A Review of the Relationship Between Emotional Learning and Memory, Sleep, and PTSD

The Association Between Adverse Childhood Experiences and Sleep in Children with Autism Spectrum Disorder

Children with autism spectrum disorder are at higher risk for adverse childhood experiences (ACEs). They are also more vulnerable to sleep problems and are less likely to obtain the recommended number of hours of sleep than neurotypical children. In the general population, ACEs have been linked to future sleep difficulties. Despite increased vulnerabilities to both ACEs and sleep problems, no study has examined this association in ASD. Using the National Survey of Children's Health across four cohorts, we examined whether ACEs were a risk factor to obtaining the recommended number of hours of sleep, while accounting for demographic and health factors typically associated with sleep duration. Findings indicate that children with ASD with more ACEs were less likely to get the recommended number of hours of sleep than children with fewer ACEs. Other factors associated with sleep included race, anxiety, autism severity, and overall health. These findings indicate that sleep problems in children with ASD are complex and multifaceted. Among other considerations, it is important for clinicians to screen children with ASD for ACEs and consider the possible impact of ACEs on sleep.

The role of objective sleep in implicit and explicit affect regulation: A comprehensive review

Impairments in sleep and affect regulation are evident across a wide range of mental disorders. Understanding the sleep factors that relate to affect regulatory difficulties will inform mechanistic understanding and aid in treatment. Despite rising interest, some research challenges in this area include integrating across different clinical and non-clinical literatures investigating the role of sleep architecture (measured with polysomnography) and experimentally manipulated sleep, as well as integrating more explicit versus implicit affect regulation processes. In this comprehensive review, we use a unifying framework to examine sleep's relationship with implicit-automatic regulation and explicit-controlled regulation, both of which are relevant to mental health (e.g., PTSD and depression). Many studies of implicit-automatic regulation (e.g., fear extinction and safety learning) demonstrate the importance of sleep, and REM sleep specifically. Studies of explicit-controlled regulation (e.g., cognitive reappraisal and expressive suppression) are less consistent in their findings, with results differing depending on the type of affect regulation and/or way that sleep was measured or manipulated. There is a clear relationship between objective sleep and affect regulation processes. However, there is a need for 1) more studies focusing on sleep and explicit-controlled affect regulation; 2) replication with the same types of regulation strategies; 3) more studies experimentally manipulating sleep to examine its impact on affect regulation and vice versa in order to infer cause and effect; and 4) more studies looking at sleep's impact on next-day affect regulation (not just overnight change in affect reactivity).

Infralimbic activity during REM sleep facilitates fear extinction memory

Rapid eye movement (REM) sleep is known to facilitate fear extinction and play a protective role against fearful memories.1,2 Consequently, disruption of REM sleep after a traumatic event may increase the risk for developing PTSD.3,4 However, the underlying mechanisms by which REM sleep promotes extinction of aversive memories remain largely unknown. The infralimbic cortex (IL) is a key brain structure for the consolidation of extinction memory.5 Using calcium imaging, we found in mice that most IL pyramidal neurons are intensively activated during REM sleep. Optogenetically suppressing the IL specifically during REM sleep within a 4-h window after auditory-cued fear conditioning impaired extinction memory consolidation. In contrast, REM-specific IL inhibition after extinction learning did not affect the extinction memory. Whole-cell patch-clamp recordings demonstrated that inactivating IL neurons during REM sleep depresses their excitability. Together, our findings suggest that REM sleep after fear conditioning facilitates fear extinction by enhancing IL excitability and highlight the importance of REM sleep in the aftermath of traumatic events for protecting against traumatic memories.

REM disruption and REM Vagal Activity Predict Extinction Recall in Trauma-Exposed Individuals

Accumulating evidence suggests that rapid eye movement sleep (REM) supports the consolidation of extinction memory. REM is disrupted in PTSD, and REM abnormalities after traumatic events increase the risk of developing PTSD. Therefore, it was hypothesized that abnormal REM in trauma-exposed individuals may pave the way for PTSD by interfering with the processing of extinction memory. In addition, PTSD patients display reduced vagal activity. Vagal activity contributes to the strengthening of memories, including fear extinction memory, and recent studies show that the role of vagus in memory processing extends to memory consolidation during sleep. Therefore, it is plausible that reduced vagal activity during sleep in trauma-exposed individuals may be an additional mechanism that impairs extinction memory consolidation. However, to date, the contribution of sleep vagal activity to the consolidation of extinction memory or any emotional memory has not been investigated. To test these hypotheses, we examined the association of extinction memory with REM characteristics and REM vagal activity (indexed as heart rate variability) in a large sample of trauma-exposed individuals (n=113). Consistent with our hypotheses, REM disruption was associated with poorer physiological and explicit extinction memory. Furthermore, higher vagal activity during REM was associated with better explicit extinction memory, and physiological extinction memory in males. These findings support the notion that abnormal REM may contribute to PTSD by impairing the consolidation of extinction memory and indicate the potential utility of interventions that target REM sleep characteristics and REM vagal activity in fear-related disorders.

The importance of REM sleep fragmentation in the effects of stress on sleep: Perspectives from preclinical studies

Psychological stress poses a risk for sleep disturbances. Importantly, trauma-exposed individuals who develop posttraumatic stress disorder (PTSD) frequently report insomnia and recurrent nightmares. Clinical studies have provided insight into the mechanisms of these sleep disturbances. We review polysomnographic findings in PTSD and identify analogous measures that have been made in animal models of PTSD. There is a rich empirical and theoretical literature on rapid eye movement sleep (REMS) substrates of insomnia and nightmares, with an emphasis on REMS fragmentation. For future investigations of stress-induced sleep changes, we recommend a focus on tonic, phasic and other microarchitectural REMS measures. Power spectral density analysis of the sleep EEG should also be utilized. Animal models with high construct validity can provide insight into gender and time following stressor exposure as moderating variables. Ultimately, preclinical studies with translational potential will lead to improved treatment for stress-related sleep disturbances.

The effect of obstructive sleep apnea severity on PTSD symptoms during the course of esketamine treatment: a retrospective clinical study

STUDY OBJECTIVES

Intranasal administration of esketamine is Food and Drug Administration-approved for treatment-resistant depression. In a recent retrospective case series, we show that it has promise in reducing symptoms of posttraumatic stress disorder (PTSD) as well. Untreated obstructive sleep apnea (OSA) is prevalent among veterans with PTSD and has been shown to interfere with other PTSD treatments. In the current study, we examined whether OSA impacts esketamine's effectiveness in reducing symptoms of PTSD or depression.

