Sleep-specific mechanisms underlying posttraumatic stress disorder: integrative review and neurobiological hypotheses

Different regulative effects of high- and low-frequency external trigeminal nerve stimulation (eTNS) on sleep activity: Preliminary study

STUDY OBJECTIVE

With the growing prominence of peripheral nerve stimulation technology, the clinical applications and potential neurophysiological mechanisms of external trigeminal nerve stimulation (eTNS) have garnered increasing attention. Despite its status as the sole neuromodulation method commonly employed in sleep, no studies have explored the effects of eTNS at varying frequencies on sleep activities. This study aims to investigate the regulatory effects of high-frequency and low-frequency eTNS on sleep activities using polysomnography.

METHODS

In this within-subjects experiment, 20 participants underwent a night of adaptation sleep, followed by 8-h sessions of sham, 120Hz-, and 2Hz-eTNS interventions in a randomized order in the sleep laboratory, with polysomnographic signals collected throughout.

RESULTS

The results indicated that 120Hz-eTNS significantly improved sleep efficiency, increased N2 sleep proportion, and reduced sleep latency, without significantly affecting sleep stage transition probabilities, sleep duration, or sleep-specific wave activities. Conversely, while 2Hz-eTNS did not impact sleep efficiency or latency, it increased the proportion of N3 sleep, stabilizes N3 sleep, and enhanced the survival probability of N3 and REM sleep duration. Additionally, it increases the density of slow oscillations (SOs), improved the coupling ratio of SO-spindles, and enhanced coupling timing accuracy.

CONCLUSIONS

These findings suggest that eTNS during sleep can indeed modulate sleep activities, with different frequencies exerting distinct regulatory effects. This may hold significant value for advancing the clinical application and efficacy of eTNS.

REM disruption and REM vagal activity predict extinction recall in trauma-exposed individuals

BACKGROUND

Accumulating evidence suggests that rapid eye movement sleep (REM) supports the consolidation of extinction memory. REM is disrupted in posttraumatic stress disorder (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.

METHODS

Trauma-exposed individuals (n = 113) underwent a 2-day fear conditioning and extinction protocol. Conditioning and extinction learning phases were followed by extinction recall 24 h later. The association of extinction recall with REM characteristics and REM vagal activity (indexed as heart rate variability) during the intervening consolidation night was examined.

RESULTS

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.

CONCLUSIONS

These findings support the notion that abnormal REM, including reduced REM vagal activity, may contribute to PTSD by impairing the consolidation of extinction memory.

Psychotherapeutic and pharmacological agents for post-traumatic stress disorder with sleep disorder: network meta-analysis

OBJECTIVE

The current guidelines and canonical norms of diagnosis or treatment for Post-traumatic stress disorder (PTSD) with sleep disorder are still conflicting and have not yet reached a consensus. This study aimed to unravel the most effective countermeasures between two categories (psychotherapy and pharmacotherapy) put forward by the National Institute for Health and Clinical Excellence (NICE) and World Federation of Societies of Biological Psychiatry (WFSBP) respectively to treat PTSD individuals co-exist with sleep disorders.

METHODS

Four databases, including PubMed, EMBASE, Cochrane Library, and APA PsyNet, were searched from inception to February 02, 2023.

RESULTS

Twenty articles with 24 Randomized controlled trials (RCTs) and a total number of 1,647 participants were included. As demonstrated in the network meta-analysis comparison results, CBT-I (standardized mean differences (SMD) = -1.51,95% confidence interval (CI):-2.55 to -0.47), CBT-I plus IRT (SMD = -1.71, 95%CI:-3.39, -0.03), prazosin (SMD = -0.87,95%CI:-1.59 to -0.16) and hydroxyzine (SMD = -1.06, 95%CI: -1.94 to -0.19) significantly reduced PTSD symptoms compared with placebo. In contrast to placebo, CBT-I (SMD = -5.61,95%CI:-8.82 to -2.40) significantly improved sleep quality. For nightmare severity, IRT (SMD =-0.65, 95%CI:-1.00 to -0.31), prazosin (SMD = -1.20,95%CI:-1.72 to -0.67) and hydroxyzine (SMD = -0.98,95%CI:-1.58 to -0.37) significantly reduced nightmare severity in comparison with placebo.

CONCLUSIONS

This study suggested that under most circumstances, psychotherapy namely CBT-I had a favorable profile, but pharmacotherapy with prazosin was effective in managing nightmare severity. The sole avail of CBT-I was recommended to improving sleep quality while CBT-I and CBT-I plus IRT showed excellent management of PTSD symptom severity. Exposure to CBT-I isrecommended for depression. The relevant clinical guidelines for the management of individuals with PTSD and sleep disorders may regard this as a reference.

PROSPERO

CRD42023415240.

Breathlessness, but not breathing instability, varies with posttraumatic stress symptoms in university students

Obstructive sleep apnea (OSA) is a chronic sleep-related breathing disorder that is highly prevalent in individuals with posttraumatic stress disorder (PTSD). The reason for this high prevalence remains unclear. We hypothesized that breathing instability, one of the key contributors to OSA, may be altered in PTSD and predispose OSA. Healthy participants (214 females, 98 males) aged 17 to 42 (M = 19.92; SD = 2.85) completed online questionnaires measuring PTSD symptomatology, sleep disturbances, and self-reported breathlessness. A subset of these participants (16 females, 14 males) aged 18 to 42 (M = 23.50; SD = 7.18) completed an in-lab breathing instability assessment, whereby they performed a series of 20-second and maximal duration breath-holds. PTSD severity positively predicted subjective perceptions of breathlessness (P < 0.001) but not objective measures of breathing instability, namely ventilation following 20-s breath-holds (P = 0.93) and maximal breath-hold duration (P = 0.41). These results suggest that breathing instability may not be the driving factor behind the high prevalence of OSA in PTSD. Instead, other factors such as a low arousal threshold, elevated ventilatory responses to arousal, or coexisting insomnia may explain the high rates of OSA in PTSD. One explanation for the discrepancy between subjective breathlessness and breathing stability measures relating to PTSD severity may be that hypervigilance and increased anxiety impacted self-perceptions of breathlessness while not altering breathing instability per se.NEW & NOTEWORTHY Obstructive sleep apnea (OSA) is more common in individuals with posttraumatic stress disorder (PTSD) than the general population for unknown reasons. This study assessed one of the key contributors to OSA, respiratory control instability, in young students with a range of posttraumatic stress symptoms. Although individuals with high PTSD symptoms reported increased subjective breathlessness, objectively measured breathing instability was not altered, suggesting respiratory instability is unlikely to increase the risk of OSA in PTSD.

Secondary RBD: Not just neurodegeneration

Rapid eye movement sleep behavior disorder is a parasomnia characterized by excessive muscle activity during rapid eye movement sleep (rapid eye movement sleep without atonia), along with dream enactment behavior. Isolated rapid eye movement sleep behavior disorder tends to occur in older males and is of concern due to the known link to Parkinson's disease and other synucleinopathies. When rapid eye movement sleep behavior disorder occurs in association with other neurological or general medical conditions, or resulting from the use of various substances, it is called secondary rapid eye movement sleep behavior disorder; the most common cause is neurodegenerative illness, specifically the synucleinopathies. Here, the focus will be on the subset of secondary rapid eye movement sleep behavior disorder in which there is no neurodegenerative disease.

