Sleep disturbances as the hallmark of PTSD: where are we now?

ENIGMA-Sleep: Challenges, opportunities, and the road map

Neuroimaging and genetics studies have advanced our understanding of the neurobiology of sleep and its disorders. However, individual studies usually have limitations to identifying consistent and reproducible effects, including modest sample sizes, heterogeneous clinical characteristics and varied methodologies. These issues call for a large-scale multi-centre effort in sleep research, in order to increase the number of samples, and harmonize the methods of data collection, preprocessing and analysis using pre-registered well-established protocols. The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) consortium provides a powerful collaborative framework for combining datasets across individual sites. Recently, we have launched the ENIGMA-Sleep working group with the collaboration of several institutes from 15 countries to perform large-scale worldwide neuroimaging and genetics studies for better understanding the neurobiology of impaired sleep quality in population-based healthy individuals, the neural consequences of sleep deprivation, pathophysiology of sleep disorders, as well as neural correlates of sleep disturbances across various neuropsychiatric disorders. In this introductory review, we describe the details of our currently available datasets and our ongoing projects in the ENIGMA-Sleep group, and discuss both the potential challenges and opportunities of a collaborative initiative in sleep medicine.

What goes around comes around: Nightmares and daily stress are bidirectionally associated in nurses

Nurses may experience frequent nightmares due to stressful work environments. Nightmares may also exacerbate stress among nurses, although this has yet to be tested empirically. We examined daily bidirectional associations between stress severity and nightmares, and moderation by post-traumatic stress disorder (PTSD) symptoms. 392 nurses (92% female; 78% White) completed 14 days of sleep diaries to assess previous-day stress severity and nightmare occurrence and severity. PTSD symptoms were assessed at baseline. Multilevel models were used to examine bidirectional, within-person associations between daily stress and nightmares, and cross-level moderation by baseline PTSD symptoms. 47.2% of nurses reported at least one nightmare across the two weeks. Days with greater stress were associated with higher odds of experiencing a nightmare (OR = 1.22, p = 0.001), as well as greater nightmare severity (b = 0.09, p = 0.033). Nightmare occurrence was associated with greater next-day stress severity (b = 0.15, p < 0.001). Daily stress and nightmare associations were similar for those with and without PTSD symptoms. Nightmares and stress may occur in a bidirectional fashion. Nurses face intense occupational demands and frequent exposure to potentially traumatic events. Studies should explore whether targeting nightmares and stress may improve nurses' health and well-being.

Sleep Power Spectral Density and Spindles in PTSD and Their Relationship to Symptom Severity

Sleep disturbances are common in post-traumatic stress disorder (PTSD), although which sleep microarchitectural characteristics reliably classify those with and without PTSD remains equivocal. Here, we investigated sleep microarchitectural differences (i.e., spectral power, spindle activity) in trauma-exposed individuals that met (n = 45) or did not meet (n = 52) criteria for PTSD and how these differences relate to post-traumatic and related psychopathological symptoms. Using ecologically-relevant home sleep polysomnography recordings, we show that individuals with PTSD exhibit decreased beta spectral power during NREM sleep and increased fast sleep spindle peak frequencies. Contrary to prior reports, spectral power in the beta frequency range (20.31-29.88 Hz) was associated with reduced PTSD symptoms, reduced depression, anxiety and stress and greater subjective ability to regulate emotions. Increased fast frequency spindle activity was not associated with individual differences in psychopathology. Our findings may suggest an adaptive role for beta power during sleep in individuals exposed to a trauma, potentially conferring resilience. Further, we add to a growing body of evidence that spindle activity may be an important biomarker for studying PTSD pathophysiology.

The Relationship of Fear-Potentiated Startle and Polysomnography-Measured Sleep in Trauma-Exposed Men and Women with and without PTSD: Testing REM Sleep Effects and Exploring the Roles of an Integrative Measure of Sleep, PTSD Symptoms, and Biological Sex

STUDY OBJECTIVES

Published research indicates that sleep is involved in emotional information processing. Using a fear-potentiated startle (FPS) and nap sleep protocol, we examined the relationship of emotional learning with REM sleep (REMS) in trauma-exposed participants. We also explored the roles of PTSD symptoms, biological sex, and an integrative measure of polysomnography-measured (PSG) sleep in the learning-sleep relationship.

METHODS

After an adaptation nap, participants (N=46) completed 2 more visits (counterbalanced): a stress-condition visit, which included FPS conditioning procedures prior to a nap and assessment of learning retention and fear extinction training after the nap, and a control visit, which included a nap opportunity without stressful procedures. FPS conditioning included a "fear" visual stimulus paired with an air blast to the neck and a "safety" visual stimulus never paired with an air blast. Retention and extinction involved presentation of the visual stimuli without the air blast. Primary analyses examined the relationship between FPS responses pre- and post- sleep with stress-condition REMS duration, controlling for control-nap REMS duration.

RESULTS

Higher safety learning predicted increased REMS and increased REMS predicted more rapid extinction learning. Similar relationships were observed with an integrative PSG sleep measure. They also showed unexpected effects of PTSD symptoms on learning and showed biological sex effects on learning-sleep relationships.

CONCLUSIONS

Findings support evidence of a relationship between adaptive emotional learning and REMS. They underscore the importance of examining sex effects in sleep-learning relationships. They introduce an integrative PSG sleep measure with potential relevance to studies of sleep and subjective and biological outcomes.

Sleep quality and outcome of exposure therapy in adults with social anxiety disorder

INTRODUCTION

Poor sleep is prevalent among individuals with social anxiety disorder (SAD) and may negatively affect exposure therapy outcomes. Poor sleep may impair memory and learning, and thus compromise fear extinction learning thought to take place in exposure therapy. We examined poor sleep as a predictor of exposure therapy outcomes for SAD and the moderating role of d-cycloserine (DCS) on this relationship.

METHODS

Participants were 152 individuals with a primary diagnosis of SAD. As part of a randomized clinical trial evaluating the efficacy of DCS for enhancing the effects of exposure therapy, they completed self-report baseline measure of sleep quality, and self-report sleep diaries assessing sleep duration (total sleep time [TST]) and sleep quality the nights before and after treatment sessions.

RESULTS

Poorer baseline sleep quality was significantly associated with slower improvement over time and worse symptom outcomes at the end of treatment and follow-up after controlling for baseline symptoms of depression and social anxiety. Greater TST the night before treatment predicted lower SAD symptoms at the next session, after controlling for symptoms at the previous session. There was no relation between prior or subsequent night sleep quality on symptoms at the next session. No associations were moderated by DCS.

CONCLUSIONS

We replicated and extended findings indicating that poor sleep quality is associated with poorer exposure therapy outcomes for SAD. Assessing for sleep difficulties before treatment initiation and incorporating sleep interventions into treatment may enhance exposure therapy outcomes for SAD.

Associations of sleep measures with neural activations accompanying fear conditioning and extinction learning and memory in trauma-exposed individuals

STUDY OBJECTIVES

Sleep disturbances increase risk of posttraumatic stress disorder (PTSD). Sleep effects on extinction may contribute to such risk. Neural activations to fear extinction were examined in trauma-exposed participants and associated with sleep variables.

METHODS

Individuals trauma-exposed within the past 2 years (N=126, 63 PTSD) completed 2 weeks actigraphy and sleep diaries, 3 nights ambulatory polysomnography and a 2-day fMRI protocol with Fear-Conditioning, Extinction-Learning and, 24h later, Extinction-Recall phases. Activations within the anterior cerebrum and regions of interest (ROI) were examined within the total, PTSD-diagnosed and trauma-exposed control (TEC) groups. Sleep variables were used to predict activations within groups and among total participants. Family wise error was controlled at p<0.05 using nonparametric analysis with 5000 permutations.

RESULTS

Initially, Fear Conditioning activated broad subcortical and cortical anterior-cerebral regions. Within-group analyses showed: (1) by end of Fear Conditioning activations decreased in TEC but not PTSD; (2) across Extinction Learning, TEC activated medial prefrontal areas associated with emotion regulation whereas PTSD did not; (3) beginning Extinction Recall, PTSD activated this emotion-regulatory region whereas TEC did not. However, the only between-group contrast reaching significance was greater activation of a hippocampal ROI in TEC at Extinction Recall. A greater number of sleep variables were associated with cortical activations in separate groups versus the entire sample and in PTSD versus TEC.

CONCLUSIONS

PTSD non-significantly delayed extinction learning relative to TEC possibly increasing vulnerability to pathological anxiety. The influence of sleep integrity on brain responses to threat and extinction may be greater in more symptomatic individuals.

