Enhanced effects of cortisol administration on episodic and working memory in aging veterans with PTSD

The Hypothalamus-Pituitary-Adrenal Axis and Social Cognition in Borderline Personality Disorder

Borderline personality disorder (BPD) is characterized by emotional instability, impulsivity and unstable interpersonal relationships. Patients experience discomforting levels of distress, inducing symptoms like dissociation, aggression or withdrawal. Social situations are particularly challenging, and acute social stress can reduce patients' cognitive and social functioning. In patients with Major Depressive Disorder or Posttraumatic Stress Disorder, which show high comorbidity with BPD, the endocrine stress response is characterized by Hypothalamus-Pituitary-Adrenal (HPA) axis dysfunction, which affects cognitive functioning. Compared to these clinical groups, research on HPA-axis function in BPD is relatively scarce, but evidence points towards a blunted cortisol reactivity to acute stress. Since BPD patients are particularly prone to social stress and experience high subjective difficulties in these situations, it seems plausible that HPA-axis dysregulation might contribute to decreased social cognition in BPD. The present review summarizes findings on the HPA-axis function in BPD and its association with social cognition following acute social stress. For this purpose, we review literature that employed a widely used social stressor (Trier Social Stress Test, TSST) to study the effects of acute social stress on social cognition and the HPA-axis response. We contrast these findings with studies on social cognition that employed Cyberball, another widely used social stressor that lacks HPA-axis involvement. We conclude that research on social cognition in BPD reveals heterogeneous results with no clear relationship between social functioning and HPA-axis response. More research is needed to better understand the psychophysiological underpinnings of impaired social cognition in BPD.

Childhood trauma affects autobiographical memory deficits through basal cortisol and prefrontal-extrastriate functional connectivity

BACKGROUND

Psychological trauma can damage the brain, especially in areas where glucocorticoid receptors are expressed, via perturbed secretion of cortisol. Childhood trauma is associated with blunted basal cortisol secretion, brain alterations, and autobiographical memory deficits referred to as overgeneral autobiographical memory (OGM). However, it remains unknown whether childhood trauma affects OGM through altered cortisol and brain alterations.

METHODS

Using resting-state fMRI in 100 healthy humans, we examined whether childhood trauma affects OGM through its related basal cortisol and brain functional connectivity (FC). Trauma and OGM were assessed using the Childhood Trauma Questionnaire (CTQ) and Autobiographical Memory Test (AMT), respectively. Basal cortisol levels were measured by 10 points-in-time across two days. Multiple mediation analysis was employed.

RESULTS

CTQ was associated with greater semantic-associate memory of OGM, a retrieval tendency toward semantic content with no specific contextual details of an experienced event, as well as blunted basal cortisol levels. While CTQ was correlated with decreased FC between the hippocampus and medial prefrontal cortex (PFC), it showed a more predominant correlation with increased FC between the lateral and anteromedial PFC and extrastriate cortex. Importantly, the increased prefrontal-extrastriate FC completely mediated the relationship between CTQ and semantic-associate memory, affected by hyposecretion of cortisol.

CONCLUSION

Childhood trauma may lead to the lack of visuoperceptual contextual details in autobiographical memory by altering basal cortisol secretion and connectivity of the prefrontal-hippocampal-extrastriate regions. The intensified prefrontal-extrastriate connectivity may contribute to OGM formation by strengthening the semantic content in memory retrieval. Understanding the mechanisms underlying the trauma-cortisol-brain-memory link will provide important clinical implications for trauma-related mental disorders.

No Effects of Acute Psychosocial Stress on Working Memory in Older People With Type 2 Diabetes

Type 2 diabetes (T2D) has been considered a public health threat due to its growing prevalence, particularly in the older population. It is important to know the effects of psychosocial stress and its potential consequences for some basic cognitive processes that are important in daily life. Currently, there is very little information about how people with T2D face acute psychosocial stressors, and even less about how their response affects working memory (WM), which is essential for their functionality and independence. Our aim was to characterize the response to an acute laboratory psychosocial stressor and its effects on WM in older people with T2D. Fifty participants with T2D from 52 to 77 years old were randomly assigned to a stress (12 men and 12 women) or control (12 men and 14 women) condition. Mood and physiological (cortisol, C, and salivary alpha-amylase, sAA) responses to tasks were measured. In addition, participants completed a WM test before and after the stress or control task. Our results showed that the TSST elicited higher negative affect and greater C and sAA responses than the control task. No significant differences in WM were observed depending on the exposure to stress or the control task. Finally, participants who showed higher C and sAA responses to the stressor had lower WM performance. Our results indicate that medically treated older adults with T2D show clear, typical mood and physiological responses to an acute psychosocial stressor. Finally, the lack of acute psychosocial stress effects on WM suggests that it could be related to aging and not to this disease, at least when T2D is adequately treated.

