Neighborhood Stress Predicts Fear of Sleep Independently of Posttraumatic Stress Disorder.

BACKGROUND: Chronic insufficient sleep is linked to a variety of adverse health outcomes, and African Americans have been found to have poorer sleep than their non-Hispanic White counterparts. African Americans disproportionately live in low-income disordered neighborhoods which increases their risk of trauma exposure and adversely affects their sleep. Fear of sleep is a construct linked to posttraumatic stress disorder (PTSD). We have reported a relationship between fear of sleep and insomnia in urban residing African Americans. Our objective is to report the relative contributions of neighborhood stress along with PTSD to fear of sleep. METHODS: The present study features a nonclinical sample of 117 African Americans (ages 18-35) who reside in DC. RESULTS: After controlling for gender, hierarchical linear regression analyses revealed that PTSD severity and perceptions of the neighborhood environment accounted for approximately 32% of the variance in sleep-related fears (∆R2 = .320, p < .001). Regression coefficients suggest that perceptions of the neighborhood (ß = .360) predict sleep-related fears to a similar degree as PTSD severity (ß = .368). CONCLUSION: Results from this study have implications for interventions to help African Americans to cope with their neighborhood environments effect on their sleep.

Strategies for Controlling Unwanted Intrusive Thoughts and Insomnia Severity in Urban-Residing Young Adult African Americans.

INTRODUCTION: Poor sleep is common in our society, particularly for African Americans, and is associated with adverse mental and physical health outcomes. Unwanted, intrusive thoughts contribute to sleep disturbances and can be engendered by living in stressful urban environments, which are disproportionately inhabited by African Americans. Studies of other populations have shown that cognitive coping strategies to manage intrusive thoughts vary in their adaptiveness. OBJECTIVE: To examine the relationship between thought control strategies and insomnia severity in urban residing young-adult African Americans. METHOD: Sixty-four young adult African Americans completed a demographic questionnaire, the Thought Control Questionnaire for Insomnia-revised, and the Insomnia Severity Index. RESULTS: There were moderate to strong positive correlations of aggressive suppression, worry, behavioral distraction, and social avoidance with ISI scores. Poor sleepers endorsed greater use of worry and aggressive suppression than good sleepers. Results from a multiple linear regression analysis revealed that aggressive suppression, social avoidance, and behavioral distraction significantly predicted insomnia severity, and aggressive suppression was the strongest predictor in the model. CONCLUSIONS: These results extend findings of aggressive suppression as a correlate of insomnia severity to an urban-residing young adult African American sample. Future research should identify adaptive approaches and the utility of modifying maladaptive strategies.

Trial of Prazosin for Post-Traumatic Stress Disorder in Military Veterans.

BACKGROUND: In randomized trials, prazosin, an α1-adrenoreceptor antagonist, has been effective in alleviating nightmares associated with post-traumatic stress disorder (PTSD) in military veterans. METHODS: We recruited veterans from 13 Department of Veterans Affairs medical centers who had chronic PTSD and reported frequent nightmares. Participants were randomly assigned to receive prazosin or placebo for 26 weeks; the drug or placebo was administered in escalating divided doses over the course of 5 weeks to a daily maximum of 20 mg in men and 12 mg in women. After week 10, participants continued to receive prazosin or placebo in a double-blind fashion for an additional 16 weeks. The three primary outcome measures were the change in score from baseline to 10 weeks on the Clinician-Administered PTSD Scale (CAPS) item B2 ("recurrent distressing dreams"; scores range from 0 to 8, with higher scores indicating more frequent and more distressing dreams); the change in score from baseline to 10 weeks on the Pittsburgh Sleep Quality Index (PSQI; scores range from 0 to 21, with higher scores indicating worse sleep quality); and the Clinical Global Impression of Change (CGIC) score at 10 weeks (scores range from 1 to 7, with lower scores indicating greater improvement and a score of 4 indicating no change). RESULTS: A total of 304 participants underwent randomization; 152 were assigned to prazosin, and 152 to placebo. At 10 weeks, there were no significant differences between the prazosin group and the placebo group in the mean change from baseline in the CAPS item B2 score (between-group difference, 0.2; 95% confidence interval [CI], -0.3 to 0.8; P=0.38), in the mean change in PSQI score (between-group difference, 0.1; 95% CI, -0.9 to 1.1; P=0.80), or in the CGIC score (between-group difference, 0; 95% CI, -0.3 to 0.3; P=0.96). There were no significant differences in these measures at 26 weeks (a secondary outcome) or in other secondary outcomes. At 10 weeks, the mean difference between the prazosin group and the placebo group in the change from baseline in supine systolic blood pressure was a decrease of 6.7 mm Hg. The adverse event of new or worsening suicidal ideation occurred in 8% of the participants assigned to prazosin versus 15% of those assigned to placebo. CONCLUSIONS: In this trial involving military veterans who had chronic PTSD, prazosin did not alleviate distressing dreams or improve sleep quality. (Funded by the Department of Veterans Affairs Cooperative Studies Program; PACT ClinicalTrials.gov number, NCT00532493 .).

