Neuropsychological processes in post-traumatic stress disorder

Neurobiological associations between smoking and internalizing disorders

People with severe mental disorders have a higher mortality rate due to preventable conditions like cardiovascular diseases and respiratory diseases. Nicotine addiction is a preventable risk factor, with tobacco use being twice as high in people with mental disorders. An integrative model that divides mental disorders into externalising, internalising, and thought disorders could be useful for identifying common causalities and risk factors. This review aims to examine the interface between smoking and internalising disorders, specifically schizophrenia, depressive disorders, and anxiety disorders. The review finds that there is a clear association between smoking behaviour and these disorders. Schizophrenia is associated with polymorphisms that result in an imbalance between glutamate and GABA release and abnormalities of dopaminergic pathways. Nicotine improves dopaminergic signalling and balances glutamatergic and GABAergic pathways, improving symptoms and increasing the risk of nicotine dependence. In depressive disorders, smoking is associated with functional changes in brain regions affected by smoking and self-medication. In anxiety disorders, there is a bidirectional relationship with smoking, involving the amygdala and changes in dopaminergic pathways and cortisol production. Smoking poses a threat to people living with psychiatric disorders and calls for further research to assess the interactions between nicotine dependence and internalising and thought disorders.

Independent and Synergistic Associations Between TBI Characteristics and PTSD Symptom Clusters on Cognitive Performance and Postconcussive Symptoms in Iraq and Afghanistan Veterans

OBJECTIVE

The investigators sought to evaluate the independent and interactive associations between mild traumatic brain injury (mTBI) characteristics and posttraumatic stress disorder (PTSD) symptoms with regard to postconcussive symptoms and cognition among treatment-seeking veterans of the U.S. conflicts in Iraq and Afghanistan.

METHODS

Sixty-seven Iraq and Afghanistan veterans who had a history of mTBI and comorbid PTSD were grouped based on injury mechanism (blast versus nonblast) and number of lifetime mTBIs (one to two versus three or more). Independent associations between mTBI characteristics and PTSD symptom clusters were evaluated with regard to cognition and postconcussive symptoms. Follow-up analyses were conducted to determine any interactive associations between TBI characteristics and PTSD symptom clusters.

RESULTS

Higher PTSD symptoms, particularly hyperarousal, were associated with poorer executive functioning and higher postconcussive symptoms. No direct relationships were observed between PTSD symptom clusters and memory or processing speed. The relationship between hyperarousal and processing speed was moderated by lifetime mTBIs, such that those with a history of at least three mTBIs demonstrated a negative association between hyperarousal and processing speed. Blast-related mTBI history was associated with reduced processing speed, compared with non-blast-related mTBI. However, an interaction was observed such that among those with blast-related mTBI history, higher re-experiencing symptoms were associated with poorer processing speed, whereas veterans without history of blast-related mTBI did not demonstrate an association between processing speed and re-experiencing symptoms.

CONCLUSIONS

Higher hyperarousal and re-experiencing symptoms were associated with reduced processing speed among veterans with repetitive and blast-related mTBI history, respectively. PTSD symptoms, specifically hyperarousal, were associated with poorer executive functioning and higher postconcussive symptoms. Limited associations were found between injury characteristics and cognition chronically following mTBI. However, these results support synergistic effects of specific PTSD symptom clusters and TBI characteristics.

Dysregulation of inflammation, neurobiology, and cognitive function in PTSD: an integrative review

Compelling evidence from animal and human research suggest a strong link between inflammation and posttraumatic stress disorder (PTSD). Furthermore, recent findings support compromised neurocognitive function as a key feature of PTSD, particularly with deficits in attention and processing speed, executive function, and memory. These cognitive domains are supported by brain structures and neural pathways that are disrupted in PTSD and which are implicated in fear learning and extinction processes. The disruption of these supporting structures potentially results from their interaction with inflammation. Thus, the converging evidence supports a model of inflammatory dysregulation and cognitive dysfunction as combined mechanisms underpinning PTSD symptomatology. In this review, we summarize evidence of dysregulated inflammation in PTSD and further explore how the neurobiological underpinnings of PTSD, in the context of fear learning and extinction acquisition and recall, may interact with inflammation. We then present evidence for cognitive dysfunction in PTSD, highlighting findings from human work. Potential therapeutic approaches utilizing novel pharmacological and behavioral interventions that target inflammation and cognition also are discussed.

Neurocognitive markers of childhood abuse in individuals with PTSD: Findings from the INTRuST Clinical Consortium

To date, few studies have evaluated the contribution of early life experiences to neurocognitive abnormalities observed in posttraumatic stress disorder (PTSD). Childhood maltreatment is common among individuals with PTSD and is thought to catalyze stress-related biobehavioral changes that might impact both brain structure and function in adulthood. The current study examined differences in brain morphology (brain volume, cortical thickness) and neuropsychological performance in individuals with PTSD characterized by low or high self-reported childhood maltreatment, compared with healthy comparison participants. Data were drawn from the INjury and TRaUmatic STress (INTRuST) Clinical Consortium imaging repository, which contains MRI and self-report data for individuals classified as PTSD positive (with and without a history of mild traumatic brain injury [mTBI]), individuals with mTBI only, and healthy comparison participants. The final sample included 36 individuals with PTSD without childhood maltreatment exposure (PTSD, n = 30 with mTBI), 31 individuals with PTSD and childhood maltreatment exposure (PTSD + M, n = 26 with mTBI), and 114 healthy comparison participants without history of childhood maltreatment exposure (HC). The PTSD + M and PTSD groups demonstrated cortical thinning in prefrontal and occipital regions, and poorer verbal memory and processing speed compared to the HC group. PTSD + M participants demonstrated cortical thinning in frontal and cingulate regions, and poorer executive functioning relative to the PTSD and HC groups. Thus, neurocognitive features varied between individuals with PTSD who did versus did not have exposure to childhood maltreatment, highlighting the need to assess developmental history of maltreatment when examining biomarkers in PTSD.

Neurocognitive functioning over the course of trauma-focused psychotherapy for PTSD: Changes in verbal memory and executive functioning

OBJECTIVES

Individuals with post-traumatic stress disorder (PTSD) have neurocognitive deficits in verbal memory and executive functioning. In this study, we examined whether memory and executive functioning changed over the course of treatment and which clinical variables were associated with change.

DESIGN

Neuropsychological assessments were administered at baseline and endpoint of a randomized controlled trial as secondary outcome.

METHODS

Trauma survivors (n = 88) diagnosed with PTSD received trauma-focused psychotherapy within a 17-week randomized controlled trial. Neuropsychological tests were the California Verbal Learning Test, Rivermead Behavioural Memory Test, Stroop Color Word Test, and Trail Making Test.

