COVID-19 Concerns, Information Needs, and Adverse Mental Health Outcomes among U.S. Soldiers.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic disrupted U.S. Military operations and potentially compounded the risk for adverse mental health outcomes by layering unique occupational stress on top of general restrictions, fears, and concerns. The objective of the current study was to characterize the prevalence of COVID-19 concerns and information needs, demographic disparities in these outcomes, and the degree to which COVID-19 concerns and information needs were associated with heightened risk for adverse mental health outcomes among U.S. Army soldiers. MATERIALS AND METHODS: Command-directed anonymous surveys were administered electronically to U.S. soldiers assigned to one of three regional commands in the Northwest United States, Europe, and Asia-Pacific Region. Surveys were administered in May to June 2020 to complete (time 1: n = 21,294) and again in December 2020 to January 2021 (time 2: n = 10,861). Only active duty or active reservists/national guard were eligible to participate. Members from other branches of service were also not eligible. RESULTS: Highly prevalent COVID-19 concerns included the inability to spend time with friends/family, social activities, and changing rules, regulations, and guidance related to COVID-19. Some information needs were endorsed by one quarter or more soldiers at both time points, including stress management/coping, travel, how to protect oneself, and maintaining mission readiness. COVID-19 concerns and information needs were most prevalent among non-White soldiers. Concerns and information needs did not decline overall between the assessments. Finally, COVID-19 concerns were associated with greater risk of multiple adverse mental health outcomes at both time points. CONCLUSIONS: COVID-19 concerns and information needs were prevalent and showed little evidence of decrement over the course of the first 6 months of the pandemic. COVID-19 concerns were consistently associated with adverse mental health outcomes. These data highlight two targets and potential demographic subgroups such that local leadership and Army medicine and public health enterprises can be better prepared to monitor and address to maintain force health and readiness in the face of possible future biomedical threats.

A Preliminary Examination of the Effects and Mechanisms of Cognitive Behavioral Therapy for Insomnia on Systemic Inflammation Among Patients with Knee Osteoarthritis.

BACKGROUND: Systemic inflammation, particularly the elevation of interleukin-6 (IL-6), plays an important role in the maintenance and progression of knee osteoarthritis. Insomnia, being highly prevalent in knee osteoarthritis, is understood to be a risk factor for systemic inflammation. The present study examined if cognitive behavioral therapy for insomnia (CBT-I) would reduce circulating IL-6 levels to a larger extent than the active control condition via greater improvement in sleep maintenance disturbance at mid-treatment, among individuals with knee osteoarthritis and insomnia disorder. METHODS: This is an ancillary study (N = 64) from a larger double-blind, randomized, active controlled clinical trial. Serum IL-6 was measured at baseline, post-treatment, and 3- and 6-month follow-ups. Sleep was measured by daily sleep diaries. RESULTS: Overall, there was no significant IL-6 trajectory differences between CBT-I and the active control (p = .64). Compared to the active control, CBT-I demonstrated greater improvement in sleep maintenance disturbance at mid-treatment (p = .01), which, in turn, was significantly associated with lower levels of IL-6 at 3-month follow-up (p < .05). Sleep maintenance disturbance at mid-treatment did not significantly predict changes in IL-6 levels at post-treatment (p = .43) and 6-month follow-up (p = .90). CONCLUSIONS: Our study demonstrates that CBT-I can be efficacious in improving sleep maintenance disturbance among individuals with knee osteoarthritis and insomnia disorder. However, no convincing evidence was found that CBT-I can substantially reduce IL-6 levels via improvement in sleep. CBT-I alone may not be effective in reducing systematic inflammation in this clinical population. TRIAL REGISTRATION: NCT00592449.

US Soldiers' Individual and Unit-level Factors Associated with Perceptions of Disinformation in the Military Context.