Nocturnal autonomic nervous system activity and morning proinflammatory cytokines in young adult African Americans.

Compromised sleep and increased sympathetic nervous system (SNS) activity are implicated in the pathogenesis of, and disparities in, cardiovascular disease. Parasympathetic dominance during sleep may be important for cardiovascular health. Sleep and autonomic balance influence immune activity, which impacts atherogenesis. We evaluated relationships between autonomic balance during sleep and morning levels of the immune activating cytokines, C-reactive protein (CRP) and interleukin (IL)-6. Ninety-four (59 female) young adult African Americans without medical conditions and substance use disorders spent 2 consecutive nights in a clinical research unit for sleep recordings and blood drawing on awakening. Cardiac tracings from the second sleep recording were analysed for heart rate variability (HRV). Body mass index was the only non-HRV measure correlated with cytokine levels. Indicators of SNS activity for the presleep, and first non-rapid eye movement (REM) and REM sleep periods were correlated independently with morning IL-6 levels. Altered autonomic balance during sleep may be a modifiable factor that influences immune activation.

Period 3 gene polymorphism and sleep adaptation to stressful urban environments.

This study's objective was to investigate the relationship between a variable-number tandem-repeat (VNTR) Period 3 gene (PER3) polymorphism and sleep adaptation to stressful urban environments. Seventy-five (49 female) African American participants (ages 18-35 years) living in neighbourhoods with high rates of violent crime were selected for the study based on converging criteria for good or poor sleep. Categorization of sleep quality was based on the Insomnia Severity Index (ISI), estimates of typical sleep duration and sleep efficiency. Other assessments included the Fear of Sleep Index (FOSI) and City Stress Inventory (CSI). Whole blood DNA was analysed for the 4 and 5 VNTR alleles using polymerase chain reaction (PCR) and restrictive enzyme digestion. Fifty-seven per cent of those who were homo- or heterozygous for the 4-repeat allele were poor sleepers versus 25% of those homozygous for the 5-repeat allele; χ2  = 4.17, P = 0.041. In a logistic regression model with all the variables with significant bivariate relationships to sleep quality group, FOSI was the only significant predictor (χ2  = 5.68, P = 0.017). FOSI scores were higher among those with the 4-repeat allele (t = 2.66, P = 0.013). The PER3 4 and 5 VNTR polymorphisms appear to influence sensitivity to the effects of stressful urban environments on sleep. While FOSI was the only variable associated independently with sleep quality category, the candidate vulnerability allele was also associated with greater 'fear of sleep'.

Sleep and Processing of Trauma Memories.

Sleep has been implicated in learning processes that appear to underlie recovery from posttraumatic stress disorder (PTSD). The importance of quality and timing of sleep following exposure-based therapies has been suggested. The present study evaluated relationships between sleep and adaptive emotional processing following written narrative exposure (WNE) to memories of traumatic events experienced by participants with clinically significant PTSD symptoms. Participants included 21 urban-residing nontreatment-seeking adults with full or subthreshold symptoms of PTSD who completed 4 sessions of 30-min WNE with the first session either in the evening or the morning. There was a significant reduction of PTSD symptom severity after WNE sessions (partial η = .65), but there was no interaction between group assignment based on the initial session's proximity to sleep and initial reduction of PTSD symptom severity (partial η = .01). Polysomnography following evening WNE revealed increased duration of total sleep and N2%, reduced N3%, and increased eye movement density during REM sleep compared with baseline recordings (dz = 0.65 to 1.15). Reduced N3% and increased REM density were associated with less improvement of PTSD symptoms (r = .58 & -.63). These findings suggest a relationship between preservation of diminished arousal during sleep and adaptive trauma memory processing.

