An investigation of the mechanisms underlying the link between abstract reasoning and intrusive memories: A trauma analogue study

Potentially traumatic events elicit intrusive memories to which some individuals are more vulnerable than others. Lower abstract reasoning capacity has been related to more intrusive memories. A more perceptual processing style when encoding the event may mediate this link. Another potential mechanism is lower attentional control, resulting in greater attentional bias toward trauma-related content. We examined both of these possibilities using a trauma-analogue paradigm. One hundred and twenty participants completed abstract reasoning tasks. Then, 90 participants watched a negative video, and 30 participants watched a neutral video. The level of perceptual processing (P1) and attentional bias (RT) towards trauma-related stimuli were measured with a pictorial Stroop task while recording EEG. Intrusive memories were recorded for 5 days. Abstract reasoning was not associated with intrusive memories. However, lower abstract reasoning tended to be associated with more perceptual processing (greater P1 amplitude) following the negative video. More perceptual processing also tended to be related to more intrusive memories for younger participants. A more pronounced attentional bias was related to more intrusive memories, but only for women. Unexpectedly, also for women, better verbal reasoning was linked to a more pronounced attentional bias. Results are compared to existing studies and future implications are discussed.

Using network models to explore the associations between posttraumatic stress disorder symptoms and subjective cognitive functioning

Several studies have identified relationships between posttraumatic stress disorder (PTSD) and cognitive functioning. Here, we aimed to elucidate the nature of this relationship by investigating cross-sectional associations between subjective cognitive functioning (SCF) and 1) the PTSD sum score, 2) symptom domains, and 3) individual symptoms. We also investigated temporal stability by testing whether results replicated over a 3-year period. We estimated partial correlation networks of DSM-5 PTSD symptoms (at baseline) and SCF (at baseline and follow-up, respectively), using data from the National Health and Resilience in Veterans Study (NHRVS; N = 1484; Mdn = 65 years). The PTSD sum score was negatively associated with SCF. SCF was consistently negatively associated with the PTSD symptom domains 'marked alterations in arousal and reactivity' and 'negative alterations in cognitions and mood', and showed robust relations with the specific symptoms 'having difficulty concentrating' and 'trouble experiencing positive feelings'. Results largely replicated at the 3-year follow-up, suggesting that some PTSD symptoms both temporally precede and are statistically associated with the development or maintenance of reduced SCF. We discuss the importance of examining links between specific PTSD domains and symptoms with SCF-relations obfuscated by focusing on PTSD diagnoses or sum scores-as well as investigating mechanisms underlying these relations. Registration Number: 37069 (https://aspredicted.org/n5sw7.pdf).

Altered neural encoding of prediction errors in assault-related posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is widely associated with deficits in extinguishing learned fear responses, which relies on mechanisms of reinforcement learning (e.g., updating expectations based on prediction errors). However, the degree to which PTSD is associated with impairments in general reinforcement learning (i.e., outside of the context of fear stimuli) remains poorly understood. Here, we investigate brain and behavioral differences in general reinforcement learning between adult women with and without a current diagnosis of PTSD. 29 adult females (15 PTSD with exposure to assaultive violence, 14 controls) underwent a neutral reinforcement-learning task (i.e., two arm bandit task) during fMRI. We modeled participant behavior using different adaptations of the Rescorla-Wagner (RW) model and used Independent Component Analysis to identify timecourses for large-scale a priori brain networks. We found that an anticorrelated and risk sensitive RW model best fit participant behavior, with no differences in computational parameters between groups. Women in the PTSD group demonstrated significantly less neural encoding of prediction errors in both a ventral striatum/mPFC and anterior insula network compared to healthy controls. Weakened encoding of prediction errors in the ventral striatum/mPFC and anterior insula during a general reinforcement learning task, outside of the context of fear stimuli, suggests the possibility of a broader conceptualization of learning differences in PTSD than currently proposed in current neurocircuitry models of PTSD.

The centrality of fear extinction in linking risk factors to PTSD: A narrative review

Recent prospective studies in emergency services have identified impaired fear extinction learning and memory to be a significant predictor of Posttraumatic Stress Disorder (PTSD), complementing a wealth of cross-sectional evidence of extinction deficits associated with the disorder. Additional fields of research show specific risk factors and biomarkers of the disorder, including candidate genotypes, stress and sex hormones, cognitive factors, and sleep disturbances. Studies in mostly nonclinical populations also reveal that the aforementioned factors are involved in fear extinction learning and memory. Here, we provide a comprehensive narrative review of the literature linking PTSD to these risk factors, and linking these risk factors to impaired fear extinction. On balance, the evidence suggests that fear extinction may play a role in the relationship between risk factors and PTSD. Should this notion hold true, this review carries important implications for the improvement of exposure-based treatments, as well as strategies for the implementation of treatment.

