Cortisol awakening response (CAR)'s flexibility leads to larger and more consistent associations with psychological factors than CAR magnitude

Relationship of sleep with diurnal cortisol rhythm considering sleep measurement and cortisol sampling schemes

Information on the relationships between the previous night's sleep and the next-day diurnal cortisol rhythm is inconsistent due to confounding factors such as sleep measurements (trait/state sleep and objective/subjective sleep) and cortisol sampling schemes. Therefore, this study aimed to investigate these relationships, considering the confounding factors. College students (n = 79) wore actigraphy for 3 days to undergo an evaluation of previous night-time sleep objectively and reported their subjective sleep parameters in a sleep diary. In addition, participants provided six salivary cortisol samples daily. Furthermore, six cortisol sampling schemes were created to reflect diurnal cortisol rhythms, and two different methods were used to calculate the index of diurnal cortisol slope (DCS). A multilevel model was created to examine the impact of both trait and state sleep on next-day diurnal cortisol rhythm. The results revealed that higher objective state sleep efficiency and longer objective state total sleep time were associated with a higher cortisol awakening response (CAR). Moreover, higher objective trait sleep efficiency and longer objective trait total sleep time were associated with higher waking cortisol levels and steeper DCS. In addition, a minimum of four saliva samples were required at different time points, including upon waking, 30 min after waking, 1 h after waking, and at bedtime, to explore the relationship of sleep efficiency/total sleep time with waking cortisol, CAR, and DCS. Furthermore, the index of the peak-to-bed slope was appropriately employed to examine the relationship between sleep efficiency and DCS, whereas the wake-to-bed slope was effective for examining the relationship between total sleep time and DCS. In summary, this study clarified the relationship between sleep and next-day diurnal cortisol rhythm and suggested a cost-effective cortisol sampling schedule and calculation methods.

Cortisol in functional neurological disorders: State, trait and prognostic biomarkers

OBJECTIVE

Biological stress dysregulation, such as a flattened cortisol awakening response (CAR), has been identified in functional neurological disorder (FND). This longitudinal study aimed to explore whether CAR alterations in FND serve as state or trait biomarkers, assessing temporal changes in cortisol and clinical outcomes to test its prognostic value.

METHODS

Salivary cortisol was measured in 53 patients with mixed FND at two visits separated by eight months (M0 and M8). CAR was calculated based on five consecutive samples, each taken with 15-min time intervals, collected upon awakening, whereas cortisol amplitude (CAmp) was calculated as the difference between the morning peak and the afternoon trough. Clinical outcome was assessed with the Functional Movement Disorder Rating Scale (S-FMDRS), Clinical global impression (CGI) scores for severity (CGI-S) and improvement (CGI-I) and the short-form health survey (SF-36).

RESULTS

No differences in CAR levels were found between M0 and M8 regardless of clinical outcome (remained flattened). However, a good clinical outcome was associated with an earlier peak in the CAR (p = .013, odds ratio: 1.78; 95%-confidence interval: 0.095-1.13). A higher CAmp at M0 predicted a better outcome at M8 (β = 1.14, 95%-confidence interval:0.15-2.13, p = .03).

CONCLUSION

A flattened CAR might represent a trait marker for FND, when an earlier peak in the CAR may serve as a state biomarker. The CAmp demonstrates predictive power for clinical outcome, potentially representing a prognostic biomarker for FND. Further replication and follow-up studies are essential to confirm this suggested role of cortisol as a multifaceted biomarker of FND.

The association between depression and the cortisol awakening response is moderated by loneliness in men from a non-clinical sample

Previous studies investigating cortisol levels in people with depression or depressive symptoms have provided mixed findings. It has been suggested that the difficulty to generalize findings across studies in this field might be related to interindividual variability in experiencing depressive symptoms in terms of clinical and social contexts. Therefore, in the present study we aimed to test the association of morning cortisol levels and depressive symptoms in a non-clinical sample of young men taking into consideration the level of perceived loneliness. We hypothesized that the level of loneliness might moderate the association between morning cortisol levels and depressive symptoms. A total of 102 participants (aged 29.9 ± 5.0 years) completed questionnaires measuring the levels of depressive and anxiety symptoms, perceived stress, and loneliness. Cortisol levels were determined in four morning samples of saliva. There were significant positive correlations of the cortisol awakening response (CAR) and the mean increase in cortisol levels during the measurement period (MnInc) with the levels of depressive symptoms and loneliness. Moreover, a significant association of the depressive symptoms by loneliness interaction with the CAR and the MnInc was found. Specifically, the correlation of depressive symptoms with the CAR and the MnInc appeared to be significant and negative at high levels of loneliness. No significant association between depressive symptoms and the CAR was observed in men with low levels of loneliness. There were no significant associations of depressive symptoms, loneliness and the depressive symptoms by loneliness interaction with cortisol levels at awakening. In conclusion, findings from the present study indicate the importance of social contexts in understanding the association between altered activity of the hypothalamic-pituitary-adrenal axis and depressive symptoms in men.