RESULTS

Significant, small- to medium-sized improvements in verbal memory, information processing speed, and executive functioning were found after trauma-focused psychotherapy (Cohen's d 0.16-0.68). Greater PTSD symptom decrease was significantly related to better post-treatment neurocognitive performance (all p < .005). Patients with comorbid depression improved more than patients with PTSD alone on interference tasks (p < .01). No differences emerged between treatment conditions and between patients on serotonergic antidepressants and those who were not.

CONCLUSIONS

This study suggests that neurocognitive deficits in PTSD can improve over the course of trauma-focused psychotherapy and are therefore at least partly reversible. Improvements over treatment are in line with previous neuropsychological and neuroimaging studies and effect sizes exceed those of practice effects. Future research should determine whether these changes translate into improved functioning in the daily lives of the patients.

PRACTITIONER POINTS

Patients with PTSD have difficulties performing verbal memory tasks (e.g., remembering a grocery list, recall of a story) and executive functioning tasks (e.g., shifting attention between two tasks, ignoring irrelevant information to complete a task). Verbal memory, information processing speed, and executive functioning significantly improved in patients with post-traumatic stress disorder over the course of trauma-focused psychotherapy. Improvements were equal in size for two different trauma-focused psychotherapies (Eye movement desensitization and reprocessing therapy and brief eclectic psychotherapy for PTSD). Medium-sized effects were found for recall of a story, whereas effects in other aspects of verbal memory, information processing speed, and executive functioning were small-sized. No causal attributions can be made because we could not include a control group without treatment for ethical reasons. Findings may be more reflective of patients who completed treatment than patients who prematurely dropped out as completers were overrepresented in our sample.

Neuropsychological predictors of response to cognitive behavioral therapy for posttraumatic stress disorder in persons with severe mental illness

This study examined whether cognitive functioning was related to treatment outcomes in persons with severe mental illness who received a cognitive behavioral therapy (CBT) program for co-occurring posttraumatic stress disorder (PTSD). The study sample was drawn from a larger controlled trial of 108 persons with severe mental illness and PTSD comparing the effects of CBT with treatment as usual on PTSD and related outcomes, with assessments conducted at baseline, post-treatment, and 3- and 6-month follow-ups. Among the 54 persons in CBT, 49 were administered a neuropsychological battery at baseline and 40 were exposed to the CBT program. Statistical analyses of these 40 participants were conducted to evaluate whether cognitive functioning was related to participation in the CBT program, completion of homework assignments, and improvements in PTSD, and other outcomes. Cognitive functioning was not related to participation in CBT or completion of homework. Lower cognitive functioning predicted less learning of information about PTSD at post-treatment and follow-up, but not less clinical benefit from CBT in PTSD diagnosis or symptoms, other symptoms, or health. The results suggest that cognitive impairment does not attenuate response to the CBT for PTSD program in persons with severe mental illness. Clinical Trials.gov Identifier: NCT00053690.

Generalized Anxiety Disorder and Social Anxiety Disorder, but Not Panic Anxiety Disorder, Are Associated with Higher Sensitivity to Learning from Negative Feedback: Behavioral and Computational Investigation

Anxiety disorders, including generalized anxiety disorder (GAD), social anxiety disorder (SAD), and panic anxiety disorder (PAD), are a group of common psychiatric conditions. They are characterized by excessive worrying, uneasiness, and fear of future events, such that they affect social and occupational functioning. Anxiety disorders can alter behavior and cognition as well, yet little is known about the particular domains they affect. In this study, we tested the cognitive correlates of medication-free patients with GAD, SAD, and PAD, along with matched healthy participants using a probabilistic category-learning task that allows the dissociation between positive and negative feedback learning. We also fitted all participants' data to a Q-learning model and various actor-critic models that examine learning rate parameters from positive and negative feedback to investigate effects of valence vs. action on performance. SAD and GAD patients were more sensitive to negative feedback than either PAD patients or healthy participants. PAD, SAD, and GAD patients did not differ in positive-feedback learning compared to healthy participants. We found that Q-learning models provide the simplest fit of the data in comparison to other models. However, computational analysis revealed that groups did not differ in terms of learning rate or exploration values. These findings argue that (a) not all anxiety spectrum disorders share similar cognitive correlates, but are rather different in ways that do not link them to the hallmark of anxiety (higher sensitivity to negative feedback); and (b) perception of negative consequences is the core feature of GAD and SAD, but not PAD. Further research is needed to examine the similarities and differences between anxiety spectrum disorders in other cognitive domains and potential implementation of behavioral therapy to remediate cognitive deficits.

An analysis of inhibitory functioning in individuals with chronic posttraumatic stress disorder

Cognitive abnormalities in posttraumatic stress disorder (PTSD) may be a function of underlying inhibitory deficits. Prepulse inhibition (PPI) and attentional blink (AB) are paradigms thought to assess inhibition. Using a sample of 28 individuals with PTSD compared to 20 trauma-exposed and 19 healthy individuals, PPI was examined using white noise that was preceded by a tone, and AB was examined using a presentation of letters in a stream of numbers. Relative to the control group, the PTSD and trauma-exposed groups did not follow the u-shaped pattern in AB, suggesting trauma-exposure and subsequent PTSD are associated with similar impairment in attention. Individuals with PTSD showed reduced PPI compared to trauma-exposed and healthy individuals, suggesting individuals with PTSD exhibit faulty automatic processing. For individuals with PTSD, PTSD severity was associated with a decline in PPI. These findings suggest a general faulty inhibitory mechanism associated with trauma exposure and PTSD.

Effects of cortisol on cognition in major depressive disorder, posttraumatic stress disorder and borderline personality disorder - 2014 Curt Richter Award Winner

Stress hormones influence a wide range of cognitive functions, including memory performance and executive function. It is well established that glucocorticoids enhance memory consolidation but impair memory retrieval. While most of the effects have been attributed to glucocorticoid receptors (GR), the importance of mineralocorticoid receptors (MR) has been also emphasized. Dysfunctions in hypothalamic-pituitary-adrenal (HPA) axis have been reported for several mental disorders. While major depressive disorder (MDD) as well as borderline personality disorder (BPD) seem to be characterized by enhanced cortisol release in concert with a reduced feedback sensitivity of the HPA axis, in posttraumatic stress disorder (PTSD) a contrary picture has been reported. Despite the fact that altered GR function has been discussed for these disorders only very few studies have investigated the effects of glucocorticoids on cognitive performance in these patients so far. In a series of studies, we investigated the effects of glucocorticoids on cognition (i.e. declarative memory, working memory and response inhibition) in different mental disorders such as MDD, PTSD and BPD. While in patients with MDD cortisol administration failed to effect memory retrieval, patients with PTSD and BPD showed enhanced rather than impaired memory retrieval after cortisol administration. These results indicate an altered sensitivity to cortisol in these disorders. Results from one of our recent studies in the field of social cognition underline the importance of the MR. We found that emotional empathy was enhanced through stimulation of the MR via fludrocortisone in healthy participants and women with BPD. This review aims to integrate these findings and discuss potential mechanisms and implications.