Does Early Psychological Intervention Promote Recovery From Posttraumatic Stress?

In the wake of the terrorist attacks at the World Trade Center, more than 9,000 counselors went to New York City to offer aid to rescue workers, families, and direct victims of the violence of September 11, 2001. These mental health professionals assumed that many New Yorkers were at high risk for developing posttraumatic stress disorder (PTSD), and they hoped that their interventions would mitigate psychological distress and prevent the emergence of this syndrome. Typically developing in response to horrific, life-threatening events, such as combat, rape, and earthquakes, PTSD is characterized by reexperiencing symptoms (e.g., intrusive recollections of the trauma, nightmares), emotional numbing and avoidance of reminders of the trauma, and hyperarousal (e.g., exaggerated startle, difficulty sleeping). People vary widely in their vulnerability for developing PTSD in the wake of trauma. For example, higher cognitive ability and strong social support buffer people against PTSD, whereas a family or personal history of emotional disorder heightens risk, as does negative appraisal of one's stress reactions (e.g., as a sign of personal weakness) and dissociation during the trauma (e.g., feeling unreal or experiencing time slowing down). However, the vast majority of trauma survivors recover from initial posttrauma reactions without professional help. Accordingly, the efficacy of interventions designed to mitigate acute distress and prevent long-term psychopathology, such as PTSD, needs to be evaluated against the effects of natural recovery. The need for controlled evaluations of early interventions has only recently been widely acknowledged.

Psychological debriefing—the most widely used method—has undergone increasing empirical scrutiny, and the results have been disappointing. Although the majority of debriefed survivors describe the experience as helpful, there is no convincing evidence that debriefing reduces the incidence of PTSD, and some controlled studies suggest that it may impede natural recovery from trauma. Most studies show that individuals who receive debriefing fare no better than those who do not receive debriefing. Methodological limitations have complicated interpretation of the data, and an intense controversy has developed regarding how best to help people in the immediate wake of trauma.

Recent published recommendations suggest that individuals providing crisis intervention in the immediate aftermath of the event should carefully assess trauma survivors' needs and offer support as necessary, without forcing survivors to disclose their personal thoughts and feelings about the event. Providing information about the trauma and its consequences is also important. However, research evaluating the efficacy of such “psychological first aid” is needed.

Some researchers have developed early interventions to treat individuals who are already showing marked stress symptoms, and have tested methods of identifying those at risk for chronic PTSD. The single most important indicator of subsequent risk for chronic PTSD appears to be the severity or number of posttrauma symptoms from about 1 to 2 weeks after the event onward (provided that the event is over and that there is no ongoing threat).

Cognitive-behavioral treatments differ from crisis intervention (e.g., debriefing) in that they are delivered weeks or months after the trauma, and therefore constitute a form of psychotherapy, not immediate emotional first aid. Several controlled trials suggest that certain cognitive-behavioral therapy methods may reduce the incidence of PTSD among people exposed to traumatic events. These methods are more effective than either supportive counseling or no intervention.

In this monograph, we review risk factors for PTSD, research on psychological debriefing, recent recommendations for crisis intervention and the identification of individuals at risk of chronic PTSD, and research on early interventions based on cognitive-behavioral therapy. We close by placing the controversy regarding early aid for trauma survivors in its social, political, and economic context.

A Chronic Longitudinal Characterization of Neurobehavioral and Neuropathological Cognitive Impairment in a Mouse Model of Gulf War Agent Exposure