Prevalence of major depressive disorder and post-traumatic stress disorder among first-time sleep center attendees

BACKGROUND

Sleep disorders and psychiatric disorders stand in a bidirectional relationship. Sleep complaints are prominent in populations with psychiatric disorders, especially amongst people with major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). Consultations at sleep clinics offer opportunities to screen psychiatric disorders and to propose primary psychiatric care.

METHODS

This descriptive study was conducted on 755 patients making their first visit to sleep clinic, with 574 seeking consultation for suspected obstructive sleep apnoea-hypopnoea syndrome (OSAHS), 139 for complaints of insomnia, and 42 for complaints of hypersomnia. The results of 387 screening scales for MDD (BDI-II) and 403 for TSPT (PCL-5) were compared according to the reason given for the consultation.

RESULTS

In the whole group, 12.1 % of patients presented a positive MDD screening and 4.9 % for PTSD. Among patients presenting with insomnia, 19.8 % had a positive screening for MDD, as compared to 9.3 % in patients presenting with suspected OSAHS (p = 0.02). Regarding PTSD, 9.7 % of patients seeking consultation because of insomnia had a positive screening, compared to 2.9 % among patients with suspected OSAHS (p = 0.03). Among patients with a positive screening for MDD, 40.5 % were not receiving antidepressant or mood stabilizer treatment.

CONCLUSION

Positive screening for MDD and PTSD are frequent in patients who attend sleep centers, especially amongst those presenting with insomnia. Nearly half of the patients with positive screening for MDD or PTSD were not receiving a dedicated pharmacological treatment. These figures emphasize systematic screening for psychiatric disorders in sleep clinics.

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).

The effect of REM-sleep disruption on affective processing: A systematic review of human and animal experimental studies

Evidence on the importance of rapid-eye-movement sleep (REMS) in processing emotions is accumulating. The focus of this systematic review is the outcomes of experimental REMS deprivation (REMSD), which is the most common method in animal models and human studies on REMSD. This review revealed that variations in the applied REMSD methods were substantial. Animal models used longer deprivation protocols compared with studies in humans, which mostly reported acute deprivation effects after one night. Studies on animal models showed that REMSD causes aggressive behavior, increased pain sensitivity, reduced sexual behavior, and compromised consolidation of fear memories. Animal models also revealed that REMSD during critical developmental periods elicits lasting consequences on affective-related behavior. The few human studies revealed increases in pain sensitivity and suggest stronger consolidation of emotional memories after REMSD. As pharmacological interventions (such as selective serotonin reuptake inhibitors [SSRIs]) may suppress REMS for long periods, there is a clear gap in knowledge regarding the effects and mechanisms of chronic REMS suppression in humans.

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.

Inhibition of Protein Synthesis Attenuates Formation of Traumatic Memory and Normalizes Fear-Induced c-Fos Expression in a Mouse Model of Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) is a debilitating psychosomatic condition characterized by impairment of brain fear circuits and persistence of exceptionally strong associative memories resistant to extinction. In this study, we investigated the neural and behavioral consequences of inhibiting protein synthesis, a process known to suppress the formation of conventional aversive memories, in an established PTSD animal model based on contextual fear conditioning in mice. Control animals were subjected to the conventional fear conditioning task. Utilizing c-Fos neural activity mapping, we found that the retrieval of PTSD and normal aversive memories produced activation of an overlapping set of brain structures. However, several specific areas, such as the infralimbic cortex and the paraventricular thalamic nucleus, showed an increase in the PTSD group compared to the normal aversive memory group. Administration of protein synthesis inhibitor before PTSD induction disrupted the formation of traumatic memories, resulting in behavior that matched the behavior of mice with usual aversive memory. Concomitant with this behavioral shift was a normalization of brain c-Fos activation pattern matching the one observed in usual fear memory. Our findings demonstrate that inhibiting protein synthesis during traumatic experiences significantly impairs the development of PTSD in a mouse model. These data provide insights into the neural underpinnings of protein synthesis-dependent traumatic memory formation and open prospects for the development of new therapeutic strategies for PTSD prevention.

REM sleep and neurodegeneration

Several brainstem, subcortical and cortical areas are involved in the generation of rapid eye movement (REM) sleep. The alteration of these structures as a result of a neurodegenerative process may therefore lead to REM sleep anomalies. REM sleep behaviour disorder is associated with nightmares, dream-enacting behaviours and increased electromyographic activity in REM sleep. Its isolated form is a harbinger of synucleinopathies such as Parkinson's disease or dementia with Lewy bodies, and neuroprotective interventions are advocated. This link might also be present in patients taking antidepressants, with post-traumatic stress disorder, or with a history of repeated traumatic head injury. REM sleep likely contributes to normal memory processes. Its alteration has also been proposed to be part of the neuropathological changes occurring in Alzheimer's disease.

Local gun violence, mental health, and sleep: A neighborhood analysis in one hundred US Cities

RATIONALE

Community gun violence significantly shapes public health and collective well-being. Understanding how gun violence is associated with community health outcomes like mental health and sleep is crucial for developing interventions to mitigate disparities exacerbated by violence exposure.

OBJECTIVE

This study examines the associations between community gun violence , insufficient sleep, and poor mental health across neighborhoods in the United States.

METHODS

We utilized a novel database covering nearly 16,000 neighborhoods in 100 US cities from 2014 through 2019. Correlated trait fixed-effects models were employed to conduct all analyses while considering various neighborhood covariates such as concentrated disadvantage, demographic composition, population density, and proximity to trauma centers.

RESULTS

Our analysis revealed that greater gun violence is associated with both insufficient sleep and poor mental health in subsequent years. There is a reciprocal relationship between poor mental health and insufficient sleep, with each partially mediating the other's association with community gun violence. Notably, gun violence exhibits the strongest direct association with poor sleep rather than with poor mental health. We found a consistent reciprocal relationship between sleep and mental health at the community level.

CONCLUSIONS

The findings highlight a complex interplay between community violence, sleep, and mental health, underlining the importance of reducing community violence through numerous long-term interventions to address health disparities across the US.

Insomnia in male veterans with and without military sexual trauma receiving care within a VA medical center

STUDY OBJECTIVES

This study evaluated the prevalence and correlates of insomnia in male veterans with military sexual trauma (MST) who currently receive care within a VA medical center.

METHODS

We evaluated cross-sectional data from a VA medical center (n = 138) using the following instruments: Insomnia Severity Index, Posttraumatic Stress Disorder Checklist, Quick Inventory of Depressive Symptomatology-Self Report, Alcohol Use Disorders Identification Test for Consumption, and a nightmare question for insomnia, posttraumatic stress disorder, depression, and drinking, respectively. Bivariate and multivariable analyses assessed the relationship between Insomnia Severity Index and other clinical variables.

RESULTS

About 31.9% screened positive for MST. When compared to those without MST (MST-), those with MST (MST+) had a higher prevalence of insomnia (95.5% vs 81.9%) and higher Insomnia Severity Index (20 ± 5.1 vs 16.7 ± 7.2, P = .003) and Posttraumatic Stress Disorder Checklist (48.5 ± 14.4 vs 38.2 ± 19.8, P = .0008) total scores. In the multivariable models, the Insomnia Severity Index total score was associated with the Posttraumatic Stress Disorder Checklist total score (P = .015) in MST+ individuals and with Quick Inventory of Depressive Symptomatology-Self Report (P < .001) in MST- individuals.

