Flashbulb memories and posttraumatic stress reactions across the life span: age-related effects of the German occupation of Denmark during World War II

MDMA-assisted psychotherapy for PTSD: Growing evidence for memory effects mediating treatment efficacy

The application of MDMA in conjunction with psychotherapy has in recent years seen a resurgence of clinical, scientific, and public interest in the treatment of posttraumatic stress disorder (PTSD). Clinical trials have shown promising safety and efficacy, but the mechanisms underlying this treatment form remain largely unestablished. This article explores recent preclinical and clinical evidence suggesting that the treatment's efficacy may be influenced by the mnemonic effects of MDMA. We review data on the effects of MDMA on fear extinction and fear reconsolidation and the utility of these processes for PTSD treatment. We corroborate our findings by incorporating research from cognitive psychology and psychopharmacology and offer recommendations for future research.

The Association Between Trauma Centrality and Posttraumatic Stress Among Syrian Refugees: The Impact of Cognitive Distortions and Trauma-Coping Self-Efficacy

While research suggests that the war in Syria has led to a drastic re-evaluation of oneself and elevated psychiatric symptoms among Syrian refugees, little is known whether these psychological reactions might be influenced by maladaptive beliefs about oneself and the world and their ability to cope with the effect of the trauma. This study aimed to provide further evidence on the association between trauma centrality, posttraumatic stress, and psychiatric comorbidity, and examine whether cognitive distortions and trauma-coping self-efficacy would mediate the impact of trauma centrality on distress among Syrian refugees residing in Sweden. Four-hundred seventy-five Syrian refugees completed a demographic page, the Harvard Trauma Questionnaire, General Health Questionnaire-28, Centrality of Event Scale, Cognitive Distortion Scales, and trauma-coping self-efficacy. Results showed that trauma centrality was significantly correlated with posttraumatic stress disorder (PTSD) and psychiatric comorbidity after adjusting the effects of trauma exposure characteristics. Cognitive distortions mediated the impact of trauma centrality on the two distress outcomes; trauma-coping self-efficacy did not but was negatively correlated with outcomes. To conclude, the war in Syria changed self-perception, outlook on life, and identity among Syrian refugees. These changes were related to increased psychological symptoms especially for those who had distorted beliefs about themselves and the world. Refugees' belief in the lack of ability to cope with the effect of the trauma impacted psychological distress independently of changes in self-perception.

The relationship between posttraumatic stress disorder, trauma centrality, interpersonal sensitivity and psychiatric co-morbidity among students in Kazakhstan: a Latent Class Analysis

BACKGROUND

Trauma can lead to trauma centrality and affect levels of interpersonal sensitivity and psychiatric co-morbidity. Whether a coexisting relationship between posttraumatic stress disorder (PTSD) and trauma centrality can influence levels of interpersonal sensitivity and psychiatric co-morbidity among university students from Kazakhstan is unknown.

AIM

To investigate the impact of the aforementioned co-existing relationship on interpersonal sensitivity and psychiatric co-morbidity among Kazakh university students.

METHODS

597 students (F = 428, M = 169) completed questionnaires measuring PTSD, psychiatric co-morbidity, interpersonal sensitivity, and trauma centrality.

RESULTS

28%, 32% and 40% met the criteria for full, partial and no-PTSD, respectively. Latent Class Analysis revealed a three-class solution: Class 1 (the altered-self group) with a low level of PTSD but a high level of trauma centrality, Class 2 (the traumatized-self group) with high levels of PTSD and trauma centrality and Class 3 (the low symptom group) with low levels of PTSD and trauma centrality. There were significant differences in the levels of interpersonal sensitivity and psychiatric co-morbidity across three classes.

CONCLUSION

There are individual differences in the display of posttraumatic stress disorder symptoms, and trauma centrality. These differences can influence interaction with others and psychological distress.