Gulf War Illness (GWI) is a chronic multisymptom illness with a central nervous system component that includes memory impairment as well as neurological and musculoskeletal deficits. Previous studies have shown that in the First Persian Gulf War conflict (1990-1991) exposure to Gulf War (GW) agents, such as pyridostigmine bromide (PB) and permethrin (PER), were key contributors to the etiology of GWI. For this study, we used our previously established mouse model of GW agent exposure (10 days PB+PER) and undertook an extensive lifelong neurobehavioral characterization of the mice from 11 days to 22.5 months post exposure in order to address the persistence and chronicity of effects suffered by the current GWI patient population, 24 years post-exposure. Mice were evaluated using a battery of neurobehavioral testing paradigms, including Open Field Test (OFT), Elevated Plus Maze (EPM), Three Chamber Testing, Radial Arm Water Maze (RAWM), and Barnes Maze (BM) Test. We also carried out neuropathological analyses at 22.5 months post exposure to GW agents after the final behavioral testing. Our results demonstrate that PB+PER exposed mice exhibit neurobehavioral deficits beginning at the 13 months post exposure time point and continuing trends through the 22.5 month post exposure time point. Furthermore, neuropathological changes, including an increase in GFAP staining in the cerebral cortices of exposed mice, were noted 22.5 months post exposure. Thus, the persistent neuroinflammation evident in our model presents a platform with which to identify novel biological pathways, correlating with emergent outcomes that may be amenable to therapeutic targeting. Furthermore, in this work we confirmed our previous findings that GW agent exposure causes neuropathological changes, and have presented novel data which demonstrate increased disinhibition, and lack of social preference in PB+PER exposed mice at 13 months after exposure. We also extended upon our previous work to cover the lifespan of the laboratory mouse using a battery of neurobehavioral techniques.

Effect of posttraumatic stress on study time in a task measuring four component processes underlying text-level reading

PURPOSE

To investigate the effect of combat-related posttraumatic stress disorder (PTSD) on 4 components underlying text-level reading comprehension.

METHOD

A group of 17 veterans with PTSD and 17 matched control participants took part. An experimental task required participants to read and study 3-sentence paragraphs describing semantic features associated with real and unreal objects. Each paragraph was followed by true-false statements that assessed knowledge access, text memory, inference, and integration.

RESULTS

The results revealed that the PTSD group took significantly longer than the control group to study the paragraphs. Although there was no group difference in test statement accuracy, the PTSD group also took significantly longer to respond to the test statements.

CONCLUSIONS

Overall, the results provide evidence for the control theory of attention but suggest that more direct measures of task-irrelevant processing during text-level reading are needed. More important, the results begin to lay a foundation for developing not only diagnostic but also intervention strategies.

Attentional and executive functions are differentially affected by post-traumatic stress disorder and trauma

BACKGROUND

Among the neurocognitive impairments observed in patients with Post-traumatic Stress Disorder (PTSD), attentional and executive dysfunctions appear to correlate with negative effects on education, work, daily life activities, and social relations, as well as the re-experiencing, avoidance, and hyperarousal symptoms of PTSD. However, there is no consensus regarding which aspects of attentional and executive functions are impaired in PTSD patients.

METHODS

Attentional and executive functions were assessed using the digit span (WAIS-III) and spatial span (WMS-III) tests under forward and backward recall conditions, the Stroop Test, and the Wisconsin Card Sorting Test (WCST). Our sample was composed of victims of urban violence who developed PTSD (PTSD+) (n = 81), victims of urban violence who did not develop PTSD (PTSD-) (n = 70), and healthy controls not exposed to trauma (HC) (n = 50).

RESULTS

The PTSD+ group had poorer performance on the spatial span forward subtest (p = 0.023; eta(2) = 0.038) and poorer execution time (p = 0.023; eta(2) = 0.042) and accuracy (p = 0.019; eta(2) = 0.044) on the Stroop Test compared to HC.

CONCLUSIONS

These data suggest that there are few differences between the PTSD+ and HC groups, which are restricted to less complex measures of attentional and executive functional processes (short term capacity, selective attention, processing speed, and inhibitory control) and are related to visual stimuli. Therefore, cognitive impairments directly correlated with the manifestation of PTSD.

Cognitive ability and decline after early life stress exposure

We examined the effects of early life stress on cognitive ability and decline among men of the Helsinki Birth Cohort Study, 10% of whom were separated temporarily (mean age at separation = 4.1 years) from their parent(s) during World War II. The men underwent the Finnish Defense Forces Basic Intellectual Ability Test twice, at 20 years and retest at 70 years. Compared with the men without childhood separation and matched for year of birth (n = 186), men separated from their parents (n = 93) scored lower by 5.5 (95% confidence interval [CI], -9.2 to -1.7), 4.2 (95% CI, -8.1 to -0.3), 3.1 (95% CI, -7.0 to 0.8), and 4.5 (95% CI, -10.5 to -1.4) standardized points (SD = 15) on verbal, visuospatial, arithmetic, and general cognitive ability, respectively, at 70 years. Longer duration of separation was associated with lower test scores. Though early life stress was also associated significantly with weaker cognitive performance at the ages 20 and 70 years, it was not associated with cognitive decline over the 50-year period within this sample.

