Healthy Warrior Effect With Deployment to United Nations Peacekeeping Operation: A Longitudinal Study Among Japan Ground Self-Defense Forces.

INTRODUCTION: The "healthy warrior effect" (HWE), in which deployed military personnel are healthier than those not deployed, is known to be associated with deployment. However, the HWE associated with deployment to United Nations (UN) peacekeeping operations (PKO) has not been examined. This study examined the HWE associated with deployment to UN PKO by examining the impact of pre-deployment mental health on the likelihood of deployment and whether this difference persisted after deployment. MATERIALS AND METHODS: This retrospective cohort study included 2,712 Japan Ground Self-Defense Forces personnel from four engineering units who consented to participate in annual mental health checks conducted between August and October 2015. The Kessler Psychological Distress Scale (K6) was used to assess general psychological distress before and after deployment. Logistic regression analysis adjusted for age, sex, and rank was conducted with deployment as the dependent variable and the pre-deployment K6 total score as the independent variable. Additionally, a mixed-effects model was performed with K6 total scores as the dependent variable, time and deployment as fixed effect factors, and the individual as the random effect factor. RESULTS: Of the participants, 254 were in the deployed group, and 2,458 were in the non-deployed group. The pre-deployment K6 total score was significantly lower (t = 5.2, P < .001) for the deployed group (0.67 ± 1.60) than for the non-deployed group (1.26 ± 2.41). Logistic regression analysis showed an odds ratio for the K6 total score before deployment as 0.87 (95% CI = 0.79-0.94). The mixed-effects model exhibited a significant negative main effect of being deployed (t = -5.1, P < .001) and a significant interaction effect between time and being deployed (t = -2.5, P = .012). CONCLUSIONS: Psychologically healthier personnel were more likely to be deployed for UN PKO and their better mental health status persisted after deployment, reflecting the HWE. However, personnel in good health may develop new mental health issues after their deployment, and more attention to health management will be essential before and after deployment.

Molecular hydrogen supplementation in mice ameliorates lipopolysaccharide-induced loss of interest.

Aim: The objective of this study was to evaluate the potential of hydrogen in preventing and treating psychiatric symptoms, particularly depressed mood and loss of interest, and to explore its underlying mechanisms. A mouse model exhibiting inflammation-derived depressive symptoms was used for the investigation. Methods: Institute of Cancer Research mice were subjected to a 7-day intervention of either 30% hydrogen or 40 g per day of air via jelly intake. On the final day, lipopolysaccharide (LPS) was intraperitoneally administered at 5 mg/kg to induce inflammation-related depressive symptoms. Behavioral and biochemical assessments were conducted 24 h post-LPS administration. Results: Following LPS administration, a decrease in spontaneous behavior was observed; however, this effect was mitigated in the group treated with hydrogen. The social interaction test revealed a significant reduction in interactions with unfamiliar mice in the LPS-treated group, whereas the hydrogen-treated group exhibited no such decrease. No significant changes were noted in the forced-swim test for either group. Additionally, the administration of LPS in the hydrogen group did not result in a decrease in zonula occludens-1, a biochemical marker associated with barrier function at the cerebrovascular barrier and expressed in tight junctions. Conclusion: Hydrogen administration demonstrated a preventive effect against the LPS-induced loss of interest, suggesting a potential role in symptom prevention. However, it did not exhibit a suppressive effect on depressive symptoms in this particular model. These findings highlight the nuanced impact of hydrogen in the context of inflammation-induced psychiatric symptoms, indicating potential avenues for further exploration and research.

Evaluating the two-item measure of engagement at work for Japan Self-Defense Forces: A cross-sectional study.

Aim: Work engagement is critical in both occupational and mental health contexts. However, no studies have compared the usefulness of the nine-, three-, and two-item measures from the Utrecht Work Engagement Scale (UWES). Therefore, this study aimed to examine the internal consistency and convergent validity of the two-item measure and compare its usefulness with the nine-item and three-item versions for assessing engagement at work among Japan Self-Defense Forces (JSDF) personnel. Methods: This cross-sectional study included 229,383 participants who underwent an annual mental health check between October 19 and December 17, 2021. To test the internal consistency of the scales, Cronbach's alpha was used. To test the convergent validity, Pearson's correlation coefficients were examined for each item corresponding to job resources, job satisfaction, stress reactions, and job demands assessed by the Brief Job Stress Questionnaire. Results: Most participants were men (89.8%). Cronbach's alpha coefficients for the nine-, three-, and two-item scales were 0.95, 0.85, and 0.80, respectively. All three versions showed significant and positive correlations with each of the items corresponding to job resources and job satisfaction. The correlation coefficients of the two-item scale were not inferior to those of the nine-item and three-item scales for job resources and job satisfaction items. Conclusion: Our results showed the internal consistency and convergent validity for the two-item measure of engagement at work among JSDF personnel. The two-item measure may be useful for briefly and efficiently assessing the actual state of workers' engagement at work.