Posttraumatic stress disorder and psychiatric co-morbidity among Syrian refugees: the role of trauma exposure, trauma centrality, self-efficacy and emotional suppression

Background: The devastation of the Syrian war can lead to a drastic re-evaluation of oneself and alteration in self-capacities. Yet, little is known regarding its impact on these domains among Syrian refugees.Aims: To investigate the inter-relationship between trauma characteristics, trauma centrality, self-efficacy, emotional suppression, PTSD and psychiatric co-morbidity among Syrian refugees.Methods: 1197 refugees from Turkey and Sweden completed the Harvard Trauma Questionnaire, General Health Questionnaire-28, Centrality of Event Scale, Generalized Self-Efficacy Scale and Courtauld Emotional Control Scale.Results: Using the DSM-IV criteria for PTSD from the Harvard Trauma Questionnaire, 43% met the criteria. The PTSD group reported significantly higher levels of trauma characteristics, trauma centrality and psychiatric co-morbidity but a lower level of self-efficacy than the non-PTSD group. Trauma characteristics were positively associated with trauma centrality; trauma centrality was negatively correlated with self-efficacy. Contrary to hypothesis, self-efficacy was positively correlated with emotional suppression which was positively correlated with psychiatric co-morbidity but not PTSD.Conclusions: The experience of war can lead to the emergence of PTSD among Syrian refugees. Exposure to war can alter self-perception, belief of personal mastery over one's future and the way emotion is expressed, all of which can have specific effects on general psychological symptoms.

How long do floods throughout the millennium remain in the collective memory?

Is there some kind of historical memory and folk wisdom that ensures that a community remembers about very extreme phenomena, such as catastrophic floods, and learns to establish new settlements in safer locations? We tested a unique set of empirical data on 1293 settlements founded in the course of nine centuries, during which time seven extreme floods occurred. For a period of one generation after each flood, new settlements appeared in safer places. However, respect for floods waned in the second generation and new settlements were established closer to the river. We conclude that flood memory depends on living witnesses, and fades away already within two generations. Historical memory is not sufficient to protect human settlements from the consequences of rare catastrophic floods.

Event centrality influences posttraumatic stress disorder symptoms via core beliefs in internally displaced older adults

OBJECTIVES

There is substantial evidence regarding the role of event centrality (EC) in posttraumatic stress disorder (PTSD) symptoms, but little research has examined the explanatory pathways linking EC with PTSD symptoms severity. The present study examined whether core beliefs (CB) mediates the relationship between EC and PTSD symptoms in internally displaced older adults.

METHOD

Internally displaced older adults (N = 279; mean age = 62 years) sheltered in two camps located in north-central Nigeria, completed Tiv language versions of self-report measures, namely, the Harvard Trauma Questionnaire, the Centrality of Event Scale, Core Beliefs Inventory, and provided relevant demographic information.

RESULTS

Analysis indicated that EC and CB were linked to greater PTSD symptoms as well as re-experiencing/intrusion, avoidance and hyperarousal symptoms severity. The mediator path was significant which implies that CB was a pathway through which EC influences PTSD symptoms clusters and overall PTSD symptomatology.

CONCLUSION

A traumatic event becoming more central in a person's identity and life story distorts entrenched beliefs about oneself, others and the world, thereby resulting in greater PTSD symptoms. Our findings suggest that considerations of disrupted world assumptions may be a salient target for prevention and treatment efforts.