A consideration of select pre-trauma factors as key vulnerabilities in PTSD

Posttraumatic stress disorder (PTSD) is a pathological response to a traumatic event. A number of risk and vulnerability factors predicting PTSD development have been identified in the literature. Many of these variables are specific factors occurring during and after exposure to a traumatic event or are not measured prospectively to assess temporal sequence. Recent research, however, has begun to focus on pre-trauma individual differences that could contribute to risk for developing PTSD. The present review proposes that a number of biological and cognitive vulnerability factors place individuals at risk for PTSD development prior to the actual experience of trauma. Accordingly, this review provides a summary of evidence for a select number of these factors as pre-trauma vulnerabilities to PTSD. Included is a discussion of biological factors, including molecular genetic studies of systems regulating serotonin, catecholamines, and glucocorticoids as well as aspects of the neuroendocrine system. Specific cognitive factors are also considered, including intelligence, neuropsychological functioning and cognitive biases such as negative attributional style and appraisals. For each factor, the present review summarizes evidence to date regarding PTSD vulnerability and highlights directions for future research in this area.

Perceptual processing advantages for trauma-related visual cues in post-traumatic stress disorder

BACKGROUND

Intrusive re-experiencing in post-traumatic stress disorder (PTSD) comprises distressing sensory impressions from the trauma that seem to occur 'out of the blue'. A key question is how intrusions are triggered. One possibility is that PTSD is characterized by a processing advantage for stimuli that resemble those that accompanied the trauma, which would lead to increased detection of such cues in the environment.

METHOD

We used a blurred picture identification task in a cross-sectional (n=99) and a prospective study (n=221) of trauma survivors.

RESULTS

Participants with acute stress disorder (ASD) or PTSD, but not trauma survivors without these disorders, identified trauma-related pictures, but not general threat pictures, better than neutral pictures. There were no group differences in the rate of trauma-related answers to other picture categories. The relative processing advantage for trauma-related pictures correlated with re-experiencing and dissociation, and predicted PTSD at follow-up.

CONCLUSIONS

A perceptual processing bias for trauma-related stimuli may contribute to the involuntary triggering of intrusive trauma memories in PTSD.

Patients with posttraumatic stress disorder show decreased cognitive control: evidence from dichotic listening

The influence of posttraumatic stress disorder (PTSD) on cognitive control and auditory attention modulation was examined with the use of a dichotic-listening (DL) task. The participants were 45 war-exposed refugees. The PTSD group comprised 22 participants meeting the DSM-IV criteria for PTSD, and the Control group comprised 23 war-exposed participants without PTSD. Both groups were tested with a consonant-vowel syllables DL task under three different attentional instructions. The two groups did not differ in the non-forced and forced-right conditions and showed, as expected, right-ear advantages. The Control group showed, as expected, a left-ear advantage in the forced-left (FL) condition. However, the PTSD group continued to show a right-ear advantage--and only minor modulation of the performance during the FL condition. This finding suggests that PTSD is associated with a reduced capacity for top-down attentional control of a bottom-up or stimulus-driven effect. The result shows that participants with PTSD have impaired cognitive control functions when tested on information processing of neutral stimuli.

Hydrocortisone responsiveness in Gulf War veterans with PTSD: effects on ACTH, declarative memory hippocampal [(18)F]FDG uptake on PET

Neuroendocrine, cognitive and hippocampal alterations have been described in Gulf War (GW) veterans, but their inter-relationships and significance for posttraumatic stress disorder (PTSD) have not been described. Hydrocortisone (Hcort) was administered to GW veterans with (PTSD+ n=12) and without (PTSD- n=8) chronic PTSD in a randomized, placebo-controlled, double-blind challenge. Changes in plasma ACTH, memory, and hippocampal [(18)F]FDG uptake on positron emission tomography were assessed. The low-dose dexamethasone suppression test was also administered. The PTSD+ group showed greater cortisol and ACTH suppression, reflecting greater peripheral glucocorticoid receptor (GR) responsiveness, and did not show an Hcort-induced decrement in delayed recall or retention. The groups had comparable relative regional hippocampal [(18)F]FDG uptake at baseline, but only the PTSD- group had an Hcort-associated decrease in hippocampal [(18)F]FDG uptake. Asymmetry in hippocampal hemispheric volumes differed between PTSD+ and PTSD- groups. This asymmetry was associated with cortisol, ACTH, retention and functional hippocampal asymmetry before, but not after, Hcort administration. Differences in brain metabolic responses between GW veterans with and without PTSD may reflect differences in peripheral and central GR responsiveness.

