Association between cortisol awakening response and memory function in major depression

The Cortisol Awakening Response: Regulation and Functional Significance

In healthy individuals, the majority of cortisol secretion occurs within several hours surrounding morning awakening. A highly studied component of this secretory period is the cortisol awakening response (CAR), the rapid increase in cortisol levels across the first 30 to 45 minutes after morning awakening. This strong cortisol burst at the start of the active phase has been proposed to be functional in preparing the organism for the challenges of the upcoming day. Here, we review evidence on key regulatory and functional processes of the CAR and develop an integrative model of its functional role. Specifically, we propose that, in healthy individuals, the CAR is closely regulated by an intricate dual-control system, which draws upon key circadian, environmental, and neurocognitive processes to best predict the daily need for cortisol-related action. Fine-tuned CAR expression, in turn, is then assumed to induce potent glucocorticoid action via rapid nongenomic and slower genomic pathways (eg, affecting circadian clock gene expression) to support and modulate daily activity through relevant metabolic, immunological, and neurocognitive systems. We propose that this concerted action is adaptive in mediating two main functions: a primary process to mobilize resources to meet activity-related demands and a secondary process to help the organism counterregulate adverse prior-day emotional experiences.

Blunted Cortisol Awakening Response Is Associated with External Attribution Bias Among Individuals with Personality Disorders

BACKGROUND/OBJECTIVES

The dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been associated with various mental disorders. One of the most commonly described parameters of HPA axis functioning is the cortisol awakening response (CAR). To date, few studies have been conducted on the relationship between personality disorders and CAR. The present study aimed to compare the CAR between individuals with personality disorders and healthy controls. Moreover, the study aimed to assess the association of CAR with cognitive biases and psychopathological symptoms in people with personality disorders.

METHODS

A total of 43 individuals with personality disorders and 45 healthy controls were enrolled. Participants completed questionnaires measuring the severity of depressive symptoms, anxiety, cognitive biases, and psychotic-like experiences. Cortisol levels were measured in four morning saliva samples: immediately after awakening, and after 15, 30, and 45 min.

RESULTS

A significantly lower CAR was found among individuals with personality disorders, even after adjustment for age, sex, and the level of education. However, the receiver operating characteristic (ROC) curve analysis showed a relatively low area under the curve (AUC = 0.362). Furthermore, a significant negative correlation was observed between the CAR and the level of external attribution bias among individuals with personality disorders. No significant associations of the CAR with psychopathological symptoms and other cognitive biases were observed.

CONCLUSIONS

Findings from this study indicate that the HPA axis activity might be altered in personality disorders. However, the clinical utility of this observation needs further studies in larger samples. External attribution might be related to the HPA axis alterations in this population.

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.

Sleep and dreaming in the light of reactive and predictive homeostasis

Dreams are often viewed as fascinating but irrelevant mental epihenomena of the sleeping mind with questionable functional relevance. Despite long hours of oneiric activity, and high individual differences in dream recall, dreams are lost into oblivion. Here, we conceptualize dreaming and dream amnesia as inherent aspects of the reactive and predictive homeostatic functions of sleep. Mental activity during sleep conforms to the interplay of restorative processes and future anticipation, and particularly during the second half of the night, it unfolds as a special form of non-constrained, self-referent, and future-oriented cognitive process. Awakening facilitates constrained, goal-directed prospection that competes for shared neural resources with dream production and dream recall, and contributes to dream amnesia. We present the neurophysiological aspects of reactive and predictive homeostasis during sleep, highlighting the putative role of cortisol in predictive homeostasis and forgetting dreams. The theoretical and methodological aspects of our proposal are discussed in relation to the study of dreaming, dream recall, and sleep-related cognitive processes.

Hair Cortisol Concentration as a Biomarker of Symptoms of Depression in the Perinatal Period

Pregnancy is a sensitive period when women experience major hormonal and psychological changes. A high prevalence of the symptoms of depression and manifested major depression rates have been reported during this period, leading to negative outcomes both for mothers and the offspring. Despite its prevalence, the aetiology of depression is not yet fully understood. Nonetheless, alterations in cortisol levels have been proposed as a reliable biomarker to identify pregnant women at risk of perinatal depression. Hair cortisol has recently been extensively used in bio-psychological studies as a suitable non-invasive biomarker for several neuropsychiatric disorders. Various studies have published evidence regarding the relationship between cortisol fluctuations during the perinatal period, measured both in hair and in other substrates, and the onset of perinatal symptoms of depression. This current review provides an overview of cortisol level changes measured in women's hair during pregnancy or the postpartum period and its association with perinatal symptoms of depression. Further studies, including repetitive measurement of both hair cortisol and depression throughout the prenatal period, must be performed to clarify the relationship between cortisol levels and perinatal symptoms of depression.