Autonomic and inflammatory consequences of posttraumatic stress disorder and the link to cardiovascular disease.

Stress- and anxiety-related disorders are on the rise in both military and general populations. Over the next decade, it is predicted that treatment of these conditions, in particular, posttraumatic stress disorder (PTSD), along with its associated long-term comorbidities, will challenge the health care system. Multiple organ systems are adversely affected by PTSD, and PTSD is linked to cancer, arthritis, digestive disease, and cardiovascular disease. Evidence for a strong link between PTSD and cardiovascular disease is compelling, and this review describes current clinical data linking PTSD to cardiovascular disease, via inflammation, autonomic dysfunction, and the renin-angiotensin system. Recent clinical and preclinical evidence regarding the role of the renin-angiotensin system in the extinction of fear memory and relevance in PTSD-related immune and autonomic dysfunction is also addressed.

Blood Pressure Dipping and Urban Stressors in Young Adult African Americans.

BACKGROUND: Blunted nocturnal blood pressure (BP) dipping is an early marker of cardiovascular risk that is prevalent among African Americans. PURPOSE: We evaluated relationships of BP dipping to neighborhood and posttraumatic stress and sleep in urban residing young adult African Americans. METHODS: One hundred thirty-six black, predominately African American, men and women with a mean age of 22.9 years (SD = 4.6) filled out surveys and were interviewed and had two, 24-h ambulatory BP recordings. RESULTS: Thirty-eight percent had BP dipping ratios < .10. Wake after sleep onset (WASO), neighborhood disorder and neighborhood poverty rates but not posttraumatic stress symptoms, and other sleep measures correlated significantly with dipping ratios. Models with the neighborhood measures that also included WASO increased the explained variance. CONCLUSIONS: Studies elucidating mechanisms underlying effects of neighborhoods on BP dipping and the role of disrupted sleep, and how they can be mitigated are important directions for future research.

Theta frequency activity during rapid eye movement (REM) sleep is greater in people with resilience versus PTSD.

Emotional memory consolidation has been associated with rapid eye movement (REM) sleep, and recent evidence suggests that increased electroencephalogram spectral power in the theta (4-8 Hz) frequency range indexes this activity. REM sleep has been implicated in posttraumatic stress disorder (PTSD) as well as in emotional adaption. In this cross-sectional study, thirty young healthy African American adults with trauma exposure were assessed for PTSD status using the Clinician Administered PTSD Scale. Two consecutive night polysomnographic (PSG) recordings were performed and data scored for sleep stages. Quantitative electroencephalographic spectral analysis was used to measure theta frequency components sampled from REM sleep periods of the second-night PSG recordings. Our objective was to compare relative theta power between trauma-exposed participants who were either resilient or had developed PTSD. Results indicated higher right prefrontal theta power during the first and last REM periods in resilient participants compared with participants with PTSD. Right hemisphere prefrontal theta power during REM sleep may serve as a biomarker of the capacity for adaptive emotional memory processing among trauma-exposed individuals.

Nocturnal autonomic balance and sleep in PTSD and resilience.

Posttraumatic stress disorder (PTSD) has been associated with heightened nocturnal autonomic nervous system (ANS) arousal and sleep disturbances. It has been suggested that relationships between sleep and nocturnal ANS activity are influenced by insomnia; however, investigation of this relationship has been limited in PTSD. This study examined nocturnal ANS activity and its relationship to sleep in PTSD and resilience. Physically healthy young adult African Americans with current PTSD (n = 20) or who had never had PTSD despite exposure to a high-impact traumatic event (resilient, n = 18) were monitored with ambulatory electrocardiograms and actigraphy for 24-hr periods. Frequency-domain heart-rate variability measures, that is, low-frequency to high-frequency ratios (LF/HF), which index sympathetic nervous system activity, and normalized HF (nHF), which indexes parasympathetic nervous system activity were examined. Normalized HF during the time-in-bed period was lower for those with PTSD than those with resilience (p = .041). Total sleep time was strongly correlated with time-in-bed LF/HF (r = -.72) and nHF (r = .75) in the resilient group, but these were not correlated in the PTSD group. The results suggest elevated nocturnal ANS arousal and dissociation between ANS activity and total sleep time in PTSD.

Validation of the Fear of Sleep Inventory (FOSI) in an urban young adult African American sample.

