Effects of Sleep after Experimental Trauma on Intrusive Emotional Memories

Sleep and the recovery from stress

The relationship between stress and sleep is multifaceted, with stress capable of both disrupting and promoting sleep depending on the nature, intensity, and duration of the stressor. While stress commonly leads to sleep fragmentation and arousal in both humans and animals, certain selective stressors, such as immune challenges and psychosocial stress, promote sleep in rodent models. Specific neural circuits, such as those involving the ventral tegmental area and lateral habenula, mediate this stress-induced sleep. Post-stress sleep may facilitate recovery, reduce anxiety, and enhance stress resilience, but the extent to which sleep versus wakefulness post-stress aids long-term adaptation is unclear. Both human and animal studies highlight a bidirectional relationship, where stress-induced changes in sleep architecture may have adaptive or maladaptive consequences. Here, we propose that post-stress sleep contributes to resilience and discuss potential mechanisms underlying this process. A deeper understanding of these pathways may provide new strategies for enhancing stress recovery and improving mental health outcomes.

The moderating effect of resilience in the association between insomnia severity and PTSD symptoms in Lebanese adolescents in the aftermath of the 2023 earthquake

The interplay between insomnia and PTSD symptoms remains misunderstood, and seems to be influenced by other factors like individual resilience. Our study examined the moderating role of resilience in the relationship between insomnia and PTSD symptoms among a sample of Lebanese adolescents, in the aftermath of the 2023 earthquake. This cross sectional study, conducted in April, 2 months after the earthquake, enrolled 546 Lebanese adolescents. We used the Sleep Self Report, the Resilience Scale for Adolescents and the 13-item Children's Impact of Event Scale. The interaction insomnia severity by resilience was significantly associated with PTSD scores. At low, moderate and high resilience levels, higher insomnia severity was significantly associated with lower PTSD. Resilience moderated the relationship between insomnia and PTSD, mitigating the detrimental impact of disrupted sleep on PTSD symptoms. This data can guide healthcare administrators and psychiatric caregivers in classifying risk factors and implementing interventions to predict PTSD development.

Valid and Reliable Attitude Scales for Measuring Clinician's Attitudes Towards Telehealth Assisted Sexual Assault Forensic Exams Using a Pre-Post Survey

The success of telehealth programs to guide clinicians to perform sexual assault medical forensic examinations relies on clinicians' positive attitudes toward telehealth services, though no validated tools to measure these variables exist. This study aims to report validity and reliability of a novel tool with two scales: Positive Beliefs and Acceptance scales for hospital nurse clinicians at sites initiating the Texas Teleforensic Remote Assistance Center (Tex-TRAC). An analysis of pre-post cross-sectional data of hospital nurse clinicians (N = 121) trained in the use of Tex-TRAC telehealth technology at seven participating hospitals in Texas from July 2022 to May 2023 was performed. The Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy and Bartlett's test of Sphericity sample size analysis were performed. Exploratory Factor Analysis (EFA) was applied for validity and internal consistency reliability Cronbach alpha (α) values were described for two scales: Positive Beliefs and Acceptance scales. Positive Beliefs scale has a KMO value of 0.810 and Barlett's test of sphericity (χ2 (6) = 380.47, P < .001). Acceptance scale has a KMO value of 0.832 and Barlett's test of sphericity (χ2 (28) = 432.19, P < .001). After Promax Oblique rotation, the final four-item Positive Beliefs scale had α = .894; the final five-item Acceptance scale had α = .876. Validity and reliability of both scales demonstrated potential usefulness for future telehealth interventions engaging Sexual Assault Nurse Examiners. Continued use of these scales could provide additional information that can be leveraged in training curriculum of similar telehealth programs like Tex-TRAC.

Targeting sleep quality in acutely traumatized individuals to reduce the risk for PTSD: study protocol for a multicentre randomized clinical trial

Background: There is a great need for feasible interventions in the initial period after a trauma that minimize the risk of developing a clinically relevant PTSD. The majority of people suffer from severe sleep disorders after a traumatic event. Because sleep is essential for processing emotional memories, we aim to improve sleep quality in acutely traumatized patients to benefit adaptive trauma processing and thereby prevent PTSD development.Objective: In a multicentre randomized controlled trial (RCT), we will investigate whether digital cognitive behavioural therapy for insomnia (dCBT-I) has the potential to not only increase sleep quality in acutely traumatized individuals but also reduce trauma-related symptoms (specific PTSD symptoms as well as related symptoms such as depression, anxiety and functional outcomes) and the risk for PTSD development in acutely traumatized individuals. Moreover, we will test if sleep disturbances pre-therapy predict the development of later PTSD symptoms.Method: We aim to recruit 104 patients who will be randomly assigned to an app-based sleep intervention utilizing CBT-I or a sleep diary as an add-on to treatment-as-usual (TAU) in outpatient acute trauma centres. Sleep quality, PTSD symptoms and everyday functioning will be measured before, after the intervention and at a 6-month follow-up.Conclusion: To our knowledge, this multicentre RCT is the first study to use dCBT-I as an early intervention for trauma. It may improve the understanding of the role of sleep in the development of PTSD and has the potential to contribute to the development of an easy-to-use early intervention for acutely traumatized individuals.

The relationship between REM sleep prior to analog trauma and intrusive memories

Intrusive memories are a common experience following trauma exposure but can develop into a symptom of posttraumatic stress disorder (PTSD). Recent research has observed a relationship between sleep disturbance and intrusive memory frequency following analog trauma exposure and disruptions in rapid eye movement (REM) sleep are found to contribute to emotional dysregulation and an amplified reaction to negative emotional stimuli. The current study examined the association between REM sleep prior to analog trauma and intrusive memories. To manipulate REM sleep, 27 healthy adults (MAge = 25.4, standard deviation = 2.89) were randomized to either a circadian misalignment (CM) condition or normal control (NC) condition for 4 nights. In CM, participants slept normally for 2 nights followed by a 4-hour phase advance on night 3 and an additional 4-hour phase advance on night 4. In NC, participants had 8-hour sleep opportunities each night. On day 5, participants watched a trauma film and kept an intrusive memory diary for the next 3 days. Greater REM sleep percentage (p = .004) and REM efficiency (p = .02) across 4 nights prior to analog trauma, independent of the group, were significantly associated with fewer intrusive memories in the 3 days after viewing the film. Findings suggest REM sleep may serve to protect individuals against experiencing intrusive memories. This is consistent with evidence suggesting REM sleep influences emotional memory regulation. Occupations (e.g. emergency services/military personnel) who experience circadian disruptions likely to decrease REM sleep (e.g. from shift work) may be at heightened risk of experiencing intrusive memories after trauma exposure, and thus at increased risk of developing PTSD.