Stress, the cortisol awakening response and cognitive function

There is evidence that stress-induced disruption of the circadian rhythm of cortisol secretion, has negative consequences for brain health. The cortisol awakening response (CAR) is the most prominent and dynamic aspect of this rhythm. It has complex regulatory mechanisms making it distinct from the rest of the cortisol circadian rhythm, and is frequently investigated as a biomarker of stress and potential intermediary between stress and impaired brain function. Despite this, the precise function of the CAR within the healthy cortisol circadian rhythm remains poorly understood. Cortisol is a powerful hormone known to influence cognition in multiple and complex ways. Studies of the CAR and cognitive function have used varied methodological approaches which have produced similarly varied findings. The present review considers the accumulating evidence linking stress, attenuation of the CAR and reduced cognitive function, and seeks to contextualize the many findings to study populations, cognitive measures, and CAR methodologies employed. Associations between the CAR and both memory and executive functions are discussed in relation to its potential role as a neuroendocrine time of day signal that synchronizes peripheral clocks throughout the brain to enable optimum function, and recommendations for future research are provided.

Acute Cortisol Levels and Memory Performance in Older People with High and Normal Body Mass Index

Previous studies have shown that healthy older adults may be less sensitive to the effects of acute cortisol levels on memory performance than young adults. Importantly, being overweight has recently been associated with an increase in both cortisol concentration and cortisol receptors in central tissues, suggesting that Body Mass Index (BMI) may contribute to differences in the relationship between memory and acute cortisol. This study investigates the role of BMI in the relationship between memory performance and acute cortisol levels in older people (M = 64.70 years; SD = 4.24). We measured cortisol levels and memory performance (working memory and declarative memory) in 33 participants with normal BMI (normal BMI = 18.50-24.99) and 36 participants with overweight BMI (overweight BMI = 25-29.99). Overweight BMI participants showed worse performance on word-list learning (p = .036, 95% CI [0.08, 2.18], η2p = 0.07). Higher cortisol levels were related to higher proactive interference (β = .364, p = .016, 95% CI [0.07, 0.66]), and BMI did not moderate any of the relationships investigated. In accordance with previous studies, our results show worse memory performance in individuals with overweight BMI. However, our results do not support the idea that memory performance in older people with higher BMI may be more sensitive to differences in acute cortisol levels than in older people with normal BMI. More research is needed to test this hypothesis with obese individuals (BMI > 30 Kg/cm2).

Magnetic resonance imaging predictors of psychotherapy treatment response in post-traumatic stress disorder: A role for the salience network

The earliest neuroimaging studies in post-traumatic stress disorder (PTSD) utilized positron emission tomography (PET) to examine the brain's response to glucocorticoid administration given predominant neurobiological models of the stress response focusing on that neuroendocrine system. This work revealed that the anterior cingulate cortex and amygdala, which is now considered part of the salience network, play a role in treatment response, and set the stage for subsequent magnetic resonance (MR) imaging studies focused on understanding the role of the salience network in the neurobiology of treatment response in PTSD. This selective review discusses magnetic resonance (MR) imaging studies that have been used to predict treatment response to cognitive-behavioral therapy (CBT) or prolonged exposure (PE) in PTSD, which have demonstrated abnormalities in processing involving the salience network, including the amygdala, anterior cingulate cortex and insula. Increased attention to environmental cues may signal alarm resulting in hypervigilance and overactive action-monitoring for the detection of threatening stimuli and an inability to integrate concomitant emotional and sensory functions in PTSD. Successful psychotherapy treatment response in PTSD appears to involve the ability to downregulate amygdala activity to trauma-related stimuli through improved regulation of attention by the anterior cingulate cortex and concomitant internal emotional states mediated by the insula. In addition, the ability to better modulate (normalize) the salience network following psychotherapy in PTSD may be associated with better crosstalk between untargeted inner thought (i.e., task-negative network) and the ability to focus attention on stimulus-dependent demands (i.e., task positive network).

