Major depression and depressive symptoms in Australian Gulf War veterans 20 years after the Gulf War

Prevalence of depression, anxiety and post-traumatic stress in war- and conflict-afflicted areas: A meta-analysis

BACKGROUND

With the rise of fragility, conflict and violence (FCV), understanding the prevalence and risk factors associated with mental disorders is beneficial to direct aid to vulnerable groups. To better understand mental disorders depending on the population and the timeframe, we performed a systematic review to investigate the aggregate prevalence of depression, anxiety and post-traumatic stress symptoms among both civilian and military population exposed to war.

METHODS

We used MEDLINE (PubMed), Web of Science, PsycINFO, and Embase to identify studies published from inception or 1-Jan, 1945 (whichever earlier), to 31-May, 2022, to reporting on the prevalence of depression, anxiety and post-traumatic stress symptoms using structured clinical interviews and validated questionnaires as well as variables known to be associated with prevalence to perform meta-regression. We then used random-effects bivariate meta-analysis models to estimate the aggregate prevalence rate.

RESULTS

The aggregate prevalence of depression, anxiety and post-traumatic stress during times of conflict or war were 28.9, 30.7, and 23.5%, respectively. Our results indicate a significant difference in the levels of depression and anxiety, but not post-traumatic stress, between the civilian group and the military group respectively (depression 34.7 vs 21.1%, p < 0.001; anxiety 38.6 vs 16.2%, p < 0.001; post-traumatic stress: 25.7 vs 21.3%, p = 0.256). The aggregate prevalence of depression during the wars was 38.7% (95% CI: 30.0-48.3, I ² = 98.1%), while the aggregate prevalence of depression post-wars was 29.1% (95% CI: 24.7-33.9, I ² = 99.2%). The aggregate prevalence of anxiety during the wars was 43.4% (95% CI: 27.5-60.7, I ² = 98.6%), while the aggregate prevalence of anxiety post-wars was 30.3% (95% CI: 24.5-36.9, I ² = 99.2%). The subgroup analysis showed significant difference in prevalence of depression, and anxiety between the civilians and military group (p < 0.001).

CONCLUSION

The aggregate prevalence of depression, anxiety and post-traumatic stress in populations experiencing FCV are 28.9, 30.7, and 23.5%, respectively. There is a significant difference in prevalence of depression and anxiety between civilians and the military personnels. Our results show that there is a significant difference in the prevalence of depression and anxiety among individuals in areas affected by FCV during the wars compared to after the wars. Overall, these results highlight that mental health in times of conflict is a public health issue that cannot be ignored, and that appropriate aid made available to at risk populations can reduce the prevalence of psychiatric symptoms during time of FCV.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=337486, Identifier 337486.

Course and Predictors of Major Depressive Disorder in the Canadian Armed Forces Members and Veterans Mental Health Follow-up Survey: Cours et Prédicteurs du Trouble de Dépression Majeure Dans l'Enquête de Suivi Sur la Santé Mentale Auprès Des Membres des Forces Armées Canadiennes et des ex-Militaires

OBJECTIVES

The present report is the first study of Canadian military personnel to use longitudinal survey data to identify factors that determine major depressive episodes (MDEs) over a period of 16 years.

METHODS

The study used data from the Canadian Armed Forces Members and Veterans Mental Health Follow-up Survey (CAFVMHS) collected in 2018 (n = 2,941, response rate 68.7%) and linked baseline data from the same participants that were collected in 2002 when they were Canadian Regular Force members. The study used structured interviews to identify 5 common Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition mental disorders and collected demographic data, as well as information about traumatic experiences, childhood adversities, work stress, and potential resilience factors. Respondents were divided into 4 possible MDE courses: No Disorder, Remitting, New Onset, and Persistent/Recurrent. Relative risk ratios (RRRs) from multinomial regression models were used to evaluate determinants of these outcomes.