INTRODUCTION: Although the US Government considers threats of misinformation, disinformation, and mal-information to rise to the level of terrorism, little is known about service members' experiences with disinformation in the military context. We examined soldiers' perceptions of disinformation impact on the Army and their units. We also investigated associations between disinformation perceptions and soldiers' sociodemographic characteristics, reported use of fact-checking, and perceptions of unit cohesion and readiness. METHODS: Active-duty soldiers (N = 19,465) across two large installations in the Southwest US completed an anonymous online survey. RESULTS: Sixty-six percent of soldiers agreed that disinformation has a negative impact on the Army. Thirty-three percent of soldiers perceived disinformation as a problem in their unit. Females were more likely to agree that disinformation has a negative impact on the Army and is a problem in their unit. Higher military rank was associated with lower odds of agreeing that disinformation is a problem in units. Most soldiers were confident about their ability to recognize disinformation (62%) and reported using fact-checking resources (53%), and these factors were most often endorsed by soldiers who agreed that disinformation is a problem for the Army and their unit. Soldiers' perceptions of unit cohesion and readiness were negatively associated with the perception that disinformation is a problem in their unit. CONCLUSION: While the majority of soldiers viewed disinformation as a problem across the Army, fewer perceived it as problematic within their units. Higher levels of reported fact-checking were most evident among those who perceived disinformation as a problem, suggesting that enhancing awareness of the problem of disinformation alone could help mitigate its deleterious impact. Perceptions of disinformation problems within units were associated with soldiers' perceptions of lower unit cohesion and readiness, highlighting misinformation, disinformation, and mal-information's impact on force readiness. Limitations and future directions are discussed.

Impact of the COVID-19 pandemic on army families: Household finances, familial experiences, and soldiers' behavioral health.

The Coronavirus Disease 2019 (COVID-19) pandemic has significantly impacted employment and finances, childcare, and behavioral health across the United States. The Behavioral Health Advisory Team assessed the pandemic's impact on the behavioral health of U.S. Army soldiers and their families. Over 20,000 soldiers at three large installation groups headquartered in the northwestern continental U.S., Republic of Korea, and Germany participated in the cross-sectional survey. Multivariable logistic regression models indicated that key demographics (gender, rank), severity of household financial impact, changes in work situation due to childcare issues, and family members' difficulty coping (both self and spouse/partner and/or child) were independently and consistently associated with greater odds of screening positive for probable clinical depression and generalized anxiety, respectively. These findings highlight how Army families were impacted similarly by the pandemic as their civilian counterparts. Army leadership may action these findings with targeted support for soldiers and their families to ensure they are utilizing supportive services available to them, and that military services continually evolve to meet soldier and family needs during times of crisis and beyond.

Cognitive reappraisal moderates the effect of combat or other exposures on negative behavioral health symptoms.

Understanding the individual differences that can buffer the impact of combat and other adverse exposures on deleterious behavioral health outcomes could lead to more targeted prevention and intervention efforts. Cognitive reappraisal, an antecedent-focused emotion regulation strategy, is linked to positive health outcomes such as lower levels of post-traumatic stress disorder, anxiety, and depression. This study examined the moderating effect of individual differences in cognitive reappraisal use on the association between combat exposure and behavioral health outcomes in active-duty U.S. Soldiers (N = 2,290). This study utilized survey data collected approximately 18 months following a combat deployment to Afghanistan in 2014. Results showed that individual differences in cognitive reappraisal use significantly moderated the effect of combat exposure on anxiety and post-traumatic stress symptoms but not depressive symptoms. Specifically, increasing combat exposures predicted a steeper increase in negative behavioral health symptoms for Soldiers reporting lesser (versus greater) cognitive reappraisal use. These findings highlight a role for cognitive reappraisal as a targetable factor that can mitigate the behavioral health consequences of exposure to combat stressors.

Prototyping Apps for the Management of Sleep, Fatigue, and Behavioral Health in Austere Far-Forward Environments: Development Study.