Symptoms of Posttraumatic Stress Disorder Among Japanese Peacekeepers Deployed in South Sudan.

Importance: Peacekeepers in United Nations missions experience potentially traumatic events, resulting in increased risk for posttraumatic stress disorder (PTSD). Understanding the course and risk factors of PTSD symptom severity is crucial to ensure personnel safety. Objective: To investigate the incidence of PTSD, symptom severity trajectories, and potential risk factors associated with adverse trajectories among Japanese peacekeepers deployed in South Sudan. Design, Setting, and Participants: Data for this 6-year prospective cohort study were collected from December 2011 to December 2018 from Japan Ground Self-Defense Force personnel deployed at the United Nations Mission in South Sudan, corresponding to before and up to 78 months after deployment. Of 3799 potential participants, 80 were excluded because of multiple deployments and 757 because of missing data, incomplete responses, or not providing informed consent. Therefore, 2962 participants were included in the analysis. Data analysis was performed from February 2022 to February 2024. Exposure: The participants were deployed to United Nations Mission in South Sudan for 6 months. Main Outcomes and Measures: The 22-item Impact of Event Scale-Revised was used to assess PTSD symptoms, with 25 or more points indicating probable PTSD (p-PTSD). Sociodemographic data were collected, and the 30-item General Health Questionnaire was administered before deployment to identify risk factors for PTSD symptom severity. Results: In the 2962 participants studied (2901 [97.9%] male; mean [SD] age, 33.9 [7.2] years), the incidence of p-PTSD was 3.95%. Latent growth mixture models identified 4 symptom severity trajectories: resilient (2143 [72.3%]), recovery (479 [16.2%]), protracted (182 [6.1%]), and delayed (158 [5.3%]). Multinomial logistic regression showed that sleep disturbance was a common risk factor for the 2 most severe trajectories (protracted: odds ratio [OR], 1.29; 95% CI, 1.08-1.54; delayed: OR, 1.26; 95% CI, 1.03-1.53), whereas older age (OR, 1.25; 95% CI, 1.06-1.48), anxiety and dysphoria (OR, 1.45; 95% CI, 1.20-1.75), and general illness (OR, 1.30; 95% CI, 1.06-1.59) were associated with the protracted trajectory. Conclusions and Relevance: This cohort study found that approximately 4% of the participants developed p-PTSD and identified 4 distinct PTSD symptom trajectories. The findings suggest that addressing sleep disturbance and general health issues could effectively prevent PTSD symptoms among peacekeepers.

Empathy and Coping Strategies Predict Quality of Life in Japanese Healthcare Professionals.

Burnout and secondary traumatic stress (STS), also referred to as compassion fatigue, are undeniable negative consequences experienced by healthcare professionals when working with patients. As frontline healthcare professionals are essential to communities, it is crucial to understand their mental health and how they cope with negative psychological responses. This study investigated the relationships between burnout, STS, compassion satisfaction, dispositional empathy, and stress management among Japanese healthcare professionals and students taking care of patients in clinical practice. The participants were 506 Japanese healthcare professionals and students (doctors, nurses, medical students, and nursing students) affiliated with Japanese Ministry of Defense Hospitals. The data were collected from March 2020 to May 2021. We assessed burnout, STS, and compassion satisfaction using the Professional Quality of Life Scale, dispositional empathy using the Interpersonal Reactivity Index, and coping with stress using the Coping Orientation to Problems Experienced Inventory (Brief-COPE). Exploratory factor analysis of the Brief-COPE yielded three factors: active coping; support-seeking; and indirect coping. Personal distress, a self-oriented emotional empathy index, was related to higher burnout and STS scores and lower compassion satisfaction. Empathic concern, an other-oriented emotional empathy index, was associated with lower burnout and higher compassion satisfaction. Active coping strategies were associated with lower burnout and higher compassion satisfaction, whereas indirect coping strategies were associated with higher burnout and STS scores. In a comparison of empathy in professional categories, nurses presented higher personal distress than nursing students, and medical doctors showed lower fantasy tendencies than medical students. These results imply the complex relationships between empathy, coping strategies, and psychological responses among healthcare professionals. Further longitudinal study is needed to explore these complex relationships and to develop more precise and effective psycho-educational interventions to prevent burnout and STS.