Sleep management in posttraumatic stress disorder: a systematic review and meta-analysis

OBJECTIVE

Post-traumatic stress disorder (PTSD) can lead to many negative secondary outcomes for patients, including sleep disturbances. The objective of this meta-analysis is (1) to evaluate the effect of interventions for adults with PTSD on sleep outcomes, PTSD outcomes, and adverse events, and (2) to evaluate the differential effectiveness of interventions aiming to improve sleep compared to those that do not.

METHODS

Nine databases were searched for relevant randomized controlled trials (RCTs) in PTSD from January 1980 to October 2019. Two independent reviewers screened 7176 records, assessed 2139 full-text articles, and included 89 studies in 155 publications for this review. Sleep, PTSD, and adverse event outcomes were abstracted and meta-analyses were performed using the Hartung-Knapp-Sidik-Jonkman method for random effects.

RESULTS

Interventions improved sleep outcomes (standardized mean difference [SMD] -0.56; confidence interval [CI] -0.75 to -0.37; 49 RCTs) and PTSD symptoms (SMD -0.48; CI -0.67 to -0.29; 44 RCTs) across studies. Adverse events were not related to interventions overall (RR 1.17; CI 0.91 to 1.49; 15 RCTs). Interventions targeting sleep improved sleep outcomes more than interventions that did not target sleep (p = 0.03). Improvement in PTSD symptoms did not differ between intervention types.

CONCLUSIONS

Interventions for patients with PTSD significantly improve sleep outcomes, especially interventions that specifically target sleep. Treatments for adults with PTSD directed towards sleep improvement may benefit patients who suffer from both ailments.

Sleep and PTSD in the Military Forces: A Reciprocal Relationship and a Psychiatric Approach

Sleep disturbances are well-recognised symptoms of Post-Traumatic Stress Disorder (PTSD). This review updates knowledge regarding the relationship between sleep during deployment, combat-related trauma, and PTSD in military personnel, from which the importance of restorative sleep results. The description of the characteristics of sleep in military forces with the considerable roles of the operational and training contexts highlights the important consequences of degraded sleep. Indeed, a lot of data suggest a dynamic link between sleep and the onset and chronicity of PTSD. We propose a reciprocal relationship model with strategies strongly recommended or already adopted by the military to promote restorative sleep before and after combat exposure. Among the alterations in a variety of sleep architecture and sleep patterns described in PTSD, the physiological hypothesis of REM sleep fragmentation in the development of PTSD symptoms may be important because REM sleep is generally associated with emotional memory. Finally, we address clinical and research perspectives that could be used to detect or restore sleep continuity before and during military deployment to possibly alleviate nightmares and insomnia related to combat exposure and PTSD occurrence and improve our understanding of sleep in PTSD.

Influence of sleep difficulty on post-traumatic stress symptoms among frontline medical staff during COVID-19 pandemic in China

Being a nurse was demonstrated to be a risk factor for post-traumatic stress symptoms (PTS) and insomnia among frontline staff during COVID-19 pandemic. The unidirectional relationship between insomnia and PTS highly suggested that insomnia could mediate the increasing risk of PTS among frontline nurses. However, no study had tried to clarify this mediation effect of insomnia during COVID-19 pandemic. This study aimed to investigate prevalence of insomnia and PTS among frontline doctors and nurses and to clarify the relationship between career (doctor/nurses), insomnia and PTS. A total of 211 frontline doctors and nurses completed the investigation. Insomnia was measured using a self-drafted questionnaire and PTS was assessed using primary care post-traumatic stress disorder screen (PC-PTSD). Three logistics regression models and one mediation model were performed to explore relationships between career, insomnia and PTS. The prevalence of PTS (PC-PTSD≥2) and insomnia (with 1 item in self-drafted insomnia questionnaire≥2) was 24.17% and 36.97%, respectively. Being a nurse was a shared risk factor of insomnia (OR = 4.16, 95%CI: 1.30 ~ 5.77, P = 0.023) and PTS (OR = 7.51, 95%CI: 1.89 ~ 40.50, P = 0.008). Compared to doctors, nurses had significantly higher prevalence of insomnia (46.32% vs. 20%, χ² = 13.27, P < 0.001) and PTS (30.14% vs. 13.33%, χ² = 6.57, P = 0.011). Insomnia was a significant partial mediator (B = 0.101, P = 0.026), which explained 32.53% proportions of relationship between being a nurse and PTS. PTS and insomnia were common symptoms, which should be considered in psychological aids among frontline medical staff. Insomnia might be a possible target of PTS intervention.

Ketamine treatment upon memory retrieval reduces fear memory in marmoset monkeys

Emotionally arousing experiences are retained very well as seen in posttraumatic stress disorder (PTSD). Various lines of evidence indicate that reactivation of these memories renders them labile which offers a potential time-window for intervention. We tested in non-human primates whether ketamine, administered during fear memory reactivation, affected passive (inhibitory) avoidance learning. For the consolidation of contextual emotional memory, the unescapable foot-shock paradigm in a passive avoidance task with two compartments (dark vs illuminated) was used. After entering the dark compartment, marmoset monkeys received four random foot-shocks (1 mA, 4 s) within 15-min. This stressful exposure increased the saliva cortisol and heart rate and impaired REM-sleep (p<0.05). One week later the monkeys were re-exposed to the stressful situation for the reconsolidation of the fearful experience. During the re-exposure the monkeys were treated with ketamine (0.5 mg/kg) or saline. In week 3, the monkeys were placed in the experimental setting to test their memory for the fearful experience. In contrast to the vehicle-treated monkeys, who avoided the dark compartment, the ketamine-treated monkeys entered the dark compartment that was previously associated with the fearful experience (p<0.05). Post-mortem analysis of the hippocampus showed that ketamine-treated animals exhibited less doublecortin positive neurons and BrdU-labeled cells in the dentate gyrus. This study reveals that a single low dose of ketamine, administered upon fear retrieval in monkeys, reduce contextual fear memory and attenuate neurogenesis in the hippocampus. These are important findings for considering ketamine as a potential candidate to target traumatic memories in PTSD.

Sex differences in stress-induced sleep deficits

Sleep disruptions are hallmarks in the pathophysiology of several stress-related disorders, including Major Depressive Disorder (MDD) and Post-Traumatic Stress Disorder (PTSD), both known to disproportionately affect female populations. Although previous studies have attempted to investigate disordered sleep in women, few studies have explored and compared how repeated stress affects sleep in both sexes in either human or animal models. We have previously shown that male rats exhibit behavioral and neuroendocrine habituation to 5 days of repeated restraint, whereas females do not; additional days of stress exposure are required to observe habituation in females. This study examined sex differences in sleep measures prior to, during, and after repeated restraint stress in adult male and female rats. Our data reveal that repeated stress increased time spent awake and decreased slow-wave sleep (SWS) and REM sleep (REMS) in females, and these effects persisted over 2 days of recovery. In contrast, the effects of stress on males were transient. These insomnia-like symptoms were accompanied by a greater number of exaggerated motor responses to waking from REMS in females, a phenotype similar to trauma-related nightmares. In sum, these data demonstrate that repeated stress produces disruptions in sleep that persist days after the stress is terminated in female rats. These disruptions in sleep produced by 5 days of repeated restraint may be due to their lack of habituation.

Moderating effects of sleep difficulties on relations between posttraumatic stress disorder symptoms and positive memory count

OBJECTIVES

Posttraumatic stress disorder (PTSD) severity relates to positive memory retrieval difficulties. One variable potentially influencing this relation is sleep difficulties. We examined moderating effects of sleep difficulties (duration and quality) on relations between PTSD severity and count of specific positive memories covarying for age, gender, and depression.

METHODS

Participants were an Amazon Mechanical Turk-recruited trauma-exposed community sample of 205 respondents (M age  = 35.44; 61.40% women).

RESULTS

Moderated regression analyses indicated significant interaction effects between sleep quality (b = 0.03; p = 0.036) and PTSD severity on specific positive memory count. Among individuals reporting better sleep quality, there were negative associations between PTSD severity and specific positive memory count (b = -0.04, SE = 0.02, p = 0.010). Similar results were obtained for PTSD's intrusion and arousal clusters.

CONCLUSION

Results support targeting sleep quality and PTSD severity to improve positive memory retrieval in PTSD and memory interventions, and the importance of considering sleep when examining links between PTSD and positive memory retrieval.

Correlates of sleep disturbance in Veterans with traumatic brain injury and chronic pain: A cross-sectional study

BACKGROUND

Few studies have investigated sleep in Veterans with comorbid traumatic brain injury (TBI) and chronic pain.

