Trait positive and negative emotionality differentially associate with diurnal cortisol activity

When virtual reality becomes psychoneuroendocrine reality: A stress(or) review

This review article was awarded the Dirk Hellhammer award from ISPNE in 2023. It explores the dynamic relationship between stressors and stress from a historical view as well as a vision towards the future of stress research via virtual reality (VR). We introduce the concept of a "syncytium," a permeable boundary that blurs the distinction between stress and stressor, in order to understand why the field of stress biology continues to inadequately measure stress alone as a proxy for the force of external stressors. Using Virtual Reality (VR) as an illustrative example to explicate the black box of stressors, we examine the distinction between 'immersion' and 'presence' as analogous terms for stressor and stress, respectively. We argue that the conventional psychological approaches to stress measurement and appraisal theory unfortunately fall short in quantifying the force of the stressor, leading to reverse causality fallacies. Further, the concept of affordances is introduced as an ecological or holistic tool to measure and design a stressor's force, bridging the gap between the external environment and an individual's physiological response to stress. Affordances also serve to ameliorate shortcomings in stress appraisal by integrating ecological interdependencies. By combining VR and psychobiological measures, this paper aims to unravel the complexity of the stressor-stress syncytium, highlighting the necessity of assessing both the internal and external facets to gain a holistic understanding of stress physiology and shift away from reverse causality reasoning. We find that the utility of VR extends beyond presence to include affordance-based measures of immersion, which can effectively model stressor force. Future research should prioritize the development of tools that can measure both immersion and presence, thereby providing a more comprehensive understanding of how external stressors interact with individual psychological states.

The cortisol awakening response in a 3 month clinical trial of service dogs for veterans with posttraumatic stress disorder

Recent literature suggests that service dogs may be a valuable complementary intervention option for posttraumatic stress disorder (PTSD) among military veterans due to the potential influence on stress response dysregulation. The aim of this short-term longitudinal study was to quantify the impact of service dogs in US military veterans with PTSD with particular attention to the cortisol awakening response. A sub aim of the study was to empirically evaluate the physiological effects of PTSD service dogs on veteran partners. We conducted a clinical trial (ID: NCT03245814) that assessed the cortisol awakening response for 245 participants at baseline and 3 months follow-up across an intervention group (service dog: veterans n = 88, partners n = 46) and control group (usual care: n = 73, partners n = 38). A total of N = 161 veterans and N = 84 partners collected whole saliva samples via a passive drool collection immediately upon waking, 30 min after waking, and 45 min after waking on three consecutive weekdays at baseline and again at follow-up. Mixed model repeated measures (MMRM) with a fixed effect of the intervention group (service dog or control) were utilized. Covariates considered for the model included time of awakening, sleep duration, sleep efficiency, prior day experiences (measured via ecological momentary assessment), traumatic brain injury, age, gender, race, ethnicity, socioeconomic status, smoking status, alcohol use, physical health, and body mass index. A total of 3951 salivary samples were collected (veterans: 2613, partners: 1338). MMRM results demonstrated that veterans with a service dog had a statistically significant higher cortisol awakening response, including the area under the curve with respect to both increase (AUCi, β = 1.46, p = 0.046) and absolute increase (AINC, β = 0.05, p = 0.035). Results were not statistically significant for partners. Findings suggest that veterans with service dogs have a higher, less blunted CAR in comparison to veterans receiving usual care alone. In veterans with a blunted morning cortisol response, service dog placement could help boost their morning cortisol response.

Teachers' situational physiological stress and affect

Since teaching is a demanding and stressful profession, the study of teachers' physiological stress in the classroom setting is an emerging field. In cross-sectional studies self-reported stress and affect are related, but less is known about the intraindividual relations between situational physiological stress and corresponding positive and negative affect. The aim of our study was to investigate the associations between situational physiological stress (six salivary cortisol samples per day) and self-reported situational affect (Positive and Negative Affect Schedule four times a day) among 61 Finnish primary school teachers over two workdays. We present a novel multilevel structural equation model (MSEM) that includes cortisol, with time since awakening as a flexibly coded time-varying covariate and affect with time since cortisol measurement as a time-varying covariate. Higher levels of teachers' situational physiological stress were related to lower situational positive affect (e.g., enthusiasm) and higher negative affect (e.g., nervousness), demonstrating the acute/situational effects of stress on affect. In our discussion, we emphasize the importance of the sequence of sampling and observations for further theoretical modeling of relations between stress and affect. We also propose practical implications for improving teachers' awareness of their well-being.