A preliminary examination of cortical neurotransmitter levels associated with heavy drinking in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) patients have low cortical concentrations of γ-aminobutyric acid (GABA) and elevated glutamate (Glu) as measured by proton magnetic resonance spectroscopy ((1)H MRS). Alcohol use disorder (AUD) is highly comorbid with PTSD, but the neurobiological underpinnings are largely unknown. We wanted to determine if PTSD patients with AUD have normalized cortical GABA and Glu levels in addition to metabolite alterations common to AUD. We compared brain metabolite concentrations in 10 PTSD patients with comorbid AUD (PAUD) with concentrtations in 28 PTSD patients without AUD and in 20 trauma-exposed controls (CON) without PTSD symptoms. We measured concentrations of GABA, Glu, N-acetylaspartate (NAA), creatine- (Cr) and choline-containing metabolites (Cho), and myo-Inositol (mI) in three cortical brain regions using (1)H MRS and correlated them with measures of neurocognition, insomnia, PTSD symptoms, and drinking severity. In contrast to PTSD, PAUD exhibited normal GABA and Glu concentrations in the parieto-occipital and temporal cortices, respectively, but lower Glu and trends toward higher GABA levels in the anterior cingulate cortex (ACC). Temporal NAA and Cho as well as mI in the ACC were lower in PAUD than in both PTSD and CON. Within PAUD, more cortical GABA and Glu correlated with better neurocognition. Heavy drinking in PTSD is associated with partially neutralized neurotransmitter imbalance, but also with neuronal injury commonly observed in AUD.

Mediators of the relationship between life events and memory functioning in a community sample of adults

The present study examines the association of frequency and severity of life events with memory functioning in a community sample of adults. We tested the hypothesis that stress-related cognitive interference mediated the effects of recent life events on cognition, in addition to examining the potential roles of fatigue, sleep disturbances, and depression. The sample consisted of 310 adults (age range 19-83) who received a battery of cognitive tests assessing their primary memory, episodic memory, and working memory. Individuals rated how stressful previous life events were when they occurred, as well as how stressful the events were for them currently. Ratings of current, but not past severity were negatively associated with working memory performance. Both stress-related cognitive interference and depressive symptoms independently mediated this association. These findings highlight the importance of intrusive and avoidant thinking as a potential focus of psychosocial treatment for remediating stress-related memory dysfunction.

Apolipoprotein E gene polymorphism, alcohol use, and their interactions in combat-related posttraumatic stress disorder

BACKGROUND

The symptomatology of posttraumatic stress disorder (PTSD) is related not only to the intensity of the causative trauma, but also to alcohol use and genetic factors. Among the many candidate genes, the apolipoprotein E gene (APOE) is thought to be associated with stress reactivity.

METHODS

Korean veterans of the Vietnam War with (n = 128) or without (n = 128) PTSD participated in this study. The Clinician-Administered PTSD Scale and Combat Exposure Scale were administered, and the severity of alcohol use was assessed among these veterans. The APOE polymorphism and clinical variables of the subjects were compared, and associations between PTSD and potential explanatory variables were tested using logistic regression analysis.

RESULTS

Higher frequencies of APOE ε2 alleles and a greater number of individuals with the ε2 allele were found in the PTSD group. Among patients with PTSD, ε2-allele noncarriers consumed alcohol in greater amounts and more frequently than did ε2-allele carriers. Regression analysis revealed a significant interactional effect between harmful drinking and the absence of the ε2 allele associated with PTSD risk.

CONCLUSIONS

These results suggest that the APOE ε2 allele operates as a susceptibility gene for combat-related PTSD, with the relationship between alcohol use and PTSD differing according to the ε2-allele status. Future studies should determine the role of the APOE in adaptation to extreme stress, the development of PTSD, and comorbid alcohol-related disorders.

Current status on behavioral and biological markers of PTSD: a search for clarity in a conflicting literature

Extensive research has identified stereotypic behavioral and biological abnormalities in post-traumatic stress disorder (PTSD), such as heightened autonomic activity, an exaggerated startle response, reduced basal cortisol levels and cognitive impairments. We have reviewed primary research in this area, noting that factors involved in the susceptibility and expression of PTSD symptoms are more complex and heterogeneous than is commonly stated, with extensive findings which are inconsistent with the stereotypic behavioral and biological profile of the PTSD patient. A thorough assessment of the literature indicates that interactions among myriad susceptibility factors, including social support, early life stress, sex, age, peri- and post-traumatic dissociation, cognitive appraisal of trauma, neuroendocrine abnormalities and gene polymorphisms, in conjunction with the inconsistent expression of the disorder across studies, confounds attempts to characterize PTSD as a monolithic disorder. Overall, our assessment of the literature addresses the great challenge in developing a behavioral and biomarker-based diagnosis of PTSD.

Neuropsychological functions and visual contrast sensitivity in schizophrenia: the potential impact of comorbid posttraumatic stress disorder (PTSD)

Previous studies have revealed a high prevalence of posttraumatic stress disorder (PTSD) in patients with other severe mental disorders, including schizophrenia. However, the neuropsychological and psychophysical correlates of comorbid PTSD are less exactly defined. The purpose of the present study was to assess immediate and delayed memory, attention, visuospatial skills, language, and basic visual information processing in patients with schizophrenia with or without PTSD. We recruited 125 patients with schizophrenia and 70 healthy controls matched for visual acuity, age, gender, education, and socioeconomic status. Twenty-one of patients with schizophrenia exhibited comorbid PTSD. We administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and visual contrast sensitivity tasks for low spatial/high temporal frequency (0.3 cycle/degree and 18 Hz) and high spatial/low temporal frequency (10 cycles/degree and 1Hz) sinusoidal gratings. All patients were clinically stable and received antipsychotic medications. Results revealed that relative to healthy controls, patients with schizophrenia exhibited significant and generalized neuropsychological dysfunctions and reduced visual contrast sensitivity, which was more pronounced at low spatial/high temporal frequency. When we compared schizophrenia patients with and without PTSD, we found that patients with comorbid PTSD displayed lower scores for RBANS attention, immediate and delayed memory, and visuospatial scores. Schizophrenia patients with or without PTSD displayed similar visual contrast sensitivity. In conclusion, comorbid PTSD in schizophrenia may be associated with worse neuropsychological functions, whereas it does not affect basic visual information processing.

