To evaluate predeployment sleep duration and insomnia symptoms in relation to the development of mental health symptoms.
Longitudinal cohort study.
The Millennium Cohort Study survey is administered ...via a secure website or US mail.
Data were from 15,204 participants who completed their first deployment between the submissions of 2 consecutive Millennium Cohort questionnaires (2001-2008).
N/A.
Using self-reported data from the Millennium Cohort Study we evaluated the association of predeployment sleep duration and insomnia symptoms on the development of new-onset mental disorders among deployers. Multivariable logistic regression was used to estimate the odds of developing posttraumatic stress disorder (PTSD), depression, and anxiety, while adjusting for relevant covariates including combat-related trauma. The study outcomes were assessed using validated instruments, including the PTSD checklist-civilian version, and the PRIME-MD Patient Health Questionnaire. We identified 522 people with new-onset PTSD, 151 with anxiety, and 303 with depression following deployment. In adjusted models, combat-related trauma and predeployment insomnia symptoms were significantly associated with higher odds of developing posttraumatic stress disorder, depression, and anxiety postdeployment.
Sleep characteristics, especially insomnia symptoms, are related to the development of mental disorders following military deployments. Assessment of insomnia symptoms predeployment may help to better identify those at highest risk for subsequent adverse mental health outcomes.
Gehrman P; Seelig AD; Jacobson IG; Boyko EJ; Hooper TI; Gackstetter GD; Ulmer CS; Smith TC; for the Millennium Cohort Study Team. Predeployment sleep duration and insomnia symptoms as risk factors for new-onset mental health disorders following military deployment.
2013;36(7):1009-1018.
Chimpanzee insectivory is seasonally variable, with pronounced peaks or set seasonal periods of consumption observed in most chimpanzee communities. This variation is interesting given that ...chimpanzees invest considerable effort into complex tool‐using behaviors to acquire insect prey. Evidence suggests this seasonal variation is related to insect behavior, but few studies have been done to empirically examine this relationship. In this study, we assessed whether a seasonal pattern of termite fishing by Nigeria‐Cameroon chimpanzees (Pan troglodytes ellioti) in Mbam & Djerem National Park, Cameroon was driven by termite behavior. We measured termite presence and termite foraging activity monthly at seven termite mounds near Ganga Research Station from April 2022 to April 2023. Macroscopic fecal analysis and camera traps placed at each mound demonstrated termite fishing in this community occurred from March to June, with a rare smaller period of termite fishing in October 2021. Average monthly rainfall, average monthly temperature, and average monthly fruit availability were used to examine potential environmental factors that could impact termite fishing seasonality. Termite presence was significantly different between months with and without chimpanzee termite fishing (t‐test, −6.569, p < .001). Termite presence was also significantly associated with average monthly rainfall (ANOVA, F = 13.9, p = .002, R2 = .775). Termites in this region appear to respond to the transition from dry to wet seasons by moving closer to the soil surface. This corresponds with greater chimpanzee termite fishing, suggesting that termite accessibility may be driving seasonal variation in this behavior.
Using an interdisciplinary approach involving remote camera trap monitoring, termite behavioral surveys, and ecological surveys, we identified key ecological factors related to a pronounced seasonal period of termite fishing in a community of the understudied Nigeria‐Cameroon chimpanzee in central Cameroon. Our results suggest the highly seasonal nature of chimpanzee termite fishing in this region is driven by seasonal variation in termite behavior mediated by rain, which makes termites more accessible to chimpanzees during periods of intermediate rainfall.