METHODS

Participants were 60 veterans with a diagnosis of major depressive disorder and PTSD who received intranasal esketamine treatment at the San Diego Veterans Affairs (VA) Medical Center. We used growth-curve modeling to examine changes in depression and PTSD symptoms following esketamine treatments and, in the subset of individuals screened for OSA (n = 24, all prescribed positive airway pressure therapy), examined the impacts of OSA severity on these trajectories.

RESULTS

We first showed that both PTSD and depressive symptoms significantly decreased over the course of esketamine treatment. In the subset of veterans screened for OSA, individuals with lower OSA severity reported the greatest reduction in PTSD symptoms, while veterans with the most severe OSA reported the least reduction in PTSD symptoms. Depression response was not affected by severity of OSA in this analysis.

CONCLUSIONS

Veterans with PTSD and depression tend to benefit from esketamine treatment, but OSA may interfere with esketamine effectiveness. Comorbid OSA should be assessed for and treated to maximize esketamine's benefits in PTSD.

CITATION

Titone MK, Hunt C, Bismark A, et al. The effect of obstructive sleep apnea severity on PTSD symptoms during the course of esketamine treatment: a retrospective clinical study. J Clin Sleep Med. 2023;19(12):2043-2051.

Beta spectral power during sleep is associated with impaired recall of extinguished fear

The failure to retain memory for extinguished fear plays a major role in the maintenance of posttraumatic stress disorder (PTSD), with successful extinction recall necessary for symptom reduction. Disturbed sleep, a hallmark symptom of PTSD, impairs fear extinction recall. However, our understanding of the electrophysiological mechanisms underpinning sleep's role in extinction retention remains underdetermined. We examined the relationship between the microarchitecture of sleep and extinction recall in healthy humans (n = 71, both male and females included) and a pilot study in individuals with PTSD (n = 12). Participants underwent a fear conditioning and extinction protocol over 2 days, with sleep recording occurring between conditioning and extinction. Twenty-four hours after extinction learning, participants underwent extinction recall. Power spectral density (PSD) was computed for pre- and post-extinction learning sleep. Increased beta-band PSD (~17-26 Hz) during pre-extinction learning sleep was associated with worse extinction recall in healthy participants (r = 0.41, p = .004). Beta PSD was highly stable across three nights of sleep (intraclass correlation coefficients > 0.92). Results suggest beta-band PSD is specifically implicated in difficulties recalling extinguished fear.

The role of affect in associations between sleep disturbances and posttraumatic stress disorder symptoms: A systematic review

Strong evidence supports a bidirectional association between sleep disturbances and posttraumatic stress disorder (PTSD). Affect - temporary internal states experienced as feeling good or bad, energized or enervated - may play a central role in explaining this link. The current systematic review summarizes the literature on associations between sleep, PTSD, and affect among trauma-exposed adults. We systematically searched five electronic databases (PubMed, PsycInfo, PTSDpubs, Web of Science, CINAHL) using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Of 2656 screened articles, 6 studies met inclusion criteria. Four findings emerged: (1) greater insomnia symptom severity predicted greater PTSD symptom severity above the influence of negative affect, (2) negative affect mediated the effect of sleep quality on next-day PTSD symptom severity, (3) positive affect mediated the effect of PTSD symptom severity on insomnia symptom severity and sleep disturbances, and (4) greater negative affect (specifically, greater anger) was associated with greater severity of PTSD and sleep disturbances. Findings highlight areas for future research, such as the need to investigate more dimensions, timescales, and methods of studies simultaneously assessing affect, sleep, and PTSD, as well as the need for more longitudinal and experimental work to determine causality across these constructs.

Effects of sleep disturbance on trauma-focused psychotherapy outcomes in posttraumatic stress disorder: A systematic review

This study aimed to synthesize existing research on the effects of sleep disturbances on trauma-focused psychotherapy outcomes in adults with posttraumatic stress disorder (PTSD). A systematic review using PubMed, PsycINFO, Embase, Web of Science, and PTSDpubs was performed up to April 2021. Two independent reviewers screened articles for inclusion, performed data extraction, and assessed risk of bias and certainty of the evidence. Narrative synthesis was conducted based on the type of sleep disorder symptom assessed. Sixteen primary studies were included in this review, the majority of which had a high overall risk of bias. Results suggested that sleep disorder symptoms were associated with higher overall PTSD severity across treatment; however, they did not interfere with treatment effectiveness, with the exception of sleep-disordered breathing. Improvements in insomnia, sleep duration, and sleep quality during treatment were associated with greater treatment gains. Certainty of the evidence ranged from low to very low. These results suggest that it may not be necessary to address sleep disorder symptoms prior to initiating trauma-focused psychotherapy. Instead, concurrent treatment of sleep- and trauma-related symptoms may be most beneficial. Continued research is needed to clarify the mechanistic relationship between sleep and treatment outcomes and to guide clinical decision-making.

Sleep efficiency predicts improvements in fear extinction and PTSD symptoms during prolonged exposure for veterans with comorbid insomnia

Prolonged exposure (PE) is an evidenced-based psychotherapy for PTSD, but many Veterans fail to achieve a clinically meaningful response. Sleep issues are prevalent in Veterans and may interfere with PE by disrupting the learning and consolidation of fear extinction memories during PE exposures. Here, we examined whether changes in fear extinction across imaginal exposures and PTSD symptoms during PE were predicted by diary-assessed levels of nightly sleep efficiency (SE; i.e., percent of time in bed spent sleeping), which may indirectly index sleep fragmentation and sleep-facilitated memory processes. Participants were Veterans with PTSD and comorbid insomnia (N = 40) participating in a clinical trial of cognitive-behavioral therapy for insomnia plus PE. SE was measured via nightly sleep diaries, fear extinction was operationalized as a reduction in peak distress between weekly imaginal exposures, and PTSD symptoms were assessed bi-weekly. Cross-lagged panel models revealed that higher sleep efficiency during the week predicted lower peak distress at the subsequent imaginal exposure and lower PTSD symptoms at the subsequent assessment, whereas PTSD symptoms and peak distress did not predict subsequent sleep efficiency. Efficient sleep may facilitate fear extinction and PTSD reduction during PE. Targeting sleep efficiency could improve PE effectiveness for Veterans with comorbid insomnia.

