have seriously considered and/or attempted suicide. Soldiers who reported daily A/ED were over three times more likely to have reported suicidal ideation or attempts, and even after adjusting for overall alcohol consumption and energy drink use alone remained approximately two times (OR = 1.99) more likely to report suicidality. CONCLUSIONS: Combination alcohol and energy drink use and heavy alcohol use contribute to suicidality and may be targets for potential intervention to address suicide risk.

Factor analysis of the Drinking Motives Questionnaire in a young adult U.S. Army sample.

Reasons for alcohol consumption are often conceptualized as deriving from internal and external sources and positive and negative reinforcement. The revised Drinking Motives Questionnaire (DMQ-R) was developed to classify reasons or motives for alcohol use which are associated with different drinking patterns. The factor structure of a subset of DMQ-R items was examined using exploratory factor analysis on a U.S. Army sample, to assess whether the DMQ-R subscales represent drinking motives typically identified by military service members. This study used the Department of Defense Survey of Health Related Behaviors Among Active Duty Military Personnel, which sampled 10,400 Army soldiers. A total of 4,475 responses were included in the analysis, which corresponded with a weighted sample of 391,185 soldiers. Principal-axis factor analysis with promax rotation identified two factors representing pleasure-seeking/enjoyment and avoiding rejection/"fitting in." These factors may be useful in investigating relationships between drinking motives and alcohol use patterns within the U.S. Army population.

Association of Firearm Ownership, Use, Accessibility, and Storage Practices With Suicide Risk Among US Army Soldiers.

Importance: Since 2004, the suicide rate among US Army soldiers has exceeded the rate of death from combat injury. It is critical to establish factors that increase the risk of acting on suicidal thoughts to guide early intervention and suicide prevention. Objective: To assess whether firearm ownership, use, storage practices, and accessibility are associated with increased risk of suicide. Design, Setting, and Participants: In this case-control study, suicide cases (n = 135) were defined as US Army soldiers who died by suicide while on active duty between August 1, 2011, and November 1, 2013. Next-of-kin and Army supervisors of soldiers who died by suicide (n = 168) were compared with propensity-matched controls (n = 137); those soldiers with a suicidal ideation in the past year (n = 118) provided structured interview data. Data were analyzed from April 5, 2018, to April 2, 2019. Main Outcomes and Measures: Firearm ownership, storage, and accessibility were assessed by using items from the World Health Organization Composite International Diagnostic Interview screening scales along with items created for the purpose of the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) study. Results: Among the 135 suicide decedents, next-of-kin reported that they had greater accessibility to firearms compared with propensity-matched controls. Specifically, suicide decedents were more likely to own 1 or more handguns compared with propensity-matched controls (odds ratio [OR], 1.9; 95% CI, 1.0-3.7; χ21 = 4.2; false discovery rate [FDR] P = .08), store a loaded gun at home (OR, 4.1; 95% CI, 1.9-9.1; χ21 = 12.2; FDR P = .003), and publicly carry a gun when not required for military duty (OR, 3.2; 95% CI, 1.4-7.3; χ21 = 7.4; FDR P = .02). The combination of these 3 items was associated with a 3-fold increase in the odds of suicide death (OR, 3.4; 95% CI, 1.2-9.4; χ21 = 5.4; FDR P = .05). Storing a loaded gun with ammunition at home or publicly carrying a gun when not on duty was associated with a 4-fold increase in the odds of suicide death (OR, 3.9; 95% CI, 1.9-7.9; χ21 = 14.1; FDR P = .002). Conclusions and Relevance: In this study, in addition to gun ownership, ease and immediacy of firearm access were associated with increased suicide risk. Discussion with family members and supervisors about limiting firearm accessibility should be evaluated for potential intervention.

Association between leukocyte telomere length and hostility in US army service members.