Understanding Fatigue, Insomnia, and COVID-19 PTSS Among Mainland Chinese During Initial Post-Zero-COVID Infection Wave: A Multi-Group Analysis

In early 2023, China experienced its first widespread COVID-19 outbreak after a policy shift. This study examines the relationship between fatigue and COVID-19-related post-traumatic stress symptoms (PTSS) in infected and uninfected individuals, exploring the potential mediating role of insomnia symptoms. An online survey of 5953 Chinese participants was conducted from 10 to 16 January 2023. Participants reported their COVID-19 infection status, fatigue, insomnia symptoms, and PTSS. Multi-group structural equation modeling (SEM) was used to test whether the mediation paths differed between infected and uninfected groups. The prevalence of fatigue, insomnia symptoms, and COVID-19 PTSS were 30.0%, 36.4%, and 5.8%. The SEM based on the bootstrapping showed that after controlling for demographics, chronic fatigue positively associated with COVID-19 PTSS in a significant way, with insomnia symptoms playing a mediating role. The multi-group analyses further revealed a partial mediation effect of insomnia symptoms on the relationship between fatigue and COVID-19 PTSS in the uninfected group (UG). However, for the infected group (IG), insomnia symptoms fully mediated the relationship between fatigue and COVID-19 PTSS. Infected individuals were more subject to the aforementioned mechanism than uninfected individuals. Addressing chronic fatigue, insomnia, and developing targeted interventions are crucial for supporting mental health across different infection statuses.

A systematic review and meta-analysis of experimental methods for modulating intrusive memories following lab-analogue trauma exposure in non-clinical populations

Experiencing trauma leads to intrusive memories (IMs), a hallmark symptom of post-traumatic stress disorder (PTSD), which also occurs transdiagnostically. Understanding why IMs increase or decrease is pivotal in developing interventions to support mental health. In this preregistered meta-analysis (PROSPERO: CRD42021224835), we included 134 articles (131 techniques, 606 effect sizes and 12,074 non-clinical participants) to investigate how experimental techniques alter IM frequency, intrusion-related distress and symptoms arising from lab-analogue trauma exposure. Eligible articles were identified by searching eight databases until 12 December 2023. To test potential publication biases, we employed methods including Egger's test and three-parameter selection models. We employed three-level multilevel modelling and meta-regressions to examine whether and how experimental techniques would modulate IM frequency and associated outcomes. Results showed that techniques (behavioural, pharmacological, neuromodulation) significantly reduced intrusion frequency (g = 0.16, 95% confidence interval [0.09, 0.23]). Notably, techniques aimed to reduce IMs also ameliorated intrusion-related distress and symptoms, while techniques that increased IMs exacerbated these related outcomes, thus highlighting IM's centrality in PTSD-like symptoms. Techniques tapping into mental imagery processing (for example, trauma reminder followed by playing Tetris) reduced intrusions when administered immediately after, or at a delayed time after trauma. Although our meta-analysis is limited to symptoms induced by lab-analogue trauma exposure, some lab-based results have now generalized to real-world trauma and IMs, highlighting the promising utility of lab-analogue trauma paradigms for intervention development.

Molecular mechanisms and therapeutic possibilities of short-chain fatty acids in posttraumatic stress disorder patients: a mini-review

This mini-review explores the role of short-chain fatty acids (SCFAs) in posttraumatic stress disorder (PTSD). Highlighting the microbiota-gut-brain axis, this study investigated the bidirectional communication between the gut microbiome and mental health. SCFAs, byproducts of gut microbial fermentation, have been examined for their potential impact on PTSD, with a focus on molecular mechanisms and therapeutic interventions. This review discusses changes in SCFA levels and bacterial profiles in individuals with PTSD, emphasizing the need for further research. Promising outcomes from clinical trials using probiotics and fermented formulations suggest potential avenues for PTSD management. Future directions involve establishing comprehensive human cohorts, integrating multiomics data, and employing advanced computational methods, with the goal of deepening our understanding of the role of SCFAs in PTSD and exploring microbiota-targeted interventions.

Prospective Bidirectional Relationship Between Sleep Duration and Posttraumatic Stress Disorder Symptoms After Suspected Acute Coronary Syndrome

OBJECTIVE

Sleep disturbance is a "hallmark" symptom of posttraumatic stress disorder (PTSD). Poor sleep (including short sleep) after combat-related trauma can also predict subsequent PTSD. Less is known about the association between sleep duration and PTSD symptoms when PTSD is induced by acute coronary syndrome (ACS). We examined the bidirectional relationship between sleep duration and PTSD symptoms over the year after hospital evaluation for ACS.

METHODS

Participants were enrolled in this observational study after emergency department evaluation for ACS. Sleep duration ("During the past month, how many hours of actual sleep did you get at night?") and cardiac event or hospitalization-induced PTSD symptoms (PTSD Checklist) were assessed at 1, 6, and 12 months after hospital discharge. Cross-lagged path analysis was used to model the effects of sleep duration and PTSD symptoms on each other. Covariates included age, sex, race/ethnicity, cardiac severity, baseline depression symptoms, and early acute stress disorder symptoms.

RESULTS

The sample included 1145 participants; 16% screened positive for probable PTSD (PTSD Checklist score ≥33). Mean sleep duration across time points was 6.1 hours. Higher PTSD symptoms predicted shorter sleep duration at the next time point (i.e., 1-6 and 6-12 months; B = -0.14 hours/10-point difference, SE = 0.03, p < .001). Shorter sleep duration was associated with higher PTSD symptoms at the next time point (B = -0.25 points/hour, SE = 0.12, p = .04).

CONCLUSIONS

Short sleep duration and PTSD symptoms are mutually reinforcing across the first year after ACS evaluation. Findings suggest that sleep, PTSD symptoms, and their relationship should be considered in the post-ACS period.

How do the sleep features that characterise depression impact memory?

Depression is associated with general sleep disturbance and abnormalities in sleep physiology. For example, compared with control subjects, depressed patients exhibit lower sleep efficiency, longer rapid eye movement (REM) sleep duration, and diminished slow-wave activity during non-REM sleep. A separate literature indicates that depression is also associated with many distinguishing memory characteristics, including emotional memory bias, overgeneral autobiographical memory, and impaired memory suppression. The sleep and memory features that hallmark depression may both contribute to the onset and maintenance of the disorder. Despite our rapidly growing understanding of the intimate relationship between sleep and memory, our comprehension of how sleep and memory interact in the aetiology of depression remains poor. In this narrative review, we consider how the sleep signatures of depression could contribute to the accompanying memory characteristics.