Factors Affecting Sleep Quality of College Students during the Coronavirus Disease 2019 Pandemic: A Cross-Sectional Study

Background and Objectives: The purpose of this study was to identify the correlation between college students' fear of coronavirus disease 2019 (COVID-19), intolerance of uncertainty, and sleep quality during the COVID-19 pandemic, and to identify factors affecting sleep quality. Materials and Methods: Data were collected through an online survey of 310 college students from three universities located in three regions in Korea. Results: The average sleep quality score of college students was 4.76 ± 2.86 points, the average fear of COVID-19 was 14.01 ± 5.05 points, and the average intolerance of uncertainty was 31.50 ± 7.92 points. Fear of COVID-19 and intolerance of uncertainty were positively correlated (r = 0.302, p < 0.001). Sleep quality was positively correlated with fear of COVID-19 (r = 0.246, p < 0.001). Sleep quality was positively correlated with intolerance of uncertainty (r = 0.212, p < 0.001). Health status was the most powerful factor that affected sleep quality (β = 0.377, p < 0.001). The next most powerful factors that affected sleep quality were fear of COVID-19 (β = 0.164, p = 0.003) and intolerance of uncertainty (β = 0.122, p = 0.027), respectively. Conclusions: These results are expected to be used as basic data for the development of health intervention programs to protect and improve the psychological well-being of college students by improving their sleep quality.

The relationship between sleep and appetitive conditioning: A systematic review and meta-analysis

This systematic review and meta-analysis (PROSPERO registration animal/human studies: CRD42021234793/CRD42021234790) examined the relationship between sleep and appetitive conditioning. Inclusion criteria included: a) appetitive conditioning paradigm; b) measure of conditioning; c) sleep measurement and/or sleep loss; d) human and/etor non-human animal samples; and e) written in English. Searches of seven databases returned 3777 publications. The final sample consisted of 42 studies using primarily animal samples and involving food- and drug-related conditioning tasks. We found sleep loss disrupted appetitive conditioning of food rewards (p < 0.001) but potentiated appetitive conditioning of drug rewards (p < 0.001). Furthermore, sleep loss negatively impacted extinction learning irrespective of the reward type. Post-learning sleep was associated with increases in REM sleep (p = 0.02). Findings suggest sleep loss potentiates the impact of psychoactive substances in a manner likely to produce an increased risk of problematic substance use. In obese/overweight populations, sleep loss may be associated with deficits in the conditioning and extinction of reward-related behaviours. Further research should assess the relationship between sleep and appetitive conditioning in humans.

Activation of ventral tegmental area vesicular GABA transporter (Vgat) neurons alleviates social defeat stress-induced anxiety in APP/PS1 mice

Introduction

Alzheimer's disease (AD) is a progressive neurodegenerative disease that results in cognitive impairment and is often accompanied by anxiety. In this study, we investigated whether the activation of VTA^Vgat neurons could reduce anxiety in APP/PS1 mice. We hypothesized that acute social defeat stress (SDS) would lead to anxiety in APP/PS1 mice, and that the activation of VTA^Vgat neurons would alleviate this anxiety.

Methods

We exposed APP/PS1 mice to acute SDS and assessed anxiety using the open field test and elevated plus-arm test. Activated VTA^Vgat neurons was tested by cfos staining. Sleep quality was detected using electroencephalogram after SDS or non-SDS procedure. Sleep duration, sleep latency, and non-rapid eye movement (NREM) percentage were analyzed. VTA^Vgat neurons were chemogenetically activated by deschloroclozapine.

Results

Our results showed that acute SDS led to anxiety in APP/PS1 mice, as evidenced by increased anxiety-related behaviors in the open field and elevated plus-arm tests. Activation of VTA^Vgat neurons by SDS led to an increase in sleep duration, primarily due to a decrease in sleep latency and an increase in NREMs. However, the quality of sleep was poor. Chemogenetical activation of VTA^Vgat neurons improved sleep quality and relieved SDS-induced anxiety. Furthermore, the anxiety state correlated negatively with sleep duration and NREM percentage and correlated positively with theta power density in APP/PS1 mice.

Discussion

Our study provides evidence that the activation of VTA^Vgat neurons alleviates SDS-induced anxiety in APP/PS1 mice, suggesting that poor sleep quality may exacerbate anxiety in AD. These findings may have important implications for the treatment of anxiety in AD, as targeting VTA^Vgat neurons could be a potential therapeutic approach.

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.

Sleep impairments in refugees diagnosed with post-traumatic stress disorder: a polysomnographic and self-report study

Background: Post-traumatic stress disorder (PTSD) is the clinical manifestation of traumatic events and is associated with sleep disturbances. Sleep disturbances, if left untreated, may perpetuate or even worsen symptoms of PTSD. Previous studies of other PTSD populations show a higher incidence of sleep impairments and sleep disorders compared to healthy controls (HCs); however, this has never been investigated in trauma-affected refugees diagnosed with PTSD.Objectives: To examine subjective sleep quality, measure sleep architecture, and identify latent sleep disorders in refugees diagnosed with PTSD compared to HCs.Method: This comparative study included 20 trauma-affected refugees diagnosed with PTSD and 20 HC matched on age, sex, and body mass index. All participants completed self-report questionnaires assessing sleep quality, insomnia severity, and disturbing nocturnal behaviour, and all took part in a one-night polysomnography (PSG) assessment.Results: Patients reported significantly poorer subjective sleep quality, sleep latency, sleep duration, and sleep efficiency compared to HCs. Subjective reports on hours spent in bed were not significantly different between patients and HCs. Patients reported significantly higher nightmare frequency and severity compared to HCs. PSG measures showed that patients had significantly reduced sleep efficiency, more awakenings, and longer REM sleep latency, and spent more time awake, whereas there was no significant differences regarding total time in bed, total sleep time, or sleep latency. The prevalence of sleep disorders was equal between groups.Conclusions: The study identified significant impairments in several sleep domains, with a preponderance of disturbed regulation of sleep resulting in awakenings. These results indicate a need for more focus on hyperarousal and nightmares as key elements of disturbed sleep in PTSD. Furthermore, the study identified a discrepancy between subjective and objective measures concerning total sleep time, raising questions regarding the causes of 'sleep state misperception'.Trial registration: ClinicalTrials.gov identifier: NCT03535636..Trial registration: Sleep Impairments in Refugees Diagnosed with PTSD (PSG-PTSD). URL: https://clinicaltrials.gov/ct2/show/NCT03535636. ClinicalTrials.gov NCT03535636. Date of registration: 24/05/2018.