Affective state and cognitive functioning in patients with intracranial tumors: validity of the neuropsychological baseline assessment

OBJECTIVES

The aim of this paper is to investigate the relationship between the affective and cognitive states of neurooncological patients prior to the neurosurgical treatment to assess associations between distress levels and neuropsychological test performance in this sample and setting.

METHODS

The prospective study population consists of 172 patients. Patients were studied preoperatively with a comprehensive test battery consisting of a variety of affective and cognitive measures. Psychological instruments included the Hospital Anxiety and Depression Scale, the Amsterdam Preoperative Anxiety and Information Scale, and the Acute Stress Disorder Scale.

RESULTS

Factor analysis revealed two factors representing subjective affective functioning: whereas one reflects the patients' more general emotional state (Hospital Anxiety and Depression Scale, Acute Stress Disorder Scale), the second reflects anxiety specifically related to the neurosurgical procedure (Amsterdam Preoperative Anxiety and Information Scale). After age and education have been accounted for via linear regression analyses, affect did not contribute to cognitive performance in any of the cognitive domains in the whole patient sample. However, in patients with extreme levels of psychiatric morbidity, there was evidence for distinct cognitive morbidity consistent with previous research.

CONCLUSIONS

Our results suggest that, for a large variety of widely used neuropsychological measures and for most neurooncological patients, the preoperative neuropsychological baseline assessment can be considered valid and dependable. In patients with extreme levels of distress, however, distinct cognitive domains might be differentially affected.

Cortisol has enhancing, rather than impairing effects on memory retrieval in PTSD

BACKGROUND

In the present study, we aimed to compare the effect of exogenous cortisol on memory retrieval in posttraumatic stress disorder (PTSD) with the effects in healthy controls. In healthy participants, administration of cortisol impairs declarative memory retrieval. Only a few studies have investigated these effects in PTSD yielding mixed results.

METHODS

In a placebo-controlled crossover study, 44 patients with PTSD and 65 healthy controls received either placebo or 10mg of hydrocortisone orally before memory testing. In addition to declarative memory retrieval (word list learning), we also tested autobiographical memory retrieval specificity.

RESULTS

In both tasks opposing effects of cortisol on memory were observed when comparing patients with controls. In controls, cortisol had impairing effects on memory retrieval, while in PTSD patients cortisol had enhancing effects on memory retrieval in both memory domains.

CONCLUSIONS

The present results suggest beneficial effects of acute cortisol elevations on hippocampal mediated memory processes in PTSD. Possible neurobiological mechanisms underlying these findings are discussed.

Influence of acute psychological trauma on time estimation behaviour: a prospective pilot study

In addition to the symptom triad of intrusions, avoidance behaviour and hyperarousal, typical and frequent characteristics of acute and chronic posttraumatic disorders are neuropsychological disturbances of working memory and executive functions. So far, however, only a very limited number of studies have dealt with their effects on the capability to assess time-related information. The purpose of this prospective study therefore was to compare persons after an acute traumatic experience with healthy controls in the course of 12 months, focusing on their ability to estimate time as a measure of their readiness of attention. 39 participants aged 17-59 years (mean age = 35.1 years, who had experienced a traumatic event and exhibited symptoms of acute stress disorder) were compared with 38 healthy controls (mean age = 36.1 years) at eight times of measurement within a period of 12 months. Performance was determined by means of a prospective time estimation task. The participants had to estimate a time interval of 5 s, once with and once without feedback about the quality of the estimates. The time estimates by the traumatised persons were significantly less precise than those by the control group. Progress analyses have shown that trauma patients exhibit larger deviations from the defined time interval, both under feedback conditions and without feedback. Psychological traumatisation leads to both an acute and long-term, demonstrable impairment of time estimation ability. The recognizable disturbance of information processing may both be a cause and a result of clinical trauma symptoms.

The contributions of self-reported injury characteristics and psychiatric symptoms to cognitive functioning in OEF/OIF veterans with mild traumatic brain injury

Mild traumatic brain injury (mTBI) affects a significant number of combat veterans returning from Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF). Although resolution of mTBI symptoms is expected over time, some individuals continue to report lingering cognitive difficulties. This study examined the contributions of self-reported mTBI injury characteristics (e.g., loss of consciousness, post-traumatic amnesia) and psychiatric symptoms to both subjective and objective cognitive functioning in a sample of 167 OEF/OIF veterans seen in a TBI clinic. Injury characteristics were not associated with performance on neuropsychological tests but were variably related to subjective ratings of cognitive functioning. Psychiatric symptoms were highly prevalent and fully mediated most of the relationships between injury characteristics and cognitive ratings. This indicates that mTBI characteristics such as longer time since injury and loss of consciousness or post-traumatic amnesia can lead to increased perceived cognitive deficits despite having no objective effects on cognitive performance. Psychiatric symptoms were associated with both cognitive ratings and neuropsychological performance, illustrating the important role that psychiatric treatment can potentially play in optimizing functioning. Finally, subjective cognitive ratings were not predictive of neuropsychological performance once psychiatric functioning was statistically controlled, suggesting that neuropsychological assessment provides valuable information that cannot be gleaned from self-report alone.

The effects of child abuse and neglect on cognitive functioning in adulthood

AIMS

Recent research has revealed that early life trauma (ELS), including abuse (sexual and/or physical) and neglect, produce lasting changes in the CNS. We posited that cognitive deficits, often observed in psychiatric patients, result, in part, due to the neurobiological consequences of ELS. Additionally, we hypothesized that the nature and magnitude of cognitive deficits would differ according to the subtype of ELS experienced.

METHOD

The Cambridge Neuropsychological Test Automated Battery (CANTAB) was used to assess neurocognitive functioning in 93 subjects (60 with ELS and 33 without). In the patients with a history of ELS, 35% and 16.7%, respectively, met criteria for current major depression and PTSD.

RESULTS

Significant associations between ELS status and CANTAB measures of memory and executive and emotional functioning were found.

CONCLUSIONS

These data suggest that exposure to ELS results in a cascade of neurobiological changes associated with cognitive deficits in adulthood that vary according to the type of trauma experienced.