Sleep Spindles Favor Emotion Regulation Over Memory Consolidation of Stressors in Posttraumatic Stress Disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is a trauma-induced condition, characterized by intrusive memories and trauma-associated anxiety. Non-rapid eye movement (NREM) sleep spindles might play a crucial role in learning and consolidating declarative stressor information. However, sleep and possibly sleep spindles are also known to regulate anxiety, suggestive of a dual role for sleep spindles in the processing of stressors. Specifically, in individuals with high PTSD symptom burden, spindles might fail to regulate anxiety levels after exposure and instead might maladaptively consolidate stressor information.

METHODS

To disentangle the role of spindles in declarative memory versus anxiety regulation after stressor exposure and to examine the role of PTSD in these processes, we measured nap sleep after a cohort of 45 trauma-exposed participants were exposed to laboratory stress. Participants (high vs. low PTSD symptoms) completed 2 visits: a stress visit involving exposure to negatively valent images before nap and a control visit. In both visits, sleep was monitored via electroencephalography. A stressor recall session occurred after the nap in the stress visit.

RESULTS

Stage 2 NREM (NREM2) spindle rates were higher in stress versus control sleep, indicative of stress-induced changes in spindles. In participants with high PTSD symptoms, NREM2 spindle rates in stress sleep predicted poorer recall accuracy of stressor images relative to participants with low PTSD symptoms, while correlating with greater reduction in stressor-induced anxiety levels after sleep.

CONCLUSIONS

Contrary to our expectations, although spindles are known to play a role in declarative memory processes, our findings highlight an important role for spindles in sleep-dependent anxiety regulation in PTSD.

To sleep or not to sleep, that is the question: A systematic review and meta-analysis on the effect of post-trauma sleep on intrusive memories of analog trauma

Distressing intrusive memories of a traumatic event are one of the hallmark symptoms of posttraumatic stress disorder. Thus, it is crucial to identify early interventions that prevent the occurrence of intrusive memories. Both, sleep and sleep deprivation have been discussed as such interventions, yet previous studies yielded contradicting effects. Our systematic review aims at evaluating existing evidence by means of traditional and individual participant data (IPD) meta-analyses to overcome power issues of sleep research. Until May 16th, 2022, six databases were searched for experimental analog studies examining the effect of post-trauma sleep versus wakefulness on intrusive memories. Nine studies were included in our traditional meta-analysis (8 in the IPD meta-analysis). Our analysis provided evidence for a small effect favoring sleep over wakefulness, log-ROM = 0.25, p < .001, suggesting that sleep is associated with a lower number of intrusions but unrelated to the occurrence of any versus no intrusions. We found no evidence for an effect of sleep on intrusion distress. Heterogeneity was low and certainty of evidence for our primary analysis was moderate. Our findings suggest that post-trauma sleep has the potential to be protective by reducing intrusion frequency. More research is needed to determine the impact following real-world trauma and the potential clinical significance.

Effect of sleep manipulations on intrusive memories after exposure to an experimental analogue trauma: A meta-analytic review

Sleep plays an important role in memory processing and is disrupted in individuals with post-traumatic stress disorder (PTSD). A growing body of research has experimentally investigated how sleep - or lack thereof - in the early aftermath of a traumatic experience contributes to intrusive memory formation. The aim of this meta-analytic review was to examine the effects of various experimental sleep manipulations (e.g., sleep deprivation, daytime naps) on intrusive memories following exposure to an experimentally induced analogue traumatic event. Eight eligible studies were systematically identified through PsycInfo and PubMed and provided sufficient data to contribute to a meta-analysis of the effects of sleep versus wakefulness on intrusive memory frequency. Sleep was found to reduce intrusive memory frequency when compared to wakefulness at a small but significant effect size (Hedge's g = 0.29). There was no evidence of publication bias and heterogeneity of effect sizes across studies was moderate. Results suggest that sleep plays a protective role in the aftermath of exposure to a traumatic event with implications for early post-trauma intervention efforts.

Modeling integrated stress, sleep, fear and neuroimmune responses: Relevance for understanding trauma and stress-related disorders

Sleep and stress have complex interactions that are implicated in both physical diseases and psychiatric disorders. These interactions can be modulated by learning and memory, and involve additional interactions with the neuroimmune system. In this paper, we propose that stressful challenges induce integrated responses across multiple systems that can vary depending on situational variables in which the initial stress was experienced, and with the ability of the individual to cope with stress- and fear-inducing challenges. Differences in coping may involve differences in resilience and vulnerability and/or whether the stressful context allows adaptive learning and responses. We provide data demonstrating both common (corticosterone, SIH and fear behaviors) and distinguishing (sleep and neuroimmune) responses that are associated with an individual's ability to respond and relative resilience and vulnerability. We discuss neurocircuitry regulating integrated stress, sleep, neuroimmune and fear responses, and show that responses can be modulated at the neural level. Finally, we discuss factors that need to be considered in models of integrated stress responses and their relevance for understanding stress-related disorders in humans.

Sleep spindles, stress and PTSD: The state of the science and future directions

Sleep spindles are a signature feature of non-REM (NREM) sleep, with demonstrated relationships to sleep maintenance and learning and memory. Because PTSD is characterized by disturbances in sleep maintenance and in stress learning and memory, there is now a growing interest in examining the role of sleep spindles in the neurobiology of PTSD. This review provides an overview of methods for measuring and detecting sleep spindles as they pertain to human PTSD and stress research, presents a critical review of early findings examining sleep spindles in PTSD and stress neurobiology, and proposes several directions for future research. In doing so, this review underscores the extensive heterogeneity in sleep spindle measurement and detection methods, the wide range of spindle features that may be and have been examined, the many persisting unknowns about the clinical and functional relevance of those features, and the problems considering PTSD as a homogeneous group in between-group comparisons. This review also highlights the progress that has been made in this field and underscores the strong rationale for ongoing work in this area.

The potential beneficial effect of sleep deprivation following traumatic events to preventing PTSD: Review of current insight regarding sleep, memory, and trauma resonating with ancient rituals-Àìsùn Oku (African) and Tsuya (Japanese)

Sleep figures in numerous ancient texts, for example, Epic of Gilgamesh, and has been a focus for countless mystical and philosophical texts. Even in the present century, sleep remains one of the most complex behaviors whose function still remains to be further explored. Current hypotheses suggest that among other functions, sleep contributes to memory processes. Memory is a core topic of study in post-traumatic stress disorder (PTSD) and other stress-related phenomena. It is widely accepted that sleep plays a major role in the consolidation of newly encoded hippocampus-dependent memories to pre-existing knowledge networks. Conversely, sleep deprivation disrupts consolidation and impairs memory retrieval. Along this line, sleep deprivation following a potentially traumatic event may interfere with the consolidation of event-related memories and, thereby, may reduce long-term post-traumatic stress-related symptoms. This review consolidates clinical and animal studies on the relationships between sleep, sleep deprivation, memory processes, and trauma exposure while introducing new contemporary insights into an ancient African tribal ritual (Àìsùn Oku) and Japanese ceremony ritual (Tsuya). We propose that these findings, focusing specifically on the effects of sleep deprivation in the immediate aftermath of traumatic events, may be explored as a possible therapeutic measure. Along with a summary of the field questions on whether sleep is performed "to remember" or "to forget" we lay the rationale for using sleep deprivation as a clinical tool. A tool that may partially prevent the long-term persistence of these traumatic events' memory and thereby, at least partly, attenuating the development of PTSD.