OBJECTIVE

To describe mood and cognitive correlates with sleep disturbance in a sample of Veterans with both TBI and chronic pain.

RESEARCH METHOD

Cross-sectional, correlational analyses were completed using baseline data from a randomized controlled trial comparing psychosocial treatments for pain in Veterans with TBI. Enrollment occurred between July 2015 and January 2017. Self-report measures of hours slept, insomnia severity, depression and PTSD symptoms were collected along with a brief neuropsychological assessment.

RESULTS

Participants (n = 221) were an average age of 37.2 years (SD = 8.2) and mostly male (89%). Participants reported sleeping an average of 4.9 h a night (SD = 1.4) with an average Insomnia Severity Index (ISI) score of 17.4 (SD = 5.4) suggesting moderate insomnia symptoms. Fewer hours slept was associated with higher depression scores (r = -0.28, p < 0.001) and slower processing speed (r = 0.23, p < 0.001). Increasing insomnia severity was associated with greater depression (r = 0.57, p < 0.001) and PTSD symptoms (r = 0.44, p < 0.001), and slower processing speed (r = -0.22, p < 0.001).

CONCLUSIONS

The average ISI score was above the clinical cut off for insomnia diagnosis. Results suggest that those with more severe insomnia symptoms report higher depression and PTSD symptoms as well as exhibit slower processing speed. Improving sleep in this population may be important for improving outcome following TBI.

Chronic antidepressant treatment rescues abnormally reduced REM sleep theta power in socially defeated rats

The effects of chronic antidepressant (AD) treatment on sleep disturbances in rodent chronic stress models have not been thoroughly investigated. Here, we show that chronic social defeat stress (SDS) in rats induces prolonged social avoidance, alterations in sleep architecture (increased total rapid eye movement [REM] sleep duration, bout, and shortened REM latency), and contextual but not cued fear memory deficits, even 1 month after the last SDS. These abnormalities were associated with changes in electroencephalography (EEG) spectral powers, including reduced REM sleep theta power during the light phase. Chronic treatment with two different classes of antidepressants (ADs), imipramine and fluoxetine, significantly ameliorated these behavioral, sleep, and EEG abnormalities. Interestingly, REM theta power was normalized by chronic (1 month) but not 1 week AD administration and solely correlated with the ratio (an objective indicator) of social interaction 1 month after the last SDS. These data suggest that reductions in REM sleep theta power, an EEG parameter that has never been directly investigated in humans, is a core sleep symptom in socially defeated rats, and, potentially, also in patients with stress-related psychiatric disorders, including major depressive and posttraumatic stress disorders.

Posttraumatic stress disorder symptoms and neurocognitive functioning in fire fighters: The mediating role of sleep problems and resilience

BACKGROUND

Firefighters are often exposed to terrible and dangerous scenes due to their duties, and thus have a high risk of developing posttraumatic stress disorder(PTSD). The purpose of the study is to examine the relationship between PTSD symptoms, sleep problems, resilience and neurocognitive functioning of firefighters, and to identify the sequential mediating effects of sleep problems and resilience on the relationship between PTSD symptoms and neurocognitive functioning (especially psychomotor speed and processing speed).

METHODS

Data were collected from 325 firefighters in eight fire departments in four regions of Korea. Subjects performed neurocognitive function tests and completed the following questionnaires: Primary Care PTSD Screening, Pittsburgh Sleep Quality Index-K and Connor-Davidson Resilience Scale-2. The correlation and dual mediation effects were analysed using SPSS 22.0 program and PROCESS macro 3.4 program.

RESULTS

PTSD symptoms, neurocognitive functioning, sleep problems and resilience were significantly correlated with each other. In the sequential mediation model, the relationship between PTSD and psychomotor speed/processing speed was sequentially mediated by sleep problems and resilience after adjusting for demographic variables.

CONCLUSIONS

The PTSD symptoms of firefighters were related to a sequential link between sleep problems, low resilience and decreased neurocognitive function. These findings could serve as a basis for more effective and integrated interventional strategies for facilitating better neurocognitive functioning in firefighters.

Sleep Quality Improvements After MDMA-Assisted Psychotherapy for the Treatment of Posttraumatic Stress Disorder

Sleep disturbances (SDs) are among the most distressing and commonly reported symptoms in posttraumatic stress disorder (PTSD). Despite increased attention on sleep in clinical PTSD research, SDs remain difficult to treat. In Phase 2 trials, 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy has been shown to greatly improve PTSD symptoms. We hypothesized that MDMA-assisted psychotherapy would improve self-reported sleep quality (SQ) in individuals with PTSD and be associated with declining PTSD symptoms. Participants in four studies (n = 63) were randomized to receive 2-3 sessions of active MDMA (75-125 mg; n = 47) or placebo/control MDMA (0-40 mg, n = 16) during all-day psychotherapy sessions. The PSQI was used to assess change in SQ from baseline to the primary endpoint, 1-2 months after the blinded sessions. Additionally, PSQI scores were measured at treatment exit (TE) and 12-month follow-up. Symptoms of PTSD were measured using the CAPS-IV. At the primary endpoint, CAPS-IV total severity scores dropped more after active MDMA than after placebo/control (-34.0 vs. -12.4), p = .003. Participants in the active dose group showed more improvement in SQ compared to those in the control group (PSQI total score ΔM = -3.5 vs. 0.6), p = .003. Compared to baseline, SQ had improved at TE, p < .001, with further significant gains reported at 12-month follow-up (TE to 12-months ΔM = -1.0), p = .030. Data from these randomized controlled double-blind studies provide evidence for the beneficial effects of MDMA-assisted psychotherapy in treating SDs in individuals with PTSD.

A network analysis investigation of the comorbidity between sleep dysfunction and PTSD symptomatology among Filipino domestic workers in Macao (SAR) China

Posttraumatic stress disorder (PTSD) is highly comorbid with sleep dysfunction. This association was previously explained based on cognitive and emotional dysfunction. The current study extends this literature by investigating the symptom level comorbidity of sleep dysfunction and DSM-5 PTSD utilizing a network approach. Participants were trauma-exposed female Filipino domestic workers (N = 1241). Network analysis was applied to 23 items: 18 items from PCL-5 measuring PTSD (Community 1) and 5 items from PSQI assessing sleep dysfunction (Community 2). The results showed that the symptoms within each community had the strongest correlations. Bridge connections were identified between the sleep dysfunction and PTSD symptom communities. Symptoms with the highest bridge strength were concentration difficulties, recklessness, irritability, and sleep disturbance. This is among the first studies investigating the comorbidity between PTSD and sleep dysfunction from the network approach. Future interventions may be developed that emphasize the bridge symptoms to address comorbidity among trauma exposed migrants.

Association Between Perceived Stress and Post-Traumatic Stress Disorder Among Medical Staff During the COVID-19 Epidemic in Wuhan City

Objective: The study aimed to examine the relationship between perceived stress and post-traumatic stress disorder (PTSD) among frontline medical staff during the lockdown in Wuhan city, China, due to the COVID-19 outbreak.

Methods: The study was conducted in August 2020, which included 516 medical staff between 21 to 65 years. The PTSD Checklist-Civilian, Perceived Stress Scale, Insomnia Severity Index, and Compassion Fatigue Short Scale were used.

Results: The results indicated that 10.5% of the medical staff experienced PTSD symptoms, and insomnia severity mediated the effect of perceived stress on PTSD. In addition, compassion fatigue moderated the association between perceived stress and PTSD.

Conclusion: The study elucidated the mechanisms underlying the association between perceived stress and PTSD. Moreover, it emphasized the importance of long-term monitoring of the mental health status of frontline medical staff who supported Wuhan. The results can serve as reference for relevant medical and health departments to formulate active interventions and preventive measures against PTSD for unsung heroes who put their lives on the line during difficult times.

The symptoms and factors associated with post-traumatic stress disorder for burns nurses: a cross-sectional study from Guangdong province in China

BACKGROUND

The symptoms of post-traumatic stress disorder (PTSD) among medical staff has become a significant issue. Environments related to burns are highly stressful for nurses and can lead to PTSD, thus affecting their mental health. It is vital to consider that the quality of burns care, and the outcomes of such treatments, may be threatened if nurses experience PTSD. We evaluated PTSD symptoms in burns nurses and explored the correlations between demographic characteristics, work-related characteristics, professional identity, turnover intention, and PTSD symptoms.

METHODS

This was a cross-sectional study involving 273 nurses working in burns unit from Guangdong, China, between July and August 2019. Nurses were recruited from 30 hospitals and completed three validated psychological questionnaires: Post-traumatic Stress Disorder Checklist-Civilian Version (PCL-C), Professional Identity Scale for Nurses (PIS), and Turnover Intention Questionnaire (TIQ). We also collated information relating to socio-demographic and work-related characteristics.