RESULTS

A history of anxiety disorders and post-traumatic stress disorder (RRRs: 1.50 to 20.55), mental health service utilization (RRRs: 1.70 to 12.34), veteran status (RRRs: 1.64 to 2.15), deployment-associated traumatic events (RRRs: 1.71 to 2.27), sexual traumas (RRRs: 1.91 to 2.93), other traumas (RRRs: 1.67 to 2.64), childhood adversities (RRRs: 1.39 to 1.97), avoidance coping (RRRs 1.09 to 1.49), higher frequency of religious attendance (RRRs: 1.54 to 1.61), and work stress (RRRs: 1.05 to 1.10) were associated with MDE courses in most analyses. Problem-focused coping (RRRs: 0.73 to 0.91) and social support (RRRs: 0.95 to 0.98) were associated with protection against MDEs.

CONCLUSIONS

The time periods following deployment and trauma exposure and during the transition from active duty to veteran status are particularly relevant for vulnerability to depression in military members. Interventions that enhance problem-focused coping and social support may be protective against MDEs in military members.

Trajectories of depression in aging veterans and former prisoners-of-war: The role of social support and hardiness

OBJECTIVES

Depression is a prevalent outcome of traumatic experiences, such as combat and war captivity. This study explores the heterogeneity of changes over time and assesses the contribution of trauma exposure (combat vs. war captivity), hardiness, and social support for depression trajectories.

METHODS

Two groups of Israeli veterans were assessed in 1991, 2003, 2008, and 2015: 149 former prisoners-of-war (ex-POWs) and 107 combat veterans. Protective factors were evaluated in 1991. Group-based trajectory modeling was conducted to identify latent trajectories of change.

RESULTS

Four trajectories of "resiliency" (62.8%), "delayed onset" (25.1%), "exacerbation" (6.2%), and "chronicity" (5.9%) were found. The majority of the resilient group were combat veterans whereas the clinical groups consisted primarily of ex-POWs. Lower hardiness and social support were related to more deleterious trajectories.

CONCLUSIONS

Spirals of loss involving hardiness and social support, normative experiences, and contextual factors may present explanations for the various depression trajectories.

First-aid Training for Combatants Without Systematic Medical Education Experience on the Battlefield: Establishment and Evaluation of the Curriculum in China

INTRODUCTION

For combatants without systematic medical education experience (CSMEE), it is necessary to participate in first-aid on the battlefield, but currently there is no effective training curriculum for CSMEE in Chinese military.

MATERIALS AND METHODS

A list of first-aid techniques based on expert consensus was formed, and then a curriculum was established according to the list. The effectiveness of the curriculum was further evaluated by comparing the scores among group A (the reserve officers trained by this curriculum), group B (the reserve officers in the military medical college trained by professional medic training system), and group C (the fresh officers trained by the Outline of Military Training and Assessment of Chinese military), through a 5-station assessment in a simulated battlefield environment, which included the following 5 techniques: tourniquet for massive extremities hemorrhage, thyrocricocentesis, thoracentesis, fixation of long bone fractures, and wound dressing with hemostatic bandage.

RESULTS

The training curriculum entitled "Implementation and Assessment Standards of First-aid Training for Combatants on the Battlefield" was established. The comparison of average scores in the 5-station assessment showed that group A had better scores than group C in tourniquet for massive extremity hemorrhage, thyrocricocentesis, and thoracentesis, with no significant differences compared with group B. Also, no significant difference between groups A and B in overall completion time and overall scores was observed, whereas an excellent candidate rate in overall score of group B was better than that of group A (87.4% vs. 80.9%, χ2 = 4.40, p = 0.036), and group A was better than group C (80.9% vs. 37.5%, χ2 = 62.01, p < 0.001).

CONCLUSION

The established training curriculum is indeed effective, which improved the CSMEE's first-aid capacity on the battlefield, and is equivalent to the level of medics.