Hostility is a common form of emotionally charged anger which can lead to maladaptive and unhealthy behaviors. Significant association between shortened telomeres and greater levels of hostility has been observed in civilian populations, but has not yet been comprehensively studied in military populations. Our study investigates the relationship between hostility, post-traumatic stress disorder (PTSD), and leukocyte telomere length (LTL) in a sample of United States Army Special Operations personnel (n = 474) who deployed to Iraq and/or Afghanistan as part of combat operations. Hostility was measured with five items from the Brief Symptom Inventory (BSI). PTSD was determined using the PTSD Checklist (PCL) total score. The LTL was assessed using quantitative polymerase chain reaction methods and regression analyses were conducted to determine the association of hostility and telomere length. PTSD subjects reported higher hostility scores compared with those without PTSD. Among the participants with PTSD, those with medium or high level of hostility had shorter LTL than those with low level hostility (P < 0.01). Stepwise regression indicated that hostility level and age, but not gender and PTSD, were negatively correlated with LTL. Univariate regression showed that total hostility score was negatively associated with LTL (CI= -0.06 to -0.002, Beta= -0.095, p < 0.039) as well as a significant correlation between LTL and hostility impulses (HI) (CI= -0.108 to -0.009, Beta= -0.106, p < 0.021) and hostility controlling (HC) (CI= -0.071 to -0.002, Beta= -0.095, p < 0.004). Multiple regression analyses revealed that, while HC has no significant association with LTL, HI was still negatively correlated with LTL (p = 0.021). Our data indicates that LTL is associated with HI levels. Prevention and treatment efforts designed to reduce hostility may help mitigate risk for LTL shortening, a process of cellular aging, and thus slow accelerated aged-related health outcomes.

Risk Factors Associated With Attempted Suicide Among US Army Soldiers Without a History of Mental Health Diagnosis.

Importance: The US Army suicide attempt rate increased sharply during the wars in Afghanistan and Iraq. Although soldiers with a prior mental health diagnosis (MH-Dx) are known to be at risk, little is known about risk among those with no history of diagnosis. Objective: To examine risk factors for suicide attempt among soldiers without a previous MH-Dx. Design, Setting, and Participants: In this retrospective longitudinal cohort study using administrative data from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS), person-month records were identified for all active-duty Regular Army enlisted soldiers who had a medically documented suicide attempt from January 1, 2004, through December 31, 2009 (n = 9650), and an equal-probability sample of control person-months (n = 153 528). Data analysis in our study was from September 16, 2017, to June 6, 2018. In a stratified sample, it was examined whether risk factors for suicide attempt varied by history of MH-Dx. Main Outcomes and Measures: Suicide attempts were identified using Department of Defense Suicide Event Report records and International Classification of Diseases, Ninth Revision, Clinical Modification E95 × diagnostic codes. Mental health diagnoses and related codes, as well as sociodemographic, service-related, physical health care, injury, subjection to crime, crime perpetration, and family violence variables, were constructed from Army personnel, medical, legal, and family services records. Results: Among 9650 enlisted soldiers with a documented suicide attempt (74.8% male), 3507 (36.3%) did not have a previous MH-Dx. Among soldiers with no previous diagnosis, the highest adjusted odds of suicide attempt were for the following: female sex (odds ratio [OR], 2.6; 95% CI, 2.4-2.8), less than high school education (OR, 1.9; 95% CI, 1.8-2.0), first year of service (OR, 6.0; 95% CI, 4.7-7.7), previously deployed (OR, 2.4; 95% CI, 2.1-2.8), promotion delayed 2 months or less (OR, 2.1; 95% CI, 1.7-2.6), past-year demotion (OR, 1.6; 95% CI, 1.3-1.8), 8 or more outpatient physical health care visits in the past 2 months (OR, 3.3; 95% CI, 2.9-3.8), past-month injury-related outpatient (OR, 3.0; 95% CI, 2.8-3.3) and inpatient (OR, 3.8; 95% CI, 2.3-6.3) health care visits, previous combat injury (OR, 1.6; 95% CI, 1.0-2.4), subjection to minor violent crime (OR, 1.6; 95% CI, 1.1-2.4), major violent crime perpetration (OR, 2.0; 95% CI, 1.3-3.0), and family violence (OR, 2.9; 95% CI, 1.9-4.4). Most of these variables were also associated with suicide attempts among soldiers with a previous MH-Dx, although the strength of associations differed. Conclusions and Relevance: Suicide attempt risk among soldiers with unrecognized mental health problems is a significant and important challenge. Administrative records from personnel, medical, legal, and family services systems can assist in identifying soldiers at risk.