BACKGROUND: Military service inherently includes frequent periods of high-stress training, operational tempo, and sustained deployments to austere far-forward environments. These occupational requirements can contribute to acute and chronic sleep disruption, fatigue, and behavioral health challenges related to acute and chronic stress and disruption of team dynamics. To date, there is no centralized mobile health platform that supports self- and supervised detection, monitoring, and management of sleep and behavioral health issues in garrison and during and after deployments. OBJECTIVE: The objective of this study was to adapt a clinical decision support platform for use outside clinical settings, in garrison, and during field exercises by medics and soldiers to monitor and manage sleep and behavioral health in operational settings. METHODS: To adapt an existing clinical decision support digital health platform, we first gathered system, content, and context-related requirements for a sleep and behavioral health management system from experts. Sleep and behavioral health assessments were then adapted for prospective digital data capture. Evidence-based and operationally relevant educational and interventional modules were formatted for digital delivery. These modules addressed the management and mitigation of sleep, circadian challenges, fatigue, stress responses, and team communication. Connectivity protocols were adapted to accommodate the absence of cellular or Wi-Fi access in deployed settings. The resulting apps were then tested in garrison and during 2 separate field exercises. RESULTS: Based on identified requirements, 2 Android smartphone apps were adapted for self-monitoring and management for soldiers (Soldier app) and team supervision and intervention by medics (Medic app). A total of 246 soldiers, including 28 medics, received training on how to use the apps. Both apps function as expected under conditions of limited connectivity during field exercises. Areas for future technology enhancement were also identified. CONCLUSIONS: We demonstrated the feasibility of adapting a clinical decision support platform into Android smartphone-based apps to collect, save, and synthesize sleep and behavioral health data, as well as share data using adaptive data transfer protocols when Wi-Fi or cellular data are unavailable. The AIRE (Autonomous Connectivity Independent System for Remote Environments) prototype offers a novel self-management and supervised tool to augment capabilities for prospective monitoring, detection, and intervention for emerging sleep, fatigue, and behavioral health issues that are common in military and nonmilitary high-tempo occupations (eg, submarines, long-haul flights, space stations, and oil rigs) where medical expertise is limited.

Mental Health Outcomes Among American Indian and Alaska Native U.S. Army Soldiers: A Serial Cross-Sectional Analysis.

INTRODUCTION: American Indian and Alaska Native (AI/AN) individuals in the USA experience higher rates of mental illness and preventable death than the general population. Published research demonstrates that AI/AN veterans experience similar disparities to other minorities compared to non-minority veterans; few studies, however, have assessed mental health outcomes in AI/AN active duty military members. The objective of this study was to determine differences in depression, anxiety, hazardous alcohol consumption, and suicidal ideation among AI/AN soldiers compared to soldiers of other races during the Coronavirus Disease 2019 (COVID-19) pandemic. MATERIALS AND METHODS: We conducted repeated cross-sectional electronic surveys to assess the mental health of active duty and activated reserve U.S. Army soldiers within three commands in the Northwestern Continental United States , Republic of Korea, and Germany during May-June 2020 (T1) and December 2020-January 2021 (T2). The primary exposure of interest in the present analysis was race and ethnicity, and the primary outcomes were probable depression with functional impairment (subsequently "depression"), probable anxiety with functional impairment (subsequently "anxiety"), hazardous alcohol use, and suicidal ideation. Multivariable logistic regression models were used to determine the association between demographics and COVID-19 concerns on mental health outcomes for each time point. RESULTS: A total of 21,293 participants responded to the survey at T1 (participation rate = 28.0%), and 10,861 participants responded to the survey at T2 (participation rate = 14.7%). In the multivariable model, AI/AN participants had 1.36 higher adjusted odds of suicidal ideation (95% CI: 1.02-1.82) at T1 and 1.50 greater adjusted odds of suicidal ideation at T2 (95% CI: 1.00-2.24), when compared to non-Hispanic White participants. During T1, there was no significant difference detected between AI/AN and non-Hispanic White participants for anxiety (adjusted odds ratio: 1.21; 95% CI: 0.91-1.60) (Table IV). However, AI/AN participants had 1.82 greater adjusted odds of anxiety when compared to non-Hispanic White participants at T2 (adjusted odds ratio: 1.82; 95% CI: 1.29-2.57). There were no significant differences detected between AI/AN participants and non-Hispanic White participants in multivariable models for either depression or hazardous alcohol use at both time points. CONCLUSIONS: Although we hypothesized that all adverse mental health outcomes would be higher for AI/AN service members at both time points, there were no significant differences at each of the time points analyzed for most of the outcomes analyzed. However, differences in suicidal ideation were found at both time points. Analyses and proposed interventions should account for diversity and heterogeneity of AI/AN populations.

COVID-19 Vaccination Attitudes and Intentions Among U.S. Soldiers: Results from the U.S. Army Behavioral Health Advisory Team (BHAT).