CONCLUSIONS

Most veterans with MST within the Veterans Health Administration had insomnia, which was associated with their underlying psychiatric comorbidity.

CITATION

Makar K, Mills A, Rivera LA, Aguiar TL, He S, Subhajit C. Insomnia in male veterans with and without military sexual trauma receiving care within a VA medical center. J Clin Sleep Med. 2024;20(6):991-994.

Explaining how childhood physical abuse and physical neglect influence adult depression: An analysis with multiple sequential mediators

BACKGROUND

Substantial evidence indicates that experiencing physical abuse and neglect during childhood significantly elevates the likelihood of developing depression in adulthood. Nevertheless, there remains a dearth of understanding regarding the mechanisms underpinning this correlation.

OBJECTIVE

In this study, we aimed to examine the associations of childhood physical abuse and physical neglect with depression using follow-up data from UK Biobank and quantified the contribution of smoking, insomnia, and BMI in these associations.

PARTICIPANTS AND SETTINGS

This study included 144,704 participants (64,168 men and 80,536 women) from UK Biobank, most of whom were white (97 %).

METHODS

Physical abuse and physical neglect were measured using two items of Childhood Trauma Screener (CTS). Data on the incidence of depression were obtained from primary care, hospital inpatient records, self-reported medical conditions, and death registries. We used a sequential mediation analysis based on the "g-formula" approach to explore the individual and joint effects of potential mediators.

RESULTS

The depression incidence rate was 1.85 per 1000 person-years for men and 2.83 per 1000 person-years for women, respectively. Results of Cox proportional risk regression showed that physical abuse (HRs: 1.39-1.53, P < 0.001) and physical neglect (HRs: 1.43-1.60, P < 0.001) are associated with depression. Smoking, insomnia, and BMI together mediated 3 %-26 % of the associations.

CONCLUSIONS

These findings contribute to our understanding of how physical abuse and physical neglect influence depression. Furthermore, a more effective reduction in the burden of depression can be achieved by managing modifiable mediators.

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 Cyclical Battle of Insomnia and Mental Health Impairment in Firefighters: A Narrative Review

The occupational requirements of full-time non-administrative firefighters include shift-work schedules and chronic exposure to alerting emergency alarms, hazardous working conditions, and psychologically traumatic events that they must attend and respond to. These compiling and enduring aspects of the career increase the firefighter's risk for insomnia and mental health conditions compared to the general population. Poor sleep quality and mental health impairments are known to coincide with and contribute to the symptom severity of one another. Thus, it is important to determine approaches that may improve sleep and/or mental health specifically for firefighters, as their occupation varies in many aspects from any other occupation. This review will discuss symptoms of insomnia and mental health conditions such as PTSD, anxiety, depression, substance abuse, and suicide in firefighters. The influencing factors of sleep and mental health will be examined including anxiety sensitivity, emotional regulation, and distress tolerance. Current sleep and mental health interventions specific to full-time firefighters are limited in number; however, the existing experimental studies will be outlined. Lastly, this review will provide support for exploring exercise as a possible intervention that may benefit the sleep and mental health of this population.

Posttraumatic Stress Disorder Symptoms and Sleep Disturbances Among Asian Indians: A Systematic Review

Substantial comorbidity exists between posttraumatic stress disorder and sleep disturbances/disorders. Such comorbidities are understudied in minority groups, including Asian Indians residing in countries outside India. Thus, we synthesized the existing literature specific to this group of Asian Indians to determine (a) prevalence estimates of posttraumatic stress disorder (PTSD) and sleep disturbances/disorders; and (b) PTSD-sleep comorbidity estimates. For this systematic review, we searched four databases (PubMed, PsycInfo, PTSDpubs, Web of Science) using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 3,796 screened articles, 9 articles (10 studies) met inclusion criteria. Study sample sizes ranged from 11 to 2,112 Asian Indians; studies were conducted in Singapore or Malaysia. No reviewed study examined PTSD. All studies examined sleep disturbances/disorders among Asian Indians; prevalence estimates were: 8.3% to 70.4% for short sleep duration, 2.0% to 22.9% for long sleep duration, 25.9% to 56.3% for poor sleep quality, 3.4% to 67.5% for insomnia diagnosis or probable insomnia, 7.7% for excessive daytime sleepiness, 3.8% to 54.6% for obstructive sleep apnea (OSA) diagnosis or high OSA risk, and 5.1% to 11.1% for sleep-disordered breathing. Specific to Asian Indians residing in countries outside India, this review advances PTSD-sleep literature by (a) suggesting substantial prevalence of sleep disturbances/disorders; (b) highlighting the need for culturally relevant sleep interventions; and (c) highlighting research gaps (e.g., no PTSD-focused research).

Disruptions in self-regulatory processes predict depression and sleep disturbance in bereaved young adults

Losing a loved one is both common and profoundly stressful for young adults. Little research has examined the longitudinal course of post-loss cognitive processing, depression, and sleep difficulties. Further, little is known about the context of other stressors or the role of individual regulatory resources, such as attentional regulation, that might determine whether loss-related cognitive processing reduces distress. This prospective study examined changes in depression and sleep disturbance over 9 weeks as a function of within- and between-person variation in stress exposure, loss-related cognitive processing, and attention regulation. Participants were 108 recently bereaved college students completing a lab-based assessment of attention regulation and four self-report surveys, spaced three weeks apart. Results revealed that most participants gradually reduced loss-related processing over the study period, with corresponding improvements in depression and sleep. Stress exposure was associated with increased processing, depression, and sleep disturbance. In exploratory analyses, high attentional alertness and slow re-orienting strengthened the association of within-person loss processing with sleep disturbance. Both within- and between-person variation in stress appear to engender risk for a prolonged course of bereavement. Future research should integrate objective attention measures with self-reported adjustment to stress to illuminate reciprocal links between depression, sleep, and loss-related cognitive processing.

Afraid and Awake: The Interaction Between Trauma and Sleep in Children and Adolescents

Traumatic experiences and sleep disturbances are both common in children and adolescents. Because of the reciprocal relationship between sleep complaints and trauma, a mental health evaluation should include not only an assessment of posttraumatic stress disorder and other trauma symptoms but also a specific evaluation of sleep-related complaints. Similarly, if a history of both trauma and sleep complaints is identified, an effective trauma-informed intervention, whether psychological, psychopharmacologic, or a combination of the two, should directly address sleep issues.

Trauma-Associated Sleep Disorder

Trauma-associated sleep disorder (TASD) is a recently described parasomnia that develops following a traumatic event. It consists of trauma-related nightmares, disruptive nocturnal behaviors, and autonomic disturbances, and shares similarities with post-traumatic stress disorder and rapid eye movement behavior disorder. The underlying pathophysiology of TASD and how it relates to other parasomnias are still not entirely understood; proposed treatment is similarly nebulous, with prazosin at the forefront along with management of comorbid sleep disorders. The purpose of this article is to characterize and highlight the clinical features of this condition.