The Fear of Sleep Inventory (FOSI) was developed to identify factors that contribute to sleep disturbances in individuals exposed to trauma. This investigation examined the psychometric properties of the FOSI in a sample of African American young adults residing in urban areas. A 5-factor structure was derived from an exploratory factor analysis and then verified by confirmatory factor analysis. FOSI factors were positively correlated with the severity of PTSD (rs = .30 to .58, all ps < .001) and insomnia symptoms (rs = .36 to .64, all ps < .001). Individuals with probable PTSD or insomnia had higher scores on the total FOSI and each of the factors compared to those without probable PTSD (all ps < .001; effect sizes: r = .32 to .62) or insomnia (all ps < .001; effect sizes: r = .42 to .70). These data expand the evidence that the FOSI identifies factors contributing to sleep disturbances in trauma-exposed individuals.

Relationships of posttraumatic stress symptoms and sleep measures to cognitive performance in young-adult African Americans.

Disturbed sleep is a prominent feature of posttraumatic stress disorder (PTSD). PTSD and disrupted sleep have been independently linked to cognitive deficits; however, synergistic effects of PTSD and poor sleep on cognition have not been investigated. The purpose of this study was to examine the effects of PTSD symptoms and objectively measured disruptions to sleep on cognitive function. Forty-four young-adult African American urban residents comprised the study sample. The Clinician-Administered PTSD Scale (CAPS; Blake et al., 1995) was utilized to determine the severity of PTSD symptoms. Participants underwent 2 consecutive nights of polysomnography. The Automated Neuropsychological Assessment Metrics (Reeves, Winter, Bleiberg, & Kang, ) was utilized to assess sustained attention and the Rey Auditory Verbal Learning Test (Schmidt, ) was used to evaluate verbal memory. PTSD symptom severity, r(42) = .40, p = .007, was significantly associated with omission errors on the sustained attention task, and sleep duration, r(42) = .41, p = .006, and rapid eye movement sleep, r(42) = .43, p = .003, were positively correlated with verbal memory. There was an interaction of PTSD symptom severity and sleep duration on omission errors such that more than 7 hours 12 minutes of sleep mitigated attentional lapses that were associated with PTSD.

The influence of PTSD, sleep fears, and neighborhood stress on insomnia and short sleep duration in urban, young adult, African Americans.

African Americans residing in stressful urban environments have high rates of insomnia and short sleep duration, both of which are associated with adverse health outcomes. However, limited data exist that explore factors influencing inadequate sleep in this high-risk population. This study sought to evaluate the contributions of demographics, trauma, posttraumatic stress disorder (PTSD) symptoms, sleep fears, and neighborhood stress to both insomnia and short sleep in urban African American young adults. Data were analyzed from self-report measures completed by 378 participants 18-35 years of age. PTSD symptom severity and sleep fears were independently associated with insomnia severity, and sleep fears was associated with sleep duration. Results have implications for preventative health intervention strategies for urban African American young adults.

Uncomplicated obesity in an African American population seeking medical weight loss.

OBJECTIVE: Obesity is highly prevalent and adds greatly to the risk of cardiovascular and metabolic diseases. However, a subset of the obese has been identified who do not appear to carry this risk. Some studies suggest that anthropomorphic correlates of risk, such as waist circumference, differ between African Americans and Whites and features of uncomplicated obesity have not been well characterized in this population. The goal of our study was to determine the prevalence and associated features of uncomplicated obesity, including relationships to waist circumference and the achievement of weight loss in primarily African American patients. DESIGN: A retrospective chart review. SETTING: Outpatient medically supervised weight loss program located at a teaching hospital in Washington, DC. PARTICIPANTS: Predominately adult African American females. RESULTS: Thirty-one percent of our population had no documented metabolic or cardiovascular disease. This group was on average younger, but had similar waist circumference (44 +/- 13.8 vs 44 +/- 6.6 inches) and achieved similar mean weight loss at 3 months (9.9 +/- 10.4 vs 10.3 +/- 12.4 lbs.) as the group with comorbid conditions. CONCLUSIONS: Waist circumference was not an indicator of risk among African American women and achieved weight loss did not depend on pre-existing comorbidities.

Mental health symptoms are comparable in patients hospitalized with acute illness and patients hospitalized with injury.