Salivary cortisol levels and appraisals of daily hassles across dimensions of the tripartite model of anxiety and depression in emerging adults

The objective of this study was to investigate how cortisol levels and appraisals of daily hassles differ across tripartite dimensions of depression and anxiety in emerging adults. Data collected from a sample of undergraduate students at a large Midwestern university was used to investigate these aims. This included salivary cortisol data collected over four days, scores on a measure of the tripartite model of anxiety and depression, and scores on a measure of daily hassles administered everyday for two weeks. Generalized estimating equations and multilevel modeling techniques were used to analyze data. Elevated cortisol levels during the awakening period and the evening period, lower total levels across the day, steeper diurnal slopes, and elevated levels of negative affect and physiological hyperarousal predicted experiences of daily hassles. Tripartite dimensions were unrelated to cortisol indices. The present study demonstrates the utility of modeling multiple cortisol indices and provides evidence of differential associations between physiological and phenomenological indices of stress.

Altered psychobiological reactivity but no impairment of emotion recognition following stress in adolescents with non-suicidal self-injury

Impairments in both stress regulation and emotion recognition have been associated with borderline personality disorder (BPD) and non-suicidal self-injury (NSSI). Although it has been proposed that emotion recognition deficits particularly emerge during stress, this hypothesis has not been fully investigated. Adolescents with and without NSSI performed emotion recognition tasks before and after the employment of the Trier Social Stress Test (TSST). The psychobiological stress response was captured with psychological self-reports (affect, stress and dissociation), physiological recordings (heart rate, HR, and heart rate variability, HRV) and endocrinological sampling of saliva (cortisol and alpha-amylase). Mixed-linear models were applied to analyze stress-induced changes in emotion recognition performance and respective stress response measures. The TSST elicited altered psychobiological stress responses in adolescents with NSSI: A more pronounced decrease in positive affect, a more pronounced increase in negative affect, a less pronounced increase in HR, a less pronounced decrease in HRV and a more pronounced increase in alpha-amylase throughout the stress induction than adolescents without NSSI. Stress responses (dissociation, negative affect, cortisol and HR) differed as a function of BPD severity on a continuum, illustrating greater reactivity on self-reports but decreased biological responsiveness in those with greater BPD severity. Stress induction had similar effects on emotion recognition in adolescents with and without NSSI. Recognition sensitivity and recognition speed equally increased, in the absence of any differences in recognition accuracy. In contrast to prominent propositions, psychosocial stress does not appear to account for impaired emotion recognition across the BPD spectrum.

Reward sensitivity modulates the brain reward pathway in stress resilience via the inherent neuroendocrine system

In the previous 10 years, researchers have suggested a critical role for the brain reward system in stress resilience. However, no study has provided an empirical link between activity in the mesostriatal reward regions during stress and the recovery of cortisol stress response. Moreover, although reward sensitivity as a trait has been demonstrated to promote stress resilience, it remains unclear whether it modulates the brain reward system in stress resilience and how this effect is achieved by the inherent neuroendocrine system. To investigate these uncertainties, 70 young adults were recruited to participate in a ScanSTRESS task, and their brain imaging data and saliva samples (for cortisol assay) were collected during the task. In addition, we assessed reward sensitivity, cortisol awakening response, and intrinsic functional connectivity of the brain in all the participants. We found that left putamen activation during stress exposure positively predicted cortisol recovery. In addition, reward sensitivity was positively linked with activation of the left putamen, and this relationship was serially mediated by the cortisol awakening response and right hippocampus-left inferior frontal gyrus intrinsic connectivity. These findings suggest that reward sensitivity modulates reward pathways in stress resilience through the interplay of the diurnal stress response system and network of the hippocampus-prefrontal circuitry. Summarily, the current study built a model to highlight the dynamic and multifaceted interaction between pertinent allostatic factors in the reward-resilience pathway and uncovered new insight into the resilience function of the mesostriatal reward system during stress.

