Sex differences in intrusive memories following trauma

Pre-Learning Stress That Is Temporally Removed from Acquisition Impairs Fear Learning

Few studies have examined the time-dependent effects of stress on fear learning. Previously, we found that stress immediately before fear conditioning enhanced fear learning. Here, we aimed to extend these findings by assessing the effects of stress 30 min prior to fear conditioning on fear learning and fear generalization. Two hundred and twenty-one healthy adults underwent stress (socially evaluated cold pressor test) or a control manipulation 30 min before completing differential fear conditioning in a fear-potentiated startle paradigm. One visual stimulus (CS+), but not another (CS-), was associated with an aversive airblast to the throat (US) during acquisition. The next day, participants were tested for their fear responses to the CS+, CS-, and several generalization stimuli. Stress impaired the acquisition of fear on Day 1 but had no significant impact on fear generalization. The stress-induced impairment of fear learning was particularly evident in participants who exhibited a robust cortisol response to the stressor. These findings are consistent with the notion that stress administered 30 min before learning impairs memory formation via corticosteroid-related mechanisms and may help us understand how fear memories are altered in stress-related psychological disorders.

The 50th anniversary of May 4, 1970 is associated with elevations of distress but no increase in mental health symptoms

Anniversaries of traumatic events are associated with increased symptoms of posttraumatic stress disorder (PTSD), depression, and anxiety, especially in individuals with prior mental health symptoms. However, research has largely focussed on 1-year anniversaries, and it is unclear whether symptom exacerbation persists for more distal, or milestone, anniversaries. Symptoms typically decrease over time after traumatic events, but major anniversaries may be associated with increases in mental health symptoms. During and 3 months after the 50th anniversary of the political protest violence at Kent State University on May 4, 1970, 115 individuals completed measures of PTSD, depression, anxiety, and anniversary-related stress. Participants reported greater stress (t(97) = 4.04 p ≤ .001) during the 50th anniversary compared to 3 months later, but there were no differences in total PTSD (t(114) = .65, p = .52) or depression/anxiety symptoms (all p's > .05). Even in higher-risk individuals (those who previously received mental health services), symptoms did not differ during versus after the anniversary. In general, long-term anniversaries may contribute to transient increases in distress but do not induce major changes in mental health symptoms.

The association between childhood maltreatment and suicidal intrusions: A cross-sectional study

Childhood maltreatment may play an important role in the transition from suicidal ideation to suicidal behavior. Recently, research has begun evaluating the association between childhood maltreatment and involuntary and distressing intrusions about one's own suicide, also called suicidal intrusions. This cross-sectional, multicenter study aimed to investigate the association between childhood maltreatment and the severity of suicidal intrusions using online questionnaires. Participants were suicidal outpatients currently receiving treatment at a Dutch mental health institution (N = 149). The Childhood Trauma Questionnaire-Short Form and Suicidal Intrusions Attributes Scale were administered online. A simple linear regression was performed followed by a multiple linear regression with backward selection to separate the predictors of childhood maltreatment subscales. Next, significant predictor variables were used to perform an additional regression analysis with gender, age, posttraumatic stress disorder (PTSD) diagnosis, and depressive symptoms as potential covariates. The results showed that childhood maltreatment was significantly associated with suicidal intrusion scores, B = .22, t(147) = 2.010, p = .046. A multiple linear regression analysis showed that the only specific form of childhood maltreatment associated with suicidal intrusions was sexual abuse; the association remained after controlling for age, gender, PTSD diagnosis and depressive symptoms, F(5, 143) = 11.15, p < .001. In summary, the present study confirms the link between childhood maltreatment, particularly childhood sexual abuse, and suicidal intrusions. This finding implies that in the treatment of suicidal intrusions and suicidality, childhood sexual abuse should be identified and targeted with evidence-based treatments for PTSD.

[How grief moved from culture to psychiatry]

Bereavement has been debated among psychiatric experts since 2000. In addition to its precise manifestations, its duration is discussed: six months for the ICD-1, one year for the DSM-5-TR. Grief is not an illness but a process that can be blocked in the announcement phase of the death or in the depression phase following the absence. In all cases, acceptance of the loss is impossible. Psychiatric treatment can define a bereaved person who is suffering too much, and can reduce his or her suffering, but it cannot accelerate the process of remembering and then resuming a life without the loved one. Social rituals and psychosocial support have had this place for millennia in cultures throughout humanity.