The effect of sleep on intrusive memories in daily life: a systematic review and meta-analysis of trauma film experiments

STUDY OBJECTIVES

To synthesize the literature on the effect of sleep versus wake on the frequency and distress of intrusive memories in everyday life after watching film clips with distressing content as a proxy for traumatic experiences.

METHODS

We conducted a systematic review by searching PubMed and PsychInfo. The last search was conducted on January 31, 2022. We included experimental studies comparing sleep and wake groups on intrusions using ecological diary methods, whereas studies lacking a wake control condition or relying solely on intrusion-triggering tasks or retrospective questionnaires were excluded. Meta-analyses were performed to evaluate the results. Risks of biases were assessed following the Cochrane guidelines.

RESULTS

Across 7 effect sizes from 6 independent studies, sleep (n = 192), as compared to wake (n = 175), significantly reduced the number of intrusive memories (Hedges' g = -0.26, p = .04, 95% CI [-0.50, -0.01]), but not the distress associated with them (Hedges' g = -0.14, p = .25, 95% CI [-0.38, 0.10]).

CONCLUSIONS

Although the results suggest that sleep reduces the number of intrusions, there is a strong need for high-powered pre-registered studies to confirm this effect. Risks of biases in the reviewed work concern the selection of the reported results, measurement of the outcome, and failure to adhere to the intervention. Limitations with the current meta-analysis include the small number of studies, which comprised only English-language articles, and the fact that it was not pre-registered.

Sleep-Directed Hypnosis Improves Subjective Sleep Quality but not Extinction Memory After Exposure to Analog Trauma

Background

Evidence-based treatments of posttraumatic stress disorder (PTSD) aim to promote fear extinction learning. Post-learning sleep, particularly slow wave sleep (SWS), promotes memory consolidation and recall. Thus, boosting SWS might strengthen extinction recall. The current study investigated whether sleep-directed hypnosis designed to increase SWS and sleep quality improves extinction recall and reduces analog PTSD symptoms.

Method

In two subsamples (remote/laboratory), 211 healthy individuals underwent fear conditioning with a traumatic film clip. On the next evening, they underwent extinction training. Thereafter, the experimental group received sleep-directed hypnosis, whereas the control group listened to a control text. Extinction recall and generalization and film-related intrusions and rumination were assessed on the following morning.

Results

Subjective sleep quality declined following exposure to an aversive film. No group differences were found in SWS though exploratory analyses indicated less rapid eye movement sleep after hypnosis. After hypnosis, the experimental group reported improved sleep quality, whereas the control group showed a further deterioration. Hypnosis had no effects on extinction retention and generalization nor on analog intrusions and rumination.

Conclusion

The current results indicate that sleep-directed hypnosis may be beneficial for improving subjective sleep quality after trauma but not for enhancing extinction memory and reducing analog PTSD symptoms.

To sleep or not to sleep - Effects on memory in normal aging and disease

Sleep behavior undergoes significant changes across the lifespan, and aging is associated with marked alterations in sleep amounts and quality. The primary sleep changes in healthy older adults include a shift in sleep timing, reduced slow-wave sleep, and impaired sleep maintenance. However, neurodegenerative and psychiatric disorders are more common among the elderly, which further worsen their sleep health. Irrespective of the cause, insufficient sleep adversely affects various bodily functions including energy metabolism, mood, and cognition. In this review, we will focus on the cognitive changes associated with inadequate sleep during normal aging and the underlying neural mechanisms.

Longitudinal associations between PTSD and sleep disturbances among World Trade Center responders

OBJECTIVE/BACKGROUND

Post-traumatic stress disorder (PTSD) is characterized by substantial disruptions in sleep quality, continuity, and depth. Sleep problems also may exacerbate PTSD symptom severity. Understanding how PTSD and sleep may reinforce one another is critical for informing effective treatments.

PATIENTS/METHODS

In a sample of 452 World Trade Center 9/11 responders (mean age = 55.22, 89.4% male, 66.1% current or former police), we examined concurrent and cross-lagged associations between PTSD symptom severity, insomnia symptoms, nightmares, and sleep quality at 3 time points ∼1 year apart. Data were analyzed using random intercept cross-lagged panel models.

RESULTS

PTSD symptom severity and sleep variables were relatively stable across time (intraclass correlation coefficients: 0.63 to 0.84). Individuals with more insomnia symptoms, more nightmares, and poorer sleep quality had greater PTSD symptom severity, on average. Within-person results revealed that greater insomnia symptoms and nightmares at Time 1 were concurrently associated with greater PTSD symptoms at Time 1. Insomnia symptoms were also concurrently associated with PTSD symptoms at Times 2 and 3, respectively. Cross-lagged and autoregressive results revealed that PTSD symptoms and nightmares predicted nightmares at the next timepoint.

CONCLUSIONS

Overall, results suggest PTSD and sleep problems may be linked at the same point in time but may not always influence each other longitudinally. Further, individuals who experience more sleep disturbances on average may suffer from more debilitating PTSD. Evidence-based treatments for PTSD may consider incorporating treatment of underlying sleep disturbances and nightmares.

Emotion dysregulation mediates the association between acute sleep disturbance and later posttraumatic stress symptoms in trauma exposed adults

Background: Sleep disturbance is common within days to weeks following a traumatic event and has been associated with emotion dysregulation, a strong risk factor for PTSD development. This study aims to examine if emotion dysregulation mediates the relationship between early post-trauma sleep disturbance and subsequent PTSD symptom severity.Methods: Adult participants (n = 125) completed questionnaires regarding sleep disturbance (via Pittsburgh Sleep Quality Index Addendum; PSQI-A) and emotion dysregulation (via Difficulties in Emotion Regulation Scale; DERS) within 2 weeks after exposure to traumatic events.Results: PTSD symptom severity was assessed with PTSD Checklist for DSM-5 (PCL-5) at 3-month follow-up. There were strong correlations between PSQI-A, DERS, and PCL-5 (r ranges between .38 and .45). Mediation analysis further revealed significant indirect effects of overall emotion regulation difficulties in the relationship between sleep disturbance at 2 weeks and PTSD symptom severity at 3 months (B = .372, SE = .136, 95% CI: [.128, .655]). Importantly, limited access to emotion regulation strategies emerged as the single, significant indirect effect in this relationship (B = .465, SE = .204, 95% CI [.127, .910]) while modelling DERS subscales as multiple parallel mediators.Conclusions: Early post-trauma sleep disturbance is associated with PTSD symptoms over months, and acute emotion dysregulation explains part of this association. Those with limited emotion regulation strategies are at particular risk of developing PTSD symptoms. Early interventions focusing on the appropriate strategies for emotion regulation may be crucial for trauma-exposed individuals.