Japanese public health nurses classified based on empathy and secondary traumatic stress: variable-centered and person-centered approaches.

BACKGROUND: Healthcare providers frequently help traumatized people and are regularly exposed to indirect trauma from their work, resulting in negative psychological responses, such as secondary traumatic stress. Empathy has been associated with patient's quality of care and secondary traumatic stress among healthcare providers. However, the relationship between dispositional empathy and secondary traumatic stress has not been fully elucidated. This study used person- and variable-centered approaches to explore the nature of this relationship. METHODS: A total of 1,006 Japanese public health nurses working in the Tohoku region and Saitama prefecture completed questionnaires that included scales assessing dispositional empathy, secondary traumatic stress, and burnout. First, we examined predictors of secondary traumatic stress using multiple linear regression analysis. Then, we conducted a latent profile analysis to classify participants into unique groups based on four subscales of dispositional empathy (i.e., empathic concern, perspective taking, personal distress, fantasy) and secondary traumatic stress. Finally, we compared the mean values of the study variables across these groups. RESULTS: The multiple regression indicated that in those working in Saitama prefecture, lifetime traumatic experiences, work-related distress, and personal distress were positively related to secondary traumatic stress, but perceived support was negatively related to secondary traumatic stress. Latent profile analysis extracted four unique subgroups. Group 1 displayed the highest secondary traumatic stress levels. Group 2 was characterized by the highest level of empathic concern, personal distress, and fantasy and the lowest perspective taking. Group 3 had a moderate secondary traumatic stress level. Group 4 had the lowest secondary traumatic stress and personal distress scores. In these four groups, the burnout scale (exhaustion, cynicism, and professional efficacy) showed a pattern similar to the secondary traumatic stress scale. CONCLUSIONS: Our person-centered approach showed that this sample of public health nurses could be classified into four unique groups based on their empathy and secondary traumatic stress scores. Although this group of public health nurses was not large, one group displayed high personal distress levels and high secondary traumatic stress levels. Further research is needed to determine effective interventions for this group.

PTSD Symptom dynamics after the great east japan earthquake: mapping the temporal structure using Dynamic Time Warping.

Background: After the Great East Japan Earthquake [GEJE], approximately 70,000 Japan Ground Self Defense Force [JGSDF] personnel were deployed, risking Post-Traumatic Stress Disorder [PTSD]. The network approach to psychopathology suggests that symptoms may cause and exacerbate each other, resulting in the emergence and maintenance of disorders, including PTSD. It is therefore important to further explore the temporal interplay between symptoms. Most studies assessing the factor structure of the Impact of Event Scale-Revised [IES-R] have used cross-sectional designs. In this study, the structure of the IES-R was re-evaluated while incorporating the temporal interplay between symptoms.Methods: Using Dynamic Time Warping [DTW] the distances between PTSD symptoms on the IES-R were modelled in 1120 JGSDF personnel. Highly correlated symptoms were clustered at the group level using Distatis three-way principal component analyses of the distance matrices. The resulting clusters were compared to the original three subscales of the IES-R using a Confirmatory Factor Analysis (CFA).Results: The DTW analysis yielded four symptom clusters: Intrusion (five items), Hyperarousal (six items), Avoidance (six items), and Dissociation (five items). CFA yielded better fit estimates for this four-factor solution (RMSEA = 0.084, CFI = 0.918, TLI = 0.906), compared to the original three subscales of the IES-R (RMSEA = 0.103, CFI = 0.873, TLI = 0.858).Conclusions: DTW offers a new method of modelling the temporal relationships between symptoms. It yielded four IES-R symptom clusters, which may facilitate understanding of PTSD as a complex dynamic system.