Lonely in the Dark: Trauma Memory and Sex-Specific Dysregulation of Amygdala Reactivity to Fear Signals

Loneliness exacerbates psychological distress and increases the risk of psychopathology after trauma exposure. However, it is still unclear whether a lack of social connectedness affects trauma-related intrusions and the neural processing of fear signals. Moreover, it is uncertain, whether loneliness plays a different role in women and men. A prestratification strategy is used and n = 47 (n = 20 women) healthy lonely individuals and n = 35 controls (n = 18 women) are recruited. Participants are exposed to an experimental trauma and evoked intrusive thoughts in daily life are monitored for three consecutive days. Functional magnetic resonance imaging is used to assess neural habituation to fearful faces and fear learning (conditioning and extinction) prior to trauma exposure. The results reveal a significant interaction between loneliness and sex such that loneliness is associated with more intrusions in men, but not in women. A similar pattern emerges at the neural level, with both reduced amygdala habituation to repeated fearful faces and amygdala hyperreactivity during the conditioning of fear signals in lonely men. The findings indicate that loneliness may confer vulnerability to intrusive memories after trauma exposure in healthy men and that this phenotype relates to altered limbic processing of fear signals.

Sex hormones and cortisol during experimental trauma memory consolidation: Prospective association with intrusive memories

Background Trauma- and stress-related disorders, such as post-traumatic stress disorder (PTSD), are more common in females than in males. Sex hormones affect learning and emotional memory formation and may be associated with the development of PTSD. Most previous studies have indexed these hormones in isolation. Objectives: To investigate associations of sex hormones and cortisol during memory consolidation on the development of intrusive memories. Methods: We employed an experimental trauma film paradigm in 61 healthy women and indexed salivary testosterone, progesterone, estradiol, and cortisol on day one and day two post experimental trauma exposure and their effects on intrusion frequency, distress, and vividness. Intrusive trauma memories were indexed by means of a diary in which participants documented intrusion frequency, distress, and vividness. Results and conclusion: Participants reported an average of 5.3 intrusions over the course of seven days (SD = 4.6, range 0-26). Progesterone, and estradiol indexed on day one predicted intrusion frequency, with higher progesterone and lower estradiol predicting more intrusive memories (p-values AUC progesterone 0.01 and estradiol 0.02). There was no evidence for associations between hormone concentration indices on day two and intrusion outcomes. Further research on the roles of gonadal and adrenal hormones in trauma memory formation is needed to advance our efforts to understand their influence on PTSD development.

Change in prevalence of post-traumatic stress disorder in the two years following trauma: a meta-analytic study

BACKGROUND

Understanding the course of post-traumatic stress disorder (PTSD) and the factors that impact this is essential to inform decisions about when and for whom screening and intervention are likely to be beneficial.

OBJECTIVE

To provide meta-analytic evidence of the course of recovery from PTSD in the first year following trauma, and the factors that influence that recovery.

METHOD

We conducted a meta-analysis of observational studies of adult PTSD prevalence which included at least two assessments within the first 12 months following trauma exposure, examining prevalence statistics through to 2 years post-trauma. We examined trauma intentionality (intentional or non-intentional), PTSD assessment method (clinician or self-report), sample sex distribution, and age as moderators of PTSD prevalence over time.

RESULTS

We identified 78 eligible studies including 16,484 participants. Pooled prevalence statistics indicated that over a quarter of individuals presented with PTSD at 1 month post-trauma, with this proportion reducing by a third between 1 and 3 months. Beyond 3 months, any prevalence changes were detected over longer intervals and were small in magnitude. Intentional trauma, younger age, and female sex were associated with higher PTSD prevalence at 1 month. In addition, higher proportions of females, intentional trauma exposure, and higher baseline PTSD prevalence were each associated with larger reductions in prevalence over time.

CONCLUSIONS

Recovery from PTSD following acute trauma exposure primarily occurs in the first 3 months post-trauma. Screening measures and intervention approaches offered at 3 months may better target persistent symptoms than those conducted prior to this point.

HIGHLIGHTS

PTSD rates in the immediate aftermath of trauma exposure decline from 27% at 1 month to 18% at 3 months post-trauma, showing significant spontaneous recovery.Problems appear to stabilize after 3 months.Screening/intervention for PTSD at 3 months post-trauma is indicated.

Sex-specific associations between traumatic experiences and resting-state functional connectivity in the Philadelphia Neurodevelopmental Cohort

Background

Traumatic experiences during childhood or adolescence are a significant risk factor for multiple psychiatric disorders and adversely affect multiple cognitive functions. Resting-state functional magnetic resonance imaging has been used to investigate the effects of traumatic experiences on functional connectivity, but the impact of sex differences has not been well documented. This study investigated sex-specific associations between resting-state functional connectivity (rsFC) and traumatic experiences in typically developing youth.