Therapeutic Effects of Tamsulosin in Nightmare Disorder: A Randomized, Double Blind, Placebo-Controlled, Cross-Over, Pilot Study

Nightmare disorder is associated with functional impairment, distress, and low quality of life; however, studies on pharmacotherapy of this debilitating disorder yielded mixed results. Prazosin, a non-selective α1 blocker is reported to be effective in treatment of post-traumatic stress disorder-related nightmares. We aimed at investigating therapeutic effects of tamsulosin which has higher affinity for blocking α1A and α1D adrenoceptors in treatment of nightmare disorder. A randomized, double blind, cross-over, placebo-controlled pilot study was conducted. Patients were randomly assigned to receive Tamsulosin 0.4 mg once daily or placebo for period of four weeks. Following a 2-week wash-out period, they were crossed over to the other group and received drug or placebo for duration of 4 additional weeks. Nightmare frequency and intensity measurements were carried out using Disturbing Dreams and Nightmares Severity Index (DDNSI). Blood pressure measurements were also performed. According to per protocol analysis, mean DDNSI scores decreased following administration of tamsulosin and a statistical trend towards significance was reported (p=0.065, d=0.236). Results of intention to treat analysis showed significant difference in DDNSI scores after drug use (p=0.030, d=0.651). Additionally, DDNSI scores dropped significantly following placebo use. However, intention to treat analysis showed no statistically significant difference pre and post placebo period (0.064, d=0.040). Tamsulosin may be effective in treatment of nightmare disorder. However, further larger clinical trials are recommended to clarify the effectiveness of tamsulosin and α1 subtypes in pharmacotherapy of nightmares.

Preliminary evidence of transcutaneous vagus nerve stimulation effects on sleep in veterans with post-traumatic stress disorder

Sleep problems are common among veterans with post-traumatic stress disorder and closely associated with hyperarousal symptoms. Transcutaneous vagus nerve stimulation (tVNS) may have potential to improve sleep quality in veterans with PTSD through effects on brain systems relevant to hyperarousal and sleep-wake regulation. The current pilot study examines the effect of 1 h of tVNS administered at "lights out" on sleep architecture, microstructure, and autonomic activity. Thirteen veterans with PTSD completed two nights of laboratory-based polysomnography during which they received 1 h of either active tVNS (tragus) or sham stimulation (earlobe) at "lights out" with randomised order. Sleep staging and stability metrics were derived from polysomnography data. Autonomic activity during sleep was assessed using the Porges-Bohrer method for calculating respiratory sinus arrhythmia (RSAP-B ). Paired t-tests revealed a small decrease in the total sleep time (d = -0.31), increase in N3 sleep (d = 0.23), and a small-to-moderate decrease in REM sleep (d = -0.48) on nights of active tVNS relative to sham stimulation. tVNS was also associated with a moderate reduction in cyclic alternating pattern (CAP) rate (d = -0.65) and small-to-moderate increase in RSAP-B during NREM sleep. Greater NREM RSAP-B was associated with a reduced CAP rate and NREM alpha power. This pilot study provides preliminary evidence that tVNS may improve sleep depth and stability in veterans with PTSD, as well as increase parasympathetically mediated nocturnal autonomic activity. These results warrant continued investigation into tVNS as a potential tool for treating sleep disturbance in veterans with PTSD.

Somatic symptoms and insomnia among bereaved parents and siblings eight years after the Utøya terror attack

Background: Levels of prolonged grief symptoms (PGS) and post-traumatic stress symptoms (PTSS) can be high, many years following bereavement after terror, but knowledge concerning somatic health is scarce. Terrorism is a serious public health challenge, and increased knowledge about long-term somatic symptoms and insomnia is essential for establishing follow-up interventions after terrorism bereavement.Objective: To study the prevalence of somatic symptoms and insomnia and their association with PGS, PTSS, and functional impairment among terrorism-bereaved parents and siblings.Methods: A cross-sectional quantitative study included 122 bereaved individuals from the Utøya terror attack in Norway in 2011. The sample comprised 88 parents and 34 siblings aged 19 years and above (Mage = 49.7 years, SDage = 13.8 years, 59.8% females). The participants completed questionnaires 8 years after the attack assessing somatic symptoms (Children's Somatic Symptoms Inventory) and insomnia (Bergen Insomnia Scale) along with measures of PGS (Inventory of Complicated Grief), PTSS (Impact of Event Scale-Revised), and functional impairment (Work and Social Adjustment Scale).Results: Fatigue was the most frequently reported somatic symptom (88% of females and 65% of males). Females reported statistically significantly more somatic symptoms than males. In total, 68% of the bereaved individuals scored above the cut-off for insomnia. There were no statistically significant gender differences for insomnia. Female gender, intrusion, and arousal were associated with somatic symptoms. Intrusion and somatic symptoms were associated with insomnia. Somatic symptoms, avoidance, and hyperarousal were associated with functional impairment.Conclusion: Many bereaved parents and siblings report somatic symptoms and insomnia eight years after the terror attack. Somatic symptoms are associated with functional impairment. Long-term follow-up and support after traumatic bereavement should focus on somatic symptoms and insomnia.

Regulation of stress-induced sleep fragmentation by preoptic glutamatergic neurons

Sleep disturbances are detrimental to our behavioral and emotional well-being. Stressful events disrupt sleep, in particular by inducing brief awakenings (microarousals, MAs), resulting in sleep fragmentation. The preoptic area of the hypothalamus (POA) is crucial for sleep control. However, how POA neurons contribute to the regulation of MAs and thereby impact sleep quality is unknown. Using fiber photometry in mice, we examine the activity of genetically defined POA subpopulations during sleep. We find that POA glutamatergic neurons are rhythmically activated in synchrony with an infraslow rhythm in the spindle band of the electroencephalogram during non-rapid eye movement sleep (NREMs) and are transiently activated during MAs. Optogenetic stimulation of these neurons promotes MAs and wakefulness. Exposure to acute social defeat stress fragments NREMs and significantly increases the number of transients in the calcium activity of POA glutamatergic neurons during NREMs. By reducing MAs, optogenetic inhibition during spontaneous sleep and after stress consolidates NREMs. Monosynaptically restricted rabies tracing reveals that POA glutamatergic neurons are innervated by brain regions regulating stress and sleep. In particular, presynaptic glutamatergic neurons in the lateral hypothalamus become activated after stress, and stimulating their projections to the POA promotes MAs and wakefulness. Our findings uncover a novel circuit mechanism by which POA excitatory neurons regulate sleep quality after stress.

Traumatic brain injury and sleep in military and veteran populations: A literature review

BACKGROUND

Traumatic brain injury (TBI) is a hallmark of wartime injury and is related to numerous sleep wake disorders (SWD), which persist long term in veterans. Current knowledge gaps in pathophysiology have hindered advances in diagnosis and treatment.

OBJECTIVE

We reviewed TBI SWD pathophysiology, comorbidities, diagnosis and treatment that have emerged over the past two decades.

METHODS

We conducted a literature review of English language publications evaluating sleep disorders (obstructive sleep apnea, insomnia, hypersomnia, parasomnias, restless legs syndrome and periodic limb movement disorder) and TBI published since 2000. We excluded studies that were not specifically evaluating TBI populations.

RESULTS

Highlighted areas of interest and knowledge gaps were identified in TBI pathophysiology and mechanisms of sleep disruption, a comparison of TBI SWD and post-traumatic stress disorder SWD. The role of TBI and glymphatic biomarkers and management strategies for TBI SWD will also be discussed.

CONCLUSION

Our understanding of the pathophysiologic underpinnings of TBI and sleep health, particularly at the basic science level, is limited. Developing an understanding of biomarkers, neuroimaging, and mixed-methods research in comorbid TBI SWD holds the greatest promise to advance our ability to diagnose and monitor response to therapy in this vulnerable population.