Glucocorticoids and Hippocampal Structure and Function in PTSD

This review examines the putative link between glucocorticoid and hippocampal abnormalities in posttraumatic stress disorder (PTSD). Increased glucocorticoid receptor (GR) sensitivity in PTSD may permit enhanced negative feedback inhibition of cortisol at the pituitary, hypothalamus, or other brain regions comprising the hypothalamic-pituitary-adrenal (HPA) axis and would be expected to affect other physiological systems that are regulated by glucocorticoids. Molecular and transcriptional studies of cortisol are consistent with the hypothesis that cortisol actions may be amplified in PTSD as a result of enhanced GR sensitivity in monocytes and some brain regions, although cortisol levels themselves are unchanged and oftentimes lower than normal. Concurrently, magnetic resonance imaging studies have demonstrated that individuals with PTSD have smaller hippocampal volume than individuals without PTSD. Initial hypotheses regarding the mechanism underlying hippocampal alterations in PTSD focused on elevated glucocorticoid levels in combination with extreme stress as the primary cause, but this explanation has not been well supported in human studies. Lack of data from neuroimaging studies preclude a firm link between PTSD onset and hippocampal volume changes. Rather, the available evidence is consistent with the possibility that smaller hippocampal volume (like reduced cortisol levels and enhanced GR sensitivity) may be a vulnerability factor for developing the disorder; limitations of hippocampal-based models of PTSD are described. We further review neuroimaging studies examining hippocampal structure and function following manipulation of glucocorticoid levels and also examining changes in the hippocampus in relationship to other brain regions. Evidence that the GR may be an important therapeutic target for the treatment of PTSD, especially for functions subserved by the hippocampus, is discussed. Implications of the current review for future research are described, with an emphasis on the need to integrate findings of glucocorticoid abnormalities with functional-imaging paradigms to formulate a comprehensive model of HPA-axis functioning in PTSD.

A single low dose of hydrocortisone enhances cognitive functioning in HIV-infected women

OBJECTIVE

Low-dose hydrocortisone (LDH) enhances aspects of learning and memory in select populations including patients with posttraumatic stress disorder and HIV-infected men. HIV-infected women show impairments in learning and memory, but the cognitive effects of LDH in HIV-infected women are unknown.

DESIGN

Double-blind, placebo-controlled, cross-over study examining the time-dependent effects of a single low-dose administration of hydrocortisone (10 mg oral) on cognition in 36 HIV-infected women. Participants were first randomized to LDH or placebo and then received the opposite treatment one month later.

METHODS

Cognitive performance was assessed 30 min and 4 h after pill administration to assess, respectively, nongenomic and genomic effects. Self-reported stress/anxiety and salivary cortisol were assessed throughout sessions.

RESULTS

LDH significantly increased salivary cortisol levels versus placebo; levels returned to baseline 4-h postadministration. At the 30-min assessment, LDH enhanced verbal learning and delayed memory, working memory, behavioral inhibition, and visuospatial abilities. At the 4-h assessment, LDH enhanced verbal learning and delayed memory compared with placebo. LDH-induced cognitive benefits related to reductions in cytokines and to a lesser extent to increases in cortisol.

CONCLUSION

The extended benefits from 30 min to 4 h of a single administration of LDH on learning and delayed memory suggest that targeting the hypothalamic-pituitary-adrenal axis may have potential clinical utility in HIV-infected women. These findings contrast with our findings in HIV-infected men who showed improved learning only at the 30-min assessment. Larger, longer term studies are underway to verify possible cognitive enhancing effects of LDH and the clinical significance of these effects in HIV.

Brief Report: Low-Dose Hydrocortisone Has Acute Enhancing Effects on Verbal Learning in HIV-Infected Men

OBJECTIVE

Glucocorticoids are released in response to stress and alter cognition and brain function through both rapid nongenomic and slow genomic mechanisms. Administration of glucocorticoids in the form of hydrocortisone enhances aspects of learning and memory in individuals with PTSD but impairs these abilities in healthy individuals. We examine the time-dependent effects of glucocorticoids on cognition in HIV-infected men.

METHODS

In a double-blind placebo-controlled crossover study, we examined the time-dependent effects of a single low dose of hydrocortisone [10 mg; low-dose hydrocortisone (LDH)] on cognition in 45 HIV-infected men. Participants were randomized to receive either LDH or placebo and one month later, were given the opposite treatment. At each intervention session, cognition was assessed 30 minutes (assessing nongenomic effects) and 4 hours (assessing genomic effects) after pill administration. Self-reported stress/anxiety and cortisol/cytokines in saliva were measured throughout each session.

RESULTS

Compared with placebo, LDH doubled salivary cortisol levels. Cortisol returned to baseline 4 hours postadministration. At the 30-minute assessment, LDH enhanced verbal learning compared with placebo. Greater increases in cortisol were associated with greater enhancements in verbal learning. LDH did not affect subjective stress/anxiety or any other cognitive outcomes at the 30-minute or 4-hour time point.

CONCLUSIONS

The rapid effects of LDH on verbal learning suggests a nongenomic mechanism by which glucocorticoids can enhance cognition in HIV-infected men. The nonenduring nature of this enhancement may limit its clinical utility but provides insight into mechanisms underlying the effects of acute glucocorticoids on learning.