Posttraumatic Stress Disorder and Psychiatric Co-morbidity among Syrian Refugees of Different Ages: the Role of Trauma Centrality

It has been documented that trauma centrality is associated with posttraumatic stress disorder (PTSD) and psychiatric co-morbidity among Syrian refugees. Whether age would influence the levels of the above constructs and the association between trauma centrality and distress outcomes is unclear. This study compared age differences in 1) the levels of trauma centrality, posttraumatic stress disorder and psychiatric co-morbidity, and 2) models depicting the association between trauma centrality and distress outcomes among Syrian refugees. One thousand one hundred and ninety-seven refugees completed the Centrality of Event Scale, Harvard Trauma Questionnaire and General Health Questionnaire-28. Age groups were divided into young, middle-aged adults and adults of 45 or above. No significant group differences were found in the proportion of refugees meeting the diagnostic criteria for PTSD. Controlling for demographic variables, all subscales of trauma centrality and psychiatric co-morbidity were significantly different between groups. Young adults reported significantly less trauma centrality and psychiatric co-morbidity than the other groups. Multiple-indicator multiple-cause modelling showed that trauma centrality was significantly correlated with PTSD and psychiatric co-morbidity. Multi-group analysis showed the model for the young adult group to be significantly different from the middle-aged group model. To conclude, age did not seem to influence the severity of PTSD among Syrian refugees. The war had a less severe impact on young adults' sense of self and other psychological problems than those who were older. The way in which young and middle-aged adults responded to distress varied depending on environment and personal characteristics.

Psychological and clinical correlates of the Centrality of Event Scale: A systematic review

The Centrality of Event Scale (CES) was introduced to examine the extent to which a traumatic or stressful event is perceived as central to an individual's identity and life story, and how this relates to Posttraumatic Stress Disorder (PTSD) symptoms. In addition, the CES has been examined in relation to a range of other conditions and dispositions. We present a systematic review of the correlates of the CES. Results from 92 publications resulted in 25 measurement categories in the six theoretical domains of trauma, negative affect and distress, autobiographical memory, personality, positive affect, and gender. The mean weighted correlations of the 25 measurement categories ranged from -.17 to .55, with standard errors from .01 to .02, allowing us to distinguish empirically among effects. Consistent with the theoretical motivation for the CES and predictions predating the review, the CES correlated positively with a range of measures, correlating most highly with measures related to trauma, PTSD, grief, and autobiographical memory. The findings show that the CES probes aspects of autobiographical memory of broad relevance to clinical disorders, and with specific implications for theories of PTSD.

Changes in perceived centrality of anxious events following cognitive behavioral therapy for social anxiety disorder and panic disorder

BACKGROUND AND OBJECTIVE

The purpose of the present study was to explore the association between reductions in symptoms of psychopathology and perceived centrality of negative autobiographical memories in participants with social anxiety disorder (SAD) or panic disorder (PD).

METHODS

Thirty-nine individuals with SAD or PD recalled and rated four negative autobiographical memories before and after ten sessions of cognitive behavioral therapy (CBT) over a three-month period. Twenty-eight healthy controls did the same before and after a three-month period.

RESULTS

As hypothesized, results showed a decrease in perceived centrality following CBT. This decrease in perceived centrality was larger, although at the trend level, for individuals who experienced reliable change on disorder-specific symptoms.

LIMITATIONS

The correlational nature of the study prevents establishing the causal relationship between changes in perceived centrality and psychopathology, and future studies should explore such mechanisms.

CONCLUSIONS

The present study adds to the emerging body of literature, investigating changes in centrality of event following psychotherapy.

Posttraumatic Stress Among Syrian Refugees: Trauma Exposure Characteristics, Trauma Centrality, and Emotional Suppression

OBJECTIVES

This study revisited the prevalence of posttraumatic stress disorder (PTSD) and examined a hypothesized model describing the interrelationship between trauma exposure characteristics, trauma centrality, emotional suppression, PTSD, and psychiatric comorbidity among Syrian refugees.

METHODS

A total of 564 Syrian refugees participated in the study and completed the Harvard Trauma Questionnaire, General Health Questionnaire (GHQ-28), Centrality of Event Scale, and Courtauld Emotional Control Scale.

