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

Factors Related to Positive Memory Count Among Trauma-Exposed Individuals: A Scoping Review

To examine the existing knowledge base on trauma experiences and positive memories, we conducted a scoping review of trauma and post-trauma factors related to positive memory count. In July 2019, we searched PubMed, Medline, PsycINFO, Web of Science, Cumulative Index of Nursing and Allied Health Literature, Embase, and PTSDpubs for a combination of words related to "positive memories/experiences," "trauma/posttraumatic stress disorder (PTSD)," and "number/retrieval." Twenty-one articles met inclusion criteria (adult samples, original articles in English, peer-reviewed, included trauma-exposed group or variable of trauma exposure, trauma exposure examined with a trauma measure/methodology, assessed positive memory count, empirical experimental/non-experimental study designs). Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines, two authors reviewed abstracts, completed a secondary search, and independently extracted data. Our review indicated (1) that depression and PTSD were most researched; (2) no conclusive relationships of positive memory count with several psychopathology (depression, acute stress disorder, eating disorder, and anxiety), cognitive/affective, neurobiological, and demographic factors; (3) trends of potential relationships of positive memory count with PTSD and childhood interpersonal traumas (e.g., sexual and physical abuse); and (4) lower positive memory specificity as a potential counterpart to greater overgeneral positive memory bias. Given variations in sample characteristics and methodology as well as the limited longitudinal research, conclusions are tentative and worthy of further investigations.

Moderating effects of sleep difficulties on relations between posttraumatic stress disorder symptoms and positive memory count

OBJECTIVES

Posttraumatic stress disorder (PTSD) severity relates to positive memory retrieval difficulties. One variable potentially influencing this relation is sleep difficulties. We examined moderating effects of sleep difficulties (duration and quality) on relations between PTSD severity and count of specific positive memories covarying for age, gender, and depression.

METHODS

Participants were an Amazon Mechanical Turk-recruited trauma-exposed community sample of 205 respondents (M age  = 35.44; 61.40% women).

RESULTS

Moderated regression analyses indicated significant interaction effects between sleep quality (b = 0.03; p = 0.036) and PTSD severity on specific positive memory count. Among individuals reporting better sleep quality, there were negative associations between PTSD severity and specific positive memory count (b = -0.04, SE = 0.02, p = 0.010). Similar results were obtained for PTSD's intrusion and arousal clusters.

CONCLUSION

Results support targeting sleep quality and PTSD severity to improve positive memory retrieval in PTSD and memory interventions, and the importance of considering sleep when examining links between PTSD and positive memory retrieval.

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.

Moderating effects of dysregulation and fear of positive emotions on the relationship between posttraumatic stress disorder symptoms and positive memory count

OBJECTIVES

We examined moderating effects of positive emotion dysregulation and fear of positive emotions in the relation between posttraumatic stress disorder (PTSD) severity and positive memory count.

METHOD

Participants were 205 trauma-exposed community individuals (Mage  = 35.44; 61.50% female).

RESULTS

Moderation analyses indicated interaction effects of PTSD severity with nonacceptance of positive emotions (b = -0.01, p = .002) and difficulties with goal-directed behaviors when experiencing positive emotions (b = -0.01, p = .006) on positive memory count.

CONCLUSIONS

Greater PTSD severity was associated with more specific positive memories when individuals reported less nonacceptance of positive emotions and fewer difficulties engaging in goal-directed behaviors in the context of positive emotions. Greater PTSD severity was associated with fewer specific positive memories when individuals reported greater nonacceptance of positive emotions and greater difficulties engaging in goal-directed behaviors in the context of positive emotions. Results support addressing positive emotion dysregulation in memory-focused interventions for PTSD.

Trauma, posttraumatic stress disorder severity, and positive memories

Positive memories play an important role in the aetiology and maintenance of posttraumatic stress disorder (PTSD). However, most trauma research/clinical work has focused solely on the role of traumatic memories. Thus, we examined the relationship between count of retrieved positive memories and PTSD severity, factors associated with count of retrieved positive memories (i.e., rumination, negative/positive emotion dysregulation, fear of positive emotions), and the relationship between positive memory phenomenological domains and PTSD severity. The sample included 185 trauma-exposed participants recruited through Amazon's Mechanical Turk (Mage = 35.69 years; 63.80% female). Results of linear/hierarchical regressions showed that (1) PTSD severity did not predict count of (specific) positive memories; (2) greater positive emotion dysregulation predicted fewer retrieved positive memories controlling for PTSD severity; and (3) greater PTSD severity predicted more negative valence, less vividness, less coherence, less accessibility, less clear time perspective, fewer sensory details, and greater distancing ratings of the retrieved positive memory, controlling for sleep quantity/quality. Findings add to the literature by informing PTSD theoretical perspectives; enhancing an understanding of positive memories in PTSD/trauma treatments; and highlighting potential clinical targets (e.g., positive emotion regulation), when integrating a focus on positive memories into PTSD intervention.

Influence of glucocorticoid and mineralocorticoid receptor stimulation on task switching

The influence of stress on executive functions has been demonstrated in numerous studies and is potentially mediated by the stress-induced cortisol release. Yet, the impact of cortisol on cognitive flexibility and task switching in particular remains equivocal. In this study, we investigated the influence of pharmacological glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) stimulation, two corticosteroid receptor types known to be responsible for cortisol effects on the brain. We conducted two experiments, each with 80 healthy participants (40 women and 40 men), and tested the effect of the unspecific MR/GR agonist hydrocortisone (Experiment I) and the more specific MR agonist fludrocortisone (Experiment II) on switch costs and task rule congruency in a bivalent, cued task switching paradigm. The results did not confirm our hypotheses; we found no significant effects of our manipulations on task switching capacity, although general switching and congruency effects were observed. We discuss the absence of MR/GR-mediated effects and propose alternative mechanisms that could explain stress induced effects on task switching.

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.

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.

The impact of stress and glucocorticoids on memory

Responses to stress are mediated by a complex network of the nervous and endocrine systems. Glucocorticoids, which are among the most important “players” in stress resilience, may have important implications in the cognitive functions, particularly in the modulation of memory. Declarative memory, the memory for facts, events and word meaning is the most studied type of memory on which glucocorticoids exert an influence, both positively through consolidation and negatively through impairment. These effects depend on the receptor type, dose, time of exposure, memory component and the salience of stimuli, retrieval being generally affected and storage being facilitated, especially for emotionally relevant events. Glucocorticoids also induce hippocampal atrophy, which is a hallmark seen in various diseases accompanied by a chronic high level of cortisol, such as the Cushing syndrome, major depression, post-traumatic stress disorder. Also, chronic stress might be a risk factor for the development of Alzheimer’s disease, especially when a genetic background and other environmental influences are present.