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Cortisol recovery can be predicted by activation of the left putamen in stress.

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Activation of the left putamen was positively linked with reward sensitivity.

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This relationship was serially mediated by the cortisol awakening response and right hippocampus-left inferior frontal gyrus intrinsic coupling.

Longitudinal associations between salivary cortisol to C-reactive protein ratios and psychological well-being in Chinese adults

BACKGROUND

Salivary C-reactive protein (CRP) could be a viable biomarker of inflammation and has been associated with stress outcomes. The hypothalamic-pituitary-adrenal axis can modulate stress-related inflammation. This study aimed to evaluate the interaction effects of immune-endocrine markers on psychological outcomes.

METHODS

The study participants were 52 healthy Chinese adults who collected 10 saliva samples over 2 consecutive days at baseline. The participants completed validated measures on anxiety, depression, positive affect, and sleep disturbance at baseline and 1 month later. The stability and diurnal patterns of salivary cortisol and CRP were investigated via paired t-tests and repeated-measures analyses of variance. Regression analysis was used to examine the longitudinal associations between immune-endocrine markers and their interactions (cortisol [Cort]: morning CRP [CRP_morn] and Cort:CRP_even) and psychological measures.

RESULTS

Salivary cortisol and CRP displayed satisfactory stability over 2 consecutive days and diurnal patterns of abrupt and gradual decline during the day, respectively. Controlling for baseline psychological measures and confounding variables, Cort_morn and diurnal cortisol slope was significantly and negatively associated with anxiety symptoms and positive affect 1 month later, respectively. Cort:CRP_even and Cort:CRP_morn was significantly and positively associated with depressive symptoms and sleep disturbance 1 month later, respectively.

CONCLUSION

These findings offer initial support for the prognostic utility of salivary cortisol and CRP and their balance as determinants of psychological health in healthy adults.

The human physiology of well-being: A systematic review on the association between neurotransmitters, hormones, inflammatory markers, the microbiome and well-being

To understand the pathways through which well-being contributes to health, we performed a systematic review according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines on the association between well-being and physiological markers in four categories, neurotransmitters, hormones, inflammatory markers, and microbiome. We identified 91 studies. Neurotransmitter studies (k_{number of studies}=9) reported only a possible positive association between serotonin and well-being. For the hormone studies (k = 48), a lower momentary cortisol level was related to higher well-being (meta-analytic r = -0.06), and a steeper diurnal slope of cortisol levels. Inflammatory marker studies (k = 36) reported negative or non-significant relations with well-being, with meta-analytic estimates of respectively r = -0.07 and r = -0.05 for C-reactive protein and interleukin-6. Microbiome studies (k = 4) reported inconsistent associations between different bacteria abundance and well-being. The results indicate possible but small roles of serotonin, cortisol, and inflammatory markers in explaining differences in well-being. The inconsistent and limited results for other markers and microbiome require further research. Future directions for a complete picture of the physiological factors underlying well-being are proposed.

The Undoing Effect of Positive Emotions: A Meta-Analytic Review

The undoing hypothesis proposes that positive emotions serve to undo sympathetic arousal related to negative emotions and stress. However, a recent qualitative review challenged the undoing effect by presenting conflicting results. To address this issue quantitatively, we conducted a meta-analytic review of 16 studies ( N = 1,220; 72 effect sizes) measuring sympathetic recovery during elicited positive emotions and neutral conditions. Findings indicated that in most cases, positive emotions did not speed sympathetic recovery compared to neutral conditions. However, when a composite index of cardiovascular reactivity was used, undoing effects were evident. Our findings suggest the need for further work on the functions of positive emotions.