Effects of limiting digital screen use on well-being, mood, and biomarkers of stress in adults

Studies have linked higher digital screen use with poorer mental health. However, there is limited experimental evidence to suggest a causal relationship. In this trial, we aimed to investigate the effects of limiting recreational digital screen use on mental well-being, mood, and biomarkers of stress in healthy young and middle-aged adults. We randomly allocated 89 families (including 164 adults) to participate in an extensive screen media reduction intervention or control. Participants in the intervention group were instructed to decrease their recreational screen use to less than 3 hours/week/person. Intervention compliance was assessed using applications and tv-monitors. Overall subjective mental well-being and mood, and collected daily biomarkers of stress (salivary cortisol and cortisone) was assessed at baseline and 2-week follow-up. Reducing recreational digital screen use resulted in significantly improved self-reported well-being and mood in adults allocated to the intervention compared to control. We observed no intervention effects for biomarkers of stress. (ClinicalTrials.gov: NCT04098913, 23/09/2019).

Depression among predictors of intermittent claudication: A cross-sectional study

PURPOSE

The aim of the present cross-sectional study was to investigate the relationship between depression and intermittent claudication (IC), independently of traditional risk factors.

MAIN METHODS

The sample consisted of 300 individuals (M age = 65.3 ± 8.7 years, 61.0% female) recruited from the offices of 33 general practitioners. Participants' medical history and the presence of major cardiovascular risk factors were recorded. Participants completed the Edinburgh Claudication Questionnaire. The role of depression (assessed by a shortened version of the Beck Depression Inventory) in predicting IC was examined using a binary logistic regression analysis - controlled for sex, age, hypertonia, diabetes, smoking, hypercholesterinemia, hazardous drinking, and body mass index (BMI).

RESULTS

The descriptive data indicated that the prevalence of depression was 57.9% in the IC subgroup and 16.1% in those free of IC. The bivariate analyses indicated that hypercholesterinemia, smoking, hazardous drinking, BMI, and depression were significantly associated with IC. Male sex and age showed a trend toward being a significant correlate of IC. Results of the multivariate analyses indicated that depressive symptomatology was significant in predicting IC (OR: 1.08 (1.05-1.11)), even after controlling for lifestyle and traditional risk factors such as smoking, hazardous drinking, and BMI. Among traditional risk factors, smoking (OR: 2.44 (1.26-4.74)), hazardous drinking (OR: 1.19 (1.02-1.40)), and hypercholesterinemia (OR: 2.17 (1.26-3.75)) showed a significant, positive relationship with IC.

CONCLUSIONS

These results underscore the importance of a multidisciplinary approach that focuses on supporting health-related behavioral changes and managing mental health symptoms when providing care for patients with IC.

Attentional bias in individuals with depression and adverse childhood experiences: influence of the noradrenergic system?

RATIONALE

Major depressive disorder (MDD) is a severe mental disorder with affective, cognitive, and somatic symptoms. Mood congruent cognitive biases, including a negative attentional bias, are important for development, maintenance, and recurrence of depressive symptoms. MDD is associated with maladaptive changes in the biological stress systems such as dysregulations of central noradrenergic alpha2-receptors in the locus coeruleus-noradrenergic system, which can affect cognitive processes including attention. Patients with adverse childhood experiences (ACE), representing severe stress experiences in early life, might be particularly affected.

OBJECTIVES

With an experimental design, we aimed to gain further knowledge about the role of noradrenergic activity for attentional bias in MDD patients with and without ACE.

METHODS

We tested the effect of increased noradrenergic activity induced by the alpha2-receptor blocker yohimbine on attentional bias in a placebo-controlled repeated measures design. Four groups were included as follows: MDD patients with and without ACE, and healthy participants with and without ACE (total N = 128, all without antidepressant medication).