Associations of Time-Related Deployment Variables With Risk of Suicide Attempt Among Soldiers: Results From the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS).

Importance: There has been limited systematic examination of whether risk of suicide attempt (SA) among US Army soldiers is associated with time-related deployment variables, such as time in service before first deployment, duration of first deployment, and dwell time (DT) (ie, length of time between deployments). Objective: To examine the associations of time-related deployment variables with subsequent SA among soldiers who had deployed twice. Design, Setting, and Participants: Using administrative data from January 1, 2004, through December 31, 2009, this longitudinal, retrospective cohort study identified person-month records of active-duty Regular Army enlisted soldiers who had served continuously in the US Army for at least 2 years and deployed exactly twice. The dates of analysis were March 1 to December 1, 2017. There were 593 soldiers with a medically documented SA during or after their second deployment. An equal-probability sample of control person-months was selected from other soldiers with exactly 2 deployments (n = 19 034). Logistic regression analyses examined the associations of time in service before first deployment, duration of first deployment, and DT with subsequent SA. Main Outcomes and Measures: Suicide attempts during or after second deployment were identified using US Department of Defense Suicide Event Report records and International Classification of Diseases, Ninth Revision, Clinical Modification E950 to E958 diagnostic codes. Independent variables were constructed from US Army personnel records. Results: Among 593 SA cases, most were male (513 [86.5%]), white non-Hispanic (392 [66.1%]), at least high school educated (477 [80.4%]), currently married (398 [67.1%]), and younger than 21 years when they entered the US Army (384 [64.8%]). In multivariable models adjusting for sociodemographics, service-related characteristics, and previous mental health diagnosis, odds of SA during or after second deployment were higher among soldiers whose first deployment occurred within the first 12 months of service vs after 12 months (odds ratio, 2.0; 95% CI, 1.6-2.4) and among those with a DT of 6 months or less vs longer than 6 months (odds ratio, 1.6; 95% CI, 1.2-2.0). Duration of first deployment was not associated with subsequent SA. Analysis of 2-way interactions indicated that the associations of early deployment and DT with SA risk were not modified by other characteristics. Multivariable population-attributable risk proportions were 14.2% for deployment within the first 12 months of service and 4.0% for DT of 6 months or less. Conclusions and Relevance: Time in service before first deployment and DT are modifiable risk factors for SA risk among soldiers.

PTSD symptom severity and sensitivity to blood, injury, and mutilation in U.S. army special operations soldiers.

Sensitivity to blood, injury, and mutilation (SBIM) may increase risk for posttraumatic stress disorder (PTSD), given that traumatic events often involve actual or perceived threat of bodily harm to oneself and/or others, including exposure to blood and other mutilation-related stimuli. A self-report questionnaire was administered to male, active duty, U.S. Army Special Operations Command soldiers who had deployed to Iraq and Afghanistan (n =694 males). We first used exploratory factor analysis to examine whether the 30-item Mutilation Questionnaire (Klorman et al., 1974) comprised a unitary measure of SBIM, finding that 10 of the items form a cohesive SBIM factor. Summed, those 10 SBIM items had a significant bivariate correlation with PTSD symptom severity. In a multiple regression analysis that included demographic characteristics and lifetime trauma exposure, SBIM was positively associated with PTSD symptom severity. Other significant multivariate predictors were high lifetime trauma exposure and junior enlisted rank. When trait neuroticism was added to the model to test the robustness of these findings, the association of SBIM with PTSD symptom severity remained significant. The results suggest that SBIM may be a risk factor for PTSD in male soldiers. Further research is warranted to improve measurement and understanding of SBIM.

Alcohol Use and Reasons for Drinking as Risk Factors for Suicidal Behavior in the U.S. Army.