The Impact of Sleep on Fear Extinction

Sleep plays a crucial role in the consolidation of memories, including those for fear acquisition and extinction training. This chapter reviews findings from studies testing this relationship in laboratory, naturalistic, and clinical settings. While evidence is mixed, several studies in humans have linked fear and extinction recall/retention to both rapid eye-movement and slow wave sleep. Sleep appears to further aid in the processing of both simulated and actual trauma and improves psychotherapeutic treatment outcomes in those with anxiety and trauma- and stressor-related disorders. This chapter concludes with a discussion of the current challenges facing sleep and emotional memory research in addition to suggestions for improving future research.

The influence of sleep on fear extinction in trauma-related disorders

In Posttraumatic Stress Disorder (PTSD), fear and anxiety become dysregulated following psychologically traumatic events. Regulation of fear and anxiety involves both high-level cognitive processes such as cognitive reattribution and low-level, partially automatic memory processes such as fear extinction, safety learning and habituation. These latter processes are believed to be deficient in PTSD. While insomnia and nightmares are characteristic symptoms of existing PTSD, abundant recent evidence suggests that sleep disruption prior to and acute sleep disturbance following traumatic events both can predispose an individual to develop PTSD. Sleep promotes consolidation in multiple memory systems and is believed to also do so for low-level emotion-regulatory memory processes. Consequently sleep disruption may contribute to the etiology of PTSD by interfering with consolidation in low-level emotion-regulatory memory systems. During the first weeks following a traumatic event, when in the course of everyday life resilient individuals begin to acquire and consolidate these low-level emotion-regulatory memories, those who will develop PTSD symptoms may fail to do so. This deficit may, in part, result from alterations of sleep that interfere with their consolidation, such as REM fragmentation, that have also been found to presage later PTSD symptoms. Here, sleep disruption in PTSD as well as fear extinction, safety learning and habituation and their known alterations in PTSD are first briefly reviewed. Then neural processes that occur during the early post-trauma period that might impede low-level emotion regulatory processes through alterations of sleep quality and physiology will be considered. Lastly, recent neuroimaging evidence from a fear conditioning and extinction paradigm in patient groups and their controls will be considered along with one possible neural process that may contribute to a vulnerability to PTSD following trauma.

Do your troubles today seem further away than yesterday? On sleep's role in mitigating the blushing response to a reactivated embarrassing episode

The "sleep to forget and sleep to remember hypothesis" proposes that sleep weakens the emotional tone of an experience while preserving or even enhancing its content. Prior experimental research however shows contradictory findings on how emotional reactivity changes after a period of sleep, likely explained by methodological variations. By addressing these inconsistencies, we investigated the mitigating effect of overnight sleep on emotional reactivity triggered by memory reactivation. Using a karaoke paradigm, we recorded participants' singing of two songs, followed by exposing them to one of the recordings (rec1) to induce an embarrassing episode. After a 12-hr period of either day-time wakefulness (N = 20) or including nighttime sleep (N = 20), we assessed emotional reactivity to the previously exposed recording (rec1) and the newly exposed recording (rec2). Emotional reactivity was assessed with a physiological measure of facial blushing as the main outcome and subjective ratings of embarrassment and valence. Sleep and wake were monitored with diaries and actigraphy. The embarrassing episode was successfully induced as indicated by objective and subjective measures. After controlling for an order effect in stimulus presentation, we found a reduction in blushing response to the reactivated recording (rec1) from pre- to post-sleep compared to wakefulness. However, emotional reactivity to the reactivated recording (rec1) and the new recording (rec2) did not differ after sleep and wakefulness. This study shows that facial blushing was reduced following overnight sleep, while subjective ratings were unaffected. Whether the beneficial effect of sleep is due to changes in memory representation or rather emotion regulation remains elusive.

Acute sleep interventions as an avenue for treatment of trauma-associated disorders

Scientific evidence that acute, posttrauma sleep disturbances (eg, nightmares and insomnia) can contribute significantly to the pathogenesis of trauma-induced disorders is compelling. Sleep disturbances precipitating from trauma are uniquely predictive of daytime posttrauma symptom occurrence and severity, as well as subsequent onset of mental health disorders, including post-traumatic stress disorder. Conversely, adequate sleep during the acute posttrauma period is associated with reduced likelihood of adverse mental health outcomes. These findings, which are broadly consistent with what is known about the role of sleep in the regulation of emotion, suggest that the acute posttrauma period constitutes a "window of opportunity" during which treatment of sleep disturbances may be especially effective for preventing or mitigating progression of aberrant psychophysiological processes. At this point, the weight of the scientific evidence supporting this possibility warrants initiation of clinical trials to confirm the benefits of targeted prophylactic sleep enhancement, and to establish treatment guidelines as appropriate.

CITATION

Swift KM, Thomas CL, Balkin TJ, Lowery-Gionta EG, Matson LM. Acute sleep interventions as an avenue for treatment of trauma-associated disorders. J Clin Sleep Med. 2022;18(9):2291-2312.

Estradiol during (analogue-)trauma: Risk- or protective factor for intrusive re-experiencing?

Intrusions, a key symptom of posttraumatic stress disorder (PTSD), can occur in the form of images but also as pain sensations. Similar to audiovisual intrusions, the frequency and persistence of pain intrusions varies greatly between individuals. In the current study, we examined whether peritraumatic circulating 17β-estradiol (E2) levels are a biologic factor associated with subsequent audiovisual (i.e., film) and pain intrusion development, and whether peritraumatic stress levels modulate this relationship. Forty-one free-cycling women participated in an ecologically informed trauma-pain-conditioning (TPC) paradigm, using trauma-films and pain as unconditioned stimuli. Independent variables were salivary peritraumatic E2 levels and stress indexed by salivary cortisol and self-reported state-anxiety during TPC. Outcomes were film- and pain-intrusions occurring during daily-life in the week following TPC and a Memory-Triggering-Task in response to conditioned stimuli 24 h after TPC. In the week after analogue-trauma, higher peritraumatic E2 levels were associated with a greater probability of experiencing film-intrusions in the beginning of the week, which switched to a lower probability toward the end of the week. This time-dependent relationship between E2 and film-intrusions only held for higher state-anxious women. In contrast, results indicated a consistent inverse relationship between peritraumatic E2 levels and pain-intrusions during daily-life and Memory-Triggering-Task. Together, these data suggest that higher peritraumatic E2 levels could be associated with lower long-term visual trauma intrusions, as well as lower pain-intrusions, and thereby possibly constitute a protective biologic factor for PTSD and potentially also for chronic pain.