Synaptic Loss and the Pathophysiology of PTSD: Implications for Ketamine as a Prototype Novel Therapeutic

PURPOSE OF REVIEW

Studies of the neurobiology and treatment of PTSD have highlighted many aspects of the pathophysiology of this disorder that might be relevant to treatment. The purpose of this review is to highlight the potential clinical importance of an often-neglected consequence of stress models in animals that may be relevant to PTSD: the stress-related loss of synaptic connectivity.

RECENT FINDINGS

Here, we will briefly review evidence that PTSD might be a "synaptic disconnection syndrome" and highlight the importance of this perspective for the emerging therapeutic application of ketamine as a potential rapid-acting treatment for this disorder that may work, in part, by restoring synaptic connectivity. Synaptic disconnection may contribute to the profile of PTSD symptoms that may be targeted by novel pharmacotherapeutics.

The association of perceived stress and verbal memory is greater in HIV-infected versus HIV-uninfected women

In contrast to findings from cohorts comprised primarily of HIV-infected men, verbal memory deficits are the largest cognitive deficit found in HIV-infected women from the Women's Interagency HIV Study (WIHS), and this deficit is not explained by depressive symptoms or substance abuse. HIV-infected women may be at greater risk for verbal memory deficits due to a higher prevalence of cognitive risk factors such as high psychosocial stress and lower socioeconomic status. Here, we investigate the association between perceived stress using the Perceived Stress Scale (PSS-10) and verbal memory performance using the Hopkins Verbal Learning Test (HVLT) in 1009 HIV-infected and 496 at-risk HIV-uninfected WIHS participants. Participants completed a comprehensive neuropsychological test battery which yielded seven cognitive domain scores, including a primary outcome of verbal memory. HIV infection was not associated with a higher prevalence of high perceived stress (i.e., PSS-10 score in the top tertile) but was associated with worse performance on verbal learning (p < 0.01) and memory (p < 0.001), as well as attention (p = 0.02). Regardless of HIV status, high stress was associated with poorer performance in those cognitive domains (p's < 0.05) as well as processing speed (p = 0.01) and executive function (p < 0.01). A significant HIV by stress interaction was found only for the verbal memory domain (p = 0.02); among HIV-infected women only, high stress was associated with lower performance (p's < 0.001). That association was driven by the delayed verbal memory measure in particular. These findings suggest that high levels of perceived stress contribute to the deficits in verbal memory observed in WIHS women.

Anxiety mediates the effect of acute stress on working memory performance when cortisol levels are high: a moderated mediation analysis

BACKGROUND

Anxiety is an aversive emotional state characterized by perceived uncontrollability and hypervigilance to threat that can frequently cause disruptions in higher-order cognitive processes like working memory. The attentional control theory (ACT) predicts that anxiety negatively affects the working memory system.

DESIGN

This study tested the association between anxiety and working memory after the addition of stress and measured the glucocorticoid, cortisol. To better understand this relationship, we utilized a moderated mediation model.

METHODS

Undergraduate students from a public university (N = 103) self-reported their anxiety levels. Participants first completed a short-term memory test. During and after a forehead cold pressor task (stress vs. control procedure) participants completed a working memory test. Salivary cortisol was taken at baseline and after the last working memory test.

RESULTS

Overall, acute stress had no effect on working memory. However, we found that anxiety levels mediated the influence of condition (stressed vs. control) on working memory, but only among those individuals who had high cortisol levels after exposure to acute stress, supporting a moderated mediation model.

CONCLUSIONS

These results imply that activation of the hypothalamic-pituitary-adrenal axis was necessary for working memory impairment in anxious individuals. These results provide support for the ACT.

Acute stress and working memory in older people

Several studies have shown that acute stress affects working memory (WM) in young adults, but the effect in older people is understudied. As observed in other types of memory, older people may be less sensitive to acute effects of stress on WM. We performed two independent studies with healthy older men and women (from 55 to 77 years old) to investigate the effects of acute stress (Trier Social Stress Test; TSST) and cortisol on WM. In study 1 (n = 63), after the TSST women (but not men) improved their performance on Digit Span Forward (a measure of the memory span component of WM) but not on Digit Span Backward (a measure of both memory span and the executive component of WM). Furthermore, in women, cortisol levels at the moment of memory testing showed a positive association with the memory span component of WM before and after the TSST, and with the executive component of WM only before the stress task. In study 2 (n = 76), although participants showed a cortisol and salivary alpha-amylase (sAA) response to the TSST, stress did not affect performance on Letter-Number Sequencing (LNS; a task that places a high demand on the executive component of WM). Cortisol and sAA were not associated with WM. The results indicate that circulating cortisol levels at the moment of memory testing, and not the stress response, affect memory span in older women, and that stress and the increase in cortisol levels after stress do not affect the executive component of WM in older men and women. This study provides further evidence that older people may be less sensitive to stress and stress-induced cortisol response effects on memory processes.