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.

A path model of associations between war-related exposure to trauma, nightmares, fear, insomnia, and posttraumatic stress among Ukrainian students during the Russian invasion

The present study examined the associations between war-related exposure, nightmares, fear, insomnia, and PTSD symptoms among university students from Western Ukraine. An online cross-sectional study was performed among 1,072 university students (80% of whom were women) during the war. Eight questions were developed to assess exposure to war, and seven items were designed regarding nightmares of war. War-related PTSD symptoms were assessed using an abbreviated six-item PTSD checklist (PCL-6), insomnia was measured using the Athens Insomnia Scale (AIS), and to examine fear of war, the Fear of COVID-19 Scale (FoCV-19S) was adopted. Positive correlations were found between exposure to war, nightmares of war, fear of war, insomnia, and war-related PTSD. The path model using structural equation modelling (SEM) analysis showed that the chain mediation partially explains the relationship between war exposure and war-related PTSD symptoms via nightmares of war, fear of war, and insomnia among university students during the Russian invasion of Ukraine. Women scored significantly higher than men in fear of war and symptoms of insomnia and PTSD, but the path model was invariant across genders. Young adults require treatment focused primarily on nightmares, insomnia, and fear of war to prevent PTSD symptoms.

Blunted Glucocorticoid Responsiveness to Stress Causes Behavioral and Biological Alterations That Lead to Posttraumatic Stress Disorder Vulnerability

BACKGROUND

Understanding why only a subset of trauma-exposed individuals develop posttraumatic stress disorder is critical for advancing clinical strategies. A few behavioral (deficits in fear extinction) and biological (blunted glucocorticoid levels, small hippocampal size, and rapid-eye-movement sleep [REMS] disturbances) traits have been identified as potential vulnerability factors. However, whether and to what extent these traits are interrelated and whether one of them could causally engender the others are not known.

METHODS

In a genetically selected rat model of reduced corticosterone responsiveness to stress, we explored posttraumatic stress disorder-related biobehavioral traits using ex vivo magnetic resonance imaging, cued fear conditioning, and polysomnographic recordings combined with in vivo photometric measurements.

RESULTS

We showed that genetic selection for blunted glucocorticoid responsiveness led to a correlated multitrait response, including impaired fear extinction (observed in males but not in females), small hippocampal volume, and REMS disturbances, supporting their interrelatedness. Fear extinction deficits and concomitant disruptions in REMS could be normalized through postextinction corticosterone administration, causally implicating glucocorticoid deficiency in two core posttraumatic stress disorder-related risk factors and manifestations. Furthermore, reduced REMS was accompanied by higher norepinephrine levels in the hippocampal dentate gyrus that were also reversed by postextinction corticosterone treatment.

CONCLUSIONS

Our results indicate a predominant role for glucocorticoid deficiency over the contribution of reduced hippocampal volume in engendering both REMS alterations and associated deficits in fear extinction consolidation, and they causally implicate blunted glucocorticoids in sustaining neurophysiological disturbances that lead to fear extinction deficits.

The Ponto-Geniculo-Occipital (PGO) Waves in Dreaming: An Overview

Rapid eye movement (REM) sleep is the main sleep correlate of dreaming. Ponto-geniculo-occipital (PGO) waves are a signature of REM sleep. They represent the physiological mechanism of REM sleep that specifically limits the processing of external information. PGO waves look just like a message sent from the pons to the lateral geniculate nucleus of the visual thalamus, the occipital cortex, and other areas of the brain. The dedicated visual pathway of PGO waves can be interpreted by the brain as visual information, leading to the visual hallucinosis of dreams. PGO waves are considered to be both a reflection of REM sleep brain activity and causal to dreams due to their stimulation of the cortex. In this review, we summarize the role of PGO waves in potential neural circuits of two major theories, i.e., (1) dreams are generated by the activation of neural activity in the brainstem; (2) PGO waves signaling to the cortex. In addition, the potential physiological functions during REM sleep dreams, such as memory consolidation, unlearning, and brain development and plasticity and mood regulation, are discussed. It is hoped that our review will support and encourage research into the phenomenon of human PGO waves and their possible functions in dreaming.

From childhood adversity to latent stress vulnerability in adulthood: the mediating roles of sleep disturbances and HPA axis dysfunction

Childhood adversity is a prominent predisposing risk factor for latent stress vulnerability, expressed as an elevated likelihood of developing stress-related psychopathology upon subsequent exposure to trauma in adulthood. Sleep disturbances have emerged as one of the most pronounced maladaptive behavioral outcomes of childhood adversity and are also a highly prevalent core feature of stress-related psychopathology, including post-traumatic stress disorder (PTSD). After reviewing the extensive literature supporting these claims, the current review addresses the notion that childhood adversity-induced sleep disturbances may play a causal role in elevating individuals' stress vulnerability in adulthood. Corroborating this, sleep disturbances that predate adult trauma exposure have been associated with an increased likelihood of developing stress-related psychopathology post-exposure. Furthermore, novel empirical evidence suggests that sleep disturbances, including irregularity of the sleep-wake cycle, mediate the link between childhood adversity and stress vulnerability in adulthood. We also discuss cognitive and behavioral mechanisms through which such a cascade may evolve, highlighting the putative role of impaired memory consolidation and fear extinction. Next, we present evidence to support the contribution of the hypothalamic-pituitary-adrenal (HPA) axis to these associations, stemming from its critical role in stress and sleep regulatory pathways. Childhood adversity may yield bi-directional effects within the HPA stress and sleep axes in which sleep disturbances and HPA axis dysfunction reinforce each other, leading to elevated stress vulnerability. To conclude, we postulate a conceptual path model from childhood adversity to latent stress vulnerability in adulthood and discuss the potential clinical implications of these notions, while highlighting directions for future research.

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.

Hypocretin role in posttraumatic stress disorder-like behaviors induced by a novel stress protocol in mice

Introduction

Posttraumatic stress disorder (PTSD) is a psychiatric disorder developed in individuals who expose to traumatic events. These patients may experience symptoms, such as recurrent unwanted memory of the traumatic event, avoidance of reminders of the trauma, increased arousal, and cognitive difficulty. The hypocretinergic system originates from the lateral hypothalamic area (LHA) and projects diffusely to the whole brain, and hypocretin may be involved in the features of stress-related disorder, PTSD.

Methods

Our study aimed to investigate the role of basolateral amygdala (BLA) hypocretin signals in the pathophysiology of PTSD-like symptoms induced by the modified multiple-prolonged stress (MPS) protocol. The BLA, a brain region involved in fear-related behaviors, receives the hypocretin projections. In this study, TCS1102, a dual hypocretin receptor antagonist, was used to block the hypocretin signal in BLA.

Results

Our data indicated that the MPS protocol is a potential PTSD-like paradigm in mice. Meanwhile, the blockade of hypocretin signaling in the BLA relieved the MPS-induced fear response, and partially reduced PTSD-like anxiety behaviors performed by the open field test (OFT) and elevated plus maze (EPM) task.

Discussion

Our findings suggest that the hypocretinergic system is a potential therapeutic approach for PTSD treatment. With further research, the hypocretin-based medication can be a candidate for human PTSD treatment.