Personnel from the Japan Ground Self-Defense Force responded to the aftermath of the 2011 Great East Japan Earthquake, putting them at increased risk of developing symptoms of Post-Traumatic Stress Disorder.In recent years, psychological research has focused increasingly on methods to map the ways in which symptoms of psychopathology cause and exacerbate each other.The Dynamic Time Warping algorithm seems to be an appropriate and useful tool to analyse the interaction between post-traumatic stress symptoms over time, especially if these are not instantaneous or linear. This can improve our understanding of psychopathology and help move towards personalized medicine.

Identifying factors related to stigma toward psychiatric illness and mental health services and attitudes of help-seeking among Japan Ground Self-Defense Force members.

The stigma that military personnel feel toward mental illness and mental healthcare hinders their access to mental health services. Stigma is influenced by culture-specifically, that held by military personnel is closely related to military culture. To our knowledge, this is the first large-scale investigation aimed at identifying the factors, including demographic factors and elements of military culture, related to stigma among members of the Japan Ground Self-Defense Force. An anonymous questionnaire was administered to 4754 members. The questionnaire included items regarding demographic factors, history of psychiatric visits, military rank, overseas deployment experience, disaster relief experience, supervisor leadership, unit cohesion, general psychological distress, stigma toward perceived mental illness, and attitudes toward help-seeking. Multiple regression analysis was used to identify the various factors related to stigma. Responses were obtained from 4305 (90.5%) participants, among which 3723 (78.3%) were valid. Multiple regression analyses revealed that a variety of factors including age, psychiatric consultation, leadership, and cohesiveness were markedly associated with stigma and attitudes toward help-seeking. This study revealed that various factors including demographic factors and military culture factors such as supervisor leadership and unit cohesion are related to stigma and attitudes toward mental health services among Japan Ground Self-Defense Force personnel. Further studies are needed to examine the results in depth.

Risk and resilience in trajectories of post-traumatic stress symptoms among first responders after the 2011 Great East Japan Earthquake: 7-year prospective cohort study.

BACKGROUND: First responders to disasters are at risk of developing post-traumatic stress disorder (PTSD). The trajectories of post-traumatic stress symptom severity differ among individuals, even if they are exposed to similar events. These trajectories have not yet been reported in non-Western first responders. AIMS: We aimed to explore post-traumatic stress symptom severity trajectories and their risk factors in first responders to the 2011 Great East Japan Earthquake (GEJE) - a historically large earthquake that resulted in a tsunami and a nuclear disaster. METHOD: A total of 55 632 Japan Ground Self-Defense Force (JGSDF) personnel dispatched to the GEJE were enrolled in this 7-year longitudinal cohort study. PTSD symptom severity was measured using the Impact of Event Scale-Revised. Trajectories were identified using latent growth mixture models (LGMM). Nine potential risk factors for the symptom severity trajectories were analysed using multinomial logistic regression. RESULTS: Five symptom severity trajectories were identified: 'resilient' (54.8%), 'recovery' (24.6%), 'incomplete recovery' (10.7%), 'late-onset' (5.7%), and 'chronic' (4.3%). The main risk factors for the four non-resilient trajectories were older age, personal disaster experiences and working conditions. These working conditions included duties involving body recovery or radiation exposure risk, longer deployment length, later or no post-deployment leave and longer post-deployment overtime. CONCLUSIONS: The majority of first responders to GEJE were resilient and developed few or no PTSD symptoms. A substantial minority experienced late-onset and chronic symptom severity trajectories. The identified risk factors can inform policies for prevention, early detection and intervention in individuals at risk of developing symptomatic trajectories.

Multiple time measurements of multidimensional psychiatric states from immediately before the COVID-19 pandemic to one year later: a longitudinal online survey of the Japanese population.

The coronavirus disease 2019 (COVID-19) pandemic has profoundly affected the mental health of both infected and uninfected people. Although most psychiatric disorders have highly overlapping genetic and pathogenic backgrounds, most studies investigating the impact of the pandemic have examined only single psychiatric disorders. It is necessary to examine longitudinal trajectories of factors that modulate psychiatric states across multiple dimensions. About 2274 Japanese citizens participated in online surveys presented in December 2019 (before the pandemic), August 2020, Dec 2020, and April 2021. These surveys included nine questionnaires on psychiatric symptoms, such as depression and anxiety. Multidimensional psychiatric time-series data were then decomposed into four principal components. We used generalized linear models to identify modulating factors for the effects of the pandemic on these components. The four principal components can be interpreted as a general psychiatric burden, social withdrawal, alcohol-related problems, and depression/anxiety. Principal components associated with general psychiatric burden and depression/anxiety peaked during the initial phase of the pandemic. They were further exacerbated by the economic burden the pandemic imposed. In contrast, principal components associated with social withdrawal showed a delayed peak, with human relationships as an important risk modulating factor. In addition, being female was a risk factor shared across all components. Our results show that COVID-19 has imposed a large and varied burden on the Japanese population since the commencement of the pandemic. Although components related to the general psychiatric burden remained elevated, peak intensities differed between components related to depression/anxiety and those related to social withdrawal. These results underline the importance of using flexible monitoring and mitigation strategies for mental problems, according to the phase of the pandemic.