BACKGROUND: High rates of mental health symptoms such as depression, anxiety, and posttraumatic stress disorder (PTSD) have been found in patients hospitalized with traumatic injuries, but little is known about these problems in patients hospitalized with acute illnesses. A similarly high prevalence of mental health problems in patients hospitalized with acute illness would have significant public health implications because acute illness and injury are both common, and mental health problems of depression, anxiety, and PTSD are highly debilitating. METHODS AND FINDINGS: In patients admitted after emergency care for Acute Illness (N = 656) or Injury (N = 661) to three hospitals across the United States, symptoms of depression, anxiety, and posttraumatic stress were compared acutely (Acute Stress Disorder) and two months post-admission (PTSD). Patients were ethnically/racially diverse and 54% female. No differences were found between the Acute Illness and Injury groups in levels of any symptoms acutely or two months post-admission. At two months post-admission, at least one symptom type was elevated for 37% of the Acute Illness group and 39% of the Injury group. Within racial/ethnic groups, PTSD symptoms were higher in Black patients with injuries than for Black patients with acute illness. A disproportionate number of Black patients had been assaulted. CONCLUSIONS: This study found comparable levels of mental health sequelae in patients hospitalized after emergency care for acute illness as in patients hospitalized after emergency care for injury. Findings of significantly higher symptoms and interpersonal violence injuries in Black patients with injury suggest that there may be important and actionable differences in mental health sequelae across ethnic/racial identities and/or mechanisms of injury or illness. Routine screening for mental health risk for all patients admitted after emergency care could foster preventive care and reduce ethnic/racial disparities in mental health responses to acute illness or injury.

Understanding sleep disturbances in African-American breast cancer survivors: a pilot study.

OBJECTIVES: The goals of this study were (i) to report the prevalence and nature of sleep disturbances, as determined by clinically significant insomnia symptoms, in a sample of African-American breast cancer survivors; (ii) to assess the extent to which intrusive thoughts about breast cancer and fear of recurrence contributes to insomnia symptoms; and (iii) to assess the extent to which insomnia symptoms contribute to fatigue. METHODS: African-American breast cancer survivors completed surveys pertaining to demographics, medical history, insomnia symptoms, and intrusive thoughts about breast cancer, fear of cancer recurrence, and fatigue. Hierarchical regression models were performed to investigate the degree to which intrusive thoughts and concerns of cancer recurrence accounted for the severity of insomnia symptoms and insomnia symptom severity's association with fatigue. RESULTS: Forty-three percent of the sample was classified as having clinically significant sleep disturbances. The most commonly identified sleep complaints among participants were sleep maintenance, dissatisfaction with sleep, difficulty falling asleep, and early morning awakenings. Intrusive thoughts about breast cancer were a significant predictor of insomnia symptoms accounting for 12% of the variance in insomnia symptom severity. After adjusting for covariates, it was found that insomnia symptom severity was independently associated with fatigue accounting for 8% of variance. CONCLUSIONS: A moderate proportion of African-American breast cancer survivors reported significant problems with sleep. Sleep disturbance was influenced by intrusive thoughts about breast cancer, and fatigue was associated with the severity of participants' insomnia symptoms. This study provides new information about sleep-related issues in African-American breast cancer survivors.

Gender differences in sleep during the aftermath of trauma and the development of posttraumatic stress disorder.

Women have a greater risk of developing posttraumatic stress disorder (PTSD) after exposure to trauma. Although sleep abnormalities have been implicated in the development of PTSD, gender differences in sleep soon after a traumatic event have not been investigated. This secondary analysis examined sleep characteristics using polysomnography in 13 female and 22 male trauma patients within a month of their traumatic injuries and assessed PTSD symptoms at 2-months post-injury. Results revealed more wake after sleep onset in women who developed PTSD compared to men who developed PTSD. Women with subsequent PTSD also had less total sleep time than women without subsequent PTSD. Findings suggest possible contributions of impaired sleep maintenance to the development of PTSD in women.

An exploratory analysis of fear of recurrence among African-American breast cancer survivors.