Sex differences in the effect of subjective sleep on fear conditioning, extinction learning, and extinction recall in individuals with a range of PTSD symptom severity

Sleep has been found to play a key role in fear conditioning, extinction learning and extinction recall, and sleep disturbances are linked to many mental disorders including post-traumatic stress disorder (PTSD). Previous studies examining associations between sleep and fear or extinction processes primarily focused on objectively measured sleep architecture. Little research has so far focused on subjective sleep measures and particularly in clinical populations, which often experience subjectively poor sleep, including PTSD. Here we investigated whether subjective sleep disturbance, sleep onset latency, wake after sleep onset or sleep efficiency were related to fear conditioning, extinction learning or extinction recall in a large sample of individuals with a range of PTSD symptom severity (n = 248). Overall, we did not find that subjective sleep was associated with fear conditioning or extinction processes. However, exploratory analyses examining the moderating effect of sex found that shorter sleep onset latency and greater sleep efficiency were associated with improved extinction recall in women with higher PTSD symptom severity. This suggests that less time falling asleep and longer time asleep while in bed may be protective in highly symptomatic women against the commonly observed impaired extinction recall in PTSD. More studies are needed to explore sex-specific effects further.

Pre-deployment threat learning predicts increased risk for post-deployment insomnia: Evidence from the Marine Resiliency Study

Insomnia is a common and impairing consequence of military deployment, but little is known about pre-deployment risk factors for post-deployment insomnia. Abnormal threat learning tendencies are commonly observed in individuals with insomnia and maladaptive responses to stress have been implicated in the development of insomnia, suggesting that threat learning could be an important risk factor for post-deployment insomnia. Here, we examined pre-deployment threat learning as a predictor of post-deployment insomnia and the potential mechanisms underlying this effect. Male servicemembers (N = 814) completed measures of insomnia, psychiatric symptoms, and a threat learning task before and after military deployment. Threat learning indices that differentiated participants with versus withoutinsomnia at post-deployment were tested as pre-deployment predictors of post-deployment insomnia. Post-deployment insomnia was linked to elevations on several threat learning indices at post-deployment, but only higher threat conditioning, as indexed by higher threat expectancy ratings to the danger cue, emerged as a pre-deployment predictor of post-deployment insomnia. This effect was independent of combat exposure levels and partially mediated by greater post-deployment nightmares. The tendency to acquire stronger expectations of aversive events following encounters with danger cues may increase risk for post-deployment insomnia, in part due to the development of more severe nightmares.

Advances in the understanding and enhancement of the human cognitive functions of learning and memory

Learning and memory are among the key cognitive functions that drive the human experience. As such, any defective condition associated with these cognitive domains could affect our navigation through everyday life. For years, researchers have been working toward having a clear understanding of how learning and memory work, as well as ways to improve them. Many advances have been made, as well as some challenges that have also been faced in the process. That notwithstanding, there are prospects with regards to the frontier of the enhancement of learning and memory in humans. This review article selectively highlights four broad areas of focus in research into the understanding and enhancement of learning and memory. Brain stimulation, effects of sleep, effects of stress and emotion, and synaptic plasticity are the main focal areas of this review, in terms of some pivotal research works, findings and theories.

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.

Worse sleep, worsening post-traumatic stress disorder (PTSD): Poor sleep quality associated with increases in PTSD symptoms amongst those experiencing high threat of the COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) pandemic is a global health crisis with the potential to elicit and worsen psychiatric symptoms, particularly post-traumatic stress disorder (PTSD) symptoms. Identifying modifiable protective factors is critical for preventing and treating PTSD symptoms both during and following the COVID-19 pandemic. The present study examined associations of self-reported sleep quality and anticipatory threat appraisals of the pandemic with PTSD symptoms 6 months later in a sample enriched for pre-pandemic trauma exposure and PTSD. The sample included 590 adults (mean age 38.2 years) who completed a baseline survey in August/September 2020 and follow-up survey in March/April 2021. The sample was recruited from a pool of participants interested in a prior study about traumatic stress. Participants self-reported sleep quality and pandemic-related anticipatory threat appraisals at baseline. PTSD symptoms were assessed at baseline and follow-up. Baseline sleep quality was associated with PTSD symptoms at follow-up controlling for baseline PTSD symptoms (B = -2.49, p = 0.001). Perceived anticipatory threat of the pandemic moderated this association such that worse sleep quality was related to more severe PTSD symptoms at follow-up for participants with higher (B = -4.07, p < 0.001) but not lower (B = -0.43, p = 0.679) anticipatory threat about the COVID-19 pandemic. These findings suggest that poor sleep quality may enhance vulnerability to later PTSD symptoms during the pandemic, particularly among those individuals who perceived the pandemic as threatening for their future. Treatments that address sleep problems may be beneficial for reducing trauma-related symptoms during and following the global health crisis.

Psychological comorbidity: Predictors of residential treatment response among U.S. service members with posttraumatic stress disorder

Residential posttraumatic stress disorder (PTSD) research in military samples generally shows that in aggregate, PTSD symptoms significantly improve over the course of treatment but can remain at elevated levels following treatment. Identifying individuals who respond to residential treatment versus those who do not, including those who worsen, is critical given the extensive resources required for such programs. This study examined predictors of treatment response among 282 male service members who received treatment in a U.S. Department of Defense residential PTSD program. Using established criteria, service members were classified as improved, indeterminate (referent), or worsened in terms of self-reported PTSD symptoms. Multinomial logistic regression results showed that for PTSD symptoms, higher levels of pretreatment PTSD symptom severity were associated with significantly lower odds of being in the improved group, adjusted odds ratio (aOR) = 0.955, p = .018. In addition, service members who completed treatment were significantly more likely to be in the improved group, aOR = 2.488, p = .048. Longer average pretreatment nightly sleep duration, aOR = 1.157, p = .035, and more severe pretreatment depressive symptoms, aOR = 1.109, p = .014, were associated with significantly higher odds of being in the improved group. These findings reveal clinical characteristics better suited for residential PTSD treatment and highlight implications for comorbid conditions.