RESULTS

The cut-off point for the PCL-C was defined as 38 points; 17.22% (n=47) of participants scored higher than or equal to 38. The PCL-C score was negatively correlated with professional identity level (P < 0.01) and positively correlated with turnover intention (P < 0.01). The workplace, mean monthly income, experience of workplace violence, and professional identity level, were important factors and all associated with the severity of PTSD.

CONCLUSION

PTSD symptoms were common in burns nurses. Attention should be paid to the mental wellbeing of these staff. Screening processes need to be initiated to identify individuals suffering from PTSD and take appropriate early interventional action.

Acupuncture for Sleep Disturbances in Post-Deployment Military Service Members: A Randomized Controlled Trial

This RCT and mixed-methods study examined the difference between two groups receiving the following interventions: (1) brief manual standardized stress acupuncture (MSSA) combined with an abbreviated Cognitive Behavioral Therapy (ACBT) versus (2) ACBT alone. Three study aims: Aim (1): Insomnia Severity Index (ISI) and Pittsburg Sleep Quality Index (PSQI) scores were analyzed using descriptive summaries, linear regression, and reliable change index (RCI). Aim (2): Journal entries were analyzed using content analysis. Aim (3): Acupuncture Expectancy Scale (AES) scores were analyzed using paired t-test and RCI. Aim (1): Both groups demonstrated similar improvements in the ISI scores (p = .480). Aim (2): The ACBT/MSSA group reported greater benefits in sleep and in other life areas including mental, physical, and social functioning. Aim (3): The AES showed that 21.6% had a clinically meaningful increase in expectations in the effect of acupuncture for stress (p = .965). The study was registered in ClinicalTrials.gov (NCT04031365) at https://clinicaltrials.gov/ct2/show/NCT04031365 on July 24, 2019.

Randomized clinical trial of bedtime sublingual cyclobenzaprine (TNX-102 SL) in military-related PTSD and the role of sleep quality in treatment response

Effective posttraumatic stress disorder (PTSD) pharmacotherapy is needed. This 12-week randomized multicenter trial evaluated efficacy and safety of TNX-102 SL, a bedtime sublingual formulation of cyclobenzaprine, in patients with military-related PTSD randomized to TNX-102 SL 2.8 mg or 5.6 mg, or placebo. Primary analysis comparing change from baseline in Clinician-Administered PTSD Scale-5 score between 2.8 mg (n=90) and placebo (n=92) was not significant. Secondary analysis of 5.6 mg (n=49) vs placebo demonstrated a mean difference of -4.5 units, p=.05, or, accounting for missing data by multiple imputation, -5.0 units, p=.03. Clinician Global Impression - Improvement responder rate was greater in 5.6 mg than placebo (p=0.04), as was mean functional improvement in Sheehan Disability Scale social domain (p=.03) and trended in work domain (p=.05). Post-hoc analyses showed early sleep improvement predicted improvement in PTSD after 12 weeks for TNX-102 SL (p<.01), not for placebo. Most common administration site reaction in TNX-102 SL groups was oral hypoaesthesia (5.6 mg, 36%; 2.8 mg, 39%; placebo, 2%), while most common systemic adverse event was somnolence (5.6 mg, 16%; 2.8 mg, 12%; placebo, 6%). This provides preliminary evidence that TNX-102 SL 5.6 mg reduces PTSD symptoms, improves sleep and psychosocial function, and is well tolerated. Clinicaltrials.gov Identifier: NCT02277704.

Cross-Lagged Relationships Between Insomnia and Posttraumatic Stress Disorder in Treatment-Receiving Veterans

Insomnia is a risk factor for the development of posttraumatic stress disorder (PTSD) while it is also plausible that PTSD symptoms can maintain insomnia symptoms. The present study examined longitudinal bidirectional relationships between insomnia and PTSD symptoms in treatment-seeking veterans. Participants were 693 ex-serving members of the Australian Defence Force who participated in an accredited, hospital-based outpatient PTSD program. Participants completed self-reported assessments of PTSD and insomnia symptoms at four time points: intake, discharge, 3-month, and 9-months posttreatment follow-up. Cross-lagged pathway analyses indicated significant bi-directional pathways between insomnia symptoms and PTSD symptoms at most time points. A final cross-lagged model between insomnia symptoms and the PTSD symptom clusters indicated that the PTSD symptom paths on insomnia symptoms, between intake and discharge, were attributable to reexperiencing PTSD symptoms. In contrast, across posttreatment follow-up time points there were significant paths of insomnia symptoms on all PTSD symptom clusters except from insomnia at 3-months to avoidance symptom at 9-months. PTSD symptoms and insomnia symptoms have bidirectional associations over time that may lead to the mutual maintenance or exacerbation of each condition following PTSD treatment. Where residual insomnia symptoms are present post-treatment, a sleep-focussed intervention is indicated and a sequenced approach to treatment recommended.

Immunization with a heat-killed bacterium, Mycobacterium vaccae NCTC 11659, prevents the development of cortical hyperarousal and a PTSD-like sleep phenotype after sleep disruption and acute stress in mice

STUDY OBJECTIVES

Sleep deprivation induces systemic inflammation that may contribute to stress vulnerability and other pathologies. We tested the hypothesis that immunization with heat-killed Mycobacterium vaccae NCTC 11659 (MV), an environmental bacterium with immunoregulatory and anti-inflammatory properties, prevents the negative impacts of 5 days of sleep disruption on stress-induced changes in sleep, behavior, and physiology in mice.

METHODS

In a 2 × 2 × 2 experimental design, male C57BL/6N mice were given injections of either MV or vehicle on days -17, -10, and -3. On days 1-5, mice were exposed to intermittent sleep disruption, whereby sleep was disrupted for 20 h per day. Immediately following sleep disruption, mice were exposed to 1-h social defeat stress or novel cage (control) conditions. Object location memory (OLM) testing was conducted 24 h after social defeat, and tissues were collected 6 days later to measure inflammatory markers. Sleep was recorded using electroencephalography (EEG) and electromyography (EMG) throughout the experiment.

RESULTS

In vehicle-treated mice, only the combination of sleep disruption followed by social defeat (double hit): (1) increased brief arousals and NREM beta (15-30 Hz) EEG power in sleep immediately post-social defeat compared to baseline; (2) induced an increase in the proportion of rapid-eye-movement (REM) sleep and number of state shifts for at least 5 days post-social defeat; and (3) induced hyperlocomotion and lack of habituation in the OLM task. Immunization with MV prevented most of these sleep and behavioral changes.

CONCLUSIONS

Immunization with MV ameliorates a stress-induced sleep and behavioral phenotype that shares features with human posttraumatic stress disorder.

Sleep disruption considerations for Paralympic athletes competing at Tokyo 2020

The role of sleep is now recognized as an important component for success in athletic performance, and sleep is proposed to be one of the most effective recovery strategies available. Insufficient sleep is commonly reported among athletes while several factors have been put forward to explain why elite athletes might experience poor sleep. However, Paralympic athletes may be predisposed to a greater risk of poor sleep due to the associated complexities of some impairment types. In fact, clinical research has previously shown that individuals with disabilities have a higher prevalence of sleep disturbances when compared to their able-bodied counterparts. However, research and evidence-based practices regarding the sleep of elite Paralympic athletes are limited. Firstly, this narrative review aims to identify challenges associated with the Paralympic games to obtain optimal sleep. Secondly, identify the specific risk factors to sleep associated with particular impairment groups within the Paralympic population, and lastly to propose potential sleep-enhancing strategies that might be of relevance for Paralympic athletes. From this review, initial observations have identified that Paralympic athletes may have a heightened risk of sleep-related problems, and importantly highlighted the current lack of understanding within this population group. Furthermore, this review identified where further research is warranted to better understand how specific impairments impact sleep and, consequently, athletic performance. Additionally, this review highlighted that the forthcoming Tokyo games may offer a unique challenge for athletes trying to obtain optimal sleep, due to the anticipated thermal demands and the consequent irregular scheduling of events.