A 14-day ecological momentary assessment study on whether resilience and early family risk moderate daily stress and affect on cortisol diurnal slope

This study examined whether resilience capacity moderates the association of daily perceived stress and affect with cortisol diurnal slope among relocated emerging adults. Relocated undergraduates (N = 98; aged 18-25 years) were recruited from three groups: Resilient, Vulnerable, and Control. The Resilient group required Risky Family Questionnaire (RFQ) scores ≥ 29 and Brief Resilience Scale (BRS) scores ≥ 3.6. The Vulnerable group required RFQ scores ≥ 29 and BRS scores ≤ 3. The comparison Control group required RFQ scores ≤ 21 and T-scores < 60 on PROMIS anxiety and depression symptoms. Mixed-effects models were used to test the unique associations of perceived stress, negative affect, and positive affect x group interactions (predictors) on diurnal cortisol slope (outcome) across 14 consecutive days. The Resilient group did not moderate the associations between daily stress or affect on cortisol diurnal slope. Instead, both the Resilient and Vulnerable groups with early family risk, showed a steeper diurnal slope unique to higher stress and a flatter slope unique to higher negative affect. Results suggest that riskier early family life was significantly associated with altered cortisol diurnal slope outcomes to stress (i.e., demand) and negative affect (i.e., distress). These associations were not attenuated by current resilience capacity.

The cortisol awakening response and the late positive potentials evoked by unpleasant emotional pictures in healthy adults

The cortisol awakening response (CAR) refers to a sharp rise in cortisol concentrations within the 45 min following morning awakening. Alterations in CAR have been associated with various internalizing symptoms and brain function. The current study aimed to investigate the association between CAR and neural activity in response to unpleasant emotional pictures. A total of 46 healthy adults (22.55 years ± 1.69) collected saliva samples at 0, 30, and 45 min post-awakening on two days to assess the CAR. In the afternoon after CAR measurement on the first day, electroencephalograms were recorded when the participants completed a passive viewing task. The results showed that a greater CAR was associated with a decreased late positive potential difference score between unpleasant and neutral stimuli. This finding indicates that a larger CAR may be associated with decreased attentional engagement to unpleasant emotional information in healthy adults.

Positive and negative affect are associated with salivary cortisol in the everyday life of older adults: A quantitative synthesis of four aging studies

Research on time-fluctuating links between positive affect and cortisol is inconsistent and mostly based on young to middle-aged samples. The current project investigated how moment-to-moment changes in positive and negative affect are associated with moment-to-moment changes in cortisol levels in older adults' daily lives and whether those associations are moderated by differences in health status (as indicated by the number of comorbidities). Affect and cortisol data collected in four separately conducted momentary assessment studies with parallel protocols were pooled to obtain a sample of N=476 individuals aged 56-88 years (M_age=71.9, SD=6.6; 52% female). Participants provided affect reports and collected salivary cortisol 5-7 times a day for a 7-day period and reported the presence of 13 different health conditions. Data were analyzed using multilevel models, with time since waking, daily behaviors associated with cortisol secretion, age, and sex controlled. Feeling more positive affect than usual was associated with lower momentary cortisol. In contrast, feeling more negative affect than usual was associated with higher momentary cortisol. Associations of momentary positive and negative affect with cortisol were weaker among participants in worse as compared to those in better health. Trait positive affectivity was associated with more curvature of waking cortisol profiles and trait negative affectivity was associated with smaller cortisol awakening responses. Findings suggest that HPA axis responses fluctuate with everyday changes in positive and negative affect in older adults, and that higher HPA reactivity may indicate preserved health in this age group.