Obesity Worsens Gulf War Illness Symptom Persistence Pathology by Linking Altered Gut Microbiome Species to Long-Term Gastrointestinal, Hepatic, and Neuronal Inflammation in a Mouse Model

Persistence of Gulf War illness (GWI) pathology among deployed veterans is a clinical challenge even after almost three decades. Recent studies show a higher prevalence of obesity and metabolic disturbances among Gulf War veterans primarily due to the existence of post-traumatic stress disorder (PTSD), chronic fatigue, sedentary lifestyle, and consumption of a high-carbohydrate/high-fat diet. We test the hypothesis that obesity from a Western-style diet alters host gut microbial species and worsens gastrointestinal and neuroinflammatory symptom persistence. We used a 5 month Western diet feeding in mice that received prior Gulf War (GW) chemical exposure to mimic the home phase obese phenotype of the deployed GW veterans. The host microbial profile in the Western diet-fed GWI mice showed a significant decrease in butyrogenic and immune health-restoring bacteria. The altered microbiome was associated with increased levels of IL6 in the serum, Claudin-2, IL6, and IL1β in the distal intestine with concurrent inflammatory lesions in the liver and hyperinsulinemia. Microbial dysbiosis was also associated with frontal cortex levels of increased IL6 and IL1β, activated microglia, decreased levels of brain derived neurotrophic factor (BDNF), and higher accumulation of phosphorylated Tau, an indicator of neuroinflammation-led increased risk of cognitive deficiencies. Mechanistically, serum from Western diet-fed mice with GWI significantly increased microglial activation in transformed microglial cells, increased tyrosyl radicals, and secreted IL6. Collectively, the results suggest that an existing obese phenotype in GWI worsens persistent gastrointestinal and neuronal inflammation, which may contribute to poor outcomes in restoring cognitive function and resolving fatigue, leading to the deterioration of quality of life.

Changes in Health Status in the Ft. Devens Gulf War Veterans Cohort: 1997-2017

Gulf War veterans (GWVs) were exposed to numerous neurotoxicants during deployment. Upon returning home, many reported a multitude of symptoms including fatigue, pain, gastrointestinal and respiratory issues, and neurological, cognitive, and mood complaints, collectively termed "Gulf War Illness (GWI)." Now, nearly 30 years post-war, many GWVs continue to suffer from these symptoms, in addition to health concerns associated with normal aging. While most research on GWVs has been cross-sectional, it is important to evaluate the progression and onset of new GWI symptoms longitudinally. The current study investigated the health of GWVs 25+ years after the war by resurveying the Ft. Devens Cohort and comparing their current health to their health reported 15 to 20 years earlier. The sample consists of 317 GWVs (~54 years old at the latest survey, 38 women) who responded to both surveys (1997-1998 and 2013-2017). Multivariable regression analyses were used to assess changes in GWI symptomatology and prevalence of medical conditions. The rates of 12 of 25 health symptoms increased significantly from the prior 1997-1998 survey. Anxiety, numbness in extremities, depressed mood, and joint pain had the greatest increase in endorsement. The rates of 7 of 16 medical conditions increased significantly from the prior 1997-1998 survey. High blood pressure, diabetes, and cancer had the greatest increase in prevalence. In summary, this study demonstrates that both symptoms and physician-diagnosed medical conditions associated with GW deployment/exposure increased in prevalence. For GWVs, focus by providers on the treatment of cognitive and mental health issues as well as cardiovascular and cerebrovascular risk factors is warranted. Targeting symptom alleviation would help improve the quality of life in these veterans until treatments addressing the entire illness become available.