Heart Rate Variability as a Translational Dynamic Biomarker of Altered Autonomic Function in Health and Psychiatric Disease

The autonomic nervous system (ANS) is responsible for the precise regulation of tissue functions and organs and, thus, is crucial for optimal stress reactivity, adaptive responses and health in basic and challenged states (survival). The fine-tuning of central ANS activity relies on the internal central autonomic regulation system of the central autonomic network (CAN), while the peripheral activity relies mainly on the two main and interdependent peripheral ANS tracts, the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). In disease, autonomic imbalance is associated with decreased dynamic adaptability and increased morbidity and mortality. Acute or prolonged autonomic dysregulation, as observed in stress-related disorders, affects CAN core centers, thereby altering downstream peripheral ANS function. One of the best established and most widely used non-invasive methods for the quantitative assessment of ANS activity is the computerized analysis of heart rate variability (HRV). HRV, which is determined by different methods from those used to determine the fluctuation of instantaneous heart rate (HR), has been used in many studies as a powerful index of autonomic (re)activity and an indicator of cardiac risk and ageing. Psychiatric patients regularly show altered autonomic function with increased HR, reduced HRV and blunted diurnal/circadian changes compared to the healthy state. The aim of this article is to provide basic knowledge on ANS function and (re)activity assessment and, thus, to support a much broader use of HRV as a valid, transdiagnostic and fully translational dynamic biomarker of stress system sensitivity and vulnerability to stress-related disorders in neuroscience research and clinical psychiatric practice. In particular, we review the functional levels of central and peripheral ANS control, the main neurobiophysiologic theoretical models (e.g., polyvagal theory, neurovisceral integration model), the precise autonomic influence on cardiac function and the definition and main aspects of HRV and its different measures (i.e., time, frequency and nonlinear domains). We also provide recommendations for the proper use of electrocardiogram recordings for HRV assessment in clinical and research settings and highlight pathophysiological, clinical and research implications for a better functional understanding of the neural and molecular mechanisms underlying healthy and malfunctioning brain-heart interactions in individual stress reactivity and psychiatric disorders.

Sleep characteristics and inflammatory markers in women with post-traumatic stress disorder

INTRODUCTION

Sexual violence is one of the most severe traumatic events. It is associated with a higher risk for post-traumatic stress disorder (PTSD) development. Sleep disturbances such as insomnia are frequently reported by PTSD patients and play a key role in the development and course of the disorder. Sleep disturbances are associated with higher levels of pro-inflammatory cytokines emphasizing the importance of sleep studies in individuals with PTSD.

OBJECTIVES

To investigate the association between subjective and objective sleep measurements and PTSD symptoms with inflammatory markers in women with PTSD following sexual assault.

METHODS

In this longitudinal study fifty-seven women with PTSD were evaluated for sleep measurements and inflammatory markers. Participants completed the Clinician-Administered PTSD Scale, the Beck Depression Inventory, the Pittsburgh Sleep Quality Index (PSQI), and the Insomnia Severity Index. In addition, patients underwent full in-lab polysomnography and serum levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and C-reactive protein (CRP) measurement. All assessments were performed at baseline and after one year. Patients received pharmacological and/or psychological interventions between baseline and one-year follow-up.

RESULTS

Despite improving PTSD symptoms severity and sleep quality (expressed in PSQI), we found an increase in the inflammatory markers IL-1β, TNF-α, IL-6 and CRP after one year of follow-up. These findings suggest that neurobiological processes may advance independently of PTSD symptoms. We found a significant increase in the levels of IL-1β and TNF-α associated with decreased slow-wave sleep (p = 0.019 and p = 0.018 respectively), IL-6 associated with arousal index (p = 0.024), and CRP associated with insomnia severity (p = 0.012), and sleep duration longer than 6 h per night (p < 0.001).

CONCLUSIONS

Sleep impairments in PTSD may be associated with a gradual and persistent alteration in the immune system, resulting in a progressive inflammatory process. Our results suggest that sleep mechanisms are involved in this incident inflammatory process in young women with PTSD.

Exploratory Study on the Associations between Lifetime Post-Traumatic Stress Spectrum, Sleep, and Circadian Rhythm Parameters in Patients with Bipolar Disorder

The present study aimed at exploring whether lifetime post-traumatic stress spectrum symptoms are associated with chronotype in patients with bipolar disorder (BD). Moreover, we explored whether the chronotype can moderate the potential associations between lifetime post-traumatic stress spectrum symptoms and rest-activity circadian and sleep-related parameters. A total of 74 BD patients were administered the Trauma and Loss Spectrum Self-Report (TALS-SR) lifetime version for lifetime post-traumatic stress spectrum symptoms, the Pittsburgh Sleep Quality Index (PSQI) for self-reported sleep quality, and the Reduced Morningness-Eveningness Questionnaire (rMEQ) to discriminate evening chronotypes (ETs), neither chronotype (NT), and morning chronotype (MT). Actigraphic monitoring was used to objectively evaluate sleep and circadian parameters. Patients classified as ET reported significantly higher scores in the re-experiencing domain, as well as poorer sleep quality, lower sleep efficiency, increased wake after sleep onset, and delayed mid-sleep point compared with both NT and MT (p-value ≤ 0.05). Moreover, ET presented significantly higher scores in the TALS-SR maladaptive coping domain than NT and lower relative amplitude than MT (p-value ≤ 0.05). Moreover, higher TALS-SR total symptomatic domains scores were significantly correlated with poor self-reported sleep quality. Regression analyses showed that the PSQI score maintained the association with the TALS total symptomatic domains scores after adjusting for potentially confounding factors (age and sex) and that no interaction effect was observed between the chronotype and the PSQI. Conclusions: This exploratory study suggests that patients with BD classified as ET showed significantly higher lifetime post-traumatic stress spectrum symptoms and more disrupted sleep and circadian rhythmicity with respect to other chronotypes. Moreover, poorer self-reported sleep quality was significantly associated with lifetime post-traumatic stress spectrum symptoms. Further studies are required to confirm our results and to evaluate whether targeting sleep disturbances and eveningness can mitigate post-traumatic stress symptoms in BD.

From childhood trauma to hyperarousal in adults: The mediating effect of maladaptive shame coping and insomnia

Introduction

A new line of insomnia research focuses on the developmental trajectories from early live stress to insomnia in adulthood. Adverse childhood experiences (ACE's) might create a vulnerability for later maladaptive coping with distress, as seen in chronic hyperarousal or insomnia. In an functional magnetic resonance imaging (fMRI) study, failure to dissociate the neurobiological components of shame from autobiographical shameful memories in insomnia was reflected by continued activation of the dorsal anterior cingulate cortex (dACC), which may be a result of maladaptive coping in the wake of ACE's. Following up on that study, the current pilot study explores the relation between ACE's, shame coping-styles, adult insomnia, hyperarousal, and neurobiology of autobiographical memory.

Methods

We used existing data (N = 57) from individuals with insomnia (N = 27) and controls (N = 30), and asked these participants to complete the childhood trauma questionnaire (CTQ). Two structural equation models were used to test the hypotheses that shame-coping styles and insomnia symptom severity mediate the association between ACE's and (1) self-rated hyperarousal symptoms and (2) dACC activation to recall of autobiographical memories.