RESULTS

A significant effect of MDD on attentional bias scores of sad face pictures (p = .037) indicated a facilitated attentional processing of sad face pictures in MDD patients (compared to non-MDD individuals). However, we found no such effect of ACE. For attentional bias of happy face pictures, we found no significant effects of MDD and ACE. Even though a higher increase of blood pressure and salivary alpha-amylase following yohimbine compared to placebo indicated successful noradrenergic stimulation, we found no significant effects of yohimbine on attentional bias of happy or sad face pictures.

CONCLUSIONS

Our results are consistent with the hypothesis of a negative attentional bias in MDD patients. However, as we found no effect of ACE or yohimbine, further research is needed to understand the mechanisms by which ACE increases the risk of MDD and to understand the biological basis of the MDD-related negative attentional bias.

Stress effects on cognitive function in patients with major depressive disorder: Does childhood trauma play a role?

Impaired cognitive functioning constitutes an important symptom of major depressive disorder (MDD), potentially associated with elevated cortisol levels. Adverse childhood experiences (ACE) enhance the risk for MDD and can contribute to disturbances in the stress systems, including cortisol and cognitive functions. In healthy participants, cortisol administration as well as acute stress can affect cognitive performance. In the current study, we tested cognitive performance in MDD patients with (N = 32) and without (N = 52) ACE and healthy participants with (N = 22) and without (N = 37) ACE after psychosocial stress induction (Trier Social Stress Test, TSST) and a control condition (Placebo-TSST). MDD predicted lower performance in verbal learning and both selective and sustained attention, while ACE predicted lower performance in psychomotoric speed and working memory. There were no interaction effects of MDD and ACE. After stress, MDD patients were more likely to show lower performance in working memory as well as in selective and sustained attention compared with participants without MDD. Individuals with ACE were more likely to show lower performance in verbal memory after stress compared with individuals without ACE. Our results indicate negative effects of MDD and ACE on distinct cognitive domains. Furthermore, MDD and/or ACE seem to enhance susceptibility for stress-related cognitive impairments.

Protocol Across study: longitudinal transdiagnostic cognitive functioning, psychiatric symptoms, and biological parameters in patients with a psychiatric disorder

BACKGROUND

Patients with psychiatric disorders, such as major depressive disorder, schizophrenia or obsessive-compulsive disorder, often suffer from cognitive dysfunction. The nature of these dysfunctions and their relation with clinical symptoms and biological parameters is not yet clear. Traditionally, cognitive dysfunction is studied in patients with specific psychiatric disorders, disregarding the fact that cognitive deficits are shared across disorders. The Across study aims to investigate cognitive functioning and its relation with psychiatric symptoms and biological parameters transdiagnostically and longitudinally.

METHODS

The study recruits patients diagnosed with a variety of psychiatric disorders and has a longitudinal cohort design with an assessment at baseline and at one-year follow-up. The primary outcome measure is cognitive functioning. The secondary outcome measures include clinical symptoms, electroencephalographic, genetic and blood markers (e.g., fatty acids), and hair cortisol concentration levels.

DISCUSSION

The Across study provides an opportunity for a transdiagnostic, bottom-up, data-driven approach of investigating cognition in relation to symptoms and biological parameters longitudinally in patients with psychiatric disorders. The study may help to find new clusters of symptoms, biological markers, and cognitive dysfunctions that have better prognostic value than the current diagnostic categories. Furthermore, increased insight into the relationship among cognitive deficits, biological parameters, and psychiatric symptoms can lead to new treatment possibilities.

TRIAL REGISTRATION

Netherlands Trial Register (NTR): NL8170.

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.

Atypical lateralization in neurodevelopmental and psychiatric disorders: What is the role of stress?