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.

Acute stress impairs recall after interference in older people, but not in young people

Stress has been associated with negative changes observed during the aging process. However, very little research has been carried out on the role of age in acute stress effects on memory. We aimed to explore the role of age and sex in the relationship between hypothalamus-pituitary-adrenal axis (HPA-axis) and sympathetic nervous system (SNS) reactivity to psychosocial stress and short-term declarative memory performance. To do so, sixty-seven participants divided into two age groups (each group with a similar number of men and women) were exposed to the Trier Social Stress Test (TSST) and a control condition in a crossover design. Memory performance was assessed by the Rey Auditory Verbal Learning Test (RAVLT). As expected, worse memory performance was associated with age; but more interestingly, the stressor impaired recall after interference only in the older group. In addition, this effect was negatively correlated with the alpha-amylase over cortisol ratio, which has recently been suggested as a good marker of stress system dysregulation. However, we failed to find sex differences in memory performance. These results show that age moderates stress-induced effects on declarative memory, and they point out the importance of studying both of the physiological systems involved in the stress response together.

Cortisol response to cosyntropin administration in military veterans with or without posttraumatic stress disorder

Studies have demonstrated altered sensitivity of the hypothalamic-pituitary-adrenal (HPA) axis to its direct regulators in veterans with posttraumatic stress disorder (PTSD), but little is known about the adrenal response to hormonal stimulation in PTSD. An increased cortisol response to synthetic corticotropin-releasing factor (CRF) was recently found to be associated with war-zone deployment and not PTSD specifically. To more accurately assess whether there is altered adrenocortical responsivity to hormonal stimulation in relation to war-zone deployment or PTSD, we performed the low-dose cosyntropin stimulation test in a sample of 45 male veterans: 13 war-zone exposed veterans with chronic PTSD (PTSD+), 22 war-zone exposed veterans without chronic PTSD (PTSD-), and 10 veterans not exposed to a war-zone and without chronic PTSD (non-exposed). Plasma cortisol and ACTH were measured at baseline and at intervals over a one hour period following intravenous administration of 1μg of cosyntropin. A significant main effect of group (PTSD+, PTSD-, non-exposed) on the cortisol response to cosyntropin was observed. Cosyntropin-stimulated plasma cortisol levels were significantly higher in the PTSD+ and PTSD- groups compared to the non-exposed group. A significant main effect of group was also observed on peak cortisol levels. These findings suggest that war-zone exposure itself has persistent effects on adrenocortical activity.

Acute glucocorticoid effects on response inhibition in borderline personality disorder

INTRODUCTION

Growing evidence suggests inhibition dysfunctions in borderline personality disorder (BPD). Moreover, abnormalities in hypothalamic-pituitary-adrenal (HPA) axis functioning have also been found in BPD patients. In healthy individuals, response inhibition has been sensitive to acute stress, and previous research indicates that effects mediated by the HPA axis become particularly apparent when emotional stimuli are processed. This study aimed to explore the influence of acute hydrocortisone administration on response inhibition of emotional stimuli in BPD patients compared to healthy control participants.

METHODS

After a single administration of 10mg hydrocortisone or placebo, 32 female BPD patients and 32 healthy female participants performed an adapted emotional go/no-go paradigm to assess response inhibition for emotional face stimuli in a cross-over study.

RESULTS

Acute cortisol elevations decreased the reaction times to target stimuli in both BPD patients and healthy controls. Patients and controls did not differ in task performance; however, BPD patients with comorbid posttraumatic stress disorder (PTSD) displayed longer reaction times than patients without PTSD. In contrast, the occurrence of comorbid eating disorder had no significant impact on go/no-go performance. No significant interaction effect between the treatment condition and the emotional valence of the face stimuli was found.

CONCLUSIONS

Acute hydrocortisone administration enhances response inhibition of face stimuli in BPD patients and healthy controls, regardless of their emotional valence. Our results agree with the suggestion that moderate cortisol enhancement increases the inhibition of task-irrelevant distracters.