Methods

The sample comprised 1395 participants, aged 8-21 years, from the Philadelphia Neurodevelopmental Cohort. Traumatic experiences were assessed based on the structured psychiatric evaluation. Sex, the number of traumatic events, and their interaction were regressed onto voxel-wise intrinsic connectivity distribution parameter values derived from resting-state functional magnetic resonance imaging. Brain regions that passed cluster correction were used as seeds to define resting-state networks.

Results

After quality control, the final sample had 914 participants with mean (SD) age 14.6 (3.3) years; 529 (57.8%) females; 437 (47.8%) experienced at least one kind of traumatic event. Four discrete anatomical clusters showed decreased functional connectivity as the number of traumatic events increased. The resting-state networks defined by using these four clusters as seeds corresponded with the somatomotor network. Sex-specific associations were identified in another three clusters for which males showed increased connectivity, and females showed decreased connectivity as the number of traumatic events increased. The resting-state networks defined by the three sex-specific clusters corresponded with the default mode network (DMN).

Conclusions

In youth without psychiatric diagnoses, traumatic experiences are associated with an alteration of rsFC in brain regions corresponding with the somatomotor network. Associations differ in direction between males and females in brain regions corresponding with the DMN, suggesting sex-specific responses to early exposure to trauma.

Translation of animal endocannabinoid models of PTSD mechanisms to humans: Where to next?

The endocannabinoid system is known to be involved in mechanisms relevant to PTSD aetiology and maintenance, though this understanding is mostly based on animal models of the disorder. Here we review how human paradigms can successfully translate animal findings to human subjects, with the view that substantially increased insight into the effect of endocannabinoid signalling on stress responding, emotional and intrusive memories, and fear extinction can be gained using modern paradigms and methods for assessing the state of the endocannabinoid system in PTSD.

Gonadal steroid hormones and emotional memory consolidation: A systematic review and meta-analysis

Anxiety and stress-related disorders are more prevalent in women and associated with negative emotional memory consolidation as well as impaired fear extinction recall. Recent research has identified a role of gonadal steroid hormones in influencing emotional memories and fear extinction, however most individual studies have small samples and employed various protocols. A systematic review and meta-analysis were conducted on studies that examined sex hormones (estrogen, progesterone, testosterone, allopregnanolone, dehydroepiandrosterone) on four aspects of memory, namely, intentional recall (k = 13), recognition memory (k = 7), intrusive memories (k = 9), and extinction recall (k = 11). The meta-analysis on natural cycling women revealed that progesterone level was positively associated with negative recall and negative intrusive memories, and this effect on intentional recall was enhanced under stress induction. Estradiol level was positively associated with extinction recall. This study reveals an important role of progesterone and estradiol in influencing emotional memory consolidation. It highlights the need to control for these hormonal effects and examine progesterone and estradiol concurrently across all menstrual phases in future emotional memory paradigms.

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.

Correlates of psychological distress in epileptic patients during the COVID-19 outbreak

INTRODUCTION

Following the severe consequences of the coronavirus disease 2019 (COVID-19) outbreak, on March 9th, 2020 the Italian Government implemented extraordinary measures to limit viral transmission, including restrictive quarantine measures. Psychological distress represents the seizure-precipitating factor most often reported by patients with epilepsy. To date, no studies have analyzed the role played by the different dimensions of psychological distress quarantine-induced in patients with epilepsy.

MATERIALS AND METHODS

We included a total of 40 patients, 18 suffered from generalized, and 22 from focal epilepsy. The patients previously seen in the outpatient clinic during the pre-lockdown period between January and February 2020 were reevaluated after the lockdown period. Psychological distress was evaluated by using the three subscales of Impact of Event Scale-Revised (IES-R). Finally, we employed logistic regression analyses to explore the demographic and clinical features associated to high scores on IES-R.

RESULTS

Patients with higher scores on IES-R Intrusion and IES-R Avoidance subscales demonstrated an increased number of epileptic attacks compared to prelockdown period. Multivariate logistic regression analyses showed that a specific subgroup of patients (i.e., older, female with more anxious symptoms) are at higher risk of increased seizure frequency.

CONCLUSIONS

Our study confirmed that the frequency of epileptic seizures increased during lockdown when compared to pre-lockdown period. The early identification of patients more vulnerable to worsening is crucial to limit the risk of requiring hospital or clinical treatment during the COVID-19 outbreak.