Cortisol activity partially accounts for a relationship between community socioeconomic position and atherosclerosis

Compared to others, individuals living in communities of socioeconomic disadvantage experience more atherosclerotic cardiovascular disease (CVD) and a greater extent of preclinical atherosclerosis. Although the mechanisms underlying these associations remain unclear, it is widely hypothesized that alterations in normative cortisol release from the Hypothalamic Pituitary Adrenal (HPA) axis may play a role in linking lower community socioeconomic position (C-SEP) to CVD risk. The current study examined this hypothesis in relation to a marker of preclinical atherosclerosis among 488 healthy midlife adults (30-54 years, Mean age= 43, 52% Female, 81% White). All participants were employed and without clinical CVD. C-SEP was estimated from census tract data, and atherosclerosis was measured as intima-medial thickness of the carotid arteries (cIMT) by duplex ultrasonography. Four indicators of HPA activity [cortisol at awakening and the cortisol awakening response (CAR), rate of diurnal decline in cortisol (diurnal slope), and total output expressed as area under the curve (AUC)] were derived from salivary cortisol measurements obtained from 5 samples on each of 3 working days. Path analyses were used to examine associations of C-SEP with cIMT and HPA activity and to test whether individual differences in HPA activity could account for any association of C-SEP with cIMT using bootstrapping (5000 iterations). All models were adjusted for age, sex, race, and composite measures of both individual-level socioeconomic position (income, education, occupation), and cardiometabolic risk (systolic and diastolic blood pressure, waist circumference, fasting lipids and glucose). Lower C-SEP was related to both greater cIMT (b = -0.004, p = .021) and a flatter diurnal slope of cortisol (b = -0.001, p = .039). An indirect effect showed attenuated diurnal slope to partially mediate the relationship between C-SEP and cIMT (95% CI = -0.0018 to -0.0001), and a residual direct effect of C-SEP on cIMT remained significant (95% CI = -0.0097 to -0.004). These results suggest that low C-SEP associations with preclinical atherosclerosis may be due in part to correlated variation in adrenocortical activity.

Social Integration and Diurnal Cortisol Decline: The Role of Psychosocial and Behavioral Pathways

OBJECTIVE

A growing number of studies have associated various measures of social integration, the diversity of social roles in which one participates, with alterations in hypothalamic-pituitary-adrenocortical (HPA) functioning. The pathways through which social integration may be linked to HPA functioning, however, are as yet unknown. The present study examined whether daily social interactions, affective responses, health behaviors, and personality help explain the association between social integration and diurnal cortisol slope.

METHODS

A sample of 456 healthy, employed adults (53.9% female, 82.0% white, 72.2% bachelor's degree or greater, mean age of 42.86 years) completed a 4-day ecological momentary assessment protocol that measured cortisol, social interactions, affect, sleep, and physical activity at frequent intervals throughout the day. Social integration was measured at baseline.

RESULTS

Regression results controlling for age, sex, race, and education indicated that more socially integrated individuals showed steeper cortisol slopes (B = -0.00253, p = .006). Exploratory analyses suggested that the consistency (i.e., reduced variability) in nightly sleep midpoint partially explained this association (B = -0.00042, 95% confidence interval = -0.00095 to -0.00001). Personality, mood, social interaction patterns, and nonsleep health behavior differences did not account for the association between social integration and HPA activity.

CONCLUSION

This study replicates previous findings linking social integration and HPA functioning, and it examines patterns of nightly sleep as possible pathways through which the association may operate. Results have implications for understanding mechanisms for health risk and for development of future interventions.

Racial exclusion causes acute cortisol release among emerging-adult African Americans: The role of reduced perceived control

Racial discrimination contributes to stress-related health disparities among African Americans, but less is known about the acute effects of racial exclusion on the hypo-pituitary-adrenocortical response and psychological mediators. Participants were 276 Black/African American emerging-adults (54% female; M _age = 21.74, SD = 2.21) who were randomly assigned to be excluded or included by White peers via the game Cyberball. Racial exclusion (vs. inclusion) predicted: greater negative affect (F(1, 276) = 104.885, p < .0001), lower perceived control (F(1, 276) = 205.523, p < .0001), and greater cortisol release (F(1, 274) = 4.575, p = .033). Racial exclusion's impact on cortisol release was mediated by lower perceived control (95% CI: .027, .112), but not negative affect (-.041, .013). These findings suggest that racial exclusion contributes to acute cortisol release, and that reduced perceived control is a consequence of racial discrimination that has important implications for the health of those who experience discrimination.

