One's sex, sleep, and posttraumatic stress disorder

Acute sleep disruption reduces fear memories in male and female mice

Sleep problems are a prominent feature of mental health conditions including post-traumatic stress disorder (PTSD). Despite its potential importance, the role of sleep in the development of and/or recovery from trauma-related illnesses is not understood. Interestingly, there are reports that sleep disruption immediately after a traumatic experience can reduce fear memories, an effect that could be utilized therapeutically in humans. While the mechanisms of this effect are not completely understood, one possible explanation for these findings is that immediate sleep disruption interferes with consolidation of fear memories, rendering them weaker and more sensitive to intervention. Here, we allowed fear-conditioned mice to sleep immediately after fear conditioning during a time frame (18 h) that includes and extends beyond periods typically associated with memory consolidation before subjecting them to 6-h of sleep disruption. Mice exposed to this delayed regimen showed dramatic reductions in fear during tests conducted immediately after sleep disruption, as well as 24 h later. This sleep disruption regimen also increased levels of mRNA encoding brain-derived neurotrophic factor (BDNF), a molecule implicated in neuroplasticity, in the basolateral amygdala (BLA), a brain area implicated in fear and its extinction. These findings raise the possibility that the effects of our delayed sleep disruption regimen are not due to disruption of memory consolidation, but instead are caused by BDNF-mediated neuroadaptations within the BLA that actively suppress expression of fear. Treatments that safely reduce expression of fear memories would have considerable therapeutic potential in the treatment of conditions triggered by trauma.

Acute sleep deprivation reduces fear memories in male and female mice

Sleep problems are a prominent feature of mental health conditions including post-traumatic stress disorder (PTSD). Despite its potential importance, the role of sleep in the development of and/or recovery from trauma-related illnesses is not understood. Interestingly, there are reports that sleep deprivation immediately after a traumatic experience can reduce fear memories, an effect that could be utilized therapeutically in humans. While the mechanisms of this effect are not completely understood, one possible explanation for these findings is that immediate sleep deprivation interferes with consolidation of fear memories, rendering them weaker and more sensitive to intervention. Here, we allowed fear-conditioned mice to sleep immediately after fear conditioning during a time frame (18 hr) that includes and extends beyond periods typically associated with memory consolidation before subjecting them to 6 hr of sleep deprivation. Mice deprived of sleep with this delayed regimen showed dramatic reductions in fear during tests conducted immediately after sleep deprivation, as well as 24 hr later. This sleep deprivation regimen also increased levels of mRNA encoding brain-derived neurotrophic factor (BDNF), a molecule implicated in neuroplasticity, in the basolateral amygdala (BLA), a brain area implicated in fear and its extinction. These findings raise the possibility that the effects of our delayed sleep deprivation regimen are not due to disruption of memory consolidation, but instead are caused by BDNF-mediated neuroadaptations within the BLA that actively suppress expression of fear. Treatments that safely reduce expression of fear memories would have considerable therapeutic potential in the treatment of conditions triggered by trauma.

Sex predicts post-concussion symptom reporting, independently of fatigue and subjective sleep disturbance, in premorbidly healthy adults after mild traumatic brain injury

The relationship between sex and post-concussion symptom (PCS) reporting after mild traumatic brain injury (mTBI) is not well understood. Subjective sleep disturbance and fatigue impact PCS reporting after mTBI and show sex differences in the normal population. This study investigated whether sex had a relationship with PCS reporting after mTBI, independently of self-reported sleep disturbance and fatigue. Ninety-two premorbidly healthy adults in the post-acute period after mTBI completed the Rivermead Post-Concussion Symptoms Questionnaire, the Pittsburgh Sleep Quality Index, the Multidimensional Fatigue Inventory and measures of depression, anxiety and post-traumatic stress symptomatology. Females (n = 23) demonstrated higher levels of fatigue (p = .019) and greater psychological distress (p = .001) than males (n = 69), but equivalent levels of sleep disturbance (p = .946). Bootstrapping analyses were undertaken because PCS responses were not normally distributed. Female sex predicted greater PCS reporting (p = .001), independently of subjective sleep disturbance, fatigue, psychological distress and litigation status. The current findings support and extend previous work showing premorbidly healthy females are at higher risk of experiencing elevated PCS after mTBI than males in the post-acute period after mTBI. It may be beneficial for clinicians to be particularly sensitive to increased symptom reporting after mTBI in females, irrespective of sleep quality, fatigue or psychological status.