RESULTS

Of the participants, 30% met the cutoff for PTSD. Trauma exposure characteristics (experiencing or witnessing horror and murder, kidnapping or disappearance of family members or friends) were associated with trauma centrality, which was associated with emotional suppression. Emotional suppression was associated with PTSD and psychiatric comorbid symptom severities. Suppression mediated the path between trauma centrality and distress outcomes.

CONCLUSIONS

Almost one-third of refugees can develop PTSD and other psychiatric problems following exposure to traumatic events during war. A traumatized identity can develop, of which life-threatening experiences is a dominant feature, leading to suppression of depression with associated psychological distress.

The relationship between trauma centrality, self-efficacy, posttraumatic stress and psychiatric co-morbidity among Syrian refugees: Is gender a moderator?

This study examined the inter-relationship between trauma centrality, self-efficacy, posttraumatic stress disorder (PTSD) and psychiatric co-morbidity among a group of Syrian refugees living in Turkey, and whether gender would moderate the mediational effect of self-efficacy on the impact of trauma centrality on distress. Seven hundred and ninety-two Syrian refugees completed the Harvard Trauma Questionnaire, General Health Questionnaire-28, Centrality of Event Scale and Generalized Self-Efficacy Scale. The results showed that 52% met the cutoff for PTSD. Trauma centrality was positively correlated with PTSD, psychiatric co-morbidity and self-efficacy. Self-efficacy was negatively correlated with PTSD only. Gender did not moderate the mediational effect of self-efficacy on the path between trauma centrality and distress outcomes. To conclude, following exposure to traumatic events, more than half reported PTSD. Perception of the future and identity construction was affected. Signs of psychological distress were evident, alongside resilience, regardless of gender.

Role of event centrality and emotion regulation in posttraumatic stress disorder symptoms among internally displaced persons

BACKGROUND

Event centrality and emotion regulation in relation to posttraumatic stress disorder (PTSD) have been documented in various global samples especially in Western cultures; but internally displaced persons (IDPs) still constitute an underrepresented population in psychotraumatology literature. This study tested the roles of event centrality and emotion regulation strategies (cognitive reappraisal and expressive suppression) in PTSD symptoms among IDPs in Nigeria.

DESIGN

The multi-group cross-sectional design was adopted.

METHODS

Tiv language versions of the Centrality of Events Scale, Emotion Regulation Questionnaire, and Harvard Trauma Questionnaire were completed by 859 IDPs in two camps located in Benue State, North-central region of Nigeria.

RESULTS

Hierarchical multiple linear regression results indicated that event centrality positively predicted PTSD symptoms. Cognitive reappraisal was a negative predictor of PTSD symptoms while expressive suppression was a positive predictor of PTSD symptoms. Bonferroni corrections indicated that expressive suppression was the strongest predictor of total PTSD symptoms, avoidance/numbing symptoms, and hyper-arousal symptoms; but event centrality was the most robust predictor of PTSD intrusion/re-experiencing symptoms.

CONCLUSION

The findings underscore recent developments in psychotraumatology indicating that the extent to which individual differences impact the development of PTSD is essential in clinical psychology research and practice.

Children's Vantage Point of Recalling Traumatic Events

This study investigated the recollections of child survivors of the 2004 Asian tsunami in terms of their vantage point and posttraumatic stress disorder (PTSD) responses. Five years after the tsunami, 110 children (aged 7–13 years) living in Aceh, Indonesia were assessed for source of memories of the tsunami (personal memory or second-hand source), vantage point of the memory, and were administered the Children’s Revised Impact of Event Scale-13. Fifty-three children (48%) met criteria for PTSD. Two-thirds of children reported direct memories of the tsunami and one-third reported having memories based on reports from other people. More children (97%) who reported an indirect memory of the tsunami recalled the event from an onlooker’s perspective to some extent than those who recalled the event directly (63%). Boys were more likely to rely on stories from others to reconstruct their memory of the tsunami, and to adopt an observer perspective. Boys who adopted an observer’s perspective had less severe PTSD than those who adopted a field perspective. These findings suggest that, at least in the case of boys, an observer perspectives of trauma can be associated with levels of PTSD.