Morning blue light treatment improves sleep complaints, symptom severity, and retention of fear extinction memory in post-traumatic stress disorder

Disrupted sleep is a major feature in numerous clinical disorders and is related to decrements in affective memory processing. The prevalence of sleep disruption in post-traumatic stress disorder (PTSD) is suggested to be a key feature that exacerbates the impaired ability to recall extinction memories during experimental fear conditioning. We hypothesized that an intervention employing blue-wavelength light therapy (BLT) to regulate sleep and stabilize circadian rhythms in patients with PTSD (i.e., via regulated morning exposure) would be associated with PTSD symptom improvement, decreased sleep-related complaints, as well as improved consolidation and retention of extinction memories relative to a fear conditioning/extinction paradigm. Eighty-two individuals with PTSD underwent a well-validated fear conditioning/extinction protocol with subsequent assignment to receive morning BLUE (BLT) or placebo AMBER (ALT) light therapy daily for 30-min over 6-weeks. Participants returned after the intervention for post-treatment extinction recall, comprised of exposure to the previously conditioned stimuli, with the difference in skin conductance response between the "extinguished" and the "never-extinguished" stimuli at follow-up. Participants also viewed previously conditioned stimuli in a novel context during a functional magnetic resonance imaging (fMRI) scan. BLUE light therapy was associated with improvements relative to correlated decreases between PTSD symptoms and sleep-related complaints. Participants receiving BLT also sustained retention of the extinction memory, while those in the placebo amber light treatment group showed impairment, characterized by the restoration of the extinguished fear response after 6-weeks. Participants in the ALT also demonstrated greater reactivity in the left insula when viewing the previously extinguished fear-conditioned stimuli in a novel context. Daily BLUE-wavelength morning light exposure was associated with greater retention of extinction learning in patients with PTSD when compared to ALT, as supported by both autonomic and neurobiological reactivity. We speculate that improved sleep facilitated by a stabilized circadian rhythm, after fear-learning, led to greater consolidation of the fear extinction memory, decreased PTSD symptom presentation, and associated decreases in sleep-related complaints. Prominent exposure treatments for PTSD incorporate principles of fear extinction, and our findings suggest that blue light treatment may facilitate treatment gains by promoting the consolidation of extinction memories via improved sleep.

Contextual fear conditioning regulates synapse-related gene transcription in mouse microglia

Microglia have been suggested to be involved in the underlying mechanism of conditional fear memory formation by regulating inflammatory cytokines. However, the mechanism linking microglia and neuronal activity related to fear conditioning remains unclear. This study characterized the transcription profile of microglia in a fear memory conditional mouse model. Compared with those in control mice microglia, the most significantly induced genes were synapse-related, whereas immune-related genes were reduced due to fear memory consolidation. Whilst the increased expression of synapse-related genes was reversed after fear memory extinction, that of immunological genes was not, strongly suggesting a connection between microglia, neurons, and a dysregulated immune response following contextual fear conditioning. Furthermore, in the hippocampal microglia, we found that the expression of neurotransmitter release regulators, γ-aminobutyric acid (GABA) receptor GABRB3 and synapsin 1/2, increased under fear memory consolidation and restored (decreased) after extinction. In addition, compared with the transcription profile in peripheral monocytes, few overlapping genes were not enriched in biological processes. Taken together, the identified conditional fear stress-induced changes in mouse microglial transcription profiles suggest that microglia-neuron communication mediates contextual fear conditioning.

Progress in Personalized Psychiatric Therapy with the Example of Using Intranasal Oxytocin in PTSD Treatment

Post-traumatic stress disorder (PTSD) is a severe mental disorder that results in the frequent coexistence of other diseases, lowers patients’ quality of life, and has a high annual cost of treatment. However, despite the variety of therapeutic approaches that exist, some patients still do not achieve the desired results. In addition, we may soon face an increase in the number of new PTSD cases because of the current global situation—both the COVID-19 pandemic and the ongoing armed conflicts. Hence, in recent years, many publications have sought a new, more personalized treatment approach. One such approach is the administration of intranasal oxytocin (INOXT), which, due to its pleiotropic effects, seems to be a promising therapeutic option. However, the current findings suggest that it might only be helpful for a limited, strictly selected group of patients.

Zolpidem Maintains Memories for Negative Emotions Across a Night of Sleep

Zolpidem, a common medication for sleep complaints, also shows secondary, unexpected memory benefits. We previously found that zolpidem prior to a nap enhanced negative, highly arousing picture memory. As zolpidem is typically administered at night, how it affects overnight emotional memory processing is relevant. We used a double-blind, placebo-controlled, within-subject, cross-over design to investigate if zolpidem boosted negative compared to neutral picture memory. Subjects learned both pictures sets in the morning. That evening, subjects were administered zolpidem or placebo and slept in the lab. Recognition was tested that evening and the following morning. We found that zolpidem maintained negative picture memory compared to forgetting in the placebo condition. Furthermore, zolpidem increased slow-wave sleep time, decreased rapid eye movement sleep time, and increased the fast spindle range in NREM. Our results suggest that zolpidem may enhance negative memory longevity and salience. These findings raise concerns for zolpidem administration to certain clinical populations.

Trauma in Context: an Integrative Treatment Model

Evidenced based trauma treatments benefit children, but they rarely suffice for youth with multiple and complex comorbidities. After the completion of standard treatments, many children continue to show residual social, behavioral, and emotional difficulties. Part of the difficulty is that while the literature on trauma describes numerous facets that contribute to the severity, expression, and outcomes of trauma exposure, clinical assessments and interventions do not sufficiently reflect that literature. Clinicians thus have little guidance on how to integrate the intricacies of client's circumstances into a trauma-informed framework. To expand the scope and efficacy of treatments and guide clinicians in selecting appropriate interventions, this paper explores factors associated with pretreatment traumatic responses and proposes an integrative treatment model that includes the trauma experience, itself, combined with pre- and post-trauma factors that are both internal and external to the child and family. Pre-trauma experiences influence the severity of traumatic responses, while post-trauma factors impact a person's ability to cope and recover. Both are important targets for direct intervention.

Effects of Sleep Deficiency on Risk, Course, and Treatment of Psychopathology

This article reviews the literature on the relationship between sleep deficiency and unipolar and bipolar depression, anxiety disorders, and posttraumatic stress disorder. We consider the evidence for sleep as a contributory causal factor in the development of psychiatric disorders, as well as sleep as an influential factor related to the outcome and recurrence of psychopathology. A case for sleep deficiency being an important treatment target when sleep and psychiatric disorders are comorbid is also made. Our recommendation is that sleep deficiency is recognized as a means to positively impact the development and course of psychopathology and, as such, is routinely assessed and treated in clinical practice.