Cortisol effects on autobiographic memory retrieval in PTSD: an analysis of word valence and time until retrieval

In healthy participants, cortisol administration has been found to impair autobiographic memory retrieval. We recently reported that administration of 10 mg of hydrocortisone had enhancing effects on autobiographical memory retrieval, i.e. more specific memory retrieval, in patients with posttraumatic stress disorder (PTSD), while in healthy controls the impairing effects were replicated. We here report a re-analysis of these data with respect to cue-word valence and retrieval time. In a placebo-controlled cross-over study, 43 patients with PTSD and 43 age- and sex-matched healthy controls received either placebo or hydrocortisone orally before the autobiographical memory test was performed. We found that the effects of cortisol on memory retrieval depended on cue-word valence and group (significant interaction effects of drug by group and drug by valence by group). The enhancing effect of cortisol on memory retrieval in PTSD seemed to be relatively independent of cue-word valence, while in the control group the impairing effects of cortisol were only seen in response to neutral cue-words. The second result of the study was that in patients as well as in controls, cortisol administration led to faster memory retrieval compared to placebo. This was seen in response to positive and (to lesser extend) to neutral cue-words, but not in response to negative cue-words. Our findings illustrate that the opposing effects of cortisol on autobiographical memory retrieval in PTSD patients and controls are further modulated by the emotionality of the cue-words.

Cannabinoids and traumatic stress modulation of contextual fear extinction and GR expression in the amygdala-hippocampal-prefrontal circuit

Considerable evidence suggests that cannabinoids modulate the behavioral and physiological response to stressful events. We have recently shown that activating the cannabinoid system using the CB1/CB2 receptor agonist WIN55,212-2 (WIN) in proximity to exposure to single-prolonged stress (SPS), a rat model of emotional trauma, prevented the stress-induced enhancement of acoustic startle response, the impairment in avoidance extinction and the enhanced negative feedback on the hypothalamic-pituitary-adrenal (HPA) axis (Ganon-Elazar and Akirav, 2012). Some of the effects were found to be mediated by CB1 receptors in the basolateral amygdala (BLA). Here we examined whether cannabinoid receptor activation in a putative brain circuit that includes the BLA, hippocampus and prefrontal cortex (PFC), could prevent the effects of traumatic stress on contextual fear extinction and alterations in glucocorticoid receptor (GR) protein levels. We found that: (i) SPS impaired contextual fear extinction tested one week after trauma exposure and that WIN prevented the stress-induced impairment of extinction when microinjected immediately after trauma exposure into the BLA or hippocampus (5 μg), but not when microinjected into the PFC, (ii) the ameliorating effects of WIN on contextual extinction were prevented by blocking GRs in the BLA and hippocampus, and (iii) SPS up regulated GRs in the BLA, PFC and hippocampus and systemic WIN administration (0.5 mg/kg) after trauma exposure normalized GR levels in the BLA and hippocampus, but not in the PFC. Cannabinoid receptor activation in the aftermath of trauma exposure may regulate the emotional response to the trauma and prevent stress-induced impairment of extinction and GR up regulation through the mediation of CB1 receptors in the BLA and hippocampus. Taken together, the findings suggest that the interaction between the cannabinoid and glucocorticoid systems is crucial in the modulation of emotional trauma.

A meta-analysis of cognitive functioning in older adults with PTSD

A meta-analysis was conducted to summarize and integrate the literature on the cognitive functioning of older adults with posttraumatic stress disorder (PTSD). We hypothesized that those with PTSD would exhibit worse performance in each of the cognitive domains studied when compared to older adults without PTSD. Major databases were queried and eleven articles met criteria for review. As predicted, there was evidence of worse performance across cognitive measures in older adult samples with PTSD relative to older samples without PTSD. The strongest effect across samples was found for lower test scores in the broad domain of memory among older adults with PTSD, and there was evidence that trauma exposure is uniquely associated with worse performance on tests specific to learning. We outline factors thought to contribute to the interactions among PTSD, cognitive deficits, and the aging process. These findings highlight the need for thorough evaluation of cognitive functioning in older adults with PTSD, particularly in the areas of processing speed, learning, memory, and executive functioning.

Effects of cortisol on memory in women with borderline personality disorder: role of co-morbid post-traumatic stress disorder and major depression

BACKGROUND

Stress and cortisol administration are known to have impairing effects on memory retrieval in healthy humans. These effects are reported to be altered in patients with major depressive disorder (MDD) and post-traumatic stress disorder (PTSD) but they have not yet been investigated in borderline personality disorder (BPD).

METHOD

In a placebo-controlled cross-over study, 71 women with BPD and 40 healthy controls received either placebo or 10 mg of hydrocortisone orally before undertaking a declarative memory retrieval task (word list learning) and an autobiographical memory test (AMT). A working memory test was also applied.

RESULTS

Overall, opposing effects of cortisol on memory were observed when comparing patients with controls. In controls, cortisol had impairing effects on memory retrieval whereas in BPD patients cortisol had enhancing effects on memory retrieval of words, autobiographical memory and working memory. These effects were most pronounced for specificity of autobiographical memory retrieval. Patients with BPD alone and those with co-morbid PTSD showed this effect. We also found that co-morbid MDD influenced the cortisol effects: in this subgroup (BPD + MDD) the effects of cortisol on memory were absent.