Conditioning- and time-dependent increases in context fear and generalization

A prominent feature of fear memories and anxiety disorders is that they endure across extended periods of time. Here, we examine how the severity of the initial fear experience influences incubation, generalization, and sensitization of contextual fear memories across time. Adult rats were presented with either five, two, one, or zero shocks (1.2 mA, 2 sec) during contextual fear conditioning. Following a recent (1 d) or remote (28 d) retention interval all subjects were returned to the original training context to measure fear memory and/or to a novel context to measure the specificity of fear conditioning. Our results indicate rats that received two or five shocks show an “incubation”-like enhancement of fear between recent and remote retention intervals, while single-shocked animals show stable levels of context fear memory. Moreover, when fear was tested in a novel context, 1 and 2 shocked groups failed to freeze, whereas five shocked rats showed a time-dependent generalization of context memory. Stress enhancement of fear learning to a second round of conditioning was evident in all previously shocked animals. Based on these results, we conclude that the severity or number of foot shocks determines not only the level of fear memory, but also the time-dependent incubation of fear and its generalization across distinct contexts.

Potentially traumatic events at different points in the life span and mental health: findings from SHARE-Israel

This study addressed the association between adversity cumulated at different points in the life span and present mental health. Data of 1,130 participants aged 50+ were drawn from the Israeli component of the Survey of Health, Ageing and Retirement in Europe (SHARE). Measures included an inventory of potentially traumatic events, mental distress (depressive symptoms), and well-being (quality of life, life satisfaction). Adversity reported to have occurred early in life was positively related to mental health (i.e., to lower distress and higher well-being), whereas adversity reported to occur in late life was negatively related (i.e., to higher distress and lower well-being). Additional analyses showed that the positive association between early-life adversity and mental health was mainly restricted to adversity in which the primary harm was to another person (other-oriented adversity). In contrast, the negative association between late-life adversity and mental health was mainly restricted to adversity in which the primary harm was to the self (self-oriented adversity). This study suggests that the differential association between cumulative adversity and mental health is best captured when accounting for both time of occurrence and adversity type.

A model for removing the increased recall of recent events from the temporal distribution of autobiographical memory

The reminiscence bump is the tendency to recall relatively many personal events from the period in which the individual was between 10 and 30 years old. This effect has only been found in autobiographical memory studies that used participants who were older than 40 years of age. The increased recall of recent events possibly obscures the reminiscence bump in the results of younger participants. In this study, a model was proposed that removes the increase for recent events from the temporal distribution. The model basically estimates a retention function based on the 10 most recent years from the observed distributions and divides the observed distributions by predictions derived from the estimated retention function. The model was examined with three simulated data sets and one experimental data set. The results of the experiment offered two practical examples of how the model could be used to investigate the temporal distribution of autobiographical memories.

The coherence of memories for trauma: evidence from posttraumatic stress disorder

Participants with posttraumatic stress disorder (PTSD) and participants with a trauma but without PTSD wrote narratives of their trauma and, for comparison, of the most-important and the happiest events that occurred within a year of their trauma. They then rated these three events on coherence. Based on participants' self-ratings and on naïve-observer scorings of the participants' narratives, memories of traumas were not more incoherent than the comparison memories in participants in general or in participants with PTSD. This study comprehensively assesses narrative coherence using a full two (PTSD or not) by two (traumatic event or not) design. The results are counter to most prevalent theoretical views of memory for trauma.

Emotion and autobiographical memory

Autobiographical memory encompasses our recollections of specific, personal events. In this article, we review the interactions between emotion and autobiographical memory, focusing on two broad ways in which these interactions occur. First, the emotional content of an experience can influence the way in which the event is remembered. Second, emotions and emotional goals experienced at the time of autobiographical retrieval can influence the information recalled. We discuss the behavioral manifestations of each of these types of interactions and describe the neural mechanisms that may support those interactions. We discuss how findings from the clinical literature (e.g., regarding depression) and the social psychology literature (e.g., on emotion regulation) might inform future investigations of the interplay between the emotions experienced at the time of retrieval and the memories recalled, and we present ideas for future research in this domain.