High Cortisol and the Risk of Dementia and Alzheimer's Disease: A Review of the Literature

Introduction: Cortisol effects on the brain are exerted through two distinct receptors, inducing complex and even opposite effects on the cerebral structures implicated in the various cognitive functions. High cortisol may also have deleterious effects on the brain structures and contribute to neurodegeneration, in particular Alzheimer’s disease (AD), via different mechanisms.

Objective: To examine the interrelationships between cortisol, cognitive impairment and AD.

Methods: Review of the literature.

Results: Clinical studies found that elevated cortisol was associated with poorer overall cognitive functioning, as well as with poorer episodic memory, executive functioning, language, spatial memory, processing speed, and social cognition; while in animals, glucocorticoid administration resulted in cognitive impairment and abnormal behavior. In cognitively healthy subjects, higher cortisol levels have been associated with an increased risk of cognitive decline and AD. Subjects with dementia and Mild Cognitive Impairment (MCI) due to AD have been found to have higher CSF cortisol levels than cognitively healthy controls. Elevated CSF cortisol may also be associated with a more rapid cognitive decline in MCI due to AD. Elevated cortisol levels have been also found in delirium. High cortisol may mediate the impact of stressful life events, high neuroticism, depression, sleep disturbances, as well as cardiovascular risk factors on cognitive performance, neurodegeneration, and cognitive decline. High cortisol may also exert neurotoxic effects on the hippocampus, and promote oxidative stress and amyloid β peptide toxicity. Further possible underlying mechanisms include the interactions of cortisol with inflammatory mediators, neurotransmitters, and growth factors.

Conclusion: Elevated cortisol levels may exert detrimental effects on cognition and contribute to AD pathology. Further studies are needed to investigate cortisol-reducing and glucocorticoidreceptor modulating interventions to prevent cognitive decline.

Happiness and Health

Research into the relationship between happiness and health is developing rapidly, exploring the possibility that impaired happiness is not only a consequence of ill-health but also a potential contributor to disease risk. Happiness encompasses several constructs, including affective well-being (feelings of joy and pleasure), eudaimonic well-being (sense of meaning and purpose in life), and evaluative well-being (life satisfaction). Happiness is generally associated with reduced mortality in prospective observational studies, albeit with several discrepant results. Confounding and reverse causation are major concerns. Associations with morbidity and disease prognosis have also been identified for a limited range of health conditions. The mechanisms potentially linking happiness with health include lifestyle factors, such as physical activity and dietary choice, and biological processes, involving neuroendocrine, inflammatory, and metabolic pathways. Interventions have yet to demonstrate substantial, sustained improvements in subjective well-being or direct impact on physical health outcomes. Nevertheless, this field shows great potential, with the promise of establishing a favorable effect on population health.

Hypothalamic-pituitary-adrenal axis activity in the comorbidity between obsessive-compulsive disorder and major depression

Major depressive disorder (MDD) is the most common psychiatric comorbidity in patients with obsessive-compulsive disorder (OCD). Hypothalamic-pituitary-adrenal (HPA) axis abnormalities have been described in both disorders and might play a role in the association between them. We aimed to study the role of HPA axis activity in the comorbidity between OCD and MDD, while controlling for psychopathological dimensions such as anxiety and depressive symptoms. We studied 324 participants belonging to four diagnostic groups: 1) MDD (n = 101), 2) OCD with comorbid MDD (n = 33), 3) OCD without MDD (n = 52), and 4) healthy subjects (n = 138). State anxiety, trait anxiety and depressive symptoms were assessed. Three HPA axis measures were analyzed in saliva: cortisol awakening response (CAR), diurnal cortisol slope (calculated using two formulas: [1] awakening to 11 p.m. [AWE diurnal slope]; [2] considering fixed time points [FTP diurnal slope] from 10 a.m. to 11 p.m.), and dexamethasone suppression test ratio after 0.25 mg of dexamethasone (DSTR). Multiple linear regression analyses were conducted to explore the contribution of clinical diagnosis and symptom dimensions to each HPA axis measure. A more flattened FTP diurnal cortisol slope was observed for OCD patients with comorbid MDD. Regarding the CAR and DSTR, a significant interaction was found between trait anxiety and OCD, as OCD patients with greater trait anxiety showed an increased CAR and reduced cortisol suppression after dexamethasone administration. Our results suggest that trait anxiety plays an important role in the relationship between HPA axis measures and OCD/MDD comorbidity.