Results

For the association between ACE's and hyperarousal, there was a significant mediation of shame-coping style (p < 0.05). This model also indicated worse shame coping with more ACE's (p < 0.05) and worse insomnia symptoms with more ACES's (p < 0.05), but no association between shame coping and insomnia symptoms (p = 0.154). In contrast, dACC activation to recall of autobiographical memories could only be explained by its direct association with ACE's (p < 0.05), albeit that in this model more ACE's were also associated with worse insomnia symptoms.

Discussion

These findings could have an implication for the approach of treatment for insomnia. It could be focused more on trauma and emotional processing instead of conventional sleep interventions. Future studies are recommended to investigate the relationship mechanism between childhood trauma and insomnia, with additional factors of attachment styles, personality, and temperament.

Sleep and day-to-day PTSD symptom variability: an ecological momentary assessment and actigraphy monitored study in trauma-exposed young adults

BACKGROUND

Disrupted sleep and post-traumatic stress disorder (PTSD) are bi-directionally linked and have been found to mutually reinforce each other on a day-to-day basis. However, most of the previous research has focused on subjective measures of sleep only.

OBJECTIVE

Here, we investigated the temporal relationship between sleep and PTSD symptoms using both subjective (sleep diary) and objective measures of sleep (actigraphy).

METHODS

Forty-one non-treatment seeking, trauma exposed young adults (age M = 24.68, SD = 8.15) with a range of PTSD symptom severities (PTSS, 0-53 on PCL-5) were recruited. Participants completed two surveys per day over four weeks to measure day-time PTSD symptoms (i.e. PTSS and number of intrusions) and night-time sleep subjectively, while wearing an actigraphy watch to measure sleep objectively.

RESULTS

Linear mixed models revealed that subjectively reported sleep disruptions were associated with elevated next-day PTSS and increasing number of intrusive memories both within and between participants. Similar results were found for daytime PTSD symptoms on night-time sleep. However, these associations were not found using objective sleep data. Exploratory moderator analyses including sex (male vs. female) found that these associations differed in strength between sexes but were generally in the same direction.

DISCUSSION

These results were in line with our hypothesis with regards to the sleep diary (subjective sleep), but not actigraphy (objective sleep). Several factors which have implications on both PTSD and sleep, such as the COVID-19 pandemic and/ or sleep-state misperception, may be potential reasons behind those discrepancies. However, this study had limited power and needs to be replicated in larger samples. Nonetheless, these results add to the current literature about the bi-directional relationship between sleep and PTSD and have clinical implications for treatment strategies.

Actigraphic sleep monitoring in patients with post-traumatic stress disorder (PTSD): A meta-analysis

OBJECTIVE

Sleep disruption is a common complaint among patients with post-traumatic stress disorder (PTSD). Modern technology of activity monitoring (actigraphy) enables extended, objective, unobtrusive recording and measuring of daytime and nighttime activity. We conducted a meta-analysis to investigate the actigraphic sleep patterns in PTSD compared with healthy controls.

METHODS

We searched through seven electronic databases from inception to July 2022. Only case-control studies comparing rest-activity variables measured by actigraphy devices between clinically diagnosed PTSD patients and healthy individuals were included.

RESULTS

We identified 12 eligible studies comparing 323 PTSD patients and 416 healthy controls. Using a random-effects model, we showed that PTSD patients have significantly lower sleep efficiency (SMD: -0.26, 95 % CI = -0.51 to -0.004, p < .05, I² = 29.31 %), more fragmented sleep (SMD: 0.52, 95 % CI = 0.17 to 0.87, p < .01, I² = 0 %), and longer time in bed (SMD: 0.41, 95 % CI = 0.07 to 0.74, p < .05, I² = 0 %) compared to healthy controls.

LIMITATIONS

This study included a limited number of studies. Publication bias was not examined on all variables, which could lead to an overestimation of effect size. Four studies involved veterans, which likely differ from civilians regarding traumatic exposure.

CONCLUSION

This meta-analytic review highlighted a pattern of sleep disturbances in PTSD patients compared with non-PTSD individuals. High-quality, large-scale studies are necessary to draw a definitive conclusion regarding the distinctive sleep profile in PTSD. Future research can pay attention to sleep-specific mechanisms underlying PTSD and explore the momentary interactions between sleep-wake variables.

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.

An examination of volumetric and cortical thickness correlates of posttraumatic nightmares in male active duty service members

Posttraumatic nightmares commonly occur after a traumatic experience. Despite significant deleterious effects on well-being and their role in posttraumatic stress disorder, posttraumatic nightmares remain understudied. The neuroanatomical structures of the amygdala, medial prefrontal cortex, hippocampus, and anterior cingulate cortex constitute the AMPHAC model (Levin and Nielsen, 2007), which is implicated in the neurophysiology of disturbing dreams of which posttraumatic nightmares is a part. However, this model has not been investigated using neuroimaging data. The present study sought to determine whether there are structural differences in the AMPHAC regions in relation to the occurrence of posttraumatic nightmares. Data were obtained from treatment-seeking male active duty service members (N = 351). Posttraumatic nightmares were not significantly related to gray matter volume, cortical surface area, or cortical thickness of any the AMPHAC regions when controlling for age and history of mild traumatic brain injury. Although the present analyses do not support an association between structural measures of AMPHAC regions and posttraumatic nightmares, we suggest that functional differences within and/or between these brain regions may be related to the occurrence of posttraumatic nightmares because functional and structural associations are distinct. Future research should examine whether functional differences may be associated with posttraumatic nightmares.

A noradrenergic-hypothalamic neural substrate for stress-induced sleep disturbances

In our daily life, we are exposed to uncontrollable and stressful events that disrupt our sleep. However, the underlying neural mechanisms deteriorating the quality of non-rapid eye movement sleep (NREMs) and REM sleep are largely unknown. Here, we show in mice that acute psychosocial stress disrupts sleep by increasing brief arousals (microarousals [MAs]), reducing sleep spindles, and impairing infraslow oscillations in the spindle band of the electroencephalogram during NREMs, while reducing REMs. This poor sleep quality was reflected in an increased number of calcium transients in the activity of noradrenergic (NE) neurons in the locus coeruleus (LC) during NREMs. Opto- and chemogenetic LC-NE activation in naïve mice is sufficient to change the sleep microarchitecture similar to stress. Conversely, chemogenetically inhibiting LC-NE neurons reduced MAs during NREMs and normalized their number after stress. Specifically inhibiting LC-NE neurons projecting to the preoptic area of the hypothalamus (POA) decreased MAs and enhanced spindles and REMs after stress. Optrode recordings revealed that stimulating LC-NE fibers in the POA indeed suppressed the spiking activity of POA neurons that are activated during sleep spindles and REMs and inactivated during MAs. Our findings reveal that changes in the dynamics of the stress-regulatory LC-NE neurons during sleep negatively affect sleep quality, partially through their interaction with the POA.

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.