Sleep Deprivation During Memory Consolidation, but Not Before Memory Retrieval, Widens Threat Generalization to New Stimuli

Past aversive experiences shape our ability to deal with future dangers, through the encoding of implicit and explicit memory traces and through the ability to generalize defensive reactions to new stimuli resembling learned threats. Numerous evidence demonstrate that sleep is important for the consolidation of memories related to threatening events. However, there is a lack of studies examining the effects of sleep deprivation on the retrieval of consolidated threat memories, and previous studies on the role of sleep in threat generalization have produced mixed results. To address these issues, here we adopted a differential threat conditioning and a delayed (second half of the night) sleep deprivation during the first or the seventh night after learning. We found no effects of sleep deprivation on either implicit or explicit threat memories, regardless of its occurrence timing. Conversely, implicit but not explicit responses to novel cues similar to a learned threat displayed a widened generalization pattern, but only if sleep deprivation took place during the first night after conditioning and not if it occurred during the seventh night after conditioning. Therefore, we propose that sleeping after exposure to danger may support optimal implicit discrimination processes to evaluate new signals in the future and that even a brief period of sleeplessness may widen threat generalization to new stimuli, which is a hallmark of several threat-related disorders.

Post-traumatic stress disorder: clinical and translational neuroscience from cells to circuits

Post-traumatic stress disorder (PTSD) is a maladaptive and debilitating psychiatric disorder, characterized by re-experiencing, avoidance, negative emotions and thoughts, and hyperarousal in the months and years following exposure to severe trauma. PTSD has a prevalence of approximately 6-8% in the general population, although this can increase to 25% among groups who have experienced severe psychological trauma, such as combat veterans, refugees and victims of assault. The risk of developing PTSD in the aftermath of severe trauma is determined by multiple factors, including genetics - at least 30-40% of the risk of PTSD is heritable - and past history, for example, prior adult and childhood trauma. Many of the primary symptoms of PTSD, including hyperarousal and sleep dysregulation, are increasingly understood through translational neuroscience. In addition, a large amount of evidence suggests that PTSD can be viewed, at least in part, as a disorder that involves dysregulation of normal fear processes. The neural circuitry underlying fear and threat-related behaviour and learning in mammals, including the amygdala-hippocampus-medial prefrontal cortex circuit, is among the most well-understood in behavioural neuroscience. Furthermore, the study of threat-responding and its underlying circuitry has led to rapid progress in understanding learning and memory processes. By combining molecular-genetic approaches with a translational, mechanistic knowledge of fear circuitry, transformational advances in the conceptual framework, diagnosis and treatment of PTSD are possible. In this Review, we describe the clinical features and current treatments for PTSD, examine the neurobiology of symptom domains, highlight genomic advances and discuss translational approaches to understanding mechanisms and identifying new treatments and interventions for this devastating syndrome.

Is PTSD an Evolutionary Survival Adaptation Initiated by Unrestrained Cytokine Signaling and Maintained by Epigenetic Change?

INTRODUCTION

Treatment outcomes for PTSD with current psychological therapies are poor, with very few patients achieving sustained symptom remission. A number of authors have identified physiological and immune disturbances in Post Traumatic Stress Disorder (PTSD) patients, but there is no unifying hypothesis that explains the myriad features of the disorder.

MATERIALS AND METHODS

The medical literature was reviewed over a 6-year period primarily using the medical database PUBMED.

RESULTS

The literature contains numerous papers that have identified a range of physiological and immune dysfunction in association with PTSD. This paper proposes that unrestrained cytokine signaling induces epigenetic changes that promote an evolutionary survival adaptation, which maintains a defensive PTSD phenotype. The brain can associate immune signaling with past threat and initiate a defensive behavioral response. The sympathetic nervous system is pro-inflammatory, while the parasympathetic nervous system is anti-inflammatory. Prolonged cholinergic withdrawal will promote a chronic inflammatory state. The innate immune cytokine IL-1β has pleiotropic properties and can regulate autonomic, glucocorticoid, and glutamate receptor functions, sleep, memory, and epigenetic enzymes. Changes in epigenetic enzyme activity can potentially alter phenotype and induce an adaptation. Levels of IL-1β correlate with severity and duration of PTSD and PTSD can be prevented by bolus administration of hydrocortisone in acute sepsis, consistent with unrestrained inflammation being a risk factor for PTSD. The nervous and immune systems engage in crosstalk, governed by common receptors. The benefits of currently used psychiatric medication may arise from immune, as well as synaptic, modulation. The psychedelic drugs (3,4-Methylenedioxymethamphetamine (MDMA), psilocybin, and ketamine) have potent immunosuppressive and anti-inflammatory effects on the adaptive immune system, which may contribute to their reported benefit in PTSD. There may be distinct PTSD phenotypes induced by innate and adaptive cytokine signaling.

CONCLUSION

In order for an organism to survive, it must adapt to its environment. Cytokines signal danger to the brain and can induce epigenetic changes that result in a persistent defensive phenotype. PTSD may be the price individuals pay for the genomic flexibility that promotes adaptation and survival.

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.

Attachment Style Moderates Polygenic Risk for Incident Posttraumatic Stress in U.S. Military Veterans: A 7-Year, Nationally Representative, Prospective Cohort Study

BACKGROUND

Posttraumatic stress disorder (PTSD) develops consequent to complex gene-by-environment interactions beyond the precipitating trauma. To date, however, no known study has used a prospective design to examine how polygenic risk scores (PRSs) interact with social-environmental factors such as attachment style to predict PTSD development.

METHODS

PRSs were derived from a genome-wide association study of PTSD symptoms (N = 186,689; Million Veteran Program cohort). We evaluated combined effects of PRS and attachment style in predicting incident PTSD in a 7-year, nationally representative cohort of trauma-exposed, European-American U.S. military veterans without PTSD (N = 1083). We also conducted multivariate gene-by-environment interaction and drug repositioning analyses to identify loci that interact with multiple environmental factors and potential pharmacotherapies that may be repurposed for this disorder.

RESULTS

Veterans with higher PTSD PRS were more likely to have an incident-positive screen for PTSD over 7 years. A gene-by-environment interaction was also observed, such that higher PRS only predicted incident PTSD in veterans with an insecure attachment style and not those with a secure attachment style. At an individual locus level, the strongest gene-by-environment interaction was observed for the rs4702 variant of the FURIN gene with cumulative lifetime trauma burden. Drug repositioning revealed that genes implicated in PRS are perturbated by the drug doxylamine.

CONCLUSIONS

Attachment style moderates polygenic risk for the development of PTSD in European-American veterans. These findings may inform PTSD prevention and treatment for veterans with high polygenic risk for PTSD and suggest a potential pharmacotherapeutic target for risk genes moderated by social-environmental factors.