Subjective and objective sleep quality in young women with posttraumatic stress disorder following sexual assault: a prospective study

Background: Most posttraumatic stress disorder (PTSD) sleep disturbances reports have been conducted in male combat veteran populations, usually decades after the disorder's onset. Given the increase in the prevalence of violence against women and the fact that women are at greater risk for developing PTSD, it is critical to examine sleep abnormalities in this population. Objectives: To examine subjective and objective sleep quality in young women with PTSD following sexual assault compared with a control group at baseline and after one year of treatment. Methods: Seventy-four women with PTSD following sexual assault and 64 healthy controls with no history of sexual assault were assessed using the Clinician-Administered PTSD Scale (CAPS-5), the Beck Depression Inventory, the Beck Anxiety Inventory, the Pittsburgh Sleep Quality Index (PSQI), the Modified Fatigue Impact Scale, and the Insomnia Severity Index. Subjects also underwent full in-lab polysomnography. PTSD participants received pharmacological and/or psychological therapy between baseline and one-year follow-up. Results: The PTSD group had significantly higher scores in the clinical and sleep measurements than the control group. Although the PTSD group reported poorer subjective sleep quality than healthy controls, there were few between-group differences in objective sleep. Analysis of the PTSD group at baseline and one-year follow-up showed that the PSQI global score was a significant predictor of PTSD improvement. Conclusions: Sleep quality is impaired in young women with PTSD and may impact long-term treatment responses. Better sleep quality is significantly associated with PTSD improvement, independent of depression and anxiety.

Impact of parental injury on adolescent sleep

STUDY OBJECTIVES

The aim of this study was to determine the impact of serious parental injury on adolescent sleep disorder diagnoses, outpatient care, and medication use.

METHODS

U.S. military personnel who sustained a serious injury and were parents of adolescents aged 10-18 years were identified. Included adolescents were enrolled in the Military Health System for 2 years before their parent's injury and 2 years after the injury. We used logistic regression clustered by adolescents to compare the odds of having a sleep diagnosis and negative binomial regression analysis clustered by adolescents to compare outpatient sleep disorder visits and sleep medication days before and after parental injury.

RESULTS

There were 96,318 parents seriously injured during 2004-2014 who had 117,577 children aged 10-18 years in 2002-2016. Approximately 2% of adolescents had a sleep disorder diagnosis, both before and after their parent's injury or illness. Outpatient sleep disorder visits increased 36% after a parent's injury (incidence rate ratio 1.36 [1.24-1.50]), with a twofold increase in insomnia visits (incidence rate ratio 2.35 [2.08-2.64]). Increases in sleep visits were most pronounced in adolescents of parents with traumatic brain injury, comorbid traumatic brain injury and posttraumatic stress disorder, battle injury, and those who were medically discharged from the military. The number of adolescents using sleep medications increased, but sleep medication days did not increase.

CONCLUSIONS

Adolescents in our study used more outpatient medical care for sleep disorders; sleep medication use increased after parental injury. Sleep disorders should be considered in the care of adolescents with injured parents.

Investigation of low dimensional feature spaces for automatic sleep staging

BACKGROUND

Automatic sleep stage classification depends crucially on the selection of a good set of descriptive features. However, the selection of a feature set with an appropriate low computational cost without compromising classification performance is still a challenge. This study attempts to represent sleep EEG patterns using a minimum number of features, without significant performance loss.

METHODS

Three feature selection algorithms were applied to a high dimensional feature space comprising 84 features. These methods were based on a bootstrapping approach guided by Gini ranking and mutual information between the features. The algorithms were tested on three scalp electroencephalography (EEG) and one ear-EEG datasets. The relationship between the information carried by different features was investigated using mutual information and illustrated by a graphical clustering tool.

RESULTS

The minimum number of features that can represent the whole feature set without performance loss was found to range between 5 and 11 for different datasets. In ear-EEG, 7 features based on Continuous Wavelet Transform (CWT) resulted in similar performance as the whole set whereas in two scalp EEG datasets, the difference between minimal CWT set and the whole set was statistically significant (0.008 and 0.017 difference in average kappa). Features were divided into groups according to the type of information they carry. The group containing relative power features was identified as the most informative feature group in sleep stage classification, whereas the group containing non-linear features was found to be the least informative.

CONCLUSIONS

This study showed that EEG sleep staging can be performed based on a low dimensional feature space without significant decrease in sleep staging performance. This is especially important in the case of wearable devices like ear-EEG where low computational complexity is needed. The division of the feature space into groups of features, and the analysis of the distribution of feature groups for different feature set sizes, is helpful in the selection of an appropriate feature set.

The impact of sleep quality on the incidence of PTSD: Results from a 7-Year, Nationally Representative, Prospective Cohort of U.S. Military Veterans

Sleep and posttraumatic stress disorder (PTSD) have a complex relationship, with some studies showing that disrupted sleep is associated with subsequent development of PTSD. The purpose of the current study was to examine the relationship between sleep quality and the development of probable PTSD in U.S. veterans surveyed as part of the National Health and Resilience in Veterans Study, a 7-year, nationally representative, prospective cohort study with four waves of data collection. Sociodemographic, military, trauma, and clinical variables were entered into a multivariate analysis to examine independent determinants of new-onset PTSD. A total of 142 (7.3 %) veterans developed PTSD over the 7-year study period. Poor/fair sleep quality at Wave 1 was associated with 60 % greater likelihood of developing PTSD, with more than twice as many veterans who developed PTSD reporting poor sleep quality at Wave 1 (47.8 % vs. 20.7 %). Younger age, using the VA as a primary source of healthcare, greater traumas since Wave, and lifetime depression were additionally associated with this outcome. Results of this study underscore the importance of self-reported sleep quality as a potential risk factor for the development of PTSD in the U.S. veteran population.

Oxidative Dysregulation in Early Life Stress and Posttraumatic Stress Disorder: A Comprehensive Review

Traumatic stress may chronically affect master homeostatic systems at the crossroads of peripheral and central susceptibility pathways and lead to the biological embedment of trauma-related allostatic trajectories through neurobiological alterations even decades later. Lately, there has been an exponential knowledge growth concerning the effect of traumatic stress on oxidative components and redox-state homeostasis. This extensive review encompasses a detailed description of the oxidative cascade components along with their physiological and pathophysiological functions and a systematic presentation of both preclinical and clinical, genetic and epigenetic human findings on trauma-related oxidative stress (OXS), followed by a substantial synthesis of the involved oxidative cascades into specific and functional, trauma-related pathways. The bulk of the evidence suggests an imbalance of pro-/anti-oxidative mechanisms under conditions of traumatic stress, respectively leading to a systemic oxidative dysregulation accompanied by toxic oxidation byproducts. Yet, there is substantial heterogeneity in findings probably relative to confounding, trauma-related parameters, as well as to the equivocal directionality of not only the involved oxidative mechanisms but other homeostatic ones. Accordingly, we also discuss the trauma-related OXS findings within the broader spectrum of systemic interactions with other major influencing systems, such as inflammation, the hypothalamic-pituitary-adrenal axis, and the circadian system. We intend to demonstrate the inherent complexity of all the systems involved, but also put forth associated caveats in the implementation and interpretation of OXS findings in trauma-related research and promote their comprehension within a broader context.

Hyperarousal symptoms and decreased right hemispheric frontolimbic white matter integrity predict poorer sleep quality in combat-exposed veterans

OBJECTIVE

Disrupted sleep is common following combat deployment. Contributors to risk include posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI); however, the mechanisms linking PTSD, mTBI, and sleep are unclear. Both PTSD and mTBI affect frontolimbic white matter tracts, such as the uncinate fasciculus. The current study examined the relationship between PTSD symptom presentation, lateralized uncinate fasciculus integrity, and sleep quality.

METHOD

Participants include 42 combat veterans with and without PTSD and mTBI. Freesurfer and Tracula were used to establish specific white matter ROI integrity via 3-T MRI. The Pittsburgh Sleep Quality Index and PTSD Checklist were used to assess sleep quality and PTSD symptoms.

RESULTS

Decreased fractional anisotropy in the right uncinate fasciculus (β = -1.11, SE = 0.47, p < .05) and increased hyperarousal symptom severity (β = 3.50, SE = 0.86, p < .001) were associated with poorer sleep quality.

CONCLUSION

Both right uncinate integrity and hyperarousal symptom severity are associated withsleep quality in combat veterans. The right uncinate is a key regulator of limbic behavior and sympathetic nervous system reactivity, a core component of hyperarousal. Damage to this pathway may be one mechanism by which mTBI and/or PTSD could create vulnerability for sleep problems following combat deployment.

Polysomnographic Sleep and Attentional Deficits in Traumatized North Korean Refugees

INTRODUCTION

Attentional deficits and sleep problems are common in refugees who have experienced trauma. In the present study, we used polysomnography (PSG) to investigate the relationship between attentional deficits and objective measures of sleep structure in traumatized North Korean refugees.