Sleep as a window to target traumatic memories

Post-traumatic stress disorder (PTSD) is a severe psychiatric disorder in which traumatic memories result in flashbacks and nightmares. With one-third of patients not responding to standard exposure-based psychotherapy, new treatment strategies are needed. Sleep offers a unique time window to enhance therapeutic efficacy. Traumatic memories that are neutralized in therapy need to be stored back into memory (consolidated) during sleep to solidify the treatment effect. New basic research shows that memory consolidation can be enhanced by presenting sounds or scents that were linked to the memory at encoding, again during sleep. This procedure, termed targeted memory reactivation (TMR), has, despite its clinical potential, not been tested in (PTSD) patients. In this narrative review, we explore the potential of TMR as a new sleep-based treatment for PTSD. First we provide the necessary background on the memory and sleep principles underlying PTSD as well as the present applications and conditional factors of TMR. Then, we will discuss the outstanding questions and most promising experimental avenues when testing TMR to treat traumatic memories.

Sleep well, mind wander less: A systematic review of the relationship between sleep outcomes and spontaneous cognition

Despite an upsurge of research on spontaneous cognition, little is known about its associations with sleep-related outcomes. This systematic review, following PRISMA guidelines, examined the relationship between sleep and spontaneous thoughts, across different definitions and measurements of sleep outcomes and spontaneous cognition, and a diversity of methodologies. Twenty-one articles with survey and/or experimental designs were identified. Self-reported disturbed sleep-comprising poor sleep quality, more insomnia symptoms, more daytime sleepiness and a tendency towards eveningness-and experimentally induced sleep deprivation were associated with a tendency to engage in disruptive mind wandering and daydreaming, but not positive-constructive daydreaming. Findings regarding circadian fluctuation in spontaneous thoughts were mixed and inconclusive. This systematic review bridges the gap between the sleep and spontaneous cognition research by contributing to the understanding of potential psychological and cognitive mechanisms of spontaneous cognition, as well as by elucidating the emotional and cognitive consequences of disturbed sleep.

Roles for Sleep in Neural and Behavioral Plasticity: Reviewing Variation in the Consequences of Sleep Loss

Sleep is a vital physiological state that has been broadly conserved across the evolution of animal species. While the precise functions of sleep remain poorly understood, a large body of research has examined the negative consequences of sleep loss on neural and behavioral plasticity. While sleep disruption generally results in degraded neural plasticity and cognitive function, the impact of sleep loss can vary widely with age, between individuals, and across physiological contexts. Additionally, several recent studies indicate that sleep loss differentially impacts distinct neuronal populations within memory-encoding circuitry. These findings indicate that the negative consequences of sleep loss are not universally shared, and that identifying conditions that influence the resilience of an organism (or neuron type) to sleep loss might open future opportunities to examine sleep's core functions in the brain. Here, we discuss the functional roles for sleep in adaptive plasticity and review factors that can contribute to individual variations in sleep behavior and responses to sleep loss.

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 posttraumatic stress disorder (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 two 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.

Circadian influence on intrusive re-experiencing in trauma survivors' daily lives

BACKGROUND

The core clinical feature of posttraumatic stress disorder (PTSD) is recurrent re-experiencing in form of intrusive memories. While a great number of biological processes are regulated by sleep and internal biological clocks, the effect of 24-hour biological cycles, named circadian rhythm, has not been investigated in the context of intrusive memories.

OBJECTIVE

Here we examined effects of time of day on frequency and characteristics of intrusive re-experiencing.

METHODS

Fifty trauma survivors reported intrusive memories for 7 consecutive days using ecological momentary assessment in their daily life. We investigated (i) time-of-day dependent effects on frequency and distribution of intrusive re-experiencing in the overall sample as well as in PTSD versus non-PTSD and (ii) time-of-day dependent effects on the memory characteristics intrusiveness, vividness, nowness and fear.

RESULTS

Intrusive memories showed a curvilinear pattern that peaked at 2pm. Intrusive memories in the PTSD group showed a constant level of intrusive re-experiencing in the afternoon and evening, whereas a descending slope was present in the non-PTSD group. In PTSD, intrusive memories might thus be experienced in a more time-scattered fashion throughout the day, indicating chronodisruption. Intrusion characteristics did not follow this pattern.

CONCLUSION

Although preliminary and based on a small sample size, these findings contribute to a better understanding of the everyday occurrence and characteristics of intrusive memories, and point to the added value of examining time-dependent effects, which can directly inform prevention and intervention science.

Sleep problems among adolescents within child and adolescent mental health services. An epidemiological study with registry linkage

Sleep problems are prevalent among adolescents, especially among those diagnosed with mental health disorders. There is insufficient knowledge about sleep among adolescents within child and adolescent mental health services (CAMHS) in comparison to the general population. The data are drawn from the youth@hordaland study, a large population-based study conducted in 2012, linked to the Norwegian Patient Registry (NPR) (n = 9077). Psychiatric disorders were based on clinical diagnoses from the NPR, while insomnia, delayed sleep-wake-phase disorder (DSWPD), and other sleep problems/patterns were assessed by self-report questionnaires from youth@hordaland. The prevalence of diagnosed sleep disorders among adolescents seeking mental health services was 0.6%, yielding an estimated prevalence of 0.07% of the population. However, questionnaire-based measurement of insomnia from the youth@hordaland study indicated that insomnia was highly prevalent across disorders in comparison to a reference group of adolescents who were not within mental health care. Insomnia ranged from 29% among adolescents diagnosed with ADHD (PR = 1.79; 95% CI 1.41-2.29) to 48% among adolescents diagnosed with depression (PR = 2.53, 95% CI 2.19-2.92). All diagnostic groups had a mean sleep efficiency below (85%), indicating poor sleep quality. Insomnia, delayed sleep-phase wake disorder, and poor sleep efficiency were confirmed as transdiagnostic sleep problems across psychiatric disorders. In addition, some disorder-specific patterns emerged, such as a higher prevalence of insomnia among adolescents with depression, and DSWPS among adolescents with conduct disorder. This underscores the need for treating sleep problems in CAMHS, and transdiagnostic treatment approaches are warranted.

Correlation between PTSD and sleep quality in community-dwelling elderly adults in Hunan province of China

BACKGROUND

To understand the occurrence of post-traumatic stress disorder (PTSD) and the current status of sleep quality among community-dwelling elderly adults in Hunan Province of China, to explore the correlation between the two, and to analyze the trend of sleep disorders in PTSD elderly adults.