Neuropsychological and neuroimaging findings in traumatic brain injury and post-traumatic stress disorder

Advances in imaging technology, coupled with military personnel returning home from Iraq and Afghanistan with traumatic brain injury (TBI) and/or post-traumatic stress disorder (PTSD), have increased interest in the neuropsychology and neurobiology of these two conditions. There has been a particular focus on differential diagnosis. This paper provides an overview of findings regarding the neuropsychological and neurobiological underpinnings of TBI and for PTSD. A specific focus is on assessment using neuropsychological measures and imaging techniques. Challenges associated with the assessment of individuals with one or both conditions are also discussed. Although use of neuropsychological and neuroimaging test results may assist with diagnosis and treatment planning, further work is needed to identify objective biomarkers for each condition. Such advances would be expected to facilitate differential diagnosis and implementation of best treatment practices.

Assessment of cognitive functions in individuals with post-traumatic symptoms after work-related accidents

The investigation of cognitive functions in individuals who developed post-traumatic symptoms after occupational accidents has been overlooked in the relevant literature. The present study was aimed at assessing attention, memory and executive functions in individuals with post-traumatic symptoms after a workplace accident. Moreover, possible presence of emotional interference from trauma-related cues on attentional performance was evaluated. Results showed that injured workers exhibited deficits in perceptual-psychomotor skills, executive functions, attention and concentration abilities, and memory as compared with healthy controls. With regards to emotional interference on attention, injured workers were found to perform significantly worse than controls specifically when exposed to trauma-related pictures. Overall, these findings suggest that post-traumatic symptoms following a workplace accident are associated with several cognitive and emotional dysfunctions, that should be carefully evaluated to help reduce the frequency and the adverse consequences of occupational accidents.

Cognitive dysfunction in post-traumatic obsessive-compulsive disorder

OBJECTIVE

To investigate whether patients who develop obsessive-compulsive disorder (OCD) after posttraumatic stress disorder, i.e. post-traumatic OCD (PsT-OCD), display a distinctive neurocognitive pattern of dysfunction.

METHODS

Patients with PsT-OCD (n = 16), pre-traumatic OCD (PrT-OCD) (n = 18), non-traumatic OCD (NonT-OCD) (n = 67) and healthy controls (n = 17) had their performance compared on the following neuropsychological tests: the Wisconsin Card Sorting Test, the Iowa Gambling Task, the Wechsler Memory Scale Logical Memory, the Brief Visual Memory Test - Revised, and the Wechsler Abbreviated Scale for Intelligence.

RESULTS

Patients with OCD, as a group, were characterized by poor set-shifting abilities and impaired verbal and visuospatial memories. Impaired set-shifting abilities were found to correlate with the severity of obsessive-compulsive symptoms in all groups of patients with OCD, with the exception of PsT-OCD. Only patients with PsT-OCD were characterized by impaired visuospatial recognition, which was found to correlate with poor set-shifting abilities in this particular group of patients, but not in individuals with other types of OCD or in healthy controls.

CONCLUSIONS

Our study suggests that PsT-OCD is associated with a distinctive pattern of neurocognitive dysfunction, thus providing support for a different subtype of OCD.

Glucocorticoid augmentation of prolonged exposure therapy: rationale and case report

RATIONALE

Prolonged exposure (PE) therapy has been found to reduce symptoms of posttraumatic stress disorder (PTSD); however, it is difficult for many patients to engage fully in the obligatory retelling of their traumatic experiences. This problem is compounded by the fact that habituation and cognitive restructuring - the main mechanisms through which PE is hypothesized to work - are not instantaneous processes, and often require several weeks before the distress associated with imaginal exposure abates.

CASE REPORTS

Two cases are described that respectively illustrate the use of hydrocortisone and placebo, in combination with PE, for the treatment of combat-related PTSD. Based on known effects of glucocorticoids on learning and memory performance, we hypothesized that augmentation with hydrocortisone would improve the therapeutic effects of PE by hastening "new" learning and facilitating decreases in the emotional impact of fear memories during the course of treatment. The veteran receiving hydrocortisone augmentation of PE displayed an accelerated and ultimately greater decline in PTSD symptoms than the veteran receiving placebo.

CONCLUSIONS

While no general conclusion can be derived from comparison of two patients, the findings are consistent with the rationale for augmentation. These case reports support the potential for an appropriately designed and powered clinical trial to examine the efficacy of glucocorticoids in augmenting the effects of psychotherapy for PTSD.

HPA axis alterations in mental disorders: impact on memory and its relevance for therapeutic interventions

Dysfunctions in hypothalamic-pituitary-adrenal (HPA) axis have been reported for several mental disorders that are also often characterized by memory disturbances. It is now well established that glucocorticoids influence cognitive processes by enhancing memory consolidation and impairing memory retrieval. There is further evidence for an association between HPA axis related disturbances and memory function in mental disorders. The present selective review provides a brief overview of HPA axis dysfunction and its impact on memory function in major depressive disorder, posttraumatic stress disorder, and borderline personality disorder. Furthermore, the relevance of these findings for therapeutic intervention is discussed.

Cognitive functioning in a population-based sample of young adults with anxiety disorders

OBJECTIVE

Cognitive functioning in anxiety disorders has received little investigation, particularly among young adults and in non-clinical samples. The present study examined cognitive functioning in a population-based sample of young adults with anxiety disorders in comparison to healthy peers.

METHODS

A population-based sample of 21-35-year-olds with a lifetime history of anxiety disorders (n=75) and a random sample of healthy controls (n=71) derived from the same population were compared in terms of performance in neuropsychological tests measuring verbal and visual short-term memory, verbal long-term memory, attention, psychomotor processing speed, and executive functioning.

RESULTS

In general, young adults with anxiety disorders did not have major cognitive impairments when compared to healthy peers. When participants with anxiety disorder in remission were excluded, persons with current anxiety disorder scored lower in visual working memory tests. Current psychotropic medication use and low current psychosocial functioning associated with deficits in executive functioning, psychomotor processing speed, and visual short-term memory.

CONCLUSION

Lifetime history of anxiety disorders is not associated with cognitive impairment among young adults in the general population. However, among persons with anxiety disorders, current psychotropic medication use and low psychosocial functioning, indicating more severe symptoms, may associate with cognitive impairments.

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.