Circadian mood variations in Twitter content

Background:

Circadian regulation of sleep, cognition, and metabolic state is driven by a central clock, which is in turn entrained by environmental signals. Understanding the circadian regulation of mood, which is vital for coping with day-to-day needs, requires large datasets and has classically utilised subjective reporting.

Methods:

In this study, we use a massive dataset of over 800 million Twitter messages collected over 4 years in the United Kingdom. We extract robust signals of the changes that happened during the course of the day in the collective expression of emotions and fatigue. We use methods of statistical analysis and Fourier analysis to identify periodic structures, extrema, change-points, and compare the stability of these events across seasons and weekends.

Results:

We reveal strong, but different, circadian patterns for positive and negative moods. The cycles of fatigue and anger appear remarkably stable across seasons and weekend/weekday boundaries. Positive mood and sadness interact more in response to these changing conditions. Anger and, to a lower extent, fatigue show a pattern that inversely mirrors the known circadian variation of plasma cortisol concentrations. Most quantities show a strong inflexion in the morning.

Conclusion:

Since circadian rhythm and sleep disorders have been reported across the whole spectrum of mood disorders, we suggest that analysis of social media could provide a valuable resource to the understanding of mental disorder.

The Protective Role of Positive Well-Being in Cardiovascular Disease: Review of Current Evidence, Mechanisms, and Clinical Implications

Positive psychological aspects of well-being-including positive emotions, optimism, and life satisfaction-are increasingly considered to have protective roles for cardiovascular disease (CVD) and longevity. A rapidly-growing body of literature has linked positive well-being with better cardiovascular health, lower incidence of CVD in healthy populations, and reduced risk of adverse outcomes in patients with existing CVD. This review first examines evidence on the associations of positive well-being with CVD and mortality, focusing on recent epidemiological research as well as inconsistent findings. Next, an overview is provided of putative biological, behavioral, and stress-buffering mechanisms that may underlie the relationship between positive well-being and cardiovascular health. Key areas for future inquiry are discussed, in addition to emerging developments that capitalize on technological and methodological advancements. Promising initial results from randomized controlled trials suggest that efforts to target positive well-being may serve as valuable components of broader CVD management programs.

Daily positive events and diurnal cortisol rhythms: Examination of between-person differences and within-person variation

Growing evidence from field studies has linked daily stressors to dysregulated patterns of diurnal cortisol. Less is known about whether naturally-occurring positive events in everyday life are associated with diurnal cortisol. The objectives of this study were to evaluate daily positive events as predictors of between-person differences and within-person (day-to-day) variations in diurnal cortisol parameters, in addition to daily positive events as buffers against the associations between daily stressors and cortisol. In the National Study of Daily Experiences, 1657 adults ages 33-84 (57% female) reported daily experiences during telephone interviews on 8 consecutive evenings. Saliva samples were collected 4 times per day on 4 interview days and assayed for cortisol. Multilevel models were used to estimate associations of daily positive events with cortisol awakening response (CAR), diurnal cortisol slope, and area under the curve (AUC). At the between-person level, people who experienced more frequent positive events exhibited a steeper diurnal cortisol slope, controlling for daily stressors, daily affect, and other covariates. At the within-person level, positive events in the morning (but not prior-night or afternoon/evening events) predicted steeper decline in cortisol across that day; positive events were also marginally associated with lower same-day AUC. Associations were not mediated by daily positive affect, and positive events did not buffer against stressor-related cortisol alterations. These findings indicate that individual differences and day-to-day variations in daily positive events are associated with diurnal cortisol patterns, independent of stressors and affect.