INTRODUCTION: The objective of this study is to characterize the associations between demographic, attitudinal, and leadership factors with COVID-19 vaccination rates, vaccination intentions among those not vaccinated, and attitudes about vaccination safety, effectiveness, and importance. METHODS: A serial cross-sectional anonymous online survey was administered to soldiers at two large U.S. Army Divisions located in the Southwestern region of the U.S. at two different time points (April-May 2021 [Time 1; T1] N = 24,629; July-August 2021 [Time 2; T2] N = 21,116). Binary logistic regressions were used to assess demographic and attitudinal predictors of vaccination receipt and vaccination intent. Multinomial logistic regressions were used to assess demographic and leadership predictors of endorsement of three vaccination attitudes concerning effectiveness, safety, and importance. RESULTS: Approximately 43% of soldiers reported that they received a COVID-19 vaccine at T1, increasing to 67% at T2. Soldiers who agreed with three separate statements on vaccination effectiveness, safety, or importance were more likely to indicate that they intended to get the vaccination at both time points. Soldiers who reported that their immediate supervisor encouraged soldiers to get a COVID-19 vaccine were more likely to indicate that the vaccination was effective, safe, or important at both time points. DISCUSSION: Negative attitudes about COVID-19 vaccines were prevalent and correlated with less intention to get a vaccination. However, prioritizing leadership engagement around the importance of vaccinations may be a simple but widely effective intervention point to increase future vaccine uptake following the development of novel vaccines to future COVID-19 variants.

Management of Acute Stress Reactions in the Military: A Stepped Care Approach.

PURPOSE OF THE REVIEW: This review highlights knowledge gaps surrounding the development and use of interventions for Acute Stress Reactions (ASRs). First, we propose that a stepped care approach to intervention for ASR be developed and utilized in military operational environments. A stepped care approach would include detection and assessment, followed by behavioral intervention, and then medication intervention for ASRs. Second, we discuss potential strategies that can be taken for the development of safe and effective ASR medications. RECENT FINDINGS: ASRs commonly occur in operational environments, particularly in military populations. ASRs impact the safety and performance of individual service members and teams, but there are currently limited options for intervention. Efforts to improve ASR detection and assessment, and development and delivery of ASR interventions for implementation in operational environments, will be critical to maintaining the safety and performance of service members.

US soldiers and the role of leadership: COVID-19, mental health, and adherence to public health guidelines.

BACKGROUND: Previous studies have documented the impact of domain-specific leadership behaviors on targeted health outcomes in employees. The goal of the present study was to determine the association between specific leadership behaviors addressing COVID-19 and US soldiers' mental health and adherence to COVID-19 public health guidelines. METHODS: An electronic, anonymous survey was administered to US Army soldiers across three major commands (N = 7,829) from December 2020 to January 2021. The primary predictor of interest was soldiers' ratings of their immediate supervisors' behaviors related to COVID-19. The outcomes were soldiers' mental health (i.e., depression and generalized anxiety) and adherence to COVID-19 public health guidelines. Covariates were rank, gender, ratings of immediate supervisors' general leadership, level of COVID-19 concerns, and COVID-19 status (e.g., tested positive, became seriously ill). Logistic regressions were used to model the unique association of COVID-19 leadership behaviors with outcomes after adjusting for covariates. RESULTS: High levels of COVID-19 leadership behaviors were associated with lesser likelihood of soldiers' screening positive for depression (AOR = 0.46; 95% CI [0.39, 0.54]) and anxiety (AOR = 0.54; 95% CI [0.45, 0.64]), and greater likelihood of frequent adherence to preventive health guidelines (AORs = 1.58; 95% CI [1.39, 1.80] to 2.50; 95% CI [2.01, 3.11]). CONCLUSION: Higher levels of COVID-19 leadership behaviors may support soldiers' mental health and encourage their adherence to COVID-19 public health guidelines. Given the link between these leader behaviors and soldier adaptation to the pandemic over and above general leadership, training for supervisors should focus on targeting specific health-promoting behaviors. Results can inform leader training for the military and other high-risk occupations.

Gender differences in aggression: A multiplicative function of outward anger expression.