Cognitive impairment and functioning in PTSD related to intimate partner violence

Posttraumatic stress disorder (PTSD) has been associated with neuropsychological impairments across multiple domains, but consensus regarding the cognitive profile of PTSD has not been reached. In this study of women with PTSD related to intimate partner violence (n = 55) and healthy, demographically similar comparison participants (NCs; n = 20), we attempted to control for many potential confounds in PTSD samples. All participants were assessed with a comprehensive neuropsychological battery emphasizing executive functioning, including inhibition, switching, and abstraction. NCs outperformed PTSD participants on most neuropsychological measures, but the differences were significant only on speeded tasks (with and without executive functioning components). The PTSD group's mean performance was within the average range on all neuropsychological tests. Within the PTSD group, more severe PTSD symptoms were associated with slower processing speed, and more severe dissociative symptoms were associated with poorer reasoning performance. These results suggest that women with PTSD related to intimate partner violence demonstrate slower than normal processing speed, which is associated with the severity of psychiatric symptoms. We speculate that the cognitive slowing seen in PTSD may be attributable to reduced attention due to a need to allocate resources to cope with psychological distress or unpleasant internal experiences.

Neuropsychological functioning in children with posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) has been associated with deficits in the areas of verbal memory and learning, executive functioning, working memory, and attention in adults. Findings have been less consistent in the few studies examining neuropsychological functioning in childhood PTSD, which are often limited by comparing children with PTSD to children without trauma histories, making it unclear whether observed neuropsychological deficits are related to trauma exposure or to PTSD symptomatology. In an ethnically diverse sample of 62 children who witnessed intimate partner violence (n = 27 PTSD+ and 35 PTSD-), children with PTSD exhibited slower and less effective learning, heightened sensitivity to interference, and impaired effect of rehearsal on memory acquisition on the California Verbal Learning Test - Children's Version, a word list learning task. Both groups performed in the below average range on measures of executive functioning, attention, and intellectual ability.

Alexithymia, absorption, and cognitive failures in depersonalization disorder: a comparison to posttraumatic stress disorder and healthy volunteers

Alexithymia, absorption, and cognitive failures are traits that have been implicated in dissociative psychopathology. Forty-six participants with depersonalization disorder (DPD), 21 with posttraumatic stress disorder, and 35 healthy controls completed measures of dissociation, alexithymia, absorption, cognitive failures, and childhood trauma. The DPD and posttraumatic stress disorder groups had significantly and comparably elevated absorption and cognitive failures scores. Only the DPD group had significantly elevated alexithymia scores, specifically in "difficulty identifying feelings." Regression analyses revealed that "alexithymia-difficulty identifying feelings" was predictive of both DPD diagnosis and depersonalization scores. In contrast, amnesia scores were predicted by childhood trauma and absorption. In conclusion, the link between depersonalization and alexithymia appeared to be specific rather than broadly related to early trauma or to trauma-spectrum psychopathology.

Ameliorating prefrontal cortical dysfunction in mental illness: inhibition of phosphotidyl inositol-protein kinase C signaling

BACKGROUND

Bipolar disorder and schizophrenia are associated with profound dysfunction of the prefrontal cortex (PFC), with bipolar disorder most associated with changes in ventromedial PFC and schizophrenia more associated with changes in dorsolateral PFC.

DISCUSSION

Recent genetic and biochemical studies have also linked these illnesses to disinhibition of phosphotidyl inositol-protein kinase C signaling. For example, DAG kinase eta, an enzyme that metabolizes DAG and thus reduces protein kinase C activity, is the gene most altered in bipolar disorder. Similarly, regulator of G protein signaling 4 is the molecule most altered in the PFC of patients with schizophrenia, and this molecule normally serves to inhibit Gq signaling. Animal studies have shown that high levels of phosphotidyl inositol-protein kinase C signaling in the PFC markedly impair PFC function at the behavioral and cellular levels. Most importantly, many effective medications for bipolar disorder and schizophrenia inhibit phosphotidyl inositol-protein kinase C signaling, either through intracellular actions (lithium, valproate) or through extracellular blockade of receptors coupled to this pathway (5HT2 receptors and alpha-1 adrenoceptors). Recent data suggest that lithium and valproate can protect gray matter in patients with bipolar disorder. These findings encourage the development of protein kinase C inhibitors for the treatment of mental illness.

Molecular mechanisms of stress-induced prefrontal cortical impairment: implications for mental illness

The symptoms of mental illness often involve weakened regulation of thought, emotion, and behavior by the prefrontal cortex. Exposure to stress exacerbates symptoms of mental illness and causes marked prefrontal cortical dysfunction. Studies in animals have revealed the intracellular signaling pathways activated by stress exposure that induce profound prefrontal cortical impairment: Excessive dopamine stimulation of D1 receptors impairs prefrontal function via cAMP intracellular signaling, leading to disconnection of prefrontal networks, while excessive norepinephrine stimulation of alpha1 receptors impairs prefrontal function via phosphatidylinositol-protein kinase C intracellular signaling. Genetic studies indicate that the genes disrupted in serious mental illness (bipolar disorder and schizophrenia) often encode for the intracellular proteins that serve as brakes on the intracellular stress pathways. For example, disrupted in schizophrenia 1 (DISC1) normally regulates cAMP levels, while regulator of G protein signaling 4 (RGS4) and diacylglycerol kinase (DGKH)-the molecule most associated with bipolar disorder- normally serve to inhibit phosphatidylinositol-protein kinase C intracellular signaling. Patients with mutations resulting in loss of adequate function of these genes likely have weaker endogenous regulation of these stress pathways. This may account for the vulnerability to stress and the severe loss of PFC regulation of behavior, thought, and affect in these illnesses. This review highlights the signaling pathways onto which genetic vulnerability and stress converge to impair PFC function and induce debilitating symptoms such as thought disorder, disinhibition, and impaired working memory.

Does the evocation of traumatic memories confound subsequent working memory performance in posttraumatic stress disorder (PTSD)?

The role of heightened arousal has been previously discussed as a contributor to neurocognitive impairment in posttraumatic stress disorder (PTSD). To investigate whether psychological effects (distraction, re-location of resources) elicited by the evocation of traumatic memories impact on subsequent cognitive performance in PTSD, two parallel versions of a working memory task were administered to 33 trauma-exposed participants (15 with and 18 without PTSD). Between first and second working memory assessment a trauma-related interview was conducted including the narration of the trauma. Levels of working memory impairment in PTSD patients remained unchanged. This study provides preliminary evidence that neurocognitive impairment is not secondary to psychological effects induced by the evocation of traumatic memories. Nevertheless, it is recommended that future PTSD research should devote more care to the order in which trauma-related and other dependent variables such as cognitive tests are presented to participants.

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.