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

Study Objectives

Self-reported sleep disturbance has been established as a risk factor and predictor for posttraumatic stress disorder (PTSD); however, less is known about the relationship between objective sleep and PTSD symptom clusters, and the specific role of hyperarousal. The present study examined the relationships between sleep continuity and architecture on PTSD symptom clusters.

Methods

Participants underwent two in-laboratory sleep studies to assess sleep continuity and architecture. They also completed the Clinician-Administered PTSD-IV scale and the Structured Clinical Interview for the DSM-IV to assess for PTSD diagnosis and other psychiatric disorders.

Results

Sleep continuity (i.e. total sleep time, sleep efficiency percent, wake after sleep onset, sleep latency) was significantly related to PTSD Cluster B (reexperiencing) symptom severity (R ² = .27, p < .001). Sleep architecture, specifically Stage N1 sleep, was significantly associated with PTSD Cluster B (t = 2.98, p = .004), C (Avoidance; t = 3.11, p = .003), and D (Hyperarosual; t = 3.79, p < .001) symptom severity independently of Stages N2, N3, and REM sleep. REM sleep variables (i.e. REM latency, number of REM periods) significantly predicted Cluster D symptoms (R ² = .17, p = .002).

Conclusions

These data provide evidence for a relationship between objective sleep and PTSD clusters, showing that processes active during Stage N1 sleep may contribute to PTSD symptomatology in civilians and veterans. Further, these data suggest that arousal mechanisms active during REM sleep may also contribute to PTSD hyperarousal symptoms.This paper is part of the War, Trauma, and Sleep Across the Lifespan Collection. This collection is sponsored by the Sleep Research Society.

Hallucinogenic drugs and their potential for treating fear-related disorders: Through the lens of fear extinction

Fear-related disorders, mainly phobias and post-traumatic stress disorder, are highly prevalent, debilitating disorders that pose a significant public health problem. They are characterized by aberrant processing of aversive experiences and dysregulated fear extinction, leading to excessive expression of fear and diminished quality of life. The gold standard for treating fear-related disorders is extinction-based exposure therapy (ET), shown to be ineffective for up to 35% of subjects. Moreover, ET combined with traditional pharmacological treatments for fear-related disorders, such as selective serotonin reuptake inhibitors, offers no further advantage to patients. This prompted the search for ways to improve ET outcomes, with current research focused on pharmacological agents that can augment ET by strengthening fear extinction learning. Hallucinogenic drugs promote reprocessing of fear-imbued memories and induce positive mood and openness, relieving anxiety and enabling the necessary emotional engagement during psychotherapeutic interventions. Mechanistically, hallucinogens induce dynamic structural and functional neuroplastic changes across the fear extinction circuitry and temper amygdala's hyperreactivity to threat-related stimuli, effectively mitigating one of the hallmarks of fear-related disorders. This paper provides the first comprehensive review of hallucinogens' potential to alleviate symptoms of fear-related disorders by focusing on their effects on fear extinction and the underlying molecular mechanisms. We overview both preclinical and clinical studies and emphasize the advantages of hallucinogenic drugs over current first-line treatments. We highlight 3,4-methylenedioxymethamphetamine and ketamine as the most effective therapeutics for fear-related disorders and discuss the potential molecular mechanisms responsible for their potency with implications for improving hallucinogen-assisted psychotherapy.

Posttraumatic Stress Symptom Severity Mediates the Relationship Between Military Sexual Trauma and Tension Reduction Behaviors in Male and Female Veterans