Validity and reliability of the Secondary Traumatic Stress Scale-Japanese version.

AIM: This study assessed the validity and reliability of the Secondary Traumatic Stress Scale-Japanese Version. METHODS: The original Secondary Traumatic Stress Scale was translated into Japanese, and Japanese items were back-translated to English to confirm the accuracy of the translation. A total of 870 public health nurses from the Tohoku region in Japan completed the Secondary Traumatic Stress Scale-Japanese Version. An exploratory factor analysis was conducted to identify the number of components. Moreover, 351 public health nurses from the Saitama prefecture in Japan also completed the scale. A confirmatory factor analysis was performed with the factor structure identified in the exploratory factor analysis. RESULTS: The exploratory factor analysis identified two components: one associated with client-related distress and the other with trauma-related distress. The confirmatory factor analysis confirmed the two-factor structure. The two-factor structure model was better than the three-factor model presented in the original validation study for the English version of the scale. The two-factor model had good internal consistency for the overall product and the subscales. Pearson correlations showed that this model had good convergent validity against the Maslach Burnout Inventory, a psychological measure similar to the Secondary Traumatic Stress Scale. Finally, the two-factor model had good discriminant validity against the Maslach Burnout Inventory. CONCLUSION: This study identified two components of the Secondary Traumatic Stress Scale-Japanese Version that differ from the three components found in the original English version. The differences in the factor structure might indicate that the factor structure was culturally influenced.

Body Mass Index and Association of Psychological Stress with Exercise Performance in Military Members: The Cardiorespiratory Fitness and Hospitalization Events in Armed Forces (CHIEF) Study.

AIMS: To investigate the influence of body mass index (BMI) on the association between psychological stress and physical fitness. BACKGROUND: Both obesity and psychological stress reduce exercise performance. OBJECTIVE: It is unknown whether obesity may modify the relationship. METHODS: A population of 4,080 military subjects in Taiwan was divided to three groups according to the BMI ≥27.0 kg/m2 (obesity), 24.0-26.9 kg/m2 (overweight) and 18.5-23.9 kg/m2 (normal weight). Normal, slight, and great psychological stress was evaluated by the Brief Symptoms Rating Scale (BSRS-5) score ≤5, 6-9, and ≥10, respectively. Aerobic and anaerobic fitness were respectively evaluated by time for a 3000-meter run and numbers of 2-minute sit-ups and 2-minute push-ups. Analysis of covariance (ANCOVA) with adjustments for age and sex was used to determine the relationship. RESULTS: The mean time (sec) for a 3000-meter run (standard error) under slight and great stress differed from that under normal stress in the normal weight (881.0 (11.0) and 877.9 (5.8) vs. 862.2 (1.7), p=0.089 and 0.0088, respectively) and in the obesity (928.1 (16.8) and 921.8 (10.7) vs. 895.2 (1.6), p=0.054 and 0.016, respectively), while the differences were not significant in the overweight (877.1 (12.7) and 877.5 (7.1) vs. 867.1 (2.1), both p >0.5). The impacts of the BMI on 2-minute sit-ups had a similar pattern with that on a 3000-meter run whereas the impact of the BMI on 2-minute push-ups was insignificant. CONCLUSIONS: Mental stress may not affect physical fitness in overweight military personnel. The mechanism is not clear and should be further investigated.

Mental health consequences for survivors of the 2011 Fukushima nuclear disaster: a systematic review. Part 2: emotional and behavioral consequences.