Assessment of Ketamine and Its Enantiomers in an Organophosphate-Based Rat Model for Features of Gulf War Illness

Approximately 33% of U.S. soldiers from the first Gulf War suffer from a multi-system disorder known as the Gulf War Illness (GWI). GW veterans suffer from a cluster of symptoms that prominently include fatigue and can include mood-related symptoms. Compared to traditional antidepressants, ketamine (KET) produces a fast-onset and long-lasting antidepressant response, but assessments of KET for GWI-related depression are lacking. The etiology of GWI is multi-factorial and exposure to organophosphates (OP) during deployment is one of the factors underlying GWI development. Here, male Sprague-Dawley rats were repeatedly exposed to an OP DFP and three months later these rats, when assessed on a battery of rodent behavioral assays, displayed signs consistent with aspects of GWI characteristics. When treated with a sub-anesthetic dose of KET (3, 5, or 10 mg/kg, i.p.), DFP-treated rats exhibited a significant improvement in immobility time, open-arm exploration, and sucrose consumption as early as 1 h and much of these effects persisted at 24-h post-KET injection. KET's stereoisomers, R-KET and S-KET, also exhibited such effects in DFP rats, with R-KET being the more potent isomer. Our studies provide a starting point for further assessment of KET for GWI depression.

Rejection Sensitivity Mediates the Relationship Between Social-Interpersonal Stressors and Depressive Symptoms in Military Context

BACKGROUND

Depression is pervasive in the military context and is likely to elicit lasting negative effects on health. Based on interpersonal models, social-interpersonal stressors are significantly associated with the development and maintenance of depression. However, little is known about the mechanisms by which these stressors increase the risk of depression in terms of social relationships. Rejection sensitivity, which refers to people who are sensitive to social rejection and tend to anxiously expect, readily perceive, and overreact to it, may play an underlying role in this process, as it is formed through social-interpersonal stressors and then aggravates further symptoms of depression.

OBJECTIVES

The current study aimed to examine the mediating effects on the relationship between social-interpersonal stressors and depressive symptoms in the military context.

METHODS

This study recruited 600 soldiers aged from 17 to 36 (M = 21.80; SD = 2.99; 100% males) with a cluster sampling method who completed Social-Interpersonal Stressors subscale, Rejection Sensitivity Questionnaire (RSQ), and Self-Rating Depression Scale (SDS). Mediation analyses examined the underlying mechanism between social-interpersonal stressors and depressive symptoms.

RESULTS

The results support the hypothesis and indicate that rejection sensitivity mediates the association between social-interpersonal stressors and depressive symptoms (B indirect = 0.02, p < 0.001, 95% CI= 0.005 to 0.044).

CONCLUSIONS

The findings suggest that interventions designed to desensitize individuals' high levels of rejection sensitivity may help to decrease their risk of depressive symptoms in the military environment. Rejection sensitivity is an important mechanism underpinning the development of depressive symptoms. Other theoretical and applied implications for prevention of depressive symptoms in the military context are discussed.

Relative risks and odds ratios: Simple rules on when and how to use them

AIM

Relative risks and odds ratios are widely reported in the medical literature, but can be very difficult to understand. We sought to further clarify these important indices.

METHODS

We illustrated both relative risks and odds ratios using bar charts, then looked at the types of study for which each statistic is suited. We demonstrated calculation of relative risks and odds ratios through analysis of tabled data from a recent published longitudinal study, using a 2 × 2 table and R, the open-source statistical programming language. Simple rules for when and how to use relative risks and odds ratios are presented.

CONCLUSION

Understanding the difference between relative risks and odds ratios and when and how to use them may aid clinical interpretation, dissemination and translation of research findings.

Living on the Edge: Emotional and Behavioral Problems in a Sample of Kosovar Veterans and Wives of Veterans 16 Years Postwar