Examining the associations between PTSD symptoms and aspects of emotion dysregulation through network analysis

Despite the clearly established link between posttraumatic stress disorder (PTSD) and emotion dysregulation, little is known about how individual symptoms of PTSD and aspects of emotion dysregulation interrelate. The network approach to mental health disorders provides a novel framework for conceptualizing the association between PTSD and emotion dysregulation as a system of interacting nodes. In this study, we estimated the structural relations among PTSD symptoms and aspects of emotion dysregulation within a large sample of women who participated in a multi-site study of sexual revictimization (N = 463). We estimated expected influence to reveal differential associations among PTSD symptoms and aspects of emotion dysregulation. Further, we estimated bridge expected influence to identify influential nodes connecting PTSD symptoms and aspects of emotion dysregulation. Results highlighted the key role of concentration difficulties in expected influence and bridge expected influence. Findings highlight several PTSD symptoms and aspects of emotion dysregulation that may be targets for future intervention.

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.

Fear of COVID-19, poor quality of sleep, irritability, and intention to quit school among nursing students: A cross-sectional study

PURPOSE

This study aims to assess the fear of coronavirus disease 2019 (COVID-19) and its influence on the students' fear of COVID-19 and intention to leave nursing school.

DESIGN AND METHODS

This study employed a cross-sectional design using self-report questionnaires distributed to 261 nursing students from the Philippines.

FINDINGS

The first-year nursing students are found to be the most fearful among the group. The students' fear of COVID-19 is associated with their high irritability, poor sleep quality, and desire to quit nursing school.

PRACTICE IMPLICATIONS

Students are perturbed by the pandemic and teachers should implement supportive, teaching-learning strategies to address the student's needs.

Sleep Difficulties Among COVID-19 Frontline Healthcare Workers

OBJECTIVE

To identify COVID-19 work-related stressors and experiences associated with sleep difficulties in HCW, and to assess the role of depression and traumatic stress in this association.

METHODS

A cross-sectional study of HCW using self-report questionnaires, during the first peak of the pandemic in Israel (April 2020), conducted in a large tertiary medical center in Israel. Study population included 189 physicians and nurses working in designated COVID-19 wards and a comparison group of 643 HCW. Mean age of the total sample was 41.7 ± 11.1, 67% were female, 42.1% physicians, with overall mean number of years of professional experience 14.2 ± 20. The exposure was working in COVID-19 wards and related specific stressors and negative experiences. Primary outcome measurement was the Insomnia Severity Index (ISI). Secondary outcomes included the Primary Care-Post Traumatic Stress Disorder Screen (PC-PTSD-5); the Patient Health Questionnaire-9 (PHQ-9) for depression; the anxiety module of the Patient-Reported Outcomes Measurement Information System (PROMIS); Pandemic-Related Stress Factors (PRSF) and witnessing patient suffering and death.

RESULTS

Compared with non-COVID-19 HCW, COVID-19 HCW were more likely to be male (41.3% vs. 30.7%) and younger (36.91 ± 8.81 vs. 43.14 ± 11.35 years). COVID-19 HCW reported higher prevalence of sleep difficulties: 63% vs. 50.7% in the non-COVID group (OR 1.62, 95% CI 1.15-2.29, p = 0.006), mostly difficulty maintaining sleep: 26.5% vs. 18.5% (OR 1.65, 95% CI 1.11-2.44, p = 0.012). Negative COVID-19 work-related experiences, specifically witnessing patient physical suffering and death, partially explained the association. Although past psychological problems and current depression and PTSD were associated with difficulty maintaining sleep, the main association remained robust also after controlling for those conditions in the full model.

CONCLUSION AND RELEVANCE

COVID-19 frontline HCW were more likely to report sleep difficulties, mainly difficulty maintaining sleep, as compared with non-COVID-19 HCW working at the same hospital. Negative patient-care related experiences likely mediated the increased probability for those difficulties. Future research is needed to elucidate the long-term trajectories of sleep difficulties among HCW during large scale outbreaks, and to identify risk factors for their persistence.

Women with abuse-related PTSD sleep more fitfully but just as long as healthy controls: an actigraphic study

STUDY OBJECTIVES

Subjective reports of sleep impairments are common in individuals with posttraumatic stress disorder (PTSD), but objective assessments of sleep have yielded mixed results.

METHODS

We investigated sleep via actigraphy and e-diary on 6 consecutive nights in a group of 117 women with PTSD after childhood abuse (CA; PTSD group), a group of 31 mentally healthy women with a history of CA (healthy trauma controls, HTC group) and a group of 36 non-traumatized mentally healthy women (healthy controls, HC group).

RESULTS

The PTSD group reported lower sleep quality, more nights with nightmares, and shorter sleep duration than both HTC and HC. Actigraphic measures showed more and longer sleep interruptions in the PTSD group compared to HTC and HC, but no difference in sleep duration. While the PTSD group underestimated their sleep duration, both HTC and HC overestimated their sleep duration. HTC did not differ from HC regarding sleep impairments.

CONCLUSIONS

Sleep in women with PTSD after CA seems to be more fragmented but not shorter compared to sleep patterns of mentally healthy control subjects. The results suggest a stronger effect of PTSD psychopathology on sleep compared to the effect of trauma per se.

Prenatal insomnia and childbirth-related PTSD symptoms: A prospective population-based cohort study

BACKGROUND

Certain populations are at high risk of experiencing a traumatic event and developing post-traumatic stress disorder (PTSD). Yet, primary preventive interventions against PTSD are lacking. It is therefore crucial to identify pre-traumatic risk factors, which could be targeted with such interventions. Insomnia may be a good candidate, but studies on civilians are sparse. Furthermore, the mechanisms at stake in the relationship between pre-traumatic insomnia and PTSD symptoms are unclear.

METHODS

This prospective population-based cohort study (n = 1,610) examined the relationship between insomnia symptoms at 32 weeks of pregnancy and childbirth-related PTSD (CB-PTSD) symptoms at eight weeks postpartum. Postnatal insomnia symptoms, prenatal psychological symptoms (depression, anxiety, PTSD, fear of childbirth), subjective birth experience (SBE) and birth medical severity were included as covariates in the analyses, which were based on a Piecewise Structural Equation Modelling approach.

RESULTS

The relationship between prenatal insomnia and CB-PTSD symptoms was mediated by negative SBE and postnatal insomnia symptoms. All relationships involving insomnia symptoms had small or very small effect sizes.