To compile the findings of studies assessing emotional and behavioral changes in the survivors of the 2011 Fukushima nuclear disaster, we performed a systematic review in August 2019 using four literature databases (PubMed, PsycINFO, Psychology and Behavioral Sciences Collection, and ICHUSHI). Peer-reviewed manuscripts, either in English or Japanese, were included in the searches. Sixty-one studies were retrieved for the review. Of these, 41 studies (67.2%) assessed emotional consequences, 28 studies (45.9%) evaluated behavioral consequences, and 8 studies (13.1%) evaluated both emotional and behavioral outcomes. The main research topic in emotional change was radiation exposure-associated risk perception, as reported in 15 studies. This risk perception included immediate health effects (eg, acute radiation syndrome) as well as future health effects (eg, future cancer and genetic effects). Lowered subjective well-being was reported in eight studies. Six studies reported perceived discrimination/stigmatization in the disaster survivors. The most critical behavioral change was an increase in suicides compared with residents in the whole of Japan or affected by the earthquake and tsunami, but not by the nuclear disaster. Increased rate of alcohol and tobacco use was reported, although the effect on one's health was inconsistent. As a conclusion, the Fukushima nuclear disaster survivors suffered issues in risk perception, well-being, stigmatization, and alcohol/tobacco use in the first 8 years after the disaster. The present study is important in order to better understand the emotional and behavioral responses to future nuclear/radiological disasters as well as other "invisible" disasters, such as chemical and biological public health crises.

Mental health consequences for survivors of the 2011 Fukushima nuclear disaster: a systematic review. Part 1: psychological consequences.

To integrate scholastic literature regarding the prevalence and characteristics of the psychological consequences faced by survivors of the 2011 Fukushima earthquake/tsunami/nuclear disaster, we conducted a systematic review of survivor studies concerning the Fukushima disaster. In August 2019, four literature databases (PubMed, PsycINFO, Psychology and Behavioral Sciences Collection, and ICHUSHI) were used in the literature search. Peer-reviewed manuscripts reporting psychological consequences, either in English or Japanese, were selected. A total of 79 studies were selected for the review. Twenty-four studies (30.4%) were conducted as part of the Fukushima Health Management Survey-large-scale cohort study recruiting the residents of the entire Fukushima prefecture. Study outcomes were primarily nonspecific psychological distress, depressive symptoms, post-traumatic stress symptoms, and anxiety symptoms. The rates of high-risk individuals determined by the studies varied significantly owing to methodological differences. Nevertheless, these rates were mostly high (nonspecific psychological distress, 8.3%-65.1%; depressive symptoms, 12%-52.0%; and post-traumatic stress symptoms, 10.5%-62.6%). Many studies focused on vulnerable populations such as children, mothers of young children, evacuees, and nuclear power plant workers. However, few studies reported on the intervention methods used or their effect on the survivors. As a conclusion, high rates of individuals with psychological conditions, as well as a wide range of mental conditions, were reported among the Fukushima nuclear disaster survivors in the first 8 years after the disaster. These findings demonstrate the substantial impact of this compound disaster, especially in the context of a nuclear catastrophe.

Assessment of Factors Associated With Long-term Posttraumatic Stress Symptoms Among 56 388 First Responders After the 2011 Great East Japan Earthquake.

Importance: First responders are at risk for developing symptoms of posttraumatic stress disorder (PTSD). Little is known about the risk factors for developing PTSD during a years-long period after complex mass disasters. Objective: To explore the long-term course of PTSD symptoms and to identify risk factors and their relative association with PTSD among first responders dispatched to the 2011 Japanese earthquake, tsunami, and nuclear disaster. Design, Setting, and Participants: This 6-year, large, prospective cohort study was part of a continuous longitudinal study of Japan Ground Self-Defense Force first responders. The data were collected at 1, 6, 12, 24, 36, 48, 60, and 72 months after mission completion from 2011 to 2017. Of approximately 70 000 eligible participants, 56 388 were enrolled in this study. Data were analyzed from 2017 to 2020. Exposures: Stress exposures owing to personal or professional disaster experience (eg, duties with body recovery or radiation exposure risk) and working conditions (eg, deployment length, postdeployment overtime work). Main Outcomes and Measures: The Impact of Event Scale-Revised score assessed PTSD symptoms; scores of at least 25 were defined as probable PTSD. Cox proportional hazards regression models assessed the risk factors for incidence of probable PTSD. Results: Among the 56 388 participants, 97.1% were men, and the median age at enrollment was 34 (range, 18-63) years. A probable PTSD rate was 2.7% at 1 month and showed a downward trend in the first year and a subsequent plateau. The cumulative incidence of probable PTSD was 6.75%. The severity of PTSD symptoms demonstrated a high degree of rank-order stability over time. Rather than professional disaster experience, sociodemographic factors and working conditions were independently associated with the incidence of probable PTSD: personal experience of the disaster (hazard ratio [HR], 1.96; 95% CI, 1.72-2.24), deployment length of at least 3 months (HR vs <1 month, 1.75; 95% CI, 1.52-2.02), increased age (HR for ≥46 vs ≤25 years, 2.28; 95% CI, 1.79-2.92), and postdeployment overtime work of at least 3 months (HR vs little to none, 1.61; 95% CI, 1.39-1.87). Conclusions and Relevance: Given these findings, in the future, first responders' PTSD symptoms might be mitigated by shortening deployment length, avoiding postdeployment overtime work, and paying special attention to the needs of personnel with personal experience of the disaster or older age. Efforts to alleviate responders' initial symptoms will be required.