METHODS

We recruited 32 North Korean refugees (mean age = 33.78 ± 14.33 years) and 39 South Korean participants (mean age = 35.03 ± 11.08 years). Sustained attention and divided attention were assessed using the Computerized Attention Test. We conducted an overnight PSG to objectively assess sleep structure. The participants also completed the Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Impact of Event Scale-Revised (IES-R), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Insomnia Severity Index (ISI).

RESULTS

The North Korean refugees showed more commission errors (CEs, p < 0.05) and a larger standard deviation (SD) of the reaction time (RT) (p < 0.05) in the sustained attention task compared to the South Korean participants. Furthermore, the North Korean refugees showed a shorter period of wake after sleep onset (WASO, p < 0.01), less time spent in N1 (p < 0.05), and more time spent in N2 (p < 0.05). The larger SD of RT in the sustained attention task in the North Korean refugees was positively correlated with WASO (r = 0.62, p < 0.01) and N1 stage (r = 0.47, p < 0.05) after controlling for age, sex, BDI, BAI, and IES-R.

CONCLUSION

The North Korean refugees showed poorer performance on the sustained attention task. Nocturnal PSG revealed shorter WASO and time spent in N1 in this population, which are independently associated with the preservation of attentional capacity. These data suggest that traumatized refugees may compensate for attentional deficits induced by their traumatic experiences via increased sleep continuity.

Sleep and fear conditioning, extinction learning and extinction recall: A systematic review and meta-analysis of polysomnographic findings

Sleep may contribute to the long-lasting consolidation and processing of emotional memories. Experimental fear conditioning and extinction paradigms model the development, maintenance, and treatment of anxiety disorders. The literature provides compelling evidence for the involvement of rapid eye movement (REM) sleep in the consolidation of such memories. This meta-analysis correlated polysomnographic sleep findings with psychophysiological reactivity to the danger (CS+) and safety stimuli (CS-), to clarify the specific role of sleep stages before and after fear conditioning, extinction learning and extinction recall. Overall, there was evidence that more pre-learning sleep stage two and less slow wave sleep was associated with higher psychophysiological reactivity to the safety stimulus during extinction learning. Preliminary evidence found here support the role of REM sleep during the post-extinction consolidation sleep phase in clinical populations with disrupted sleep, but not in healthy controls. Furthermore, the meta-regressions found that sex moderated the associations between sleep and psychophysiological reactivity throughout the paradigm providing evidence for diverging correlations in male and females. Specifically, increased post-extinction REM was associated with poorer extinction and safety recall in females while the opposite was found in males. These results have implications for future research in the role of sleep in emotional memory processing.

Sleep parameters improvement in PTSD soldiers after symptoms remission

Eye movement desensitization and reprocessing (EMDR) is a psychotherapy for the treatment of posttraumatic stress disorder (PTSD). It is still unclear whether symptoms remission through EMDR therapy is associated with a beneficial effect on one of the PTSD symptoms, sleep disturbance. Our objective was therefore to study sleep parameters before and after symptom remission in soldiers with PTSD. The control group consisted of 20 healthy active duty military men who slept in a sleep lab with standard polysomnography (PSG) on two sessions separated by one month. The patient group consisted of 17 active duty military with PTSD who underwent EMDR therapy. PSG-recorded sleep was assessed 1 week before the EMDR therapy began and 1 week after PTSD remission. We found that the increased REMs density after remission was positively correlated with a greater decrease of symptoms. Also, the number of EMDR sessions required to reach remission was correlated with intra-sleep awakenings before treatment. These results confirm the improvement of some sleep parameters in PTSD after symptoms remission in a soldier's population and provide a possible predictor of treatment success. Further experiments will be required to establish whether this effect is specific to the EMDR therapy.

The spectral fingerprint of sleep problems in post-traumatic stress disorder

Study Objectives

Sleep problems are a core feature of post-traumatic stress disorder (PTSD). The aim of this study was to find a robust objective measure for the sleep disturbance in patients having PTSD.

Methods

The current study assessed EEG power across a wide frequency range and multiple scalp locations, in matched trauma-exposed individuals with and without PTSD, during rapid eye movement (REM) and non-REM (NREM) sleep. In addition, a full polysomnographical evaluation was performed, including sleep staging and assessment of respiratory function, limb movements, and heart rate. The occurrence of sleep disorders was also assessed.

Results

In patients having PTSD, NREM sleep shows a substantial loss of slow oscillation power and increased higher frequency activity compared with controls. The change is most pronounced over right-frontal sensors and correlates with insomnia. PTSD REM sleep shows a large power shift in the opposite direction, with increased slow oscillation power over occipital areas, which is strongly related to nightmare activity and to a lesser extent with insomnia. These pronounced spectral changes occur in the context of severe subjective sleep problems, increased occurrence of various sleep disorders and modest changes in sleep macrostructure.

Conclusions

This is the first study to show pronounced changes in EEG spectral topologies during both NREM and REM sleep in PTSD. Importantly, the observed power changes reflect the hallmarks of PTSD sleep problems: insomnia and nightmares and may thus be specific for PTSD. A spectral index derived from these data distinguishes patients from controls with high effect size, bearing promise as a candidate biomarker.

Association between change in sleep duration and posttraumatic stress symptoms in natural disaster victims: the mediating role of resilience

OBJECTIVE

This study investigated the association between changes in sleep duration after disaster and post-traumatic stress disorder (PTSD) symptoms and the mediating role of resilience on the association.

METHODS

Data were collected from 2951 Korean adults who were victims of a natural disaster and did not have any mental or medical illnesses before the event. They completed a long-term survey on changes in life for disaster victims using computer-aided personal interviews. Changes in sleep duration before and one month after experiencing a disaster were assessed using a self-reported questionnaire. Resilience levels and PTSD symptoms were measured using the Brief Resilience Scale and the Impact of Event Scale - Revised, respectively, and more than 33 of the IES-R score items were defined as significant PTSD symptoms. Multivariate logistic regression was used to examine the associations between changes in sleep duration and PTSD symptoms. Additionally, mediating studies were conducted to identify the role of resilience on the association.

RESULTS

Compared with participants without significant PTSD symptoms, those with PTSD symptoms were more likely to be older and female (group without significant PTSD symptom: mean age = 56.12 ± 18.70 years, female sex = 49.24%; group with significant PTSD symptoms: mean age = 60.88 ± 15.66 years, female sex = 59.52%). Compared with disaster victims without changes in sleep duration, those who had shorter sleep duration after disaster had a higher risk of significant PTSD symptoms (OR = 2.89, 95% Cl = 2.31-3.62, p < 0.001). In the mediating study, resilience level significantly mediated the relationship between reduced sleep duration and PTSD symptoms (direct effect: β = 0.208, 95% Cl = 0.166-0.250, p < 0.001; indirect effect: β = 0.007, 95% Cl = 0.002-0.011, p < 0.001; total effect: β = 0.215, 95% Cl = 0.173-0.257, p < 0.001).

CONCLUSION

This study revealed that individuals with reduced sleep duration after disaster had a higher risk of PTSD symptoms, while those with increased sleep duration did not. In addition, mediating effects of resilience level on the relationship between reduced sleep duration and significant PTSD symptoms were observed.

Efficacy and Underlying Mechanism of Acupuncture in the Treatment of Posttraumatic Stress Disorder: A Systematic Review of Animal Studies

Acupuncture is a nonpharmacological intervention that can be useful in the clinical management of posttraumatic stress disorder (PTSD), especially in situations with a lack of medical resources, including large-scale PTSD events such as disasters. Some clinical studies have reported the clinical effect of acupuncture in improving PTSD symptoms, but the underlying therapeutic mechanism has yet to be explored. Therefore, this review summarized the underlying therapeutic mechanisms of acupuncture in animal PTSD models. A comprehensive search was conducted in 14 electronic databases, and two independent researchers performed study selection, data extraction, and the methodological quality assessment. Twenty-four relevant studies were included in this review and summarized according to the proposed main mechanisms. In behavioral evaluation, acupuncture, including manual acupuncture and electro-acupuncture, reduced anxiety and fear responses and weakened fear conditioning, improved sleep architecture, reduced depressive symptoms, and alleviated disturbance of spatial learning and memory of PTSD animal models. The therapeutic mechanisms of acupuncture proposed in the included studies could be classified into two categories: (1) regulation of stress responses in the neuroendocrine system and (2) promotion of neuroprotection, neurogenesis, and synaptic plasticity in several brain areas. However, the methodological quality of the included animal studies was not high enough to produce robust evidence. In addition, mechanistic studies on specific aspects of acupuncture that may affect PTSD, including expectancy effects, in human PTSD subjects are also needed.