Hemispheric asymmetries are a major organizational principle of the human brain. In different neurodevelopmental and psychiatric disorders, like schizophrenia, autism spectrum disorders, depression, dyslexia and posttraumatic stress disorder, functional and/or structural hemispheric asymmetries are altered compared to healthy controls. The question, why these disorders all share the common characteristic of altered hemispheric asymmetries despite vastly different etiologies and symptoms remains one of the unsolved mysteries of laterality research. This review is aimed at reviewing potential reasons for why atypical lateralization is so common in many neurodevelopmental and psychiatric disorders. To this end, we review the evidence for overlaps in the genetic and non-genetic factors involved in the ontogenesis of different disorders and hemispheric asymmetries. While there is evidence for genetic overlap between different disorders, only few asymmetry-related loci have also been linked to disorders and importantly, those effects are mostly specific to single disorders. However, there is evidence for shared non-genetic influences between disorders and hemispheric asymmetries. Most neurodevelopmental and psychiatric disorders show alterations in the hypothalamic-pituitary adrenocortical (HPA) axis and maternal as well as early life stress have been implicated in their etiology. Stress has also been suggested to affect hemispheric asymmetries. We propose a model in which early life stress as well as chronic stress not only increases the risk for psychiatric and neurodevelopmental disorders but also changes structural and functional hemispheric asymmetries leading to the aberrant lateralization patterns seen in these disorders. Thus, pathology-related changes in hemispheric asymmetries are not a factor causing disorders, but rather a different phenotype that is affected by partly overlapping ontogenetic factors, primarily stress.

Examining reactivity patterns in burnout and other indicators of chronic stress

INTRODUCTION

Burnout symptomatology is associated with various negative health consequences; however, the mechanisms underlying these associations remain unclear. One potential pathway involves alterations in the acute stress response. The aims of the present study were to examine burnout-associated alterations in stress-reactivity patterns, during a standardized social stressor compared to a control condition, as well as to examine whether effects associated with greater burnout symptomatology were distinct from other, conceptually overlapping indicators of chronic stress (i.e. depressive symptomatology and elevated hair cortisol concentration [HCC]).

MATERIALS AND METHODS

In a randomized two-factor design a total of 70 employed males with varying burnout symptoms but without evidence of physical or psychiatric disease were exposed to the Trier Social Stress Test for Groups (TSST-G) or a non-stressful control condition. Acute stress reactivity was assessed using self-report stress measures and non-invasive biomarkers. Associations among acute stress reactivity, burnout and depressive symptoms (assessed with self-report measures), as well as HCC were analysed using repeated measure ANCOVAs and moderation analysis.

RESULTS

Burnout symptomatology was associated with elevated stress perception independent of the experimental condition. In addition, depressive symptomatology was associated with enhanced anticipatory appraisal, whereas HCC was not related to any subjective stress measure. On a physiological level, burnout and depressive symptomatology, as well as HCC were associated with a pattern of blunted cardiovascular reactivity, however the timing of this effect varied.

CONCLUSION

Our results indicate burnout-associated modulations in stress reactivity, which diverge, at least partly, from other indicators of chronic stress.

Examining stress: an investigation of stress, mood and exercise in medical students

OBJECTIVES

Stress is an event that threatens homoeostasis and thus causes physiological and behavioural responses to reinstate equilibrium. Excessive and/or chronic stress can be psychologically and physiologically detrimental. Examinations can represent a significant source of stress for students. The hypothalamic-pituitary-adrenal axis (HPA) is the core endocrine stress system. Investigations into the HPA response to examinations have yielded inconsistent results. The aim of this study is to further explore the relationship between examination stress, HPA axis activity, mood, sleep and exercise in students undergoing a naturalistic examination period stressor.

METHODS

In total, 16 medical students participated. Students completed self-reported stress, anxiety, mood, sleep and physical activity questionnaires, and provided saliva samples during an examination-free period and an examination period 1 month later. The cortisol awakening response, representative of HPA activity, was determined from saliva samples by enzyme-linked immunosorbent assay.

RESULTS

Anxiety levels increased (p=0.04) and mood decreased (p=0.05) during the examination period. There was concomitant decease in physical activity levels (p=0.02). There was no significant increase in HPA activity during the examination period (p=0.29). Sleep quality did not significantly worsen (p=0.55) during the examination period.

CONCLUSIONS

Examination periods are associated with increased anxiety levels, lower mood and decreased physical activity. Future studies incorporating examination results and cognitive function may help to identify potential protective interventional strategies, while optimising performance.