Memory and executive dysfunctions associated with acute posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) in its chronic form has been associated with a number of neurocognitive impairments involving emotionally neutral stimuli. It remains unknown whether such impairments also characterize acute PTSD. In the present investigation, neurocognitive functions were examined in trauma exposed individuals with (n=21) and without (n=16) acute PTSD, as well as in a group of individuals never exposed to trauma (n=17) using specific and standardized tasks such as the Rey Auditory Verbal Learning Test, the Aggie's Figure Learning Test, the Autobiographical Memory Interview, the D2 test, the Stroop task, the digit and visual span tasks of the Wechsler Memory Scale-III, the Trail Making Test, the Tower of London and the vocabulary subtest of the Wechsler Adult Intelligence Scale-III. A number of deficits in the cognitive domains of memory, high-level attentional resources, executive function and working memory were found in the group with a diagnosis of acute PTSD only and not among the other groups. The findings, which point to the possibility of disturbed fronto-temporal system function in trauma-exposed individuals with acute PTSD, are particularly relevant for the early clinical management of this disorder.

Eventos estressores e estratégias de coping em adolescentes: implicações na aprendizagem

Ao longo da vida, nos deparamos com eventos com os quais não nos percebemos capacitados a lidar, o que pode gerar um estado de tensão no organismo denominado estresse. As alterações decorrentes do estresse e o impacto que provoca na vida das pessoas podem agravar a desadaptação do indivíduo em seu desenvolvimento, sobretudo no ambiente escolar. O presente artigo explora as relações entre eventos de vida estressores, estresse e estratégias de coping em adolescentes, discutindo as possíveis implicações desses fatores na aprendizagem. Além disso, são descritos os fatores ambientais e a neurobiologia do estresse, bem como o papel da resiliência no enfrentamento de situações estressantes.

Elevated maternal cortisol levels during pregnancy are associated with reduced childhood IQ

BACKGROUND

In animal models, there is evidence to suggest a causal link between maternal cortisol levels during pregnancy and offspring outcomes; however, evidence for this relationship in humans is inconclusive. We address important confounders of this association by estimating the relationship between maternal cortisol levels in late pregnancy and childhood IQ in a birth cohort and in a subsample of siblings.

METHODS

This study included 832 children who were members of the Collaborative Perinatal Project. Maternal serum collected between 1959 and 1966 during the third trimester of pregnancy was analysed for free cortisol. We investigated the relationship between maternal cortisol in quintiles and full, verbal and performance scale scores on the Wechsler Intelligence Scale for Children at age 7 years, adjusting for prenatal and family characteristics. We repeated this analysis among 74 discordant sibling pairs using a fixed effects approach, which adjusts for shared family characteristics.

RESULTS

Maternal cortisol levels were negatively related to full-scale IQ, an effect driven by verbal IQ scores. Compared with those in the lowest quintile of cortisol exposure, the verbal IQ of children in the highest quintile of exposure was 3.83 points lower [95% confidence interval (CI): -6.44 to -1.22]. Within sibling pairs, being in the highest quintile of exposure was associated with verbal IQ scores 5.5 points lower (95% CI: -11.24 to 0.31) compared with the other quintiles.

CONCLUSION

These findings are consistent with prior human and animal studies, and suggest that exposure to high levels of maternal cortisol during pregnancy may be negatively related to offspring cognitive skills independently of family attributes that characterize the postnatal environment.

The effect of pre-existing vulnerability factors on a laboratory analogue trauma experience

This study examined how pre-existing emotional and personality vulnerability factors affect responses to an analogue trauma experience. Sixty-eight undergraduate participants viewed a distressing film and completed measures of trait anxiety, intelligence, depression, trait dissociation, as well as changes in state anxiety, then recorded intrusions over the following week. Results revealed that trait anxiety, depression, trait dissociation, change in anxiety, and post-state anxiety were associated with intrusion frequency. Post-state anxiety mediated the relationship between trait anxiety, depression and trait dissociation, and intrusions. Implications for PTSD theories and laboratory trauma analogue research examining specific elements of cognitive models of PTSD are discussed.