Aim: This study aimed to explore the effects of war traumatic exposure on emotional and behavioral problems in a sample of Kosovar war veterans and the wives of veterans 16 years after the 1998-1999 war, as well as whether the level of education, income, well-being, and substance use are predictors for emotional and behavioral problems. Methods: Self-report data were obtained from 373 adults, 247 male war veterans (66.2% of the sample) and 126 wives of other male war veterans (33.8% of the sample). The sample was recruited from a list of war veterans provided by the Kosovar National Association of War Veterans. The mean age of participants was 45.42 [standard deviation (SD), 7.64] years. Measurements comprised a sociodemographic brief structured interview, the Well-Being Index (WHO-5), the Harvard Trauma Questionnaire, and the Adult Self Report (ASR). Logistic regression analysis was conducted to explore if the demographic variables were predictors for ASR general scales and subscales. Multivariate analysis of covariance was performed by adding as covariates the continuous variables pointed out in the logistic regression analysis as discriminating factors between the groups. Post hoc analyses were corrected, and we estimated partial η2 to measure the effect size. Results: The higher traumatic exposure during the war, the greater the tendency to have emotional problems and behavioral problems for both kinds of participants. The result showed that there were no differences on the prevalence of emotional and behavioral problems between the two groups, and both veterans and wives of veterans had no differences on seeking professional help for their emotional and behavioral problems. Wives of veterans living in rural areas showed higher scores on almost all ASR scales compared with those living in urban areas or even with those of veterans from urban and rural areas. Veterans with elementary education level had the highest scores compared with other groups. Veterans with poor well-being had the highest scores compared with other groups. Using Internalizing, Externalizing, and Total Problems as outcome variables and trauma exposure, smoking, drinking alcohol, and well-being as predictors, we found that the model was a significant predictor for both male and female participants on these three scales. Conclusion: The relationship found between the level of exposure to traumatic events and emotional and behavior problems, as well as the factors that moderated such relations, in war veterans and their wives, should help global mental health researchers address the contextual dimensions of this relationship and identify better ways to prevent and treat those problems.

Evaluation of an equine-assisted therapy program for veterans who identify as 'wounded, injured or ill' and their partners

The aim of this study was to evaluate outcomes of an equine-assisted therapy program for Defence Force veterans and their partners across the psychological domains of depression, anxiety, stress, posttraumatic stress, happiness, and quality of life, as well as compare the outcomes of an Individual and Couples program. A non-controlled, within-subjects longitudinal design was utilized with assessment at three time points (pre-intervention, post-intervention, and three months follow-up). Between-subjects analysis with two groups was also conducted to compare the outcomes of the Individual and Couples programs. Participants were recruited from ten programs in 2016 with a total of 47 veterans and partners from both an Individual program (n = 25; veterans only) and a Couples program (n = 22). Outcome measures included the Depression Anxiety Stress Scale-21, Posttraumatic Stress Disorder Checklist for DSM-5, Oxford Happiness Questionnaire, and Quality-of-Life Enjoyment and Satisfaction Questionnaire-Short Form. Paired samples t-tests revealed that within both the Individual and Couples programs, there were significantly fewer psychological symptoms and significantly greater levels of happiness and quality of life at post-intervention compared to pre-intervention. Reduced psychological symptoms were maintained at the three months follow-up for participants of the Couples program only. Independent samples t-tests revealed participants in the Couples program reported significantly less symptoms of depression, stress, and posttraumatic stress disorder (PTSD) at follow-up compared to participants in the Individual program. These results indicate there may only be meaningful benefits for equine-assisted therapy in the reduction of depression, stress, and PTSD symptoms for veterans, if partners are integrated into the intervention.

Deployment of personnel to military operations: impact on mental health and social functioning

This Campbell systematic review examines the effects of deployment on mental health. The review summarizes evidence from 185 studies. All studies used observational data to quantify the effect of deployment. This review includes studies that evaluate the effects of deployment on mental health. A total of 185 studies were identified. However, only 40 of these were assessed to be of sufficient methodological quality to be included in the final analysis. The studies spanned the period from 1993 to 2017 and were mostly carried out in the USA, UK and Australia. The studies all had some important methodological weaknesses. None of the included studies used experimental designs (random assignment). Deployment to military operations negatively affects the mental health functioning of deployed military personnel. For assessments taken more than 24 months since exposure, we consistently found adverse effects of deployment on all mental health domains (PTSD, depression, substance abuse/dependence, and common mental disorders), particularly on PTSD. For assessments taken less than 24 months (or a variable number of months since exposure) the evidence was less consistent and in many instances inconclusive.