Mineralocorticoid receptor function and cognition in health and disease

The steroid hormone cortisol is released in response to stress and exerts its effects in the brain via two different receptors: the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). This review - dedicated to Dirk Hellhammer - focusses on the role of MR on cognitive and emotional function in healthy individuals and in stress-associated disorders such as major depressive disorder (MDD) or borderline personality disorder (BPD). Animal data and studies from healthy individuals converge such that MR play an important role in the appraisal of new situations and the following response selection. Decision-making and empathy are important determinants of this response selection and both are affected by MR function. Furthermore, MR are crucially involved in visuospatial navigation and memory in young and elderly healthy individuals whereas the exact physiological role of MR in verbal learning and verbal memory needs to be further characterized. In contrast to studies in healthy participants, age played a moderating role on the effects of MR stimulation on cognition in depressed patients. In young depressed patients, MR stimulation exerted beneficial effects on verbal memory and executive function, whereas in elderly depressed patients MR stimulation led to impaired verbal learning and visuospatial memory. Similar to healthy controls, BPD patients showed enhanced emotional empathy but not cognitive empathy after MR stimulation. Accordingly, this make MR an interesting target for potential pharmacological augmentation of psychotherapy in BPD. Given the important role MR play in cognitive and emotional function in health and disease, further studies should examine whether MR modulation can alleviate cognitive and emotional problems in patients with stress-associated disorders.

Multilevel Interactions of Stress and Circadian System: Implications for Traumatic Stress

The dramatic fluctuations in energy demands by the rhythmic succession of night and day on our planet has prompted a geophysical evolutionary need for biological temporal organization across phylogeny. The intrinsic circadian timing system (CS) represents a highly conserved and sophisticated internal "clock," adjusted to the 24-h rotation period of the earth, enabling a nyctohemeral coordination of numerous physiologic processes, from gene expression to behavior. The human CS is tightly and bidirectionally interconnected to the stress system (SS). Both systems are fundamental for survival and regulate each other's activity in order to prepare the organism for the anticipated cyclic challenges. Thereby, the understanding of the temporal relationship between stressors and stress responses is critical for the comprehension of the molecular basis of physiology and pathogenesis of disease. A critical loss of the harmonious timed order at different organizational levels may affect the fundamental properties of neuroendocrine, immune, and autonomic systems, leading to a breakdown of biobehavioral adaptative mechanisms with increased stress sensitivity and vulnerability. In this review, following an overview of the functional components of the SS and CS, we present their multilevel interactions and discuss how traumatic stress can alter the interplay between the two systems. Circadian dysregulation after traumatic stress exposure may represent a core feature of trauma-related disorders mediating enduring neurobiological correlates of trauma through maladaptive stress regulation. Understanding the mechanisms susceptible to circadian dysregulation and their role in stress-related disorders could provide new insights into disease mechanisms, advancing psychochronobiological treatment possibilities and preventive strategies in stress-exposed populations.

Cortisol levels and cognitive profile in major depression: A comparison of currently and previously depressed patients

The association between depressive symptoms and elevated cortisol levels, and depression and cognitive functioning, has been less robust in outpatients with symptoms in the mild to moderate range. Furthermore, the association between elevated cortisol levels and cognitive functioning is unclear. In the present study, currently depressed (n = 37), previously depressed (n = 81) and never depressed controls (n = 50) were assessed on a range of neuropsychological measures. Salivary cortisol was measured in the morning and evening. Participants with current depression were non-hospitalized and had symptoms predominately in the mild to moderate range. Elevated salivary evening cortisol, but not morning cortisol, was significantly related to depressive symptoms. The difference in cortisol levels between the previously depressed group and the never depressed controls was not significant. The groups had significantly different cognitive profiles, with the currently depressed performing poorer on tasks related to working memory compared to the never depressed controls. Both the currently and previously depressed performed worse on attentional tasks. The findings indicate that outpatients with mild to moderate depression have elevated cortisol levels and limited mild cognitive impairments. Furthermore, mild impairments in attention may persist after remission, indicating that this could be a trait-marker in depression. The present study did not find support for a significant relationship between cortisol and cognitive functioning.

Targeting hypothalamic-pituitary-adrenal axis hormones and sex steroids for improving cognition in major mood disorders and schizophrenia: a systematic review and narrative synthesis