IMPORTANCE Beginning in 2005, the incidence of suicide deaths in the US military began to sharply increase. Unique stressors, such as combat deployments, have been assumed to underlie the increasing ...incidence. Previous military suicide studies, however, have relied on case series and cross-sectional investigations and have not linked data during service with postservice periods. OBJECTIVE To prospectively identify and quantify risk factors associated with suicide in current and former US military personnel including demographic, military, mental health, behavioral, and deployment characteristics. DESIGN, SETTING, AND PARTICIPANTS Prospective longitudinal study with accrual and assessment of participants in 2001, 2004, and 2007. Questionnaire data were linked with the National Death Index and the Department of Defense Medical Mortality Registry through December 31, 2008. Participants were current and former US military personnel from all service branches, including active and Reserve/National Guard, who were included in the Millennium Cohort Study (N = 151 560). MAIN OUTCOMES AND MEASURES Death by suicide captured by the National Death Index and the Department of Defense Medical Mortality Registry. RESULTS Through the end of 2008, findings were 83 suicides in 707 493 person-years of follow-up (11.73/100 000 person-years 95% CI, 9.21-14.26). In Cox models adjusted for age and sex, factors significantly associated with increased risk of suicide included male sex, depression, manic-depressive disorder, heavy or binge drinking, and alcohol-related problems. None of the deployment-related factors (combat experience, cumulative days deployed, or number of deployments) were associated with increased suicide risk in any of the models. In multivariable Cox models, individuals with increased risk for suicide were men (hazard ratio HR, 2.14; 95% CI, 1.17-3.92; P = .01; attributable risk AR, 3.5 cases/10 000 persons), and those with depression (HR, 1.96; 95% CI, 1.05-3.64; P = .03; AR, 6.9/10 000 persons), manic-depressive disorder (HR, 4.35; 95% CI, 1.56-12.09; P = .005; AR, 35.6/10 000 persons), or alcohol-related problems (HR, 2.56; 95% CI, 1.56-4.18; P <.001; AR, 7.7/10 000 persons). A nested, matched case-control analysis using 20:1 control participants per case confirmed these findings. CONCLUSIONS AND RELEVANCE In this sample of current and former military personnel observed July 1, 2001-December 31, 2008, suicide risk was independently associated with male sex and mental disorders but not with military-specific variables. These findings may inform approaches to mitigating suicide risk in this population.
Most previous attempts to determine the psychological cost of military deployment have been limited by reliance on convenience samples, lack of pre-deployment data or confidentiality and ...cross-sectional designs.
This study addressed these limitations using a population-based, prospective cohort of U.S. military personnel deployed in support of the operations in Iraq and Afghanistan.
The sample consisted of U.S. military service members in all branches including active duty, reserve and national guard who deployed once (n = 3393) or multiple times (n = 4394). Self-reported symptoms of post-traumatic stress were obtained prior to deployment and at two follow-ups spaced 3 years apart. Data were examined for longitudinal trajectories using latent growth mixture modelling.
Each analysis revealed remarkably similar post-traumatic stress trajectories across time. The most common pattern was low-stable post-traumatic stress or resilience (83.1% single deployers, 84.9% multiple deployers), moderate-improving (8.0%, 8.5%), then worsening-chronic post-traumatic stress (6.7%, 4.5%), high-stable (2.2% single deployers only) and high-improving (2.2% multiple deployers only). Covariates associated with each trajectory were identified.
The final models exhibited similar types of trajectories for single and multiple deployers; most notably, the stable trajectory of low post-traumatic stress preto post-deployment, or resilience, was exceptionally high. Several factors predicting trajectories were identified, which we hope will assist in future research aimed at decreasing the risk of post-traumatic stress disorder among deployers.
Objective: To describe current and future career-span health research in the US Department of Defense Millennium Cohort Study. Methods: Collaborating with all military service branches and the ...Department of Veterans Affairs, the Millennium Cohort Study, lunched in 2001, before September 11 and the start of deployments in Afghanistan and Iraq, to conduct coordinated strategic research to determine any effects of military occupational and deployment-related exposures, on long-term health. Results: More than 150,000 consenting members represent demographic, occupational, military, and health characteristics of the US military. More than 70% of the first two panels have submitted follow-up questionnaires and >50% have deployed since 2001. Conclusions: Prospective cohort data have identified subgroups of military populations at higher risk or more resilient to decrements in mental and physical health. Continued career span and beyond follow-up will answer long-term health questions related to military service.