A neurocognitive model of borderline personality disorder: effects of childhood sexual abuse and relationship to adult social attachment disturbance

Borderline personality disorder (BPD) is a paradigmatic disorder of adult attachment, with high rates of antecedent childhood maltreatment. The neurocognitive correlates of both attachment disturbance and maltreatment are both presently unknown in BPD. This study evaluated whether dimensional adult attachment disturbance in BPD is related to specific neurocognitive deficits, and whether childhood maltreatment is related to these dysfunctions. An outpatient BPD group (n=43) performed nearly 1 SD below a control group (n=26) on short-term recall, executive, and intelligence functions. These deficits were not affected by emotionally charged stimuli. In the BPD group, impaired recall was related to attachment-anxiety, whereas executive dysfunction was related to attachment-avoidance. Abuse history was correlated significantly with executive dysfunction and at a trend level with impaired recall. Neurocognitive deficits and abuse history exhibited both independent and interactive effects on adult attachment disturbance. These results suggest that (a) BPD patients' reactivity in attachment relationships is related to temporal-limbic dysfunction, irrespective of the emotional content of stimuli, (b) BPD patients' avoidance within attachment relationships may be a relational strategy to compensate for the emotional consequences of frontal-executive dysregulation, and (c) childhood abuse may contribute to these neurocognitive deficits but may also exert effects on adult attachment disturbance that is both independent and interacting with neurocognitive dysfunction.

Disruption of bradycardia associated with discriminative conditioning in combat veterans with PTSD

The effects of combat-related posttraumatic stress disorder (PTSD) on heart rate (HR) responding associated with a discriminative delay eyeblink (EB) conditioning paradigm are reported. Combat PTSD+, Combat PTSD-, and Noncombat PTSD- veterans were assessed with psychometric self-report measures, and baseline heart rate variability (HRV) was measured before receiving a 72-trial session of discriminative EB classical conditioning. Two types (red or green light) of conditioned stimuli (CS) were used: one (CS+) predicted a tone, followed immediately by an aversive stimulus (corneal airpuff); the other (CS-) predicted a tone alone, not followed by the airpuff. The light signal was presented for 5 seconds, during which HR was measured. On all psychometric measures, the PTSD+ subgroup was significantly different from the PTSD- subgroups (Combat + Noncombat), and the PTSD- subgroups did not significantly differ from each other. A linear deceleration in HR to CS+ and CS- signals was found in the combined PTSD- subgroup and on CS- trials in the PTSD+ subgroup, but was not present on CS+ trials in the PTSD+ subgroup. Results are interpreted with respect to a behavioral stages model of conditioned bradycardia and in terms of neural substrates which are both critical to HR conditioning and known to be abnormal in PTSD.

A review on cognitive impairments in depressive and anxiety disorders with a focus on young adults

BACKGROUND

There is growing evidence for cognitive dysfunction in depressive and anxiety disorders. Nevertheless, the neuropsychological profile of young adult patients has not received much systematic investigation. The following paper reviews the existing literature on cognitive impairments in depressive and anxiety disorders particularly among young adults. Additionally, the focus of young adult age group and the effect of confounding variables on study results are discussed.

METHODS

Electronic database searches were conducted to identify research articles focusing on cognitive impairments in depressive or anxiety disorders among young adults published in English during years 1990-2006.

RESULTS

Cognitive impairments are common in young adults with major depression and anxiety disorders, although their nature remains partly unclear. Accordingly, executive dysfunction is evident in major depression, but other more specific deficits appear to depend essentially on disorder characteristics. The profile of cognitive dysfunction seems to depend on anxiety disorder subtype, but at least obsessive-compulsive disorder is associated with deficits in executive functioning and visual memory. The conflicting results may be explained by heterogeneity within study participants, such as illness status, comorbid mental disorders, and medication, and other methodological issues, including inadequate matching of study groups and varying testing procedures.

LIMITATIONS

The study is a comprehensive review, but not a formal meta-analysis, due to methodological heterogeneity.

CONCLUSIONS

Cognitive impairments are common in major depression and anxiety disorders. However, more research is needed to confirm and widen these findings, and to expand the knowledge into clinical practice. Controlling of confounding variables in future studies is highly recommended.

Deficits in visual functions and neuropsychological inconsistency in Borderline Personality Disorder

For Borderline Personality Disorder (BPD) cognitive and perceptual impairments were reported in some but not all studies. The aim of the present study was to analyze the neuropsychological performance of BPD patients in different domains. Predominant impairments of visual functions and an increased intra-individual variation of test performances within neuropsychological domains were expected. We investigated 22 patients with BPD and a matched sample of 22 healthy control subjects. A comprehensive clinical and neuropsychological test battery was administered. Effect sizes indicate primarily deficits of visual functions such as visual memory (Wechsler Memory Scale-Revised, WMS-R: Visual pair associates and visual reproduction, Complex Figure Test: Recall) and visuo-spatial abilities (Leistungspruefsystem, LPS 9 and 10: Spatial imagination and embedded figures), but also of executive functions (Tower of Hanoi, Trail Making Test-B, semantic and figural fluency, LPS 4: Reasoning). In addition, the intra-individual ranges of neuropsychological test results in BPD patients were increased compared to those of healthy subjects. This finding might be due to a high degree of temporary stress that interferes with effective cognitive processing. Further research is needed to confirm the present results and to control for stress during the test procedure.

Neuropsychological functioning in posttraumatic stress disorder and alcohol abuse

Studies have shown differences in neuropsychological functioning between groups with posttraumatic stress disorder (PTSD) and control participants. Because individuals with PTSD often have a history of comorbid alcohol abuse, the extent to which an alcohol confound is responsible for these differences remains a concern. The current study compares neuropsychological testing scores in 4 groups of veterans with and without PTSD (PTSD+ and PTSD-, respectively) and with and without a history of alcohol abuse (ETOH+ and ETOH-, respectively): n for PTSD+/ETOH- = 30, n for PTSD+/ETOH- = 37, n for PTSD-/ETOH+ = 30, and n for PTSD-/ETOH- = 31. Results showed that PTSD, when alcohol, educational level, vocabulary, and depression are controlled for, was associated with decreased verbal memory, attention, and processing speed performance. Alcohol abuse history was associated with decreased visual memory performance. By controlling for alcohol and depression, the authors can more conclusively demonstrate that verbal memory and attention differences are associated with PTSD.

Neurocognitive function in monozygotic twins discordant for combat exposure: relationship to posttraumatic stress disorder

Neuropsychological deficits have been reported among trauma survivors with posttraumatic stress disorder (PTSD). It is often assumed that these cognitive difficulties are toxic consequences of trauma exposure. Alternatively, they may reflect preexisting characteristics that contribute to the likelihood of developing PTSD. To address this possibility, the authors evaluated cognitive performance in monozygotic twin pairs who were discordant for combat exposure. Pairs were grouped according to whether the combat-exposed brother developed PTSD. The combat-unexposed cotwins of combat veterans with PTSD largely displayed the same performance as their brothers, which was significantly lower than that of non-PTSD combat veterans and their brothers. The results support the notion that specific domains of cognitive function may serve as premorbid risk or protective factors in PTSD.