Cognitive deficits are a core feature of serious mental illnesses such as schizophrenia, major depressive disorder (MDD) and bipolar disorder (BD) and are a common cause of functional disability. There is limited efficacy of pharmacological interventions for improving the cognitive deficits in these disorders. As pro-cognitive pharmacological treatments are lacking, hormones or drugs that target the endocrine system may become potential candidates for 'repurposing' trials aiming to improve cognition. We aimed to study whether treatment with drugs targeting the hypothalamic-pituitary-adrenal (HPA) axis and sex steroids can improve cognition in patients with schizophrenia, MDD or BD. A systematic search was performed using PubMed (Medline), PsychInfo and clinicaltrials.gov, and a narrative synthesis was included. The systematic review identified 12 studies dealing with HPA-related drugs (mifepristone [n = 3], cortisol synthesis inhibitors [ketoconazole, n = 2], dehydroepiandrosterone [n = 5], fludrocortisone [n = 2]) and 14 studies dealing with sex steroids (oestradiol [n = 2], selective oestrogen receptor modulators [raloxifene, n = 7], pregnenolone [n = 5]). Positive trials were found for BD (mifepristone), MDD (dehydroepiandrosterone and fludrocortisone) and schizophrenia (dehydroepiandrosterone, raloxifene and pregnenolone). A replication of positive findings by at least two clinical trials was found for mifepristone in BD and raloxifene and pregnenolone in schizophrenia. The use of drugs targeting hormones related to the HPA axis and sex steroids is a promising field of research that might help to improve the cognitive outcome of patients with schizophrenia, bipolar disorder and major depressive disorder in the near future.

Hypothalamic-pituitary-adrenal axis activity and cognition in major depression: The role of remission status

OBJECTIVES

Neuropsychological deficits and hypothalamic-pituitary-adrenal (HPA) axis dysfunction have been described in major depressive disorder (MDD). We conducted an exploratory study to investigate the role of remission status in the relationship between HPA axis and cognition in MDD.

METHODS

Ninety-seven MDD patients (44 remitted, 53 non-remitted) and 97 healthy controls (HC) were evaluated. We measured verbal and visual memory, working memory, processing speed, attention, and executive function. Three HPA axis measures were assessed: cortisol awakening response (CAR), diurnal cortisol slope, and cortisol suppression ratio with 0.25mg of dexamethasone (DSTR). Multiple linear regression analyses were performed to study the relationship between cortisol measures and cognition while controlling for potential confounders. We conducted an overall analysis in all participants to compare both MDD-remitted and MDD non-remitted groups with respect to HC. Another analysis including MDD patients only was used to explore a moderating effect by remission status.

RESULTS

MDD patients showed poorer cognitive performance compared with HC, without significant differences between remitters and non-remitters. Cortisol measures did not differ between remitters and non-remitters. Although most HPA axis measures were not associated with cognitive dysfunction, we found significant associations between cognitive performance in MDD-remitters and cortisol measures for visual memory, processing speed and executive function. A significant moderating effect for remission status was found between cortisol diurnal slope (but neither CAR nor DSTR) and performance in processing speed or executive function.

CONCLUSIONS

Remission status in MDD appears to moderate the association between some cognitive domains (processing speed and executive function) and HPA axis activity.

Stress and Depression: a Crucial Role of the Mineralocorticoid Receptor

Cortisol and corticosterone act on the appraisal process, which comprises the selection of an appropriate coping style and the encoding of the experience for storage in the memory. This action exerted by the stress hormones is mediated by mineralocorticoid receptors (MRs), which are expressed abundantly in the limbic circuitry, particularly in the hippocampus. Limbic MR is down-regulated by chronic stress and during depression but induced by antidepressants. Increased MR activity inhibits hypothalamic-pituitary-adrenal axis activity, promotes slow wave sleep, reduces anxiety and switches circuit connectivity to support coping. Cortisol and emotion-cognition are affected by MR gene haplotypes based on rs5522 and rs2070951. Haplotype 1 (GA) moderates the effects of (early) life stressors, reproductive cycle and oral contraceptives. MR haplotype 2 (CA) is a gain of function variant that protects females against depression by association with an optimistic, resilient phenotype. Activation of MR therefore may offer a target for alleviating depression and cognitive dysfunction. Accordingly, the MR agonist fludrocortisone was found to enhance the efficacy of antidepressants and to improve memory and executive functions in young depressed patients. In conclusion, CORT coordinates via MR the networks underlying how an individual copes with stress, and this action is complemented by the widely distributed lower affinity glucocorticoid receptor (GR) involved in the subsequent management of stress adaptation. In this MR:GR regulation, the MR is an important target for promoting resilience.