Memory in posttraumatic stress disorder: properties of voluntary and involuntary, traumatic and nontraumatic autobiographical memories in people with and without posttraumatic stress disorder symptoms

One hundred fifteen undergraduates rated 15 word-cued memories and their 3 most negatively stressful, 3 most positive, and 7 most important events and completed tests of personality and depression. Eighty-nine also recorded involuntary memories online for 1 week. In the first 3-way comparisons needed to test existing theories, comparisons were made of memories of stressful events versus control events and involuntary versus voluntary memories in people high versus low in posttraumatic stress disorder (PTSD) symptom severity. For all participants, stressful memories had more emotional intensity, more frequent voluntary and involuntary retrieval, but not more fragmentation. For all memories, participants with greater PTSD symptom severity showed the same differences. Involuntary memories had more emotional intensity and less centrality to the life story than voluntary memories. Meeting the diagnostic criteria for traumatic events had no effect, but the emotional responses to events did. In 533 undergraduates, correlations among measures were replicated and the Negative Intensity factor of the Affect Intensity Measure correlated with PTSD symptom severity. No special trauma mechanisms were needed to account for the results, which are summarized by the autobiographical memory theory of PTSD.

Posttraumatic Stress Disorder and Older Women

This article examines the literature related to the identification and treatment of post traumatic stress disorder in older women. From this review, several key findings emerge. Consistent in the research literature is the fact that American women are more at risk for PTSD than are men as a result of the high frequency of sexual and domestic physical abuse that women experience. Studies on older women and PTSD indicate that older women are underdiagnosed and are more typically perceived as suffering from depression, anxiety or poor physical health. It was found consistently that older women who present with age-related stressors may not be asked about earlier trauma history or it may not be understood within the context of trauma related variables. In several research studies, trauma history was often not identified either as a result of current assessment practice or because women from certain age cohorts did not disclose trauma-related data to health professionals. Key researchers emphasize the necessity of clinicians, staff and medical personnel to attend to the historical variables present in trauma histories of older women. Researchers underscore the importance of understanding the impact of early and repeated trauma, especially interpersonal trauma, on the physical health and social functioning of older women- even though a significant amount of time may have elapsed since exposure. These findings indicate that further study of PTSD in older women is warranted. The paper concludes with a discussion of assessment and treatment options.

Introduction: The Need to Address Older Women's Mental Health Issues

Women are the primary consumers of mental health services. Ironically, research addressing their unique needs lags behind that of men's issues. The aging process introduces an important variable that accentuates the relative lack of information and specific treatment guidelines for older women who are confronted by mental health problems. This volume offers a comprehensive overview for the health professional who is seeking a greater depth of understanding with respect to the study of mental health problems in general, and how these issues pertain specifically to women and the aging process. A second goal of this project is to provide the practicing therapist and counselor with a research update and a broad clinical perspective offered by seasoned clinicians. Using current psychiatric diagnosis as a framework, the contributions address the range of mental health problems, including dementia and cognitive impairment, schizophrenia, alcohol abuse, mood and anxiety disorders, traumatic and dissociative conditions, sexual and eating disorders, and personality disorders. It is hoped that this book will inform, inspire and encourage students and health professionals in their work with middle aged and older women who are facing mental health challenges.