Numerous studies attest to the prevalence and complex negative consequences associated with military sexual trauma (MST). However, relatively less is known about male survivors and about the interaction of psychological problems such as posttraumatic stress disorder (PTSD) symptoms and emotion management difficulties following MST. The current study examined the path of psychological distress following MST in both male and female veterans. We predicted that (a) history of MST would predict more severe PTSD symptoms, which in turn would predict greater use of dysfunctional emotion management strategies (specifically, tension reduction behaviors) and that (b) PTSD symptoms would mediate the relationship between history of MST and tension reduction behaviors. Finally, we explored whether the indirect (i.e., mediating) effect was moderated by gender. Data were obtained from pretreatment paper and pencil assessments administered as part of standard clinical care from 338 veterans seeking treatment at a Veterans Affairs (VA) mental health specialty clinic. Veterans who endorsed MST experienced more severe PTSD symptoms and greater reported use of tension reduction behaviors. Bootstrapping testing the indirect effect revealed that PTSD symptoms mediated the relationship between history of MST and tension reduction behaviors. An exploratory moderated mediation analysis found that the indirect effect did not differ as a function of gender. PTSD symptoms appear to mediate the relationship between MST and tension reduction behaviors in veterans, regardless of gender. While previous research has suggested that civilian men report a greater number of tension reduction behaviors following a sexual assault compared to civilian women, we did not find the same gender differences among veterans. These results may provide support for using trauma-focused treatment even when MST survivors are reporting high-risk tension reduction behaviors.

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.

Associations of Intimate Partner Violence, Sexual Assault, and Posttraumatic Stress Disorder With Menopause Symptoms Among Midlife and Older Women

Importance

Little is known about the prevalence of traumatic exposures among midlife and older women and the association of these traumatic exposures with health issues.

Objective

To examine the associations of intimate partner violence (IPV), sexual assault, and posttraumatic stress with menopause symptoms among midlife and older women.

Design, Setting, and Participants

A cross-sectional analysis of data from a multiethnic cohort of 2016 women 40 to 80 years of age in the Kaiser Permanente Northern California health care system was conducted from November 15, 2008, to March 30, 2012. Statistical analysis was conducted from June 8, 2016, to September 6, 2017.

Exposures

Lifetime physical or emotional IPV, sexual assault, and current symptoms of posttraumatic stress disorder, assessed with standardized questionnaires.

Main Outcomes and Measures

Difficulty sleeping, vasomotor symptoms, and vaginal symptoms, assessed with standardized questionnaires.

Results

Among the 2016 women enrolled, the mean (SD) age was 60.5 (9.5) years, and 792 of 2011 with race/ethnicity data (39.4)% were non-Latina white (403 [20.0%] Latina, 429 [21.3%] black, and 387 [19.2%] Asian). Lifetime emotional IPV was reported by 423 women (21.0%), lifetime physical IPV was reported by 316 women (15.7%), sexual assault was reported by 382 women (18.9%), and 450 of 2000 women (22.5%) had current clinically significant symptoms of posttraumatic stress disorder. In multivariable analyses adjusted for age, race/ethnicity, educational level, body mass index, menopause status, hormone therapy, and parity, symptoms of posttraumatic stress disorder were associated with difficulty sleeping (odds ratio [OR], 3.02; 95% CI, 2.22-4.09), vasomotor symptoms (hot flashes: OR, 1.69; 95% CI, 1.34-2.12; night sweats: OR, 1.72; 95% CI, 1.37-2.15), and vaginal symptoms (vaginal dryness: OR, 1.73; 95% CI, 1.37-2.18; vaginal irritation: OR, 2.20; 95% CI, 1.66-2.93; pain with intercourse: OR, 2.16; 95% CI, 1.57-2.98). Emotional IPV was associated with difficulty sleeping (OR, 1.36; 95% CI, 1.09-1.71), night sweats (OR, 1.50; 95% CI, 1.19-1.89), and pain with intercourse (OR, 1.60; 95% CI, 1.14-2.25). Physical IPV was associated with night sweats (OR, 1.33; 95% CI, 1.03-1.72). Sexual assault was associated with vaginal symptoms (vaginal dryness: OR, 1.41; 95% CI, 1.10-1.82; vaginal irritation: OR, 1.42; 95% CI, 1.04-1.95; pain with intercourse: OR, 1.44; 95% CI, 1.00-2.06).

Conclusions and Relevance

Lifetime history of IPV or sexual assault and current clinically significant symptoms of posttraumatic stress disorder are common and are associated with menopause symptoms. These findings highlight the need for greater recognition of these exposures by clinicians caring for midlife and older women.