Individuals with a higher (vs. lower) tendency to outwardly express anger (i.e., greater anger-out) generally exhibit greater aggression; men (vs. women) also tend to be more aggressive. Although the general aggression model posits that multiple person variables trigger aggression, the combined effects of multiple person variables are poorly understood. Thus, the aim of this study was to examine the nature of the relation between gender, anger-out, and reactive aggression. In particular, we were interested in whether the effects of anger-out and gender are additive or multiplicative. Specifically, we tested whether men exhibit higher levels of aggression than women at a consistent ratio across all levels of anger-out (i.e., the multiplicative model) or at a fixed amount depending on the level of anger-out (i.e., the additive interaction model). To this end, undergraduate participants (N = 203) completed a task in which they were falsely instructed that their objective was to respond more quickly than a same-sex opponent. They were told that whoever responded more quickly would administer a white noise burst to the opponent and choose its intensity, which served as our measure of aggression. Compared to an additive interaction model, the multiplicative model exhibited a better fit. Specifically, men displayed proportionately more aggression than women with the same level of anger-out. Research on and treatment for aggression should consider the multiplicative effects of factors related to aggression.

Tired and angry: Sleep, mental health, and workplace relational aggression.

Workplace relational aggression incurs substantial costs to organizations in the form of reduced employee effectiveness and can exact a personal toll on the targets of the aggression. The extant literature contains limited studies related to physiological variables in predicting the perpetration of workplace relational aggression. Using survey data from a large US military sample (N = 2290), this research tested a hypothesized indirect effects model of sleep and relational aggression against unit members. Results suggest that subjective sleep duration and discontinuity are associated indirectly with perpetrating relational aggression against unit members through higher levels of poor mental health symptoms. Moreover, this association was more robust at higher versus lower levels of trait anger. This research is among the first to examine sleep disturbance or mental health as potential upstream factors associated with instigating relational aggression in the workplace. This is also among the first scientific studies on perpetrating relational aggression against unit members in the US military.

Sleep disturbance mediates the association of adverse childhood experiences with mental health symptoms and functional impairment in US soldiers.

Adverse childhood experiences (ACEs) can have long-term impacts on a person's mental health, which extend into adulthood. There is a high prevalence of ACEs among service members. Further, service members also report frequently experiencing disrupted sleep. We hypothesized that disrupted sleep may serve a mechanistic function connecting ACEs to functional impairment and poorer mental health. In a cross-sectional sample (n = 759), we found evidence for an indirect effect of ACEs on mental health outcomes through disrupted sleep. In a different sample using two time-points (n = 410), we found evidence for an indirect effect of ACEs on changes in mental health outcomes and functional impairment during a reset period, through changes in disrupted sleep during the same period. Implications, limitations and future research directions are discussed.

Objective changes in activity levels following sleep extension as measured by wrist actigraphy.

OBJECTIVE/BACKGROUND: It is widely established that insufficient sleep can lead to adverse health outcomes. Paradoxically, epidemiologic research suggests that individuals who report habitual nightly sleep greater than 9 h also are at risk for adverse health outcomes. Further, studies have shown that long sleepers have decreased activity levels, which may partially explain the relationship between long sleep duration and mortality. The influence of sleep extension (longer time in bed) on levels of daily activity has not yet been established. The current study examined whether a week of sleep extension altered activity levels within the subsequent daily waking active and sleep period in order to determine whether increased time in bed indeed is related to decreased activity levels. METHODS: A total of 26 healthy volunteers wore wrist accelerometer devices (Actiwatch 2.0, Philips) in order to objectively measure sleep and activity for six days during their normal schedules and for six days during a sleep extension (10 h time in bed) intervention. RESULTS: There were no significant or clinically-relevant differences in 24-h activity or activity during the active or sleep period between baseline and sleep extension conditions. There were no main or interaction effects of day and condition when daily activity counts were compared between baseline and sleep extension conditions for the 24 h period (Day: F(5, 21) = 1.92, p = 0.12; Condition: F(1,25) = 2.93, p = 0.09; Day by Condition: F(5,21) = 0.32, p = 0.83), Active Waking Period (Day: F(5,25) = 1.53, p = 0.18; Condition: F(1,25) = 0.26, p = 0.61; Day by Condition: F(5,21) = 0.55, p = 0.74) or Nightly Sleep (Day: F(5,21) = 0.86, p = 0.51; Condition: F(1,25) = 1.78, p = 0.19; Day by Condition: F(5,21) = 0.79, p = 0.56) periods. In contrast, there was a main effect of condition when examining sleep duration by day between conditions (Day: F(5,21) = 1.60, p = 0.16; Condition: F(1,25) = 167.31, p < 0.001; Day by Condition: F(5,21) = 2.31, p = 0.07), such that sleep duration was longer during the sleep extension condition. DISCUSSION: Sleep duration increased during six days of a sleep extension protocol but activity levels remained similar to their baseline (normal) sleep schedule. The current findings suggest that extending time in bed alone does not alter waking activity counts in young healthy adults. The link between extended sleep and adverse health outcomes may be attributable to other phenotypic factors, or other biological correlates of extended sleep and poor health.