Plain language summary

Deployment to military operations negatively affects the mental health functioning of deployed military personnel: While additional research is needed, the current evidence strongly supports the notion that deployment negatively affects mental health functioning of deployed military personnel.What is this review about?: When military personnel are deployed to military operations abroad they face an increased risk of physical harm, and an increased risk of adverse shocks to their mental health.The primary condition under consideration is deployment to an international military operation. Deployment to a military operation is not a uniform condition; rather, it covers a range of scenarios. Military deployment is defined as performing military service in an operation at a location outside the home country for a limited time period, pursuant to orders.The review included studies that reported outcomes for individuals who had been deployed. This review looked at the effect of deployment on mental health outcomes. The mental health outcomes are: post-traumatic stress disorder (PTSD), major depressive disorder (MDD), common mental disorders (depression, anxiety and somatisation disorders) and substance-related disorders.By identifying the major effects of deployment on mental health and quantifying these effects, the review can inform policy development on deployment and military activity as well as post-deployment support for veterans. In this way the review enables decision-makers to prioritise key areas.What are the main findings of this review?: What studies are included?: This review includes studies that evaluate the effects of deployment on mental health. A total of 185 studies were identified. However, only 40 of these were assessed to be of sufficient methodological quality to be included in the final analysis. The studies spanned the period from 1993 to 2017 and were mostly carried out in the USA, UK and Australia. The studies all had some important methodological weaknesses. None of the included studies used experimental designs (random assignment).Does deployment have an effect on mental health?: Deployment to military operations negatively affects the mental health functioning of deployed military personnel. For assessments taken more than 24 months since exposure, we consistently found adverse effects of deployment on all mental health domains (PTSD, depression, substance abuse/dependence, and common mental disorders), particularly on PTSD. For assessments taken less than 24 months (or a variable number of months since exposure) the evidence was less consistent and in many instances inconclusive.What do the findings of this review mean?: The odds of screening positive for PTSD and depression were consistently high in the longer term. This suggests that efforts should be increased to detect and treat mental disorders, as effects may be long-lasting.Overall the risk of bias in the majority of included studies was high. While it is difficult to imagine a randomised study design to understand how deployment affects mental health, other matters such as changes to personnel policy, or unanticipated shocks to the demand for military personnel, could potentially be a rich source of quasi-experimental variation.How up-to-date is this review?: The review authors searched for studies up to 2017. This Campbell systematic review was published in March 2018.