LIMITATIONS

This study used self-report questionnaires. Postnatal insomnia and CB-PTSD symptoms were concurrently measured.

CONCLUSION

Prenatal insomnia symptoms may impair the ability to cope with a difficult birth experience and contribute to postnatal insomnia, a risk factor for CB-PTSD. Thus, prenatal insomnia symptoms may be a promising target for CB-PTSD primary preventive interventions, although other prenatal psychological symptoms could also be considered. Even beyond the perinatal context, future studies on pre-traumatic insomnia and PTSD should include post-traumatic insomnia as a covariate.

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.

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.

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.

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.

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.

Teaching During a Pandemic: A Model for Trauma-Informed Education and Administration

Coronavirus disease 2019 (COVID-19) realities have demanded that educators move swiftly to adopt new ways of teaching, advising, and mentoring. We suggest the centering of a trauma-informed approach to education and academic administration during the COVID-19 pandemic using the Substance Abuse and Mental Health Services Administration's (SAMHSA) guidance on trauma-informed approaches to care. In our model for trauma-informed education and administration (M-TIEA), SAMHSA's four key organizational assumptions are foundational, including a realization about trauma and its wide-ranging effects; a recognition of the basic signs and symptoms of trauma; a response that involves fully integrating knowledge into programs, policies, and practices; and an active process for resisting retraumatization. Since educators during the pandemic must follow new restrictions regarding how they teach, we have expanded the practice of teaching in M-TIEA to include both academic administrators' decision making about teaching, and educators' planning and implementation of teaching. In M-TIEA, SAMHSA's six guiding principles for a trauma-informed approach are infused into these two interrelated teaching processes, and include the following: safety; trustworthiness and transparency; peer support; collaboration and mutuality; empowerment, voice, and choice; and cultural, historical, and gender issues. M-TIEA's organizational assumptions, processes, and principles are situated within an outer context that acknowledges the potential influences of four types of intersectional traumas and stressors that may occur at multiple socioecological levels: pandemic-related trauma and stressors; other forms of individual, group, community, or mass trauma and stressors; historical trauma; and current general life stressors. This acknowledges that all trauma-informed work is dynamic and may be influenced by contextual factors.

Investigating the effect of a nap following experimental trauma on analogue PTSD symptoms

Cognitive models assume that the incomplete integration of a traumatic experience into the autobiographical memory results in typical symptoms associated with post-traumatic stress disorder (PTSD) such as intrusive re-experiencing. Sleep supports the integration of new experiences into existing memory networks through memory consolidation. In fifty-six females, we investigated whether a 90-min daytime nap (n = 33) compared to a wake period (n = 23) after being exposed to an experimental trauma (i.e. a trauma film) prevents PTSD analogue symptoms. Intrusive memories were recorded for seven days using a diary, overall PTSD symptoms were assessed using the Impact of Event Scale (IES-R) and affective response to trauma cues were measured one week after experimental trauma. The two groups did not differ in any of the analogue PTSD symptoms. However, participants obtaining rapid eye movement (REM) sleep in the nap experienced less distressing intrusive memories. Moreover, the duration of REM sleep and slow wave activity was negatively correlated with analogue PTSD symptoms. Our findings suggest that even a short sleep period after experimental trauma can play a protective role in trauma memory formation but only if the nap contains REM sleep. Our data provide additional evidence for a critical role of REM sleep in PTSD development.

Circulating endocannabinoids and prospective risk for depression in trauma-injury survivors

Biological mechanisms associated with response to trauma may impact risk for depression. One such mechanism is endocannabinoid signaling (eCB), a neuromodulatory system comprised of the CB1 subtype of cannabinoid receptors (CB1R), encoded by the CNR1 gene, and two primary endogenous ligands: 2-arachidonoylglycerol (2-AG) and N-arachidonylethanolamine (AEA), hydrolyzed by monoacylglycerol lipase (gene name MGLL) and fatty acid amide hydrolase (gene name FAAH). Preclinical data suggest that eCB/CB1R signaling acts as a stress buffer and its loss or suppression increases depression-like behaviors. We examined circulating concentrations of the eCBs (2-AG and AEA) days and six months after a traumatic injury as a marker of eCB/CB1R signaling and as predictors of Center for Epidemiologic Studies of Depression Scale-Revised [CESD-R] scores as a measure of depression severity six months after injury. We also explored associations of CNR1, FAAH, and MGLL genetic variance with depression severity at six months. Results from hierarchical multiple linear regressions showed that higher 2-AG serum concentrations after trauma predicted greater depression at six months (β = 0.23, p = 0.007); neither AEA after trauma, nor 2-AG and AEA at six months were significant predictors (p's > 0.305). Carriers of minor allele for the putative single nucleotide polymorphism in the CNR1 gene rs806371 (β = 0.19, p = 0.024) experienced greater depression at six months. These data suggest that the eCB signaling system is highly activated following trauma and that eCB/CB1R activity contributes to long-term depression risk.

Posttraumatic Stress Disorder and the Developing Adolescent Brain

Posttraumatic stress disorder (PTSD) in adolescents is common and debilitating. In contrast to adult PTSD, relatively little is known about the neurobiology of adolescent PTSD, nor about how current treatments may alter adolescent neurodevelopment to allow recovery from PTSD. Improving our understanding of biological mechanisms of adolescent PTSD, taken in the context of neurodevelopment, is crucial for developing novel and personalized treatment approaches. In this review, we highlight prevailing constructs of PTSD and current findings on these domains in adolescent PTSD. Notably, little data exist in adolescent PTSD for prominent adult PTSD constructs, including threat learning and attentional threat bias. Most work to date has examined general threat processing, emotion regulation, and their neural substrates. These studies suggest that adolescent PTSD, while phenomenologically similar to adult PTSD, shows unique neurodevelopmental substrates that may impair recovery but could also be targeted in the context of adolescent neuroplasticity to improve outcomes. Both cross-sectional and longitudinal data suggest abnormal frontolimbic development compared with typically developing youths, a pattern that may differ from resilient youths. Whether current treatments such as trauma-focused psychotherapy engage these targets and restore healthy neurodevelopment remains an open question. We end our review by highlighting emerging areas and knowledge gaps that could be addressed to better characterize the biology underlying adolescent PTSD. Emerging studies in computational modeling of decision making, caregiver-related transmission of traumatic stress, and other areas may offer new targets that could harness adolescent neurobehavioral plasticity to improve resilience and recovery for some of our most vulnerable youths.