Sleep extension reduces pain sensitivity.

INTRODUCTION: Insufficient sleep increases pain sensitivity in healthy individuals. Additionally, extending sleep (eg, increasing nocturnal sleep time or adding a mid-day nap) has been shown to restore pain sensitivity to baseline levels in sleep deprived/restricted individuals. Whether sleep extension can reduce pain sensitivity beyond baseline levels in non-sleep restricted/deprived individuals remains unknown. METHODS: In a sample of 27 healthy, pain-free, normally-sleeping individuals (17 males, mean age ∼24 yrs), we examined the impact of five nights of sleep extension on pain sensitivity. Pain threshold (elapsed time until the participant reported pain) and pain tolerance (total time the participant kept the hand submerged in the cold water) were measured using the Cold Pressor Task. Furthermore, we assessed the extent to which self-reported sleep amount in relation to the minimal subjective sleep requirement for adequate performance (sleep credit) was associated with pain sensitivity changes. RESULTS: On average individuals slept almost 2 extra hours per night. Our results indicate that sleep extension increases pain tolerance beyond baseline levels. However, sleep extension did not impact pain threshold. We also found that individuals with a smaller sleep credit (ie, those who habitually obtain less sleep than they feel they need) experienced greater increases in pain tolerance after extending sleep. CONCLUSIONS: The present findings suggest that sleep extension may increase pain tolerance but not pain threshold in healthy individuals who normally sleep the recommended amount. Our findings also support the idea that sleep credit may be a strong indicator of sleep debt in the context of pain sensitivity.

Combat exposure, post-traumatic stress symptoms, and health-related behaviors: the role of sleep continuity and duration.

STUDY OBJECTIVES: Aggression, substance misuse, and other health risk behaviors are common among combat veterans. We examined whether sleep quality and quantity predict the association between combat exposure, post-traumatic stress symptoms, and adverse health-related behaviors. METHODS: Soldiers (N = 2420) from a brigade combat team completed surveys assessing combat experiences, and psychological and behavioral health factors, approximately 3 months following deployment to Afghanistan in 2011. RESULTS: Respondents were 93.5% male; 73% were age 18-29 years old. The response rate was 80% (3076/3832); 94% (2876/3076) of the soldiers who attended the recruitment briefings consented to participate in this research. Complete data were available across the variables used in this study for up to 2420 soldiers. Sleep continuity disturbance accounted for the association of combat exposure with post-traumatic stress symptoms and aggression, alcohol use, and risky behavior. Moreover, for soldiers who reported sleep duration of <6 hr per day, the indirect association of combat exposure and post-traumatic stress on aggression, alcohol use, risky behavior, and opioid use was strongest. CONCLUSIONS: This study is the first to model sleep problems as a predictor of the association between combat exposure and post-traumatic stress symptoms and frequently reported health-related behavior problems. Sleep disturbance is highly prevalent among Warfighters. While not fully preventable in operational contexts, these problems can be effectively mitigated postdeployment with appropriate policy and intervention resources. Improving the sleep characteristics of combat-exposed soldiers following deployment should reduce subsequent post-traumatic stress and related health compromising behavior, thereby enhancing force readiness.

Limited Efficacy of Caffeine and Recovery Costs During and Following 5 Days of Chronic Sleep Restriction.

Objectives: To investigate the effects of caffeine on psychomotor vigilance and sleepiness during sleep restriction and following subsequent recovery sleep. Methods: Participants were N = 48 healthy good sleepers. All participants underwent five nights of sleep satiation (time-in-bed [TIB]: 10 hours), followed by five nights of sleep restriction (TIB: 5 hours), and three nights of recovery sleep (TIB: 8 hours) in a sleep laboratory. Caffeine (200 mg) or placebo was administered in the form of chewing gum at 08:00 am and 12:00 pm each day during the sleep restriction phase. Participants completed hourly 10-minute psychomotor vigilance tests and a modified Maintenance of Wakefulness Test approximately every 4 hours during the sleep restriction and recovery phases. Results: Caffeine maintained objective alertness compared to placebo across the first 3 days of sleep restriction, but this effect was no longer evident by the fourth day. A similar pattern of results was found for Maintenance of Wakefulness Test sleep latencies, such that those in the caffeine group (compared to placebo) did not show maintenance of wakefulness relative to baseline after the second night of restriction. Compared to placebo, participants in the caffeine condition displayed slower return to baseline in alertness and wakefulness across the recovery sleep period. Finally, the caffeine group showed greater N3 sleep duration during recovery. Conclusions: Caffeine appears to have limited efficacy for maintaining alertness and wakefulness across 5 days of sleep restriction. Perhaps more importantly, there may be recovery costs associated with caffeine use following conditions of prolonged sleep loss.