Executive summary

BACKGROUND: When military personnel are deployed to military operations abroad they face an increased risk of physical harm, and an increased risk of adverse shocks to their mental health. Research suggests that the increased risk to mental health is mainly due to the hazards of war, combat exposure: firing weapons, road side bombs, seeing fellow soldiers, friends, civilians, and enemies being injured, maimed or killed. These experiences may lead to severe mental stress. The adverse impact on mental health is the psychological cost of war, and it is of interest to policymakers to learn the magnitude of these effects. This review sets out to synthesise available evidence about the consequences of deployment for deployed military personnel in the mental health and social functioning domains.OBJECTIVES: The objective of this review isto synthesise the consequences of deployment to military operation on the mental health and social functioning of deployed military personnel.SEARCH METHODS: We searched electronic databases, grey literature, and references from primary studies and related reviews. No language or date restrictions were applied to the searches. We searched the following electronic databases: Academic Search Elite, Cochrane Library, EMBASE, ERIC, MEDLINE, PsycINFO, Science Citation Index, Social Science Citation Index, SocINDEX, as well as the Nordic platforms: bibliotek.dk, BIBSYS, and LIBRIS. The conclusions of this review are based on the most recent searches performed. The last search was performed in April 2017.SELECTION CRITERIA: Primary studies had to meet the following inclusion criteria: Participants: The participants should be military personnel.Intervention: The condition should be deployment to a military operation.Comparison: The relevant comparisons were either comparing a) deployed military personnel to non-deployed military personnel, b) deployed military personnel to military personnel deployed elsewhere, for example personnel deployed to non-combat operations, c) military personnel deployed to the same operation but stratified by combat exposure.Outcomes: The study should report on one or more mental health outcomes, and/or social functioning for the deployed participants. In particular studies should report on one or more of the following mental health outcomes: PTSD, major depression, substance abuse or dependence (including alcohol), and common mental disorders (depression and anxiety disorders). The following social functioning outcomes were relevant: employment, and homelessness.Study Designs: Both experimental and quasi-experimental designs with a comparison group were eligible for inclusion in the review. Studies were excluded if they: Reported on deployments taking place before 1989.Used a within group pre-post study design.Did not report on at least one of the mental health or social functioning outcomes. DATA COLLECTION AND ANALYSIS: The total number of potentially relevant studies constituted31,049records. A total of 185 studies met the inclusion criteria and were critically appraised by the review authors. The final selection of 185 studies was from 13 different countries.Forty eight of the 185 studies did not report effect estimates or provide data that would allow the calculation of an effect size and standard error. Fifty four studies were excluded because of overlapping samples. The majority of those studies were from USA but the main reason for not using studies from USA in the synthesis was lack of information to calculate an effect size. Nearly half the studies from the UK could not be used in the synthesis due to overlap of data samples. Forty three studies were judged to have a very high risk of bias (5 on the scale) and, in accordance with the protocol, we excluded these from the data synthesis on the basis that they would be more likely to mislead than inform., Thus a total of 40 studies, from five different countries, were included in the data synthesis.Random effects models were used to pool data across the studies. We used the odds ratio. Pooled estimates were weighted with inverse variance methods, and 95% confidence intervals were calculated. The meta-analyses were carried out by time since exposure (short, medium, long, and other time since exposure) and by type of comparison (deployed versus non-deployed, all deployed but stratified by either combat operations versus non-combat operations, or stratified by combat exposure). We performed single factor subgroup analysis. The assessment of any difference between subgroups was based on 95% confidence intervals. Funnel plots were used to assess the possibility of publication bias. Sensitivity analysis was used to evaluate whether the pooled effect sizes were robust across components of methodological quality.MAIN RESULTS: The findings were mixed, depending on the outcome, the time since exposure and the approach (deployed versus non-deployed termed absolute or stratified by extent of combat termed relative) used to investigate the effect. It was not possible to analyse the outcomes homelessness and employment. All studies that could be used in the data synthesis reported on the impact of deployment on mental health; PTSD, depression, substance use or common mental disorder.For assessments taken less than 24 months since exposure the evidence was inconclusive either because too few studies reported results in the short and medium term and/or the degree of heterogeneity between studies was large.For assessments taken at other time points (a variable number of months since exposure) the evidence was inconclusive for the relative comparisons due to either too few studies or a substantial degree of heterogeneity between studies. For the absolute comparison the analysis of common mental disorder was inconclusive, whereas the average effects of PTSD and depression were positive and statistically significant (PTSD odds ratio (OR) was 1.91 (95% confidence interval (CI): 1.28 to 2.85) and OR=1.98 (95% CI: 1.05 to 3.70) for depression). The analysis concerning substance use indicated that deployed participants did not have higher odds of screening positive for substance use compared to non-deployed participants (OR=1.15 (95% CI: 0.98 to 1.36)).For assessments taken more than 24 months post exposure, meta-analyses indicated that the odds of screening positive for PTSD, depression, substance use and common mental disorder were higher for participants in the deployed group compared to participants in the group that were not deployed (PTSD OR=3.31 (95% CI: 2.69 to 4.07), OR=2.19 (95% CI: 1.58 to 3.03) for depression, OR=1.27 (95% CI: 1.15 to 1.39) for substance use, and OR=1.64 (95% CI: 1.38 to 1.96) for common mental disorder). Likewise, participants reporting high combat exposure had higher odds of screening positive for PTSD and depression than participants reporting lower exposure for long term assessments (PTSD OR=3.05 (95% CI: 1.94 to 4.80) and OR=1.81 (95% CI: 1.28 to 2.56) for depression). The analyses of substance use and common mental disorder were inconclusive due to too few studies.On the basis of the prevalence of mental health problems in pre-deployed or non-deployed population based comparison sampleswe would therefore expect the long term prevalence of PTSD in post-deployed samples to be in the range 6.1 - 14.9%, the long term prevalence of depression to be in the range from 7.6% to 18%, the long term prevalence of substance use to be in the range from 2.4% to 17.5% and the prevalence of common mental disorder to be in the range from 10% to 23%.Sensitivity analyses resulted in no appreciable change in effect size, suggesting that the results are robust.It was only possible to assess the impact of two types of personnel characteristics (branch of service and duty/enlistment status) on the mental health outcomes. We found no evidence to suggest that the effect of deployment on any outcomes differ between these two types of personnel characteristics.AUTHORS' CONCLUSIONS: Deployment to military operations negatively affects the mental health functioning of deployed military personnel. We focused on the effect of deployment on PTSD (post-traumatic stress disorder), depression, substance abuse/dependence, and common mental disorders (depression and anxiety disorders). For assessments taken less than 24 months (or a variable number of months since exposure) the evidence was less consistent and in many instances inconclusive. For assessments taken more than 24 months since exposure, we consistently found adverse effects of deployment on all domains, particularly on PTSD. There is increased political awareness of the need to address post deployment mental health problems. The odds of screening positive for PTSD and depression were consistently high in the longer term. This suggests that efforts should be increased to detect and treat mental disorders, as effects may be long lasting. Mental illness is of particular concern in the military for operational reasons, but they may be hard to detect in the military setting because a military career is intimately linked with mental and physical strength.It was not possible to examine a number of factors which we had reason to expect would impact on the magnitude of the effect. This would have been particularly relevant from a policy perspective because these are direct parameters that one could use to optimally "organize" deployment in order to minimize impacts on mental health functioning.While additional research is needed, the current evidence strongly supports the notion that deployment negatively affects mental health functioning of deployed military personnel. The next step is to begin to examine preventive measures and policies for organizing deployment, in order to minimize the effects on mental health.