Heterogeneity in patterns of posttraumatic stress disorder symptoms and sleep disturbances among firefighters: Latent profile analyses

Firefighters are at increased risk for posttraumatic stress disorder (PTSD) symptoms and sleep disturbances due to occupational trauma exposure as well as the nature of their job (e.g., shift work, workplace stress). PTSD symptoms co-occur with sleep disturbances, including poor sleep quality, short sleep duration, and low sleep efficiency. No published studies have examined subgroups of firefighters based on PTSD symptoms and sleep disturbances. Thus, we used latent profile analysis to identify the best-fitting class solution to categorize firefighters based on endorsed PTSD symptoms and sleep disturbances and examined relations between the optimal class solution and health covariates (i.e., anger reactions, depression symptoms, emotion regulation difficulties, number of traumatic event types). The sample included 815 trauma-exposed firefighters (M_age = 38.63; 93.20% male). Results indicated three latent subgroups: High PTSD-Sleep Disturbances, Moderate PTSD-Sleep Disturbances, and Low PTSD-Sleep Disturbances. Multinomial logistic regression indicated that endorsing greater anger reactions, depression symptoms, and emotion regulation difficulties increased the chances of being in the more severe classes. Endorsing greater number of traumatic event types increased the chances of being in the Moderate vs. Low PTSD-Sleep Disturbances Classes. Findings improve our understanding of subgroups of firefighters based on PTSD and sleep disturbances and underscore the importance of addressing depression symptoms, anger management, and emotion regulation skills for firefighters reporting more severe PTSD symptoms and sleep disturbances.

Controllable and Uncontrollable Stress Differentially Impact Fear Conditioned Alterations in Sleep and Neuroimmune Signaling in Mice

Stress induces neuroinflammation and disrupts sleep, which together can promote a number of stress-related disorders. Fear memories associated with stress can resurface and reproduce symptoms. Our previous studies have demonstrated sleep outcomes can be modified by stressor controllability following stress and fear memory recall. However, it is unknown how stressor controllability alters neuroinflammatory signaling and its association with sleep following fear memory recall. Mice were implanted with telemetry transmitters and experienced escapable or inescapable footshock and then were re-exposed to the shuttlebox context one week later. Gene expression was assessed with Nanostring® panels using RNA extracted from the basolateral amygdala and hippocampus. Freezing and temperature were examined as behavioral measures of fear. Increased sleep after escapable stress was associated with a down-regulation in neuro-inflammatory and neuro-degenerative related genes, while decreased sleep after inescapable stress was associated with an up-regulation in these genes. Behavioral measures of fear were virtually identical. Sleep and neuroimmune responses appear to be integrated during fear conditioning and reproduced by fear memory recall. The established roles of disrupted sleep and neuroinflammation in stress-related disorders indicate that these differences may serve as informative indices of how fear memory can lead to psychopathology.

Longing for sleep after violence: The impact of PTSD symptoms, avoidance, and pain on insomnia among female veterans

Women survivors of intimate partner violence often struggle with mental and physical problems that arise from incidents of violence. Beyond posttraumatic stress disorder (PTSD), the most common outcome, women also may suffer from debilitating chronic pain due to physical injuries sustained during particularly violent physical and/or sexual encounters. This may be a key interaction to explore as PTSD can lead to avoidance of distressing experiences, including chronic pain, resulting in enduring medical problems such as extreme sleep difficulties. This study aimed to identify if posttraumatic stress disorder (PTSD) symptoms from intimate partner violence (IPV) experiences had a conditional indirect effect on insomnia via chronic pain severity moderated by experiential avoidance among women. Female Veterans of at least 18 years of age completed online surveys at three timepoints (T1-T3) between 2014 and 2017 that included measures of PTSD, chronic pain, experiential avoidance, and insomnia. A total of 411 women participated in the initial survey at T1; 208 had a lifetime history of IPV experiences. The conditional indirect effect of PTSD symptoms (T1) on insomnia (T3) via chronic pain (T2) contingent upon experiential avoidance (T2) was also significant, demonstrating a significant moderated mediation model. This model was not significant for women without a history of IPV at T1. The findings indicate that women with IPV-related PTSD symptoms who are highly avoidant are more likely to experience chronic pain, leading to worse insomnia. Women without IPV experiences did not exhibit this same pattern. Findings have implications for improving trauma-focused treatment, approach coping strategies, pain management, and sleep interventions to address these deleterious psychological and medical issues.

Post-traumatic stress disorder prevalence and sleep quality in fire victims and rescue workers in southern Brazil: a cross-sectional study

OBJECTIVES

This survey was conducted to evaluate the prevalence of post-traumatic stress disorder (PTSD) and the sleep quality in victims and rescue team of the third deadliest nightclub fire in the world.

STUDY DESIGN

A cross-sectional study.

METHODS

Participants were victims and rescue workers exposed to a fire at a nightclub, which occurred in January 2013 in Southern Brazil. The Pittsburgh Sleep Quality Index (PSQI), composed of seven subjective sleep variables (including daytime dysfunction), and PTSD Checklist - Civilian version (PCL-C) were applied to all people who sought medical attention at the local reference center in the first year after the event. Comprehensive information was obtained concerning sociodemographic factors, health status, and sleep complaints.

RESULTS

A total of 370 individuals, 190 victims and 180 rescue workers, were included. Participants were 70% male, with an average age of 29 years. The prevalence of PTSD was 31.9%, ranging from 24.4% for rescue workers to 38.9% for victims. The prevalence of poor sleep quality was 65.9%, ranging from 56.1% for rescue workers to 75.3% for victims. Most of the participants with PTSD (91.5%) had PSQI scores >5 (poor sleepers), against 54.0% of the non-PTSD individuals. All seven PSQI subscores showed significant differences between PTSD and non-PTSD individuals, especially daytime dysfunction. Sex, shift work, previous psychiatric disease, and sleep quality remained associated with PTSD in adjusted models, with a prevalence ratio (95% CI) of 1.76 (1.28-2.43) in females, 1.73 (1.17-2.55) in shift workers, 1.36 (1.03-1.80) in individuals with psychiatric disease history, and 5.42 (2.55-11.52) in poor sleepers.

CONCLUSIONS

The presence of daytime dysfunction increased by at least tenfold the prevalence of PTSD in this sample. Considering that daytime dysfunction was shown to be strongly associated with PTSD, sleep-related issues should be addressed in the assessment of individuals exposed to traumatic events, both victims and rescuers. Factors like shift work and female sex were also associated with PTSD, especially among victims.

Associations between residual hyperarousal and insomnia symptoms in veterans following a 2-week intensive outpatient program for posttraumatic stress disorder

Many returning military service members and veterans who were deployed following the September 11, 2001, terrorist attacks (9/11) suffer from posttraumatic stress disorder (PTSD) and insomnia. Although intensive treatment programs for PTSD have shown promise in the treatment of PTSD symptoms, recent research has demonstrated that sleep disturbance shows little improvement following intensive trauma-focused treatment. The aim of the present study was to evaluate changes in self-reported insomnia symptoms among veterans and service members following participation in a 2-week intensive program for PTSD. We further aimed to investigate if residual PTSD symptoms, specifically hyperarousal, were associated with residual insomnia symptoms. Participants (N = 326) completed self-report assessments of insomnia, PTSD symptoms, and depressive symptoms at pre- and posttreatment. At pretreatment, 73.9% of participants (n = 241) met the criteria for moderate or severe insomnia, whereas at posttreatment 67.7% of participants (n = 203) met the criteria. Results of paired t tests demonstrated statistically significant differences between pre- and posttreatment Insomnia Severity Index scores; however, the effect size was small, d = 0.34. Analyses revealed that posttreatment hyperarousal symptoms were associated with posttreatment insomnia. These findings suggest that although an intensive program for service members and veterans with PTSD may significantly reduce insomnia symptoms, clinically meaningful residual insomnia symptoms remain. Further research is warranted to elucidate the association between residual hyperarousal and insomnia symptoms following intensive trauma-focused treatment.