Verbal and nonverbal memory functioning in posttraumatic stress disorder (PTSD)

Although there is evidence for memory impairment in posttraumatic stress disorder (PTSD), it remains unclear whether memory impairment is confined to verbal material or whether memory for nonverbal material is also affected. We examined verbal and nonverbal memory for free recall and recognition in 40 patients with PTSD and 40 healthy controls. Analyses showed that patients with PTSD displayed attenuated memory performance for both short- and long-term recall, which was not further moderated by type of material. The influence of attention, verbal intelligence, and depression was investigated. Our findings suggest that both verbal and nonverbal memory are compromised in PTSD.

INTEGRATIVE ASSESSMENT OF BRAIN FUNCTION IN PTSD: BRAIN STABILITY AND WORKING MEMORY

Posttraumatic Stress Disorder (PTSD) is characterized by symptoms of hyperarousal, avoidance and intrusive trauma-related memories and deficits in everyday memory and attention. Separate studies in PTSD have found abnormalities in electroencephalogram EEG, in event-related potential (ERP) and behavioral measures of working memory and attention. The present study seeks to determine whether these abnormalities are related and the extent to which they share this relationship with clinical symptoms. EEG data were collected during an eyes-open paradigm and a one-back working memory task. Behavioral and clinical data (CAPS) were also collected. The PTSD group showed signs of altered cortical arousal as indexed by reduced alpha power and an increased theta/alpha ratio, and clinical and physiological measures of arousal were found to be related. The normal relationship between theta power and ERP indices of working memory was not affected in PTSD, with both sets of measures reduced in the disordered group. Medication appeared to underpin a number of abnormal parameters, including P3 amplitude to targets and the accuracy, though not speed, of target detection. The present study helps to overcome a limitation of earlier studies that assess such parameters independently in different groups of patients that vary in factors such as comorbidity, medication status, gender and symptom profile. The present study begins to shed light on the relationship between these measures and suggests that abnormalities in brain working memory may be linked to underlying abnormalities in brain stability.

Integrative assessment of brain and cognitive function in post-traumatic stress disorder

The present study combined neuropsychological and electrophysiological measures to obtain a comprehensive profile of the everyday attentional and memory dysfunction reported in PTSD. The event-related potential (ERP) literature has consistently found abnormalities in late components (N2, P3) reflecting working memory (WM) function. However, the neuropsychological profile reported in the literature has considerable variation. The present study examined ERP activity in 33 PTSD participants and matched controls during a standard two-tone auditory oddball task. Neuropsychological assessment was carried out using a task battery assessing a wide range of cognitive functions. Consistent with previous work, the PTSD group showed delayed N2 latency and reduced P3 target amplitude, together with slower and less accurate target detection. Scalp topography provided evidence of widespread abnormality during WM function, but with strongest effects broadly over the left hemisphere. Neuropsychological testing found concomitant difficulties on factorial measures of verbal memory retention/access and sustained attention but enhanced performance on measures of immediate recall. This integrative pattern of effects reflects a specific impairment in the operation of working memory systems that guide ongoing, planned behavior and that facilitate the acquisition and retention of new memories.

Differential time courses and specificity of amygdala activity in posttraumatic stress disorder subjects and normal control subjects

BACKGROUND

Previous neuroimaging studies have demonstrated exaggerated amygdala responses to negative stimuli in posttraumatic stress disorder (PTSD). The time course of this amygdala response is largely unstudied and is relevant to questions of habituation and sensitization in PTSD exposure therapy.

METHODS

We applied blood oxygen level dependent functional magnetic resonance imaging and statistical parametric mapping to study amygdala responses to trauma-related and nontrauma-related emotional words in sexual/physical abuse PTSD and normal control subjects. We examined the time course of this response by separate analysis of early and late epochs.

RESULTS

PTSD versus normal control subjects have a relatively increased initial amygdala response to trauma-related negative, but not nontrauma-related negative, versus neutral stimuli. Patients also fail to show the normal patterns of sensitization and habituation to different categories of negative stimuli. These findings correlate with measured PTSD symptom severity.

CONCLUSIONS

Our results demonstrate differential time courses and specificity of amygdala response to emotional and control stimuli in PTSD and normal control subjects. This has implications for pathophysiologic models of PTSD and treatment response. The results also extend previous neuroimaging studies demonstrating relatively increased amygdala response in PTSD and expand these results to a largely female patient population probed with emotionally valenced words.

A broader view of trauma: A biopsychosocial-evolutionary view of the role of the traumatic stress response in the emergence of pathology and/or growth

The main goal of this paper is to articulate a biopsychosocial evolutionary approach to understanding the traumatic stress response. The secondary goal of this paper is to draw out the general clinical implications of this approach. I articulate seven interconnected and overlapping empirically grounded theoretical conclusions: (1) Stress is best understood as a prerational form of biopsychological feedback regarding the organism's relationship with its environment; (2) The normal outcome of traumatic stress is growth, rather than pathology; (3) Most psychopathology is a function of the maladaptive modulation of the stress response; (4) Trauma always leaves the individual transformed on a biological, as well as psychological, level; (5) The general biological process underlying stress responses is universal, but the specific dynamics are always a function of the unique sociocultural environment and psychological makeup of the individual; (6) The biology underlying stable psychopathological symptoms may change even as the psychological symptoms remain the same; and (7) Rationality is humanity's evolutionarily newest and most sophisticated stress-reduction behavioral mechanism, and the most important aspect of restoring psychological health to the trauma victim.

The accumulative effect of trauma exposure on short-term and delayed verbal memory in a treatment-seeking sample of female rape victims

The accumulative effect of prior high-magnitude trauma exposure on memory was examined in 73 rape victims, 92% of whom had current posttraumatic stress disorder (PTSD). Participants were administered the Logical Memory component of the Wechsler Memory Scale, the Quick Test to obtain an estimate of intelligence, and were assessed for prior traumatic experiences. Prior exposure to high-magnitude stressors (e.g., child rape, being kidnapped) was significantly correlated with poorer performance on the memory tasks. Regression analyses controlling for estimated IQ and psychopathology severity demonstrated that magnitude of prior trauma exposure predicted performance on the memory task, suggesting that in the current sample, deficits in verbal memory may be related (in part) to the degree of accumulative stress experienced over the lifetime.