METHODS

A simple random sample containing 1,173 community-dwelling elderly adults in Hunan Province was established between March and May 2022, and an on-site face-to-face survey was administered using the PTSD Checklist-Civilian Version (PCL-C) with good reliability and validity, the Pittsburgh Sleep Quality Index (PSQI) scale, and a self-designed general condition questionnaire.

RESULTS

The incidence of PTSD in the 1,173 participants was 14.3% (168/1,173). The total incidence of sleep disorders was 40.9% (480/1,173); more specifically, the incidence of sleep disorders in participants with no PTSD symptom, in participants with mild-to-moderate PTSD symptoms, and in participants with severe PTSD symptoms was 36.3, 69.8, and 66.7%, respectively. The Spearman's rank correlation analysis showed that the total PTSD score and the scores of each dimension (i.e., re-experiencing symptom cluster, avoidance symptom cluster and hypervigilance symptom cluster) were positively correlated with the total PSQI score and its dimension scores (i.e., sleep quality, time to fall asleep, sleep duration, sleep efficiency, sleep disturbance, hypnotic medication, and daytime function) (P < 0.05). The correlation coefficients ranged from 0.013 to 0.495. For all PSQI dimensions, the differences across participants with different degrees of PTSD were statistically significant (P < 0.05).

CONCLUSIONS

The overall status of PTSD and sleep quality in community-dwelling elderly adults in Hunan Province was not optimistic. The elderly with PTSD were more prone to sleep disorders, and the more severe the symptoms of PTSD, the poorer the sleep quality was. However, differences were observed in the scores of each dimension of sleep across participants with different degrees of PTSD. Regardless of the degree of PTSD symptoms, the sleep quality of the elderly is severely affected, and the occurrence rate is not unlimited.

Sleep and anxiety: From mechanisms to interventions

Anxiety is the most common mental health problem worldwide. Epidemiological studies show that sleep disturbances, particularly insomnia, affect ∼50% of individuals with anxiety, and that insufficient sleep can instigate or further exacerbate it. This review outlines brain mechanisms underlying sleep and anxiety, by addressing recent human functional/structural imaging studies on brain networks underlying the anxiogenic impact of sleep loss, and the beneficial effect of sleep on these brain networks. We discuss recent developments from human molecular imaging studies that highlight the role of specific brain neurotransmitter mechanisms, such as the adenosinergic receptor system, on anxiety, arousal, and sleep. This review further discusses frontline sleep interventions aimed at enhancing sleep in individuals experiencing anxiety, such as nonbenzodiazepines/antidepressants, lifestyle and sleep interventions and cognitive behavioral therapy for insomnia. Notwithstanding therapeutic success, up to ∼30% of individuals with anxiety can be nonresponsive to frontline treatments. Thus, we address novel non-invasive brain stimulation techniques that can enhance electroencephalographic slow waves, and might help alleviate sleep and anxiety symptoms. Collectively, these findings contribute to an emerging biological framework that elucidates the interrelationship between sleep and anxiety, and highlight the prospect of slow wave sleep as a potential therapeutic target for reducing anxiety.

Sleep and interrogation: does losing sleep impact criminal history disclosure?

STUDY OBJECTIVES

Despite centuries of using sleep deprivation to interrogate, there is virtually no scientific evidence on how sleep shapes behavior within interrogation settings. To evaluate the impact of sleeplessness on participants' behavior during investigative interviews, an experimental study examined the impact of sleep restriction on disclosure of past illegal behavior.

METHODS

Healthy participants from a university community (N = 143) either maintained or curbed their sleep (up to 4 h a night) across 2 days with sleep monitored via actigraphy. They were then asked to disclose past illegal acts and interviewed about them. Next, they were reinterviewed following an example of a detailed memory account (model statement). Disclosures were blindly coded for quantity and quality by two independent raters.

RESULTS

Sleep-restricted individuals reported similar offenses, but less information during their disclosure with slightly less precision. Model statement increased disclosure but did not reduce the inhibiting impact of sleep loss. Mediation analysis confirmed the causal role of sleep as responsible for experimental differences in amount of information, and participants' reports suggested impaired motivation to recall information played a role.

CONCLUSIONS

The findings suggest that even moderate sleep loss can inhibit criminal disclosure during interviews, point to motivational factors as responsible, and suggest investigators should be cautious when interrogating sleepy participants.

Insomnia Symptoms and Acute Coronary Syndrome-Induced Posttraumatic Stress Symptoms: A Comprehensive Analysis of Cross-sectional and Prospective Associations

BACKGROUND

Acute coronary syndrome (ACS) induces clinically significant posttraumatic stress symptoms (PTSS) in 12% of patients. Subjective sleep problems are a risk factor for the development of PTSS, but this is underexplored in patients with ACS.

PURPOSE

To examine the association of insomnia symptoms with ACS-induced PTSS.

METHODS

In this longitudinal study with 154 patients (all white, 84.4% male, mean age 58.7 years) with a verified ACS, insomnia symptoms were interviewer assessed at hospital admission and at 3 months, using the Jenkins Sleep Scale (JSS)-4. ACS-induced PTSS were assessed with the Clinician-Administered Posttraumatic Stress Disorder Scale 3 months after hospital admission. In multivariable linear models, insomnia symptoms were regressed on PTSS, adjusting for demographics, clinical variables, health behaviors, and psychological data, including cognitive depressive symptoms.

RESULTS

Greater insomnia symptoms at admission (β = .165, p = .034), greater increase in insomnia symptoms from admission to 3 months (β = .233, p = .008), and greater insomnia symptoms at 3 months (β = .239, p = .002) were independently associated with more severe total PTSS at 3 months. Concerning the individual PTSS clusters, both insomnia symptoms at admission (β = .214, p = .007) and at 3 months (β = .213, p = .012) were independently associated with reeexperiencing symptoms. Removing sleep items from PTSS scores and excluding patients on antidepressants in two sensitivity analyses did not substantially change the results.

CONCLUSIONS

Insomnia symptoms could play an important role in the development and severity of ACS-induced PTSS. This relationship seems not simply explained by the fact that sleeping difficulties are inherent to the phenotype of posttraumatic stress disorder.

CLINICAL TRIAL INFORMATION

NCT01781247.