BACKGROUND: Fear of recurrence (FOR) is a psychological concern that has been studied extensively in cancer survivors but has not been adequately examined in African-American breast cancer survivors. PURPOSE: This exploratory study describes the extent and nature of FOR in African-American breast cancer survivors. FOR is examined in relation to socio-demographic characteristics, treatment-related characteristics, psychological distress, and quality of life (QOL). METHODS: Participants completed questionnaires assessing FOR, psychological distress, QOL, and demographic and treatment characteristics. Pearson r correlations, t tests, and ANOVAs were used to determine the association between FOR and demographic and treatment-related characteristics. Hierarchical multiple regression models were performed to investigate the degree to which FOR dimensions account for the variance in QOL and psychological distress. RESULTS: Fifty-one African-American breast cancer survivors participated in this study. The mean age of participants was 64.24 (SD = 12.3). Overall fears as well as concerns about death and health were rated as low to moderate. Role worries and womanhood worries were very low. Inverse relationships were observed between age and FOR dimensions. FOR was positively correlated with measures of psychological distress and negatively correlated with QOL. FOR significantly accounted for a portion of the variance in QOL and distress after controlling for other variables. CONCLUSIONS: This study suggests that African-American women in this sample demonstrated some degree of FOR. Results indicate that FOR among African-American breast cancer survivors decreases with age and time since diagnosis and co-occurs with psychological distress as well as diminished quality of life.

Evaluation of suvorexant for trauma-related insomnia.

STUDY OBJECTIVES: Effective pharmacological treatments for sleep disturbance related to trauma with and without co-occurring posttraumatic stress disorder (PTSD) are needed. There is debate regarding what effects on rapid eye movement sleep (REMS) would be beneficial. Suvorexant is the first dual orexin receptor antagonist (DORA) approved for the treatment of insomnia. In contrast to most psychotropic agents, DORAs can enhance REMS while reducing arousal. We evaluated 6 weeks of suvorexant treatment for trauma-related insomnia in a double-blind, placebo-controlled clinical trial with clinical and polysomnographic evaluation. METHODS: Participants with insomnia that followed a traumatic event were recruited from the community. Representation of current, past-only, and never having met criteria for PTSD was similar and most participants had experienced trauma-related nightmares. Participants were randomly assigned to receive suvorexant or placebo, initially at 10 mg and increased to 20 mg after 1 week, if tolerated. Polysomnography was obtained for screening, at baseline, and at 2 weeks of treatment. RESULTS: The thirty-seven evaluable participants had significant improvement of PTSD and insomnia symptoms, however, there were no significant interactions with treatment condition. Medication was well tolerated with only one dropout being related to side effects. Within the suvorexant group increased REM segment duration correlated with concurrent PTSD symptom reduction. Nightmares remitted in all of the participants who received suvorexant and all but one of those receiving placebo. CONCLUSIONS: A robust placebo response undermined detecting a medication effect. Further evaluation of DORAs for trauma-related insomnia, as well as factors contributing to placebo-response, are warranted.

The association of polysomnographic sleep on posttraumatic stress disorder symptom clusters in trauma-exposed civilians and veterans.

Study Objectives: Self-reported sleep disturbance has been established as a risk factor and predictor for posttraumatic stress disorder (PTSD); however, less is known about the relationship between objective sleep and PTSD symptom clusters, and the specific role of hyperarousal. The present study examined the relationships between sleep continuity and architecture on PTSD symptom clusters. Methods: Participants underwent two in-laboratory sleep studies to assess sleep continuity and architecture. They also completed the Clinician-Administered PTSD-IV scale and the Structured Clinical Interview for the DSM-IV to assess for PTSD diagnosis and other psychiatric disorders. Results: Sleep continuity (i.e. total sleep time, sleep efficiency percent, wake after sleep onset, sleep latency) was significantly related to PTSD Cluster B (reexperiencing) symptom severity (R 2 = .27, p < .001). Sleep architecture, specifically Stage N1 sleep, was significantly associated with PTSD Cluster B (t = 2.98, p = .004), C (Avoidance; t = 3.11, p = .003), and D (Hyperarosual; t = 3.79, p < .001) symptom severity independently of Stages N2, N3, and REM sleep. REM sleep variables (i.e. REM latency, number of REM periods) significantly predicted Cluster D symptoms (R 2 = .17, p = .002). Conclusions: These data provide evidence for a relationship between objective sleep and PTSD clusters, showing that processes active during Stage N1 sleep may contribute to PTSD symptomatology in civilians and veterans. Further, these data suggest that arousal mechanisms active during REM sleep may also contribute to PTSD hyperarousal symptoms.This paper is part of the War, Trauma, and Sleep Across the Lifespan Collection. This collection is sponsored by the Sleep Research Society.