Sleep Early After Trauma

Abstract. Posttraumatic stress disorder (PTSD) is characterized by intrusive re-experiencing of emotional memories of a traumatic event. Such memories are formed after exposure to trauma in the context of a cascading stress response including high levels of emotional arousal and stress hormone release. Sleep could be a key modulator of early memory formation and re-consolidation processes. Initial studies have investigated this association in this early time period, that is, hours and days after trauma exposure, and its role in modulating trauma memories and PTSD. The time is thus ripe to integrate findings from these studies. The current review consolidated evidence from five experimental and seven naturalistic studies on the association between trauma, sleep, and the development of intrusive emotional memories and PTSD, respectively. Together, the studies point to a potential protective role of sleep after trauma for the development of intrusive memories and PTSD. Findings regarding key sleep architecture features are more mixed and require additional investigation. The findings are important for prevention and intervention science.

Correlates of grief-related disorders and mental health outcomes among adult refugees exposed to trauma and bereavement: A systematic review and future research directions

BACKGROUND

With conflict driving millions of refugees away from their homes worldwide, there has been an increase in interest in the field of refugee trauma. However, while trauma and bereavement interlink, prior studies have focused on trauma and its related disorders (PTSD) and predictive factors. This paper reviewed up-to-date literature on the prevalence rates of prolonged grief disorder (PGD), its comorbidities, and associated risk factors among adult refugees.

METHOD

We systematically reviewed the literature using five databases (PsycINFO, PsycARTICLES, Psychology and Behavioral Sciences Collection, Academic Search Elite, and PubMed). The process of study selection was designed according to PRISMA guidelines.

RESULTS

The initial search generated 126 articles, of which 12 met the inclusion criteria. The pooled prevalence of PGD was 33.2% (95% CI: 15.2-54.2%). Being an older refugee, traumatic and multiple losses implying the death of first-degree relatives appeared to be consistent risk factors for PGD, combined PTSD/PGD, depression, idioms of distress, and functional impairment. PGD, PTSD, and PTSD/PGD intersect on PTSD-intrusions and painful memories.

LIMITATIONS

All included studies adopted a cross-sectional design, thus limiting the understanding of causal pathways.

CONCLUSIONS

Our findings showed that the high prevalence of PGD and related comorbidities were influenced by the load of traumatic circumstances surrounding the death(s). The findings shed light on the current proposed grief-related diagnostic criteria . Psychopathological and transcultural aspects are discussed, and we provide concrete recommendations for improvements to future research in this field.

An alternative theory for hormone effects on sex differences in PTSD: The role of heightened sex hormones during trauma

Women are at least twice as susceptible to developing post-traumatic stress disorder (PTSD) compared to men. Although most research seeking to explain this discrepancy has focussed on the role of oestradiol during fear extinction learning, the role of progesterone has been overlooked, despite relatively consistent findings being reported concerning the role of progesterone during consolidation of emotional and intrusive memories. In this review article, we outline literature supporting the role of progesterone on memory formation, with particular emphasis on potential memory-enhancing properties of progesterone when subjects are placed under stress. It is possible that progesterone directly and indirectly exerts memory-enhancing effects at the time of trauma, which is an effect that may not be necessarily captured during non-stressful paradigms. We propose a model whereby progesterone's steroidogenic relationship to cortisol and brain-derived neurotrophic factor in combination with elevated oestradiol may enhance emotional memory consolidation during trauma and therefore present a specific vulnerability to PTSD formation in women, particularly during the mid-luteal phase of the menstrual cycle.

Sex differences in neural stress responses and correlation with subjective stress and stress regulation

Emotional stress responses, encompassing both stress reactivity and regulation, have been shown to differ between men and women, but the neural networks supporting these processes remain unclear. The current study used functional neuroimaging (fMRI) to investigate sex differences in neural responses during stress and the sex-specific relationships between these responses and emotional stress responses for men and women. A significant sex by condition interaction revealed that men showed greater stress responses in prefrontal cortex (PFC) regions, whereas women had stronger responses in limbic/striatal regions. Although men and women did not significantly differ in emotional stress reactivity or subjective reports of stress regulation, these responses were associated with distinct neural networks. Higher dorsomedial PFC responses were associated with lower stress reactivity in men, but higher stress reactivity in women. In contrast, while higher ventromedial PFC stress responses were associated with worse stress regulation in men (but better regulation in women), dynamic increases in vmPFC responses during stress were associated with lower stress reactivity in men. Finally, stress-induced hippocampal responses were more adaptive for women: for men, high and dynamically increasing responses in left hippocampus were associated with high stress reactivity, and dynamic increases in the left (but not right) hippocampus were associated with worse stress regulation. Together, these results reveal that men and women engage distinct neural networks during stress, and sex-specific neural stress responses facilitate optimal emotional stress responses.