The Many Faces of Sleep Disorders in Post-Traumatic Stress Disorder: An Update on Clinical Features and Treatment

Sleep disorders and nightmares are core symptoms of post-traumatic stress disorder (PTSD). The relationship seems to be bidirectional, and persistent disturbed sleep may influence the course of the disorder. With regard to sleep quality, insomnia and nocturnal anxiety symptoms, as well as nightmares and stressful dreams, are the most prominent sleep symptoms. Polysomnographic measurements reveal alterations of the sleep architecture and fragmentation of rapid eye movement sleep. In addition, sleep disorders, such as sleep-related breathing disorders and parasomnias are frequent comorbid conditions. The complex etiology and symptomatology of trauma-related sleep disorders with frequent psychiatric comorbidity require the application of multimodal treatment concepts, including psychological and pharmacological interventions. However, there is little empirical evidence on the effectiveness of long-term drug treatment for insomnia and nightmares. For nondrug interventions, challenges arise from the current lack of PTSD-treatment concepts integrating sleep- and trauma-focused therapies. Effective therapy for sleep disturbances may consequently also improve well-being during the day and probably even the course of PTSD. Whether early sleep interventions exert a preventive effect on the development of PTSD remains to be clarified in future studies.

Experimental trauma rapidly modifies functional connectivity

Traumatic events can produce emotional, cognitive and autonomous physical responses. This may ultimately lead to post-traumatic stress disorder (PTSD), a psychiatric syndrome which requires comprehensive treatment. Trauma exposure alters functional connectivity; however, onset and nature of these changes are unknown. Here, we explore functional connectivity changes at rest directly after experimental trauma exposure. Seventy-three healthy subjects watched either a trauma or a control film. Resting state functional magnetic resonance imaging measurements were conducted before and directly after the film. Seed-based analyses revealed trauma-related changes in functional connectivity, specifically including decreases of connectivity between amygdala and middle temporal gyrus and increases between hippocampus and precuneus. These central effects were accompanied by trauma-related increases in heart rate. Moreover, connectivity between the amygdala and middle temporal gyrus predicted subsequent trauma-related valence. Our results demonstrate rapid functional connectivity changes in memory-related brain regions at rest after experimental trauma, selectively relating to changes in emotions evoked by the trauma manipulation. Results could represent an early predictive biomarker for the development of trauma-related PTSD and thus provide an indication for the need of early targeted preventive interventions.

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.

Sexual harassment and assault predict sleep disturbances and is partly mediated by nightmares: Findings from a national survey of all university students in Norway

Sexual harassment and assault is common in most domains of society, and has been linked to several adverse outcomes, including reduced sleep quality. However, less is known about the possible impact of sexual harassment and assault on various sleep problems among university students. In a sample of 49,051 students in Norway (69.2% women), we examined i) the associations of varying extents of sexual harassment (unwanted sexual comments, looks or gestures, photographs, indecent exposure, and physical harassment) and sexual assault (attempted or completed rape), with meeting Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) diagnostic criteria of insomnia and with sleep duration, ii) the association of cumulative exposure to sexual harassment/assault with insomnia and sleep duration, and iii) to what extent nightmares could explain the association between sexual harassment and insomnia and sleep duration. For both genders, all forms of harassments with the exception of "indecent exposure" and "unwanted sexual photographs" for men were negatively associated with sleep duration, with the strongest associations being found for "rape" and "attempted rape". For both genders, the odds of insomnia increased as a function of cumulative harassment exposure. Similarly, a graded, negative association was found between cumulative harassment and sleep duration for both genders. Mediation analyses showed that 28% of the observed association between cumulative harassment and insomnia, and 15% of the association between cumulative harassment and sleep duration, was mediated by frequency of nightmares.

Neurobiology and Neuroprotective Benefits of Sleep

PURPOSE OF REVIEW

This article outlines the neurocircuitry underlying sleep-wake and circadian physiology with a focus on the fundamental roles that sleep and circadian health play in optimal neurologic function.

RECENT FINDINGS

The foundation of sleep and wake promotion is laid primarily by the "fast-acting" neurotransmitters: γ-aminobutyric acid (GABA) for sleep and glutamate for wake. External to these primary systems are a host of modulatory systems that are characterized by two flip-flop switches of mutually inhibitory neurotransmitter systems that facilitate transitions between wake and sleep as well as non-rapid eye movement (non-REM) and REM sleep. Additional mechanisms are in place to help coordinate the sleep-wake states with environmental, metabolic, and behavioral demands. The complexity of the evolutionarily preserved sleep-wake and circadian systems, the proportion of the day dedicated to the natural sleeping period, as well as the neurocognitive dysfunction and neurodegeneration caused by deficient sleep highlight the importance of defining, assessing, and optimizing the sleep health of our patients and ourselves.

SUMMARY

Exciting discoveries continue to elucidate the underlying mechanisms of sleep and wake state coordination, reinforcing fundamental healthy practices and paving the way for new interventions that preserve and promote optimal neurologic health.

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.

Altered sleep behavior in a genetic mouse model of impaired fear extinction

Sleep disturbances are a common complaint of anxiety patients and constitute a hallmark feature of post-traumatic stress disorder (PTSD). Emerging evidence suggests that poor sleep is not only a secondary symptom of anxiety- and trauma-related disorders but represents a risk factor in their development, for example by interfering with emotional memory processing. Fear extinction is a critical mechanism for the attenuation of fearful and traumatic memories and multiple studies suggest that healthy sleep is crucial for the formation of extinction memories. However, fear extinction is often impaired in anxiety- and trauma-related disorders-an endophenotype that is perfectly modelled in the 129S1/SvImJ inbred mouse strain. To investigate whether these mice exhibit altered sleep at baseline that could predispose them towards maladaptive fear processing, we compared their circadian sleep/wake patterns to those of typically extinction-competent C57BL/6 mice. We found significant differences regarding diurnal distribution of sleep and wakefulness, but also sleep architecture, spectral features and sleep spindle events. With regard to sleep disturbances reported by anxiety- and PTSD patients, our findings strengthen the 129S1/SvImJ mouse models' face validity and highlight it as a platform to investigate novel, sleep-focused diagnostic and therapeutic strategies. Whether the identified alterations causally contribute to its pathological anxiety/PTSD-like phenotype will, however, have to be addressed in future studies.

Go to Bed and You MIGHT Feel Better in the Morning—the Effect of Sleep on Affective Tone and Intrusiveness of Emotional Memories

Purpose of Review

It is important to examine what effect sleep has after an emotional experience. More knowledge about this topic could help inform us whether there are any potential sleep interventions that could help make sure that memories of negative emotional experiences are processed in the most adaptive manner possible.

Recent Findings

Findings on the role of sleep in altering reactivity to emotional stimuli have been highly varied, with significant findings in opposite directions. A new exciting development in the field is several studies finding that sleep seems to make memories of negative experiences less intrusive.

Summary

This review has mainly aimed to give an overview of the field, and of which issues need to be resolved. We argue for there being a strong need for standardization of how data are analyzed and presented, as well as for better methods for determining to what extent the effects of sleep are specific for a particular memory, or represent general changes in emotional reactivity.