Contrasting Models of Posttraumatic Stress Disorder: Reply to

We address the four main points in Monroe and Mineka (2008)'s Comment. First, we first show that the DSM PTSD diagnosis includes an etiology and that it is based on a theoretical model with a distinguished history in psychology and psychiatry. Two tenets of this theoretical model are that voluntary (strategic) recollections of the trauma are fragmented and incomplete while involuntary (spontaneous) recollections are vivid and persistent and yield privileged access to traumatic material. Second, we describe differences between our model and other cognitive models of PTSD. We argue that these other models share the same two tenets as the diagnosis and we show that these two tenets are largely unsupported by empirical evidence. Third, we counter arguments about the strength of the evidence favoring the mnemonic model, and fourth, we show that concerns about the causal role of memory in PTSD are based on views of causality that are generally inappropriate for the explanation of PTSD in the social and biological sciences.

A memory-based model of posttraumatic stress disorder: evaluating basic assumptions underlying the PTSD diagnosis

In the mnemonic model of posttraumatic stress disorder (PTSD), the current memory of a negative event, not the event itself, determines symptoms. The model is an alternative to the current event-based etiology of PTSD represented in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; American Psychiatric Association, 2000). The model accounts for important and reliable findings that are often inconsistent with the current diagnostic view and that have been neglected by theoretical accounts of the disorder, including the following observations. The diagnosis needs objective information about the trauma and peritraumatic emotions but uses retrospective memory reports that can have substantial biases. Negative events and emotions that do not satisfy the current diagnostic criteria for a trauma can be followed by symptoms that would otherwise qualify for PTSD. Predisposing factors that affect the current memory have large effects on symptoms. The inability-to-recall-an-important-aspect-of-the-trauma symptom does not correlate with other symptoms. Loss or enhancement of the trauma memory affects PTSD symptoms in predictable ways. Special mechanisms that apply only to traumatic memories are not needed, increasing parsimony and the knowledge that can be applied to understanding PTSD.

The reappearance hypothesis revisited: recurrent involuntary memories after traumatic events and in everyday life

Recurrent involuntary memories are autobiographical memories that come to mind with no preceding retrieval attempt and that are subjectively experienced as being repetitive. Clinically, they are classified as a symptom of posttraumatic stress disorder. The present work is the first to systematically examine recurrent involuntary memories outside clinical settings. Study 1 examines recurrent involuntary memories among survivors of the tsunami catastrophe in Southeast Asia in 2004. Study 2 examines recurrent involuntary memories in a large general population. Study 3 examines whether the contents of recurrent involuntary memories recorded in a diary study are duplicates of, or differ from, one another. We show that recurrent involuntary memories are not limited to clinical populations or to emotionally negative experiences; that they typically do not come to mind in a fixed and unchangeable form; and that they show the same pattern regarding accessibility as do autobiographical memories in general. We argue that recurrent involuntary memories after traumas and in everyday life can be explained in terms of general and well-established mechanisms of autobiographical memory.

Acute predator stress impairs the consolidation and retrieval of hippocampus-dependent memory in male and female rats

We have studied the effects of an acute predator stress experience on spatial learning and memory in adult male and female Sprague-Dawley rats. All rats were trained to learn the location of a hidden escape platform in the radial-arm water maze (RAWM), a hippocampus-dependent spatial memory task. In the control (non-stress) condition, female rats were superior to the males in the accuracy and consistency of their spatial memory performance tested over multiple days of training. In the stress condition, rats were exposed to the cat for 30 min immediately before or after learning, or before the 24-h memory test. Predator stress dramatically increased corticosterone levels in males and females, with females exhibiting greater baseline and stress-evoked responses than males. Despite these sex differences in the overall magnitudes of corticosterone levels, there were significant sex-independent correlations involving basal and stress-evoked corticosterone levels, and memory performance. Most importantly, predator stress impaired short-term memory, as well as processes involved in memory consolidation and retrieval, in male and female rats. Overall, we have found that an intense, ethologically relevant stressor produced a largely equivalent impairment of memory in male and female rats, and sex-independent corticosterone-memory correlations. These findings may provide insight into commonalities in how traumatic stress affects the brain and memory in men and women.