Personality, Cortisol, and Cognition in Non-demented Elderly Subjects: Results from a Population-Based Study

Certain personality traits, in particular higher neuroticism, have been associated, on one hand, with elevated cortisol levels, and on the other hand, with poorer cognitive performance. At the same time, several studies highlighted the association between high cortisol and poor cognitive functioning. Here, we hypothesized that increased cortisol may be associated with poorer cognition and with certain personality traits (mainly high neuroticism), and that personality might explain the association between cortisol and cognition. A cross-sectional analysis was conducted using data from Colaus/PsyColaus, a population-based study involving residents of Lausanne, Switzerland. Salivary cortisol samples (upon waking, 30 min after waking, at 11 am and at 8 pm) along with cognitive and personality measures were obtained from 643 non-demented participants aged at least 65. Personality traits were assessed using the NEO Five-Factor Inventory (NEO-FFI). We examined the links between the cortisol Area under the Curve (AUC), the Clinical Dementia Rating Sum of Boxes (CDRSOB) and the NEO-FFI scores. No association was found between personality traits and the CDRSOB or the MMSE score, controlling for age, sex, depression, education and BMI. However, the executive functioning domain z-score was negatively associated with agreeableness (p = 0.005; slope = -0.107 [-0.181; -0.033]) and openness (p = 0.029; slope = -0.081 [-0.154; -0.008]) after controlling for age, sex, depression, education and BMI. The CDRSOB score was positively associated with the cortisol AUC after controlling for age, sex, BMI, education and depression, (p = 0.003; slope = 0.686 [0.240; 1.333]). This association remained significant after controlling for personality traits and for the interaction between personality traits and the cortisol AUC (p = 0.006; slope = 0.792 [0.233; 1.352]. High agreeableness and openness might be associated with poorer executive performance in later life. Increased cortisol may be associated with both specific personality traits (high extraversion, low openness) and worse cognitive performance. Increased salivary cortisol does not mediate the relationship between personality traits and cognitive impairment.

Stress vulnerability in male youth with Internet Gaming Disorder

Internet Gaming Disorder [IGD] was introduced as new behavioral addiction in DSM-5 Section 3. Vulnerability to stress is a potential predisposing factor for IGD. Given a lack of preexisting empirical data, the study investigated differences in the psychological and neurobiological response to acute stress in patients with IGD. 24 young men (mean age 18.38 years; range 13-25 years) fulfilling DSM-5 criteria for IGD and 25 matched controls underwent the Trier Social Stress Test [TSST]. Participants provided hair samples for the analysis of basal hypothalamic-pituitary-adrenal [HPA] axis activity and clinical interviews were conducted to assess psychopathology. During the experiment, participants reported on their subjective stress experience and momentary affect, provided samples of salivary cortisol and their heart rate was continuously recorded. Patients with IGD reported greater everyday and chronic stress, as well as psychopathological comorbidity. No differences were found on measures of hair cortisol. Compared to controls, IGD patients showed an attenuated cortisol response (χ²₍₇₎=25.75, p<0.001) and greater negative affect (χ²₍₇₎=17.25, p=0.016) in response to acute stress. Heart rate (χ²₍₁₎=5.49, p=0.019), negative affect (χ²₍₁₎=5.60, p=0.018) and subjective stress (χ²₍₁₎=5.55, p=0.019) were transiently increased in IGD patients. After adjusting for sportive activities, IGD patients showed transiently decreased cortisol (χ²₍₁₎=5.20, p=0.022), potentially indicating general HPA-axis dysfunction beyond altered reactivity. Stress reactivity showed correlations with IGD symptom severity. Findings illustrate differences in acute psychological and neurobiological stress reactivity in patients with IGD. Alterations of the stress response system may be involved in the development and maintenance of IGD.