Learning and memory impairment in PTSD: relationship to depression

Memory function was studied in combat veterans with posttraumatic stress disorder (PTSD), combat veterans without PTSD, and noncombat veterans. The Vocabulary and Digit Span subtests of the WAIS and Logical Memory (LMS) and Verbal Paired Associates (VPAS) subtests of the Wechsler Memory Scale III were administered. Combat veterans with PTSD showed impaired memory on the LMS and VPAS compared to combat veterans without PTSD or noncombat veterans. Veterans with PTSD also showed lower WAIS Vocabulary subtest scores--but not digit span subtest scores--than combat veterans without PTSD or noncombat veterans. Medication status, co-morbid diagnosis, and age all failed to account for these memory differences, but when self-assessed depression--as measured by the Zung Self-Rating Depression Scale--or anxiety--as measured by the Spielberger State-Trait Anxiety Scale--was statistically removed, group differences on these memory measures were no longer significant. However, using a stepwise regression procedure, in which both anxiety and depression were employed to predict the LMS and VPAS scores, only the Zung scale reliably predicated performance. The present results, showing that PTSD is associated with general learning and memory impairments, is an important finding, but the specific effects of depression as a mediator of these deficits should be further studied.

IQ and posttraumatic stress symptoms in children exposed to interpersonal violence

BACKGROUND

The literature is mixed as to the relationship between intelligence quotient (IQ) and Posttraumatic Stress Disorder (PTSD) symptomatology in adult populations. Even less is known about the relationship in children who have been traumatized.

METHODS

Fifty-nine children and adolescents (mean age = 10.6) with a history of interpersonal violence were evaluated with respect to PTSD symptomatology, number of traumas, and estimated Verbal, Performance and Full scale IQ scores. PTSD symptomatology included symptom levels for cluster B (re-experiencing), cluster C (avoidance and numbing), and cluster D (Hypervigilance) and criterion F, functional impairment.

RESULTS

Results indicated that Full scale and Verbal IQ were significantly associated with the number of traumas, re-experiencing symptoms, and impairment. Performance IQ was only associated with impairment. Regression analyses suggested that together PTSD symptomatology predicted Full scale and Verbal IQ but nor Performance IQ and impairment was the single best predictor of IQ generally.

CONCLUSIONS

Findings provide support for an association between PTSD symptoms and IQ, particularly verbal IQ. Two possible reasons for this relationship are that higher levels of Verbal IQ may serve as a premorbid protective factor against the development of re-experiencing symptoms, or performance on post-trauma Verbal IQ measures may be negatively impacted by expression of PTSD symptoms. Longitudinal studies are needed to clarify which of these two possibilities explains the association.

The intellectual performance of traumatized children and adolescents with or without posttraumatic stress disorder

This study compared the Wechsler Intelligence Scale for Children-III (WISC-III) scores of traumatized youth with posttraumatic stress disorder (PTSD) to the scores of trauma-exposed and nonexposed comparison groups without PTSD. All groups were free of additional major childhood psychiatric disorders. The PTSD group scored significantly lower than the comparison groups on verbal subtests, but not on performance subtests. The scores of the trauma-exposed PTSD negatives and nontrauma exposed controls were not significantly different. Accordingly, PTSD and not a history of trauma exposure in the absence of PTSD was associated with lower verbal IQ.

An analogue study of intrusions

According to cognitive theorists, intrusive trauma memories have their origin in how information during the event is processed. Two studies investigated functional cognitive strategies during medical crises that might protect against intrusions. In Study 1, interviews with health-care professionals were used to identify cognitive strategies judged to be effective in controlling emotions and dealing with medical crises. Study 2 systematically manipulated the use of those strategies in a trauma analogue film paradigm. Experimental participants reported fewer intrusions, and less fear and avoidance of film-related stimuli during the subsequent week than controls. The manipulation did not affect anxiety during the film or memory disorganization. Implications for cognitive theories of intrusion development are discussed.