Effect of interaction between a specific subtype of child abuse and the FKBP5 rs1360780 SNP on DNA methylation among patients with bipolar disorder.

BACKGROUND: Child abuse is a risk factor for mood disorders, and linked to decreased DNA methylation (DNAm) of FKBP5 intron 7 through interactions with the single nucleotide polymorphism (SNP) rs1360780. However, no study has investigated which specific subtypes of child abuse are related to decreased DNAm of FKBP5 intron 7 in mood disorders. We therefore aimed to examine the relationship among various subtypes of child abuse, rs1360780, and the DNAm level of FKBP5 intron 7. METHODS: A total of 190 subjects (87 patients with major depressive disorder [MDD], 61 patients with bipolar disorder [BD], and 42 healthy controls) participated. The Child Abuse and Trauma Scale (CATS) was used to evaluate child abuse. Whole blood was processed for genotyping, and pyrosequencing was conducted to assess the DNAm level of FKBP5 intron 7. A multiple regression analysis was used to analyze the DNAm level as a dependent variable, and the CATS subtypes and rs1360780 were used as independent variables. RESULTS: Emotional abuse/neglect, one of the specific subtypes of child abuse, was related to lower DNAm of FKBP5 intron 7 interacting with rs1360780 in the BD patients. There were no significant results in the MDD patients or the controls. LIMITATIONS: Since the study was limited to Japanese individuals, particularly those with MDD and BD, the findings are not generalizable. Furthermore, as child abuse was measured retrospectively, there may be recall bias. CONCLUSIONS: This finding indicates that a specific subtype of child abuse may play an important role in the development of BD.

Investigation of the impact of preconditioning with lipopolysaccharide on inflammation-induced gene expression in the brain and depression-like behavior in male mice.

Although several recent studies have suggested that neuroinflammation plays a role in depression, both medication and neuroinflammatory preventive strategies have been poorly investigated. Recent studies have indicated that preconditioning with lipopolysaccharide (LPS) reduces the damage that occurs following ischemic stroke and brain trauma. However, to date, the effects of LPS preconditioning on psychiatric symptoms have not been reported. Thus, we assessed gene expression and behavioral changes affected by preconditioning with low-dose (LD) LPS in male mice with systemic inflammation induced by administration of high-dose (HD) LPS. mRNA expression analyses of cytokine-, glial-, and oxidative stress-associated genes revealed that majority of these genes responded to HD LPS. Differential gene expression in the presence and absence of LD LPS preconditioning, identified a subset of genes that may contribute to the mechanism of LPS preconditioning in the brain. Notably, LPS preconditioning attenuated an increase in expression of the astrocyte marker Gfap caused by systemic inflammation, suggesting that astrocytes have a key role in endotoxin tolerance in the brain induced by LPS preconditioning. As increased astrocyte in the brain of patients with depression is suggested to contribute to the pathophysiology of major depression, LPS preconditioning might be applicable to the prevention and treatment of depression. Unfortunately, in this study, LPS preconditioning did not show a reversal effect on behavior decline due to high-dose LPS-induced systemic inflammation. Alternative aspects of behavioral changes should be assessed to identify behavioral components that are affected by LPS preconditioning. Nonetheless, the findings in the present study indicate the possibility of the mechanism of endotoxin tolerance induction in the brain via astrocyte regulation by LPS preconditioning. Since there has been reported pharmacological significance of astrocytes in psychiatric disorders, regulation of endotoxin tolerance might be a key method to control psychiatric symptoms.