The approach to monitoring anticoagulation in adult patients receiving heparin on extracorporeal membrane oxygenation (ECMO) support is controversial. The objective of this study was to compare the ...correlation between anti-Xa and activated partial thromboplastin time (aPTT) with heparin dose and to describe their association with clinical events in adult ECMO patients. We conducted a retrospective single-center study of 34 adult ECMO patients whose heparin was monitored by anti-Xa and/or aPTT. The heparin dose-to-assay correlation coefficient was 0.106 for aPTT and 0.414 for anti-Xa (p < 0.001). Major thrombotic and hemorrhagic events occurred in 14.7% and 26.5% of patients, respectively. The median anti-Xa in patients who experienced a major thrombotic event was 0.09 (0.06–0.25) IU/mL compared with 0.36 (0.26–0.44) IU/mL in patients who did not (p = 0.031), whereas the median aPTT did not differ between these groups. The maximum aPTT in patients who experienced a major bleed was 96.9 (76.0–200) seconds compared with 63.5 (44.4–98.6) seconds in patients who did not (p = 0.049), whereas the maximum anti-Xa did not differ between these groups. Monitoring both anti-Xa and aPTT may be warranted to safely provide understanding of pure heparin activity as well as underlying bleeding diatheses in adult ECMO patients.
Objective To describe new onset and persistence of self reported post-traumatic stress disorder symptoms in a large population based military cohort, many of whom were deployed in support of the wars ...in Iraq and Afghanistan.Design Prospective cohort analysis.Setting and participants Survey enrolment data from the millennium cohort (July 2001 to June 2003) obtained before the wars in Iraq and Afghanistan. Follow-up (June 2004 to February 2006) data on health outcomes collected from 50 184 participants.Main outcome measures Self reported post-traumatic stress disorder as measured by the posttraumatic stress disorder checklist—civilian version using Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria.Results More than 40% of the cohort were deployed between 2001 and 2006; between baseline and follow-up, 24% deployed for the first time in support of the wars in Iraq and Afghanistan. New incidence rates of 10-13 cases of post-traumatic stress disorder per 1000 person years occurred in the millennium cohort. New onset self reported post-traumatic stress disorder symptoms or diagnosis were identified in 7.6-8.7% of deployers who reported combat exposures, 1.4-2.1% of deployers who did not report combat exposures, and 2.3-3.0% of non-deployers. Among those with self reported symptoms of post-traumatic stress disorder at baseline, deployment did not affect persistence of symptoms.Conclusions After adjustment for baseline characteristics, these prospective data indicate a threefold increase in new onset self reported post-traumatic stress disorder symptoms or diagnosis among deployed military personnel who reported combat exposures. The findings define the importance of post-traumatic stress disorder in this population and emphasise that specific combat exposures, rather than deployment itself, significantly affect the onset of symptoms of post-traumatic stress disorder after deployment.
To determine the associations between deployment in support of the wars in Iraq and Afghanistan and sleep quantity and quality.
Longitudinal cohort study
The Millennium Cohort Study survey is ...administered via a secure website or US mail.
Data were from 41,225 Millennium Cohort members who completed baseline (2001-2003) and follow-up (2004-2006) surveys. Participants were placed into 1 of 3 exposure groups based on their deployment status at follow-up: nondeployed, survey completed during deployment, or survey completed postdeployment.
N/A.
Study outcomes were self-reported sleep duration and trouble sleeping, defined as having trouble falling asleep or staying asleep. Adjusted mean sleep duration was significantly shorter among those in the deployed and postdeployment groups compared with those who did not deploy. Additionally, male gender and greater stress were significantly associated with shorter sleep duration. Personnel who completed their survey during deployment or postdeployment were significantly more likely to have trouble sleeping than those who had not deployed. Lower self-reported general health, female gender, and reporting of mental health symptoms at baseline were also significantly associated with increased odds of trouble sleeping.
Deployment significantly influenced sleep quality and quantity in this population though effect size was mediated with statistical modeling that included mental health symptoms. Personnel reporting combat exposures or mental health symptoms had increased odds of trouble sleeping. These findings merit further research to increase understanding of temporal relationships between sleep and mental health outcomes occurring during and after deployment.
PDF