Characteristics of U.S. Veteran Patients with Major Depressive Disorder who require "next-step" treatments: A VAST-D report

OBJECTIVE

Finding effective and lasting treatments for patients with Major Depressive Disorder (MDD) that fail to respond optimally to initial standard treatment is a critical public health imperative. Understanding the nature and characteristics of patients prior to initiating "next-step" treatment is an important component of identifying which specific treatments are best suited for individual patients. We describe clinical features and demographic characteristics of a sample of Veterans who enrolled in a "next-step" clinical trial after failing to achieve an optimal outcome from at least one well-delivered antidepressant trial.

METHODS

1522 Veteran outpatients with nonpsychotic MDD completed assessments prior to being randomized to study treatment. Data is summarized and presented in terms of demographic, social, historical and clinical features and compared to a similar, non-Veteran sample.

RESULTS

Participants were largely male and white, with about half unmarried and half unemployed. They were moderately severely depressed, with about one-third reporting recent suicidal ideation. More than half had chronic and/or recurrent depression. General medical and psychiatric comorbidities were highly prevalent, particularly PTSD. Many had histories of childhood adversity and bereavement. Participants were impaired in multiple domains of their lives and had negative self-worth.

LIMITATIONS

These results may not be generalizable to females, and some characteristics may be specific to Veterans of US military service. There was insufficient data on age of clinical onset and depression subtypes, and three novel measures were not psychometrically validated.

CONCLUSIONS

Characterizing VAST-D participants provides important information to help clinicians understand features that may optimize "next-step" MDD treatments.