The impact of the 1991 Gulf War on the mind and brain: findings from neuropsychological and neuroimaging research

Many veterans of the 1991 Gulf War (GW) have complained of somatic and cognitive symptoms that may be neurological in nature. However, whether or not changes in brain function are associated with GW service continues to be debated. Studies of GW veterans using objective, performance-based neuropsychological measures have yielded inconsistent findings, with those indicating deficits among GW veterans typically revealing only relatively mild levels of neuropsychological impairment. Further, performances on objective neuropsychological tasks show little correspondence to subjective perceptions of cognitive functioning. Although preliminary magnetic resonance spectroscopy (MRS) studies demonstrate reduced N-acetylaspartate-to-creatine (NAA/Cr) ratio in select brain regions among GW veterans who report health concerns, this work requires further replication with larger, more representative samples. There is no evidence from neuroimaging studies of a non-specific effect of GW service or of changes in brain structure or function related to health status when conventional radiological methods are used. Owing to the paucity of objective exposure, baseline health data, and the now significant time elapsed since the GW, aetiological issues may never be fully resolved. Therefore, research addressing clinical management of GW veterans with neuropsychological dysfunction and neuroimaging abnormalities may prove more fruitful than exclusive focus on aetiology.

Retrieval and emotional processing of traumatic memories in posttraumatic stress disorder: Peripheral and central correlates

Posttraumatic stress disorder (PTSD) is thought to be characterized by dysfunctional memory processes, i.e., the automatic re-experiencing of the traumatic event and the inability to consciously recall facts about the traumatic event, as well as altered emotional processing of trauma-relevant cues. The present study examined the cerebral mechanisms underlying the cued recall of trauma-specific memories and the emotional processing of the presented cues in 16 PTSD patients, 15 trauma-exposed subjects without PTSD and 16 healthy controls. Subjects received questions about their specific trauma as well as other disastrous and neutral events while the electroencephalogram and heart rate were measured. The PTSD patients showed no impairment in trauma-specific declarative memory compared to non-PTSD subjects but had some deficits in general declarative memory as assessed by the Wechsler Memory Scale-Revised. Compared to healthy control subjects, PTSD patients displayed increased P300 and late positive complex amplitudes to trauma-specific questions, indicating enhanced emotional processing of these cues. In line with their behavioral performance, both trauma-exposed groups showed decreased terminal contingent negative variation amplitudes to trauma-specific questions over frontal electrodes reflecting altered memory retrieval. Within-group comparisons revealed that only the PTSD group but not the other groups showed a differentiation between trauma-specific and neutral questions with respect to the LPC, tCNV and P300. Concordantly with previous studies, PTSD patients showed elevated resting heart rate compared to the healthy controls. These findings are discussed in the context of current models of the role of declarative memory in the development and maintenance of PTSD.

Progress and controversy in the study of posttraumatic stress disorder

Research on posttraumatic stress disorder (PTSD) has been notable for controversy as well as progress. This article concerns the evidence bearing on the most contentious issues in the field of traumatic stress: broadening of the definition of trauma, problems with the dose-response model of PTSD, distortion in the recollection of trauma, concerns about "phony combat vets," psychologically toxic guilt as a traumatic stressor, risk factors for PTSD, possible brain-damaging effects of stress hormones, recovered memories of childhood sexual abuse, and the politics of trauma.

Psychological mechanisms in acute response to trauma

Traumatic events are common, but posttraumatic stress disorder (PTSD) is relatively rare. These facts have prompted several questions: What variables increase risk for PTSD among trauma-exposed people? Can we distinguish between pathologic and nonpathologic responses to traumatic stressors? If so, what psychobiological mechanisms mediate pathologic responses? Prospective studies have identified certain individual difference variables as heightening risk (e.g., lower intelligence, negative personality traits). Studies on peritraumatic and acute-phase response have identified certain dissociative symptoms (e.g., time slowing, derealization) and cognitive appraisal (e.g., belief that one is about to die) as harbingers of later PTSD. Negative appraisal of acute symptoms themselves may foster chronic morbidity (e.g., that symptoms signify shameful moral weakness or prefigure impending psychosis). Further attempts to elucidate pathologic mechanisms in the cognitive psychology laboratory and via biological challenges are warranted.

Attention, learning, and memory performances and intellectual resources in Vietnam veterans: PTSD and no disorder comparisons

Attention, learning, memory, and estimated intellectual potential were examined in 26 Vietnam veterans diagnosed with posttraumatic stress disorder (PTSD) and in 21 Vietnam veterans without mental disorders. Results revealed PTSD-associated cognitive deficits on tasks of sustained attention, working memory, initial learning, and estimated premorbid intelligence but not on measures of focus of attention, shift of attention, or memory savings. Cognitive task performances adjusted for estimated native intelligence remained negatively correlated with PTSD severity. An intellectual measure adjusted for cognitive task performances was negatively correlated with PTSD severity, even after the authors statistically controlled the level of combat exposure. Results suggested that although intellectual resources may constitute a vulnerability-protective factor for PTSD development, PTSD was associated with cognitive impairment independent of intellectual functioning.