REM deprivation but not sleep fragmentation produces a sex-specific impairment in extinction

REM sleep is essential for learning and memory processes, particularly emotional learning. Manipulations of REM sleep impair learning and memory and sleep architecture is often altered following a learning experience; for example, short term REM deprivation immediately after fear conditioning results in impaired extinction. In light of research demonstrating sex-dependent differences in fear conditioning as well as differences in sleep architecture, the present study investigated the effects of short term REM deprivation on the extinction of conditioned fear in male and female rats. In addition, given evidence that sleep fragmentation, which is a consequence of REM deprivation, can negatively impact learning and memory, this manipulation was compared to REM deprivation and a control condition. Male and female rats were exposed to fear conditioning followed by 6 h of REM deprivation, sleep fragmentation, or a control condition. Two extinction sessions were conducted at 48 h intervals after conditioning. REM deprivation, but not sleep fragmentation or the control condition, impaired extinction of conditioned fear. However, this effect was seen only in male rats. This study is the first to explore the effects of sleep manipulations on memory in female rats and suggests that female rats are more resilient to the deleterious effects of REM deprivation. In addition, it demonstrates that REM deprivation but not fragmentation of sleep is responsible for impairment in extinction of conditioned fear.

Current Status of Animal Models of Posttraumatic Stress Disorder: Behavioral and Biological Phenotypes, and Future Challenges in Improving Translation

Increasing predictability of animal models of posttraumatic stress disorder (PTSD) has required active collaboration between clinical and preclinical scientists. Modeling PTSD is challenging, as it is a heterogeneous disorder with ≥20 symptoms. Clinical research increasingly utilizes objective biological measures (e.g., imaging, peripheral biomarkers) or nonverbal behaviors and/or physiological responses to complement verbally reported symptoms. This shift toward more-objectively measurable phenotypes enables refinement of current animal models of PTSD, and it supports the incorporation of homologous measures across species. We reviewed >600 articles to examine the ability of current rodent models to probe biological phenotypes of PTSD (e.g., sleep disturbances, hippocampal and fear-circuit dysfunction, inflammation, glucocorticoid receptor hypersensitivity) in addition to behavioral phenotypes. Most models reliably produced enduring generalized anxiety-like or depression-like behaviors, as well as hyperactive fear circuits, glucocorticoid receptor hypersensitivity, and response to long-term selective serotonin reuptake inhibitors. Although a few paradigms probed fear conditioning/extinction or utilized peripheral immune, sleep, and noninvasive imaging measures, we argue that these should be incorporated more to enhance translation. Data on female subjects, on subjects at different ages across the life span, or on temporal trajectories of phenotypes after stress that can inform model validity and treatment study design are needed. Overall, preclinical (and clinical) PTSD researchers are increasingly incorporating homologous biological measures to assess markers of risk, response, and treatment outcome. This shift is exciting, as we and many others hope it not only will support translation of drug efficacy from animal models to clinical trials but also will potentially improve predictability of stage II for stage III clinical trials.

Sex-related effects of sleep deprivation on depressive- and anxiety-like behaviors in mice

Anxiety and depressive symptoms are generated after paradoxical sleep deprivation (PSD). However, it is not clear whether PSD produces differential effects between females and males. The aim of this study was to assess the effect of PSD on anxiety- and depressive-like behaviors between sexes. Male and female BALB/c mice were divided in three groups: the control group, the 48-h PSD group and the 96-h PSD group. Immediately after PSD protocols, the forced swimming and open field test were applied. Sucrose consumption test was used to evaluate the middle-term effect of PSD. We found that corticosterone serum levels showed significant differences in the 96-h PSD females as compared to 96-h PSD males. In the open-field test, the 48-h and 96-h PSD females spent more time at the periphery of the field, and showed high locomotion as compared to males. In the elevated plus maze, the 48-h PSD females spent more time in closed arms than males, which is compatible with anxiety-like behavior. The forced swim test indicated that the 96-h PSD males spent more time swimming as compared to the 96-h PSD females. Remarkably, the 96-h PSD males had lower sucrose intake than the 96-h PSD females, which suggest that male mice have proclivity to develop a persistent depressive-like behavior late after PSD. In conclusion, male mice showed a significant trend to depressive-like behaviors late after sleep deprivation. Conversely, female have a strong tendency to display anxiety- and depressive-like behaviors immediately after sleep deprivation.