CONCLUSIONS

The present results demonstrate beneficial effects of acute cortisol elevations on hippocampal-mediated memory processes in BPD. The absence of these effects in patients with co-morbid MDD suggests that these patients differ from other BPD patients in terms of their sensitivity to glucocorticoids (GCs).

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.

Treatment-related alteration of cortisol predicts change in neuropsychological function during acute treatment of late-life anxiety disorder

OBJECTIVE

Older adults with anxiety disorders are burdened by impairment in neurocognition, which may be mediated by elevated circulating cortisol levels. In a randomized controlled trial of acute serotonin-reuptake inhibitor treatment for late-life anxiety disorder, we examined whether change in salivary cortisol concentrations during treatment predicted improvements in measures of memory and executive function.

METHODS

We examined 60 adults aged 60 years and older, who took part in a 12-week trial of escitalopram versus placebo for generalized anxiety disorder. All subjects had pre-treatment and post-treatment assessments that included monitoring of peak and total daily cortisol and a comprehensive neuropsychological evaluation.

RESULTS

Salivary cortisol changes during treatment showed significant associations with changes in immediate and delayed memory but no association with executive tasks (measures of working memory and set shifting). Analyses suggested that a decrease in cortisol due to serotonin-reuptake inhibitor treatment was responsible for the memory changes: memory improvement was seen with cortisol reduction among patients receiving escitalopram but not among patients receiving placebo.

CONCLUSION

Serotonin-reuptake inhibitor-induced alteration in circulating cortisol during treatment of generalized anxiety disorder predicted changes in immediate and delayed memory. This finding suggests a novel treatment strategy in late-life anxiety disorders: targeting hypothalamic-pituitary- adrenal axis dysfunction to improve memory.

Membrane mineralocorticoid but not glucocorticoid receptors of the dorsal hippocampus mediate the rapid effects of corticosterone on memory retrieval

This study was aimed at determining the type of the glucocorticoid membrane receptors (mineralocorticoid receptors (MRs) or glucocorticoid receptors (GRs)) in the dorsal hippocampus (dHPC) involved in the rapid effects of corticosterone or stress on memory retrieval. For that purpose, we synthesized corticosterone-3-O-carboxymethyloxime-bovine serum albumin conjugate (Cort-3CMO-BSA) conjugate (a high MW complex that cannot cross the cell membrane) totally devoid of free corticosterone, stable in physiological conditions. In a first experiment, we evidenced that an acute stress (electric footshocks) induced both a dHPC corticosterone rise measured by microdialysis and memory retrieval impairment on delayed alternation task. Both the endocrinal and cognitive effects of stress were blocked by metyrapone (a corticosterone synthesis inhibitor). In a second experiment, we showed that bilateral injections of either corticosterone or Cort-3CMO-BSA in dHPC 15 min before memory testing produced impairments similar to those resulting from acute stress. Furthermore, we showed that anisomycin (a protein synthesis inhibitor) failed to block the deleterious effect of Cort-3CMO-BSA on memory. In a third experiment, we evidenced that intra-hippocampal injection of RU-28318 (MR antagonist) but not of RU-38486 (GR antagonist) totally blocked the Cort-3CMO-BSA-induced memory retrieval deficit. In a fourth experiment, we demonstrated that RU-28318 administered 15 min before stress blocked the stress-induced memory impairments when behavioral testing occurred 15 min but not 60 min after stress. Overall, this study provides strong in vivo evidence that the dHPC membrane GRs, mediating the rapid and non-genomic effects of acute stress on memory retrieval, are of MR but not GR type.

Minireview: Stress-related psychiatric disorders with low cortisol levels: a metabolic hypothesis

Several stress-associated neuropsychiatric disorders, notably posttraumatic stress disorder and chronic pain and fatigue syndromes, paradoxically exhibit somewhat low plasma levels of the stress hormone cortisol. The effects appear greatest in those initially traumatized in early life, implying a degree of developmental programming, perhaps of both lower cortisol and vulnerability to psychopathology. In these conditions, lowered cortisol is not due to any adrenal or pituitary insufficiency. Instead, two processes appear involved. First, there is increased target cell sensitivity to glucocorticoid action, notably negative feedback upon the hypothalamic-pituitary-adrenal (stress) axis. Altered density of the glucocorticoid receptor is inferred, squaring with much preclinical data showing early life challenges can permanently program glucocorticoid receptors in a tissue-specific manner. These effects involve epigenetic mechanisms. Second, early life trauma/starvation induces long-lasting lowering of glucocorticoid catabolism, specifically by 5α-reductase type 1 (predominantly a liver enzyme) and 11β-hydroxysteroid dehydrogenase type 2 (in kidney), an effect also seen in model systems. These changes reflect a plausible early-life adaptation to increase the persistence of active cortisol in liver (to maximize fuel output) and kidney (to increase salt retention) without elevation of circulating levels, thus avoiding their deleterious effects on brain and muscle. Modestly lowered circulating cortisol and increased vulnerability to stress-associated disorders may be the outcome. This notion implies a vulnerable early-life phenotype may be discernable and indicates potential therapy by modest glucocorticoid replacement. Indeed, early clinical trials with cortisol have shown a modicum of promise.