Sleep and Interpersonal Violence: A Systematic Review

Sleep disturbance is a significant public health issue that disproportionately affects survivors of interpersonal violence (IPV). This systematic review presents data on the relationship of IPV and sleep. Inclusion criteria for this review were studies that included subjects 18 years of age or older, used an IPV measure and sleep disturbance measure, and were published in a peer-reviewed journal in English. A total of 23 articles met full inclusion criteria and were included in the present review. Studies were largely cross sectional, were conducted in a wide range of clinical and nonclinical samples, and utilized a variety of measures to assess IPV (sexual violence, physical violence, or psychological aggression perpetrated by an intimate partner or sexual or physical violence by any perpetrator in childhood or adulthood) and sleep disturbances (both general sleep disturbance excluding specific sleep disorders and the two specific sleep disorders of insomnia and nightmares). The findings examined the prevalence and association of sleep disturbance in IPV samples from population and community studies, the prevalence and association of sleep disturbance in IPV studies, and the associations between post-traumatic stress disorder and sleep disturbance in IPV samples. All studies identified a relationship between IPV and sleep disturbance. The results of this review provide important information for clinicians, researchers, and policy makers on the prevalence of and relationship between IPV and sleep disturbance.

Are adversities and worries during the COVID-19 pandemic related to sleep quality? Longitudinal analyses of 46,000 UK adults

Background

There are concerns that both the experience of adversities during the COVID-19 pandemic and worries about experiencing adversities will have substantial and lasting effects on mental health. One pathway through which both experience of and worries about adversity may impact health is through effects on sleep.

Methods

We used data from 46,284 UK adults in the COVID-19 Social Study assessed weekly from 01/04/2020-12/05/2020 to study the association between adversities and sleep quality. We studied six categories of adversity including both worries and experiences of: illness with COVID-19, financial difficulty, loss of paid work, difficulties acquiring medication, difficulties accessing food, and threats to personal safety. We used random-effect within-between models to account for all time-invariant confounders.

Results

Both the total number of adversity experiences and total number of adversity worries were associated with lower quality sleep. Each additional experience was associated with a 1.16 (95% CI = 1.10, 1.22) times higher odds of poor quality sleep while each additional worry was associated with a 1.20 (95% CI = 1.17, 1.22) times higher odds of poor quality sleep. When considering specific experiences and worries, all worries and experiences were significantly related to poorer quality sleep except experiences relating to employment and finances. Having a larger social network offered some buffering effects on associations but there was limited further evidence of moderation by other social or psychiatric factors.

Conclusion

Poor sleep may be a mechanism by which COVID-19 adversities are affecting mental health. This highlights the importance of interventions that support adaptive coping strategies during the pandemic.

Sleep Problems among Disaster Victims: A Long-Term Survey on the Life Changes of Disaster Victims in Korea

This study aimed to assess sleep problems and their underlying factors in victims of disasters such as typhoons, heavy rains, fires, and earthquakes. Data from the long-term survey on life changes among disaster victims in 2019 obtained by the National Disaster Management Research Institute were used. The study included 1358 victims of natural and social disasters in Korea between 2012 and 2018. Sleep problems were assessed using a survey on subjective sleep quality and the use of sleeping medication. The data were analyzed using the chi-square test, t-test, and binominal logistic regression. The results showed that the factors affecting subjective sleep quality included disaster type, time elapsed after disaster, subjective health status, depression, and posttraumatic stress disorder. The factors affecting sleep medication use included age, time elapsed after disaster, and posttraumatic stress disorder. Therefore, interventions and support systems should be provided to prevent the prolongation of sleep problems.

Prevalence and Characteristics of Posttraumatic Nightmares in War- and Conflict-Affected Students

INTRODUCTION

Recurrent nightmares, frequently associated with traumatic experiences, may impair quality of life and daily functioning. However, there have been few studies of posttraumatic nightmares occurring among children and youth, in particular for trauma-exposed populations in conflict zones.

METHODS

Using two quantitative data sets, this study investigates the prevalence and characteristics of recurrent nightmares among conflict-exposed young people in the Gaza Strip (N = 300) and examines the characteristics of posttraumatic nightmares and their association with academic functioning among treatment-seeking students in Gaza (N = 1093).

RESULTS

Among 300 students (10-12 years old) who lived in the ongoing conflict area in Gaza, nightmares were often mentioned, with 56% reporting recurrent nightmares with an average weekly frequency of 4.20 nights in the past week (SD = 1.94) and a mean duration of 2.48 years (SD = 2.01). Similarly, the large sample of 1093 students (6-17 years of age) who sought help for nightmares and sleep disturbance reported recurrent traumatic nightmares on average 4.57 nights per week, with an average duration of 2.82 years. Their self-reported academic functioning was negatively affected by whether they experienced nightmares but was not associated with nightmare frequency or intensity.

DISCUSSION

Given the high prevalence of nightmares and the relation between nightmares and academic functioning, students in conflict-affected areas appear to be a particularly vulnerable group. This study proposes screening and treating conflict-affected students for recurrent posttraumatic nightmares.

Manipulation of REM sleep via orexin and GABAA receptor modulators differentially affects fear extinction in mice: effect of stable versus disrupted circadian rhythm

Sleep disruption, and especially REM sleep disruption, is associated with fear inhibition impairment in animals and humans. The REM sleep-fear inhibition relationship raises concern for individuals with PTSD, whose sleep disturbance is commonly treated with hypnotics which disrupt and/or decrease REM sleep, such as benzodiazepines or 'Z-drugs'. Here, we examined the effects of the Z-drug zolpidem, a GABAA receptor positive allosteric modulator, as well as suvorexant, an orexin receptor antagonist (hypnotics which decrease and increase REM sleep, respectively) in the context of circadian disruption in murine models of fear inhibition-related processes (i.e., fear extinction and safety learning). Adult male C57Bl/6J mice completed fear and safety conditioning before undergoing shifts in the light-dark (LD) cycle or maintaining a consistent LD schedule. Fear extinction and recall of conditioned safety were thereafter tested daily. Immediately prior to onset of the light phase between testing sessions, mice were treated with zolpidem, suvorexant, or vehicle (methylcellulose). EEG/EMG analysis showed temporal distribution of REM sleep was misaligned during LD cycle-shifts, while REM sleep duration was preserved. Suvorexant increased REM sleep and improved fear extinction rate, relative to zolpidem, which decreased REM sleep. Survival analysis demonstrated LD shifted mice treated with suvorexant were faster to achieve complete extinction than vehicle and zolpidem-treated mice in the LD shifted condition. By contrast, retention of conditioned safety memory was not influenced by either treatment. This study thus provides preclinical evidence for the potential clinical utility of hypnotics which increase REM sleep for fear extinction after PTSD-relevant sleep disturbance.

Prior sleep problems and adverse post-traumatic neuropsychiatric sequelae of motor vehicle collision in the AURORA study

STUDY OBJECTIVES

Many patients in Emergency Departments (EDs) after motor vehicle collisions (MVCs) develop post-traumatic stress disorder (PTSD) or major depressive episode (MDE). This report from the AURORA study focuses on associations of pre-MVC sleep problems with these outcomes 8 weeks after MVC mediated through peritraumatic distress and dissociation and 2-week outcomes.

METHODS

A total of 666 AURORA patients completed self-report assessments in the ED and at 2 and 8 weeks after MVC. Peritraumatic distress, peritraumatic dissociation, and pre-MVC sleep characteristics (insomnia, nightmares, daytime sleepiness, and sleep duration in the 30 days before the MVC, trait sleep stress reactivity) were assessed retrospectively in the ED. The survey assessed acute stress disorder (ASD) and MDE at 2 weeks and at 8 weeks assessed PTSD and MDE (past 30 days). Control variables included demographics, MVC characteristics, and retrospective reports about PTSD and MDE in the 30 days before the MVC.

RESULTS

Prevalence estimates were 41.0% for 2-week ASD, 42.0% for 8-week PTSD, 30.5% for 2-week MDE, and 27.2% for 8-week MDE. Pre-MVC nightmares and sleep stress reactivity predicted 8-week PTSD (mediated through 2-week ASD) and MDE (mediated through the transition between 2-week and 8-week MDE). Pre-MVC insomnia predicted 8-week PTSD (mediated through 2-week ASD). Estimates of population attributable risk suggest that blocking effects of sleep disturbance might reduce prevalence of 8-week PTSD and MDE by as much as one-third.

CONCLUSIONS

Targeting disturbed sleep in the immediate aftermath of MVC might be one effective way of reducing MVC-related PTSD and MDE.