Neuropsychological function in Gulf War veterans: relationships to self-reported toxicant exposures

BACKGROUND

The present study was aimed at (1) exploring evidence of central nervous system (CNS) dysfunction among Gulf War (GW) veterans on neuropsychological tests and (2) examining whether performance on neuropsychological tests was related to specific neurotoxicant exposures experienced in the Gulf.

METHODS

The GW-deployed groups were selected using stratified random sampling methods from two distinct cohorts of GW veterans. A comparison group that had been called up for GW service but deployed to Germany rather than the Gulf also was examined. Neuropsychological function was assessed using a pre-determined battery chosen to include tests known to be highly sensitive to the behavioral effects of the neurotoxicants thought to have been present in the Gulf.

RESULTS

Self-reported exposures were related to neuropsychological test performance controlling for post-traumatic stress disorder, major depression, and other known covariates of neuropsychological test performance. Results showed that GW-deployed veterans performed more poorly than the Germany-deployed veterans on several specific neuropsychological tests, but after adjustment for multiple comparisons, only the differences in mood complaints remained significant. Within the GW-deployed group, self-reported exposure to chemical warfare agents was associated with poorer performance on cognitive tests involving specific functional domains.

CONCLUSIONS

Results provide evidence that there are subtle differences in CNS function among GW-deployed veterans who report chemical warfare agent exposure while in the GW theater.

Meta-analysis of risk factors for posttraumatic stress disorder in trauma-exposed adults

Meta-analyses were conducted on 14 separate risk factors for posttraumatic stress disorder (PTSD), and the moderating effects of various sample and study characteristics, including civilian/military status, were examined. Three categories of risk factor emerged: Factors such as gender, age at trauma, and race that predicted PTSD in some populations but not in others; factors such as education, previous trauma, and general childhood adversity that predicted PTSD more consistently but to a varying extent according to the populations studied and the methods used; and factors such as psychiatric history, reported childhood abuse, and family psychiatric history that had more uniform predictive effects. Individually, the effect size of all the risk factors was modest, but factors operating during or after the trauma, such as trauma severity, lack of social support, and additional life stress, had somewhat stronger effects than pretrauma factors.

Apparent symptom overreporting in combat veterans evaluated for PTSD

Psychometric studies have consistently shown that combat veterans evaluated for posttraumatic stress disorder (PTSD) appear to overreport psychopathology as exhibited by (a) extreme and diffuse levels of psychopathology across instruments measuring different domains of mental illness, and (b) extreme elevations on the validity scale of the MMPI-MMPI-2, in a "fake-bad" direction. The phenomenon of this ubiquitous presentational style is not well understood at present. In this review we describe and delineate the assessment problem posed by this apparent symptom overreporting, and we review the literature regarding several potential explanatory factors. Finally, we address conceptual and practical issues relevant to reaching a better understanding of the phenomenon, and ultimately the clinical syndrome of combat-related PTSD, in both research and clinical settings.

Qualitative block design analysis in posttraumatic stress disorder

Qualitative and quantitative Block Design performance was examined in Vietnam combat veterans with PTSD diagnoses (n = 23) and Vietnam combat veterans without PTSD or other mental disorders diagnoses (n = 19). Results indicated that PTSD-diagnosed veterans committed more single block rotations than the comparison sample, and that their errors occurred more frequently in right hemispace than errors made by the comparison sample. The two groups did not differ in the number of configural errors made, errors committed in left hemispace, or in quantitative performance measures. Findings are suggestive of relative left hemisphere hypoactivation and are congruent with prior research documenting cerebral asymmetries in emotional disorders.

Head injury as a predictor of psychological outcome in combat veterans

Although it is recognized that psychosocial variables influence the expression of psychopathology following trauma exposure, physiological variables have received less attention as potential mediators of psychological outcome in trauma victims. The purpose of this study was to examine the relationship of head injury to psychological outcome in 171 combat veterans seeking compensation for service-connected disabilities for mental disorders attributed to etiologies other than head injury. Veterans underwent structured psychiatric diagnostic interview and completed self-report measures of combat exposure, posttraumatic stress disorder (PTSD), depression, and occurrence of head injury. Comparisons between veterans with and without history of head injury indicated that head injury was associated with more severe depression. Regression analysis suggested that head injury predicted depression, but not PTSD, severity.