OBJECTIVE: High levels of alcohol use and alcohol-related problems are associated with suicidal behaviors (i.e., seriously considering and/or attempting suicide) in military and civilian populations. Examination of reasons for drinking alcohol may identify subgroups of soldiers who may either be at risk for suicidal behaviors or resilient to suicidality. METHOD: We examined the associations among reasons for drinking, level of alcohol use, and past year suicidality in 3,813 U.S. Army soldiers using the Department of Defense Survey of Health-Related Behaviors among Active Duty Military Personnel. RESULTS: Six percent of soldiers reported suicidal thoughts and behaviors within the past year. Those who reported the highest level of alcohol use were more likely to have seriously considered and/or attempted suicide. Drinking to avoid rejection/"fit in" was associated with suicidality, even after adjusting for level of alcohol consumption, post-traumatic stress disorder, and depression. Although unadjusted analyses revealed a relation of pleasure-seeking drinking motives to suicidality, this association did not remain significant after controlling for covariates. CONCLUSIONS: Drinking to avoid rejection/"fit in" is associated with suicidality above overall alcohol consumption. Screening for this reason for drinking may be useful for suicide prediction and prevention.

Risk for suicidal behaviors associated with PTSD, depression, and their comorbidity in the U.S. Army.

BACKGROUND: Suicide rates have risen considerably in the United States Army in the past decade. Suicide risk is highest among those with past suicidality (suicidal ideation or attempts). The incidence of posttraumatic stress disorder (PTSD) and depressive illnesses has risen concurrently in the U.S. Army. We examined the relationship of PTSD and depression, independently and in combination, and rates of past-year suicidality in a representative sample of U.S. Army soldiers. METHODS: This study used the DoD Survey of Health Related Behaviors Among Active Duty Military Personnel (DoD HRB) (N=5927). Probable PTSD and depression were assessed with the PTSD Checklist (PCL) and the 10-item short form of the Center for Epidemiologic Studies Depression Scale (CES-D), respectively. Past-year suicidality was assessed via self-report. RESULTS: Six percent of Army service members reported suicidality within the past year. PTSD and MDD were each independently associated with past-year suicidality. Soldiers with both disorders were almost three times more likely to report suicidality within the past year than those with either diagnosis alone. Population-attributable risk proportions for PTSD, depression, and both disorders together were 24%, 29%, and 45%, respectively. LIMITATIONS: The current study is subject to the limitations of a cross-sectional survey design and the self-report nature of the instruments used. CONCLUSIONS: PTSD and depression are each associated with suicidality independently and in combination in the active duty component of the U.S. Army. Soldiers presenting with either but especially both disorders may require additional outreach and screening to decrease suicidal ideation and attempts.

Total blood mercury levels and depression among adults in the United States: National Health and Nutrition Examination Survey 2005-2008.

BACKGROUND: Mercury is a neurotoxicant linked with psychiatric symptoms at high levels of exposure. However, it is unclear whether an association is present at the low exposure levels in the US adult population. MATERIALS AND METHODS: Cross-sectional associations of total blood mercury and depression were assessed in 6,911 adults age ≥20 in the National Health and Nutrition Examination Survey (NHANES), 2005-2008. The Patient Health Questionnaire-9 was used to assess depression (high likelihood of a depressive spectrum disorder diagnosis; score 5-27). RESULTS: Unadjusted survey weighted logistic regression suggested that higher total blood mercury was associated with lower odds of depression (Odds Ratio  = 0.49, 95% Confidence Interval: 0.36-0.65, comparing the highest and lowest mercury quintiles). This association largely disappeared after adjustment for sociodemographic variables (income-poverty ratio, education, marital status). However, in age-stratified analyses, this inverse relationship remained in older adults (age ≥40) even after adjustment for sociodemographic variables. Simulation analyses adjusting for expected confounding effects of fish intake suggested that the inverse relationship among older adults may be plausibly attributed to residual confounding (Odds Ratio  = 0.75, 95% Confidence Interval: 0.50-1.12, comparing the highest and lowest mercury quintiles). CONCLUSIONS: Higher total blood mercury was not associated with increased odds of depression. The lower odds of depression in older adults with higher total blood mercury may be due to residual confounding.