The cortisol awakening response is associated with performance of a serial sequence reaction time task

There is emerging evidence of a relationship between the cortisol awakening response (CAR) and the neural mechanisms underlying learning and memory. The aim of this study was to determine whether the CAR is associated with acquisition, retention and overnight consolidation or improvement of a serial sequence reaction time task. Salivary samples were collected at 0, 15, 30 and 45 min after awakening in 39 healthy adults on 2 consecutive days. The serial sequence reaction time task was repeated each afternoon. Participants completed the perceived stress scale and provided salivary samples prior to testing for cortisol assessment. While the magnitude of the CAR (Z score) was not associated with either baseline performance or the timed improvement during task acquisition of the serial sequence task, a positive correlation was observed with reaction times during the stable performance phase on day 1 (r=0.373, p=0.019). Residuals derived from the relationship between baseline and stable phase reaction times on day 1 were used as a surrogate for the degree of learning: these residuals were also correlated with the CAR mean increase on day 1 (r=0.357, p=0.048). Task performance on day 2 was not associated with the CAR obtained on this same day. No association was observed between the perceived stress score, cortisol at testing or task performance. These data indicate that a smaller CAR in healthy adults is associated with a greater degree of learning and faster performance of a serial sequence reaction time task. These results support recognition of the CAR as an important factor contributing to cognitive performance throughout the day.

Mineralocorticoid receptor stimulation improves cognitive function and decreases cortisol secretion in depressed patients and healthy individuals

Memory and executive function are often impaired in patients with major depression, while cortisol secretion is increased. Mineralocorticoid receptors (MR) are abundantly expressed in the hippocampus and in the prefrontal cortex, brain areas critical for memory, executive function, and cortisol inhibition. Here, we investigated whether MR stimulation with fludrocortisone (1) improves memory and executive function and (2) decreases cortisol secretion in depressed patients and healthy individuals. Twenty-four depressed patients without medication and 24 age-, sex-, and education-matched healthy participants received fludrocortisone (0.4 mg) or placebo in a randomized, double-blind, within-subject cross-over design. We measured verbal memory, visuospatial memory, executive function, psychomotor speed, and salivary cortisol secretion during cognitive testing between 1400 and 1700 hours. For verbal memory and executive function, we found better performance after fludrocortisone compared with placebo across groups. No treatment effect on other cognitive domains emerged. Depressed patients performed worse than healthy individuals in psychomotor speed and executive function. No group effect or group × treatment interaction emerged on other cognitive domains. Fludrocortisone decreased cortisol secretion across groups and there was a significant correlation between cortisol inhibition and verbal memory performance. Our data suggest a crucial role of MR in verbal memory and executive function and demonstrate the possibility to improve cognition in depressed patients and healthy individuals through MR stimulation.

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.

Cognitive performance in irritable bowel syndrome: evidence of a stress-related impairment in visuospatial memory

BACKGROUND

Central nervous system (CNS) dysfunction is a prominent feature of the functional gastrointestinal (GI) disorder, irritable bowel syndrome (IBS). However, the neurobiological and cognitive consequences of key pathophysiological features of IBS, such as stress-induced changes in hypothalamic-pituitary-adrenal (HPA)-axis functioning, is unknown. Our aim was to determine whether IBS is associated with cognitive impairment, independently of psychiatric co-morbidity, and whether cognitive performance is related to HPA-axis function.

METHOD

A cross-sectional sample of 39 patients with IBS, a disease control group of 18 patients with Crohn's disease (CD) in clinical remission and 40 healthy age- and IQ-matched control participants were assessed using the Paired Associates Learning (PAL), Intra-Extra Dimensional Set Shift (IED) and Spatial Working Memory (SWM) tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and a computerized Stroop test. HPA-axis function was determined by measuring the cortisol awakening response (CAR).

RESULTS

IBS patients exhibited a subtle visuospatial memory deficit at the PAL six- pattern stage (p = 0.03), which remained after psychiatric co-morbidity was controlled for (p = 0.04). Morning cortisol levels were lower in IBS (p = 0.04) and significantly associated with visuospatial memory performance within IBS only (p = 0.02).

CONCLUSIONS

For the first time, altered cognitive function on a hippocampal-mediated test of visuospatial memory, which was related to cortisol levels and independent of psychiatric co-morbidity, has been identified in IBS. Visuospatial memory impairment may be a common, but currently neglected, component of IBS. Further elucidation of the nature of this impairment may lead to a greater understanding of the underlying pathophysiology of IBS, and may provide novel therapeutic approaches.