Machine Learning Based Suicide Ideation Prediction for Military Personnel.

Military personnel have greater psychological stress and are at higher suicide attempt risk compared with the general population. High mental stress may cause suicide ideations which are crucially driving suicide attempts. However, traditional statistical methods could only find a moderate degree of correlation between psychological stress and suicide ideation in non-psychiatric individuals. This article utilizes machine learning techniques including logistic regression, decision tree, random forest, gradient boosting regression tree, support vector machine and multilayer perceptron to predict the presence of suicide ideation by six important psychological stress domains of the military males and females. The accuracies of all the six machine learning methods are over 98%. Among them, the multilayer perceptron and support vector machine provide the best predictions of suicide ideation approximately to 100%. As compared with the BSRS-5 score ≥7, a conventional criterion, for the presence of suicide ideation ≥1, the proposed algorithms can improve the performances of accuracy, sensitivity, specificity, precision, the AUC of ROC curve and the AUC of PR curve up to 5.7%, 35.9%, 4.6%, 65.2%, 4.3% and 53.2%, respectively; and for the presence of more severely intense suicide ideation ≥2, the improvements are 6.1%, 26.2%, 5.8%, 83.5%, 2.8% and 64.7%, respectively.

Association of Psychological Stress with Physical Fitness in a Military Cohort: The CHIEF Study.

INTRODUCTION: Psychological stress is associated with sedentary behavior, which may impair exercise performance. The aim of our study was to examine the association between psychological stress and physical fitness in military personnel. METHOD: A military cohort of 4080 subjects in Taiwan was used for the analysis. The Brief Symptoms Rating Scale (BSRS-5) includes items of anxiety, depression, hostility, interpersonal sensitivity, and insomnia measured by a five-point Likert-type scale of 0-4. Psychological stress was defined as normal (n = 3657), slight (n = 314), and great (n = 109) by BSRS-5 score ≤5, 6-9, and ≥10, respectively. Aerobic fitness and anaerobic fitness were evaluated by the time of 3000-meter running and the numbers of 2-min sit-ups and 2-min push-ups, respectively. Multiple linear and logistic regression analyses were used to determine the relationship. RESULTS: As compared with normal stress, slight and great stress were positive dose-dependently correlated with 3000-meter running time (ß = 9.09 and 14.44; P = 0.0032 and 0.048, respectively) after adjusting for age, sex, service specialty, body mass index, systolic blood pressure, cigarette smoking, alcohol intake, hemoglobin levels, and exercise frequency. Similarly, those with slight stress were more likely to be the worst 10% performers in the 3000-meter run test relative to the normal individuals (odds ratio and 95% confidence intervals: 1.50, 1.00-2.24). By contrast, there was no relationship of psychological stress with the numbers of 2-min sit-ups and 2-min push-ups. CONCLUSIONS: Our findings suggest that the presence of higher psychological stress on military personnel may reduce their cardiorespiratory fitness but not affect the anaerobic fitness.

The effects of eicosapentaenoic acid dietary supplementation on behavioral parameters and expression of hippocampal brain-derived neurotrophic factor in an animal model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a trauma- and stressor-related disorder, characterized by bi-directional symptomatic manifestations of increase in both hyperarousal/hypervigilance and numbing/avoidance. In our previous reports, we have proposed an animal model of PTSD using avoidance/escape task sessions in the shuttle box after delivering an inescapable foot-shock traumatization in the same box (Wakizono et al., 2007), and demonstrated the efficacy of 2-week administration of antidepressant on the hyperarousal/hypervigilant behavioral parameters (Sawamura et al., 2004) in the model. In this study, we observed a partial but significant efficacy of oral supplementation of eicosapentaenoic acid (EPA) for five weeks on the numbing/avoidance behavior in the experimental model. Additionally, western blot analyses using brain-derived neurotrophic factor (BDNF) monoclonal antibody revealed a decreased expression of BDNF protein, in the hippocampal region of the rats, due to foot-shock traumatization and a significantly increased expression of BDNF protein after oral EPA supplementation. The results indicate a possibility that alteration of the numbing/avoidance behavior parallels the expression of hippocampal BDNF in the rat brain. The present study suggests a possibility that EPA supplementation in the treatment of PTSD ameliorates persistent numbing/avoidance symptoms. (185 words).