Investigating the link between subjective sleep quality, symptoms of PTSD and level of functioning in a sample of trauma-affected refugees

STUDY OBJECTIVES

To examine whether baseline sleep quality is associated with baseline symptoms of posttraumatic stress disorder (PTSD) and level of functioning, and whether baseline sleep quality and improvement of sleep quality are specific predictors of change in PTSD symptoms and level of functioning.

METHODS

Data were derived from a four-armed randomised controlled superiority trial (N=219 trauma-affected refugees). All four groups received treatment as usual consisting of a 10-12 months bio-psycho-social treatment program with an additional differential treatment component added to each arm. We performed bivariate correlation analyses, multiple linear regression analyses and mediation analyses to examine associations between baseline sleep quality, change in sleep quality and treatment response for PTSD symptoms and level of functioning.

RESULTS

Baseline sleep quality correlated with symptoms of PTSD (r = .33) and level of functioning (r=0.15). Baseline sleep quality, improvement of sleep quality and improvement of general well-being were predictors of treatment response for symptoms of PTSD and level of functioning when controlling for age, gender, and baseline symptoms of PTSD and depression.

CONCLUSIONS

We found that good sleep quality at baseline and improvement of sleep quality were predictors of PTSD treatment response. However, treatment response was more closely associated with improvement in general well-being. The results indicate that the effect of improved sleep quality was partly mediated by a more general mental state improvement. Further research is needed to differentiate if a selected subgroup of patients may profit from sleep enhancing treatment.

Dynamic psychosocial risk and protective factors associated with mental health in Emergency Medical Service (EMS) personnel

BACKGROUND

EMS personnel have a heightened risk of developing posttraumatic stress disorder (PTSD) and major depression relative to other occupational populations necessitating a greater understanding of the risk and protective factors that operate each day in relation to this risk. This study examined dynamic psychosocial factors and their relationship with daily mental health symptoms among EMS workers. The psychosocial factors examined consisted of occupational stressors, sleep disturbance, social conflict, meaning made from the day's challenges, recovery activities, social support, and perceived prosocial impact.

METHOD

Seventy-nine EMS workers recruited from an emergency medical service provider in Central New York completed a daily assessment for 8 days asking questions about occupational stressors encountered, sleep efficiency, social conflicts, meaning made from the day's challenges, recovery activities engaged in, social support received, and perceived prosocial impact.

RESULTS

Daily occupational stressors were associated with elevated daily PTSD symptom severity (b = 0.13, SE = 0.06, p = .023). Social conflicts were associated with greater depression symptom severity (b = 0.75, SE = 0.14, p < .001); the meaning made from day's stressors (b = -0.17, SE = 0.05, p = .002) and the recovery activities engaged in (b = -0.30, SE = 0.07, p < .001) were associated with lower daily depression symptom severity.

LIMITATIONS

A relatively modest sample size and small sampling window may constrain the generalizations made from this study.

CONCLUSIONS

Occupational stressors and social conflicts are key risk factors related to the daily expression of PTSD and depression symptom severity in EMS workers. The meaning made from the day's challenges and the recovery activities engaged in may protect against depression. These results reveal several dynamic psychosocial factors that aid in understanding features of the work day that contribute to the mental health burden observed among EMS personnel.

The Effect of Self-Reported REM Behavior Disorder Symptomology on Intrusive Memories in Post-Traumatic Stress Disorder

Background: PTSD is characterised by severe sleep disturbances, which is increasingly recognised to in many cases consist of similar symptomology to sleep disorders such as REM Behaviour Disorder (RBD). The present study aimed to investigate whether different aspects of sleep quality influence intrusive memory development and whether PTSD status moderates this relationship. Participants and Methods: 34 PTSD, 52 trauma-exposed (TE) and 42 non-trauma exposed (NTE) participants completed an emotional memory task, where they viewed 60 images (20 positive, 20 negative and 20 neutral) and, two days later, reported how many intrusive memories they had of each valence category. Participants also completed three measures of sleep quality: the Pittsburgh Sleep Quality Index, the REM Behaviour Disorder Screening Questionnaire and total hours slept before each session. Results: The PTSD group reported poorer sleep quality than both TE and NTE groups on all three measures, and significantly more negative intrusive memories than the NTE group. Mediation analyses revealed that self-reported RBD symptomology before the second session mediated the relationship between PTSD status and intrusive memories. Follow-up moderation analyses revealed that self-reported RBD symptomology before the second session was only a significant predictor of intrusion in the PTSD group, though with a small effect size. Conclusions: These findings suggest that RBD symptomology is an indicator of consolidation of intrusive memories in PTSD but not trauma-exposed or healthy participants, which supports the relevance of characterising RBD in PTSD.

Trauma-Related Sleep Problems and Associated Health Outcomes in Police Officers: A Path Analysis

Police officers are frequently exposed to two different types of potentially traumatic events: one dealing with physical threats to self and the other involving the witnessing of harm to others. These different types of traumatic experiences are thought to produce various posttraumatic reactions. Furthermore, sleep problems are also reported as a hallmark of posttraumatic stress disorder. There is evidence, however, that sleep problems may mediate the relationship between posttraumatic stress disorder symptoms and health outcomes, especially physical health and depression. Previous research has shown this to be the case among officers from large urban agencies. The purpose of the present study was to test a model involving a pathway from trauma type and posttraumatic stress disorder symptoms to physical health and depression that is mediated by sleep quality in officers (N = 193) using data from small- to mid-size police agencies. Results revealed that sleep problems served as a mediator between posttraumatic stress disorder hyperarousal and avoidance symptoms and health outcomes, that the trauma types are related to different posttraumatic stress disorder symptoms, and that complicated relationships exist between the study variables. In addition, the results indicated that approximately 25% of our sample displayed probable partial posttraumatic stress disorder or probable full posttraumatic stress disorder, causing substantial functional impairment. Suggestions for improving officer health and performance in the field are provided. Specifically, it appears that interventions designed to address posttraumatic stress disorder hyperarousal symptoms related to personal life threat and the posttraumatic stress disorder avoidance symptoms related to the witnessing of human suffering may maximize officer sleep quality and ultimately overall wellness. In particular, mindfulness-based interventions are well suited for addressing these symptom clusters.

Sleep to remember, sleep to forget: Rapid eye movement sleep can have inverse effects on recall and generalization of fear memories

Rapid Eye Movement (REM) sleep has been shown to modulate the consolidation of fear memories, a process that may contribute to the development of Post-Traumatic Stress Disorder (PTSD). However, contradictory findings have been reported regarding the direction of this modulation and its differential effects on recall versus generalization. In two complementary experiments, we addressed this by employing sleep deprivation protocols together with a novel fear-conditioning paradigm that required the discrimination between coexisting threat and safety signals. Using skin conductance responses and functional imaging (fMRI), we found two opposing effects of REM sleep: While REM impaired recall of the original threat memories, it improved the ability to generalize these memories to novel situations that emphasized the discrimination between threat and safety signals. These results, as well as previous findings in healthy participants and patients diagnosed with PTSD, could be explained by the degree to which the balance between threat and safety signals for a given stimulus was predictive of threat. We suggest that this account can be integrated with contemporary theories of sleep and fear learning, such as the REM recalibration hypothesis.

Pandemic dreams: quantitative and qualitative features of the oneiric activity during the lockdown due to COVID-19 in Italy

Objective

The lockdown due to COVID-19 pandemic had a strong impact on daily habits, emotional experience, mental health and sleep. A large body of evidence suggests that dreams are affected by both waking experiences and sleep pattern. In this view, the lockdown should have induced intense modifications in dreaming activity. The aim of the study was to assess dream features during the lockdown in Italy.

Methods

We used an online survey to collect self-reported demographic, clinical, sleep and dream data. Our sample included 1091 participants.

Results

Results point to an increased dream frequency, emotional load, vividness, bizarreness and length during the lockdown, compared to a pre-lockdown period. Higher dream frequency and specific qualitative features were found in females and subjects with poor sleep quality, nocturnal disruptive behaviours and depressive symptoms. Most of the dream features assessed during the lockdown were predicted by age, gender, depressive symptoms, presence/absence of other people at home, and territorial area. A specific focus on sleep features revealed that sleep duration and several sleep quality indexes were the best predictors of dream variables. During the lockdown, dreams were also characterized by increased negative emotions, which were particularly frequent in females, younger adults, and participants with poor sleep quality, nocturnal disruptive behaviours, anxiety and depressive symptoms.

Conclusions

Our results confirm the hypothesis of a strong influence of the pandemic on dreaming, supporting both the hypothesis of continuity between wake and sleep mental processes and the view of a crucial influence of sleep quality and duration on dreaming activity.