Partial Sleep Deprivation Attenuates the Positive Affective System: Effects Across Multiple Measurement Modalities.

Objective: Ample behavioral and neurobiological evidence links sleep and affective functioning. Recent self-report evidence suggests that the affective problems associated with sleep loss may be stronger for positive versus negative affective state and that those effects may be mediated by changes in electroencepholographically measured slow wave sleep (SWS). In the present study, we extend those preliminary findings using multiple measures of affective functioning. Design: In a within-subject randomized crossover experiment, we tested the effects of one night of sleep continuity disruption via forced awakenings (FA) compared to one night of uninterrupted sleep (US) on three measures of positive and negative affective functioning: self-reported affective state, affective pain modulation, and affect-biased attention. Setting: The study was set in an inpatient clinical research suite. Participants: Healthy, good sleeping adults (N = 45) were included. Measurement and Results: Results indicated that a single night of sleep continuity disruption attenuated positive affective state via FA-induced reductions in SWS. Additionally, sleep continuity disruption attenuated the inhibition of pain by positive affect as well as attention bias to positive affective stimuli. Negative affective state, negative affective pain facilitation, nor negative attention bias were altered by sleep continuity disruption. Conclusions: The present findings, observed across multiple measures of affective function, suggest that sleep continuity disruption has a stronger influence on the positive affective system relative to the negative affective affective system.

Attention and interpretation processes and trait anger experience, expression, and control.

This study explored attention and interpretation biases in processing facial expressions as correlates of theoretically distinct self-reported anger experience, expression, and control. Non-selected undergraduate students (N = 101) completed cognitive tasks measuring attention bias, interpretation bias, and Spielberger's State-Trait Anger Expression Inventory (STAXI-2). Attention bias toward angry faces was associated with higher trait anger and anger expression and with lower anger control-in and anger control-out. The propensity to quickly interpret ambiguous faces as angry was associated with greater anger expression and its subcomponent of anger expression-out and with lower anger control-out. Interactions between attention and interpretation biases did not contribute to the prediction of any anger component suggesting that attention and interpretation biases may function as distinct mechanisms. Theoretical and possible clinical implications are discussed.

Evidence for Sustained Mechanical Pain Sensitization in Women With Chronic Temporomandibular Disorder Versus Healthy Female Participants.

UNLABELLED: Generalized dysfunction of the nociceptive system has been hypothesized to be an important pathophysiologic process underlying temporomandibular disorder (TMD) pain. Studies have not identified sensitization to painful stimuli administered prospectively across consecutive days among participants with TMD with chronic pain. We attempted to isolate an empirically derived laboratory-based marker of sustained mechanical pain sensitization. We examined whether this index accounted for variance in prospective assessments of clinical TMD pain. Participants were women with a clinical diagnosis of chronic TMD (n = 30) and healthy female controls (n = 30). Pain thresholds were assessed using digital algometry 4 times at 12-hour intervals over 48 consecutive hours and clinical TMD pain via follow-up telephone assessments. Sustained mechanical pain sensitization, defined by statistically significant linear decrements in pressure pain thresholds across the consecutive testing sessions, discriminated chronic TMD and control participants. An index of sustained sensitization at the masseter accounted for unique variance in clinical TMD pain over the subsequent 3-month assessment period, even controlling for mean pain threshold and baseline pain severity. These preliminary findings highlight discriminant and predictive validity characteristics of a novel marker of protracted pain sensitization among women with chronic TMD pain. PERSPECTIVE: A laboratory-based and empirically defined marker of sustained mechanical pain sensitization over the course of days with acceptable discriminant and predictive validity was identified. This marker may represent a clinically useful marker of chronic TMD pain in women.