Sleep and REM sleep disturbance in the pathophysiology of PTSD: the role of extinction memory

Post-traumatic stress disorder (PTSD) is accompanied by disturbed sleep and an impaired ability to learn and remember extinction of conditioned fear. Following a traumatic event, the full spectrum of PTSD symptoms typically requires several months to develop. During this time, sleep disturbances such as insomnia, nightmares, and fragmented rapid eye movement sleep predict later development of PTSD symptoms. Only a minority of individuals exposed to trauma go on to develop PTSD. We hypothesize that sleep disturbance resulting from an acute trauma, or predating the traumatic experience, may contribute to the etiology of PTSD. Because symptoms can worsen over time, we suggest that continued sleep disturbances can also maintain and exacerbate PTSD. Sleep disturbance may result in failure of extinction memory to persist and generalize, and we suggest that this constitutes one, non-exclusive mechanism by which poor sleep contributes to the development and perpetuation of PTSD. Also reviewed are neuroendocrine systems that show abnormalities in PTSD, and in which stress responses and sleep disturbance potentially produce synergistic effects that interfere with extinction learning and memory. Preliminary evidence that insomnia alone can disrupt sleep-dependent emotional processes including consolidation of extinction memory is also discussed. We suggest that optimizing sleep quality following trauma, and even strategically timing sleep to strengthen extinction memories therapeutically instantiated during exposure therapy, may allow sleep itself to be recruited in the treatment of PTSD and other trauma and stress-related disorders.

Effects of sleep on memory for conditioned fear and fear extinction

Learning and memory for extinction of conditioned fear is a basic mammalian mechanism for regulating negative emotion. Sleep promotes both the consolidation of memory and the regulation of emotion. Sleep can influence consolidation and modification of memories associated with both fear and its extinction. After brief overviews of the behavior and neural circuitry associated with fear conditioning, extinction learning, and extinction memory in the rodent and human, interactions of sleep with these processes will be examined. Animal and human studies suggest that sleep can serve to consolidate both fear and extinction memory. In humans, sleep also promotes generalization of extinction memory. Time-of-day effects on extinction learning and generalization are also seen. Rapid eye movement (REM) may be a sleep stage of particular importance for the consolidation of both fear and extinction memory as evidenced by selective REM deprivation experiments. REM sleep is accompanied by selective activation of the same limbic structures implicated in the learning and memory of fear and extinction. Preliminary evidence also suggests extinction learning can take place during slow wave sleep. Study of low-level processes such as conditioning, extinction, and habituation may allow sleep effects on emotional memory to be identified and inform study of sleep's effects on more complex, emotionally salient declarative memories. Anxiety disorders are marked by impairments of both sleep and extinction memory. Improving sleep quality may ameliorate anxiety disorders by strengthening naturally acquired extinction. Strategically timed sleep may be used to enhance treatment of anxiety by strengthening therapeutic extinction learned via exposure therapy. (PsycINFO Database Record

Sleep in psychogenic nonepileptic seizures and related disorders

Psychogenic nonepileptic seizures (PNES), a form of functional neurological symptom disorder (FNSD), are very rarely seen in genuine, electroencephalography (EEG)-confirmed sleep. However, they are more commonly reported as a nocturnal occurrence, likely from a state that is misidentified as sleep (termed by some as "pseudosleep"). Sleep state can be helpful to distinguish FNSD from other neurological disorders. Pseudo-cataplexy, a form of "psychogenic" narcolepsy, "pseudo-parasomnia" and PNES can have a similar presentation. PNES and posttraumatic stress disorder (PTSD) frequently share previously experienced psychological trauma, and therefore the sleep abnormalities found in PTSD may be similarly present in PNES. Future research should use EEG monitoring to evaluate the sleep physiology of patients with FNSD such as PNES, as insights into sleep abnormalities may enable further understanding of the etiology and manifestations of PNES.

Animal models of fear relapse

Whereas fear memories are rapidly acquired and enduring over time, extinction memories are slow to form and are susceptible to disruption. Consequently, behavioral therapies that involve extinction learning (e.g., exposure therapy) often produce only temporary suppression of fear and anxiety. This review focuses on the factors that are known to influence the relapse of extinguished fear. Several phenomena associated with the return of fear after extinction are discussed, including renewal, spontaneous recovery, reacquisition, and reinstatement. Additionally, this review describes recent work, which has focused on the role of psychological stress in the relapse of extinguished fear. Recent developments in behavioral and pharmacological research are examined in light of treatment of pathological fear in humans.