PTSD in the elderly: the interaction between trauma and aging

BACKGROUND

Because an increasingly large cohort of individuals is approaching their elderly years, there is concern about how the healthcare system will cope with the greater demands placed upon it. One area of concern is the impact of trauma and post traumatic stress disorder (PTSD) in the aged. Although several reviews have highlighted the lack of knowledge and research on the topic, there still remain gaps in the literature. Nevertheless, some recent behavioral, endocrinological and neuroimaging studies may provide new insights into the discussion. The central aims of this paper are to summarize the etiological, epidemiological and clinical aspects of PTSD, trauma, and the elderly, and to integrate this knowledge with (i) what is known about PTSD in adults, and (ii) the behavioral, hormonal and cerebral changes associated with healthy aging.

METHODS

A comprehensive search was performed with ISI Web of Science and PubMed for articles pertinent to the psychology and biology of PTSD, trauma, and the elderly.

RESULTS

There exist both significant similarities and differences between adults and elderly with PTSD concerning cognitive and biological profile. Evidence suggests that PTSD in the elderly does not follow a simple clinical trajectory.

CONCLUSIONS

PTSD in the elderly must be considered within the context of normal aging. Strong claims about an interaction between PTSD and aging are difficult to make due to sample heterogeneity, but it is clear that PTSD in this age group presents unique aspects not seen in younger cohorts. Further research must integrate their studies with the biological, psychological, and social changes already associated with the aging process.

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.

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.

Status of glucocorticoid alterations in post-traumatic stress disorder

The current status of glucocorticoid alterations in post-traumatic stress disorder (PTSD) will be described in this chapter. Emphasis will be placed on data that suggest that at least some glucocorticoid-related observations in PTSD reflect pretraumatic glucocorticoid status. Recent observations have provided some evidence that pretraumatic glucocorticoid alterations may arise from genetic, epigenetic, and possibly other environmental influences that serve to increase the likelihood of developing PTSD following trauma exposure, as well as modulate attendant biological alterations associated with its pathophysiology. Current studies in the field of PTSD employ glucocorticoid challenge strategies to delineate effects of exogenously administered glucocorticoids on neuroendocrine, cognitive, and brain function. Results of these studies have provided an important rationale for using glucocorticoid strategies in the treatment of PTSD.

Hydrocortisone reduces emotional distracter interference in working memory

Several studies have shown that stress and glucocorticoids can impair prefrontal-dependent working memory (WM) performance. WM is the ability to attend to the task at hand, and to maintain relevant information in mind during a delay while ignoring irrelevant stimuli. Here, it is investigated whether stress hormones impair WM by reducing the ability to suppress distracting, irrelevant neutral and emotional stimuli. Hydrocortisone (35 mg) (n=23) or placebo (n=21) was administered to young, healthy men, who performed a Sternberg WM task with neutral and emotional irrelevant distracters shown in the delay-phase of the task, between encoding and recognition of the relevant stimuli for WM. Contrary to expectations, enhanced WM performance with higher processing speed and a reduction of errors was found in the hydrocortisone group compared to placebo. Moreover, hydrocortisone significantly reduced the distraction by emotional stimuli. These findings show that cortisol effects on WM are not unambiguous and contrast with previous findings on the impairing effects of cortisol on WM. Dose-response studies could give more insight into the specific modulating effects of glucocorticoids on suppression of irrelevant emotional distraction.

Effect of cortisol levels on working memory performance in elderly subjects with Alzheimer's disease

BACKGROUND: Subjects with Alzheimer's disease (AD) have elevated cortisol levels as a result of hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Acute administration of hydrocortisone has been associated with working memory (WM) performance in young adults. OBJECTIVE: To investigate whether cortisol levels are associated with WM performance in subjects with AD. METHOD: Eighty subjects were included, comprising 40 patients with mild AD and 40 healthy elderly controls. WM was assessed using the Digit Span Backward test (DSB). Saliva samples were collected to determine cortisol levels. RESULTS: AD subjects had poorer performance on the DSB than controls (p=0.002) and also presented higher levels of cortisol than control group (p=0.04). No significant correlation was observed between the DSB and cortisol levels in both groups (r= -0.29). CONCLUSION: In this study, elevated cortisol levels were not associated with poorer WM performance in patients with AD or in healthy elderly subjects.