Women who pre-game: A study of stress and alcohol use in female collegiate predrinkers

Introduction: This study examined the relationship between stress and pre-gaming (i.e., drinking prior to going out to an event) in female college students. Methods: Thirty-four female college students were grouped as pre-gamers or non-pre-gamers based on self-reported drinking patterns. They completed surveys about alcohol use and mental health and provided a set of salivary cortisol samples upon waking, 30 min later, and at 10am on the same day. Results: Pre-gamers and non-pre-gamers did not differ on demographics or psychosocial variables. Pre-gamers reported riskier drinking overall and had greater endorsement of social, coping, and enhancement drinking motives. Pre-gamers also had lower cortisol levels 30 min after waking and exhibited attenuated CAR. Conclusions: Female collegiate pre-gamers may differ from their peers not only in terms of alcohol consumption and drinking motives, but also on attenuated CAR, a physiological biomarker associated with stress dysregulation and vulnerability to addictive behaviors.

Biomarker Response to Mindfulness Intervention in Veterans Diagnosed with Post-traumatic Stress Disorder

Objectives

This study evaluates the effects of treatment with mindfulness-based stress reduction (MBSR) compared to the active control, present-centered group therapy (PCGT), on morning plasma cortisol, interleukin-6 (IL-6), and C-reactive protein (CRP) in veterans diagnosed with post-traumatic stress disorder (PTSD).

Methods

In a post hoc exploratory analysis, we pooled biomarkers and clinical outcomes of mindfulness, PTSD, and depression from two randomized controlled trials comparing MBSR (n = 104) to PCGT (n = 106) in U.S. military veterans diagnosed with PTSD. Linear mixed-effects modeling was used to evaluate associations between changes in biomarkers and clinical outcomes from baseline to 9-week primary endpoint and 16-week follow-up endpoint.

Results

Cortisol levels were inversely related to self-reported PTSD symptoms at baseline (p = 0.02). Cortisol increased from baseline to 9-week endpoint for both groups, but significantly less so in the MBSR group compared to PCGT group (mean difference 1.69 ± 0.8 SE; p = 0.035). Changes in IL-6 and CRP did not differ between groups at either baseline or week 9. From baseline to week 9, increased mindfulness was significantly associated with increased cortisol (p = 0.02) and decreased PTSD and depression severity (p < 0.01). Increased IL-6 and CRP were significantly associated with decreased PTSD severity (p < 0.05), but not depression. Pooled analysis corroborated earlier findings that MBSR is significantly better than PCGT in improving clinical outcomes. Increased mindfulness was strongly associated with improved symptoms.

Conclusions

Increased mindfulness is associated with a recalibration of cortisol levels which may be indicative of therapeutic response, especially in patients with lower baseline cortisol. Furthermore, mindfulness-based practices improve symptoms of PTSD and depression in a significant correlation with self-reported levels of mindfulness.

Clinical Trial Registration clinicaltrialsgov

NCT01532999 and NCT01548742.

Stress, mindfulness, and systemic lupus erythematosus: An overview and directions for future research

Although the pathogenesis of autoimmunity is not fully understood, it is thought to involve genetic, hormonal, immunologic, and environmental factors. Stress has been evaluated as a potential trigger for autoimmunity and disease flares in patients with systemic lupus erythematosus (SLE). The physiologic changes that occur with stress involve numerous catecholamines, hormones, and cytokines that communicate intricately with the immune system. There is some evidence that these systems may be dysregulated in patients with autoimmune disease. Mindfulness-based techniques are practices aimed at mitigating stress response and have been shown to improve quality of life in general population. This review will discuss pathophysiology of chronic stress as it relates to SLE, evidence behind mindfulness-based practices in these patients, and directions for future research.

Daily cortisol awakening response and menstrual symptoms in young females

Menstrual symptoms include some rhythmical changes and stress perception but women differ in duration and severity of these symptoms. It is not known whether these differences are associated with cortisol awakening response (CAR). The aim of the current study was to follow young women daily for the CAR and menstrual parameters throughout the whole menstrual cycle. Healthy and regularly cycling young women (n = 16, 17 to 31-year-old) participated in the current study. The daily records of severity of problems (DRSP) was filled in daily by the participants. CAR was also assessed daily form the salivary samples collected at a 0-, 15-, 30- and 60-min post-awakening. In terms of daily awakening cortisol profiles, women had either 2-20 (n = 3), or 20-200 (n = 8) or 200-2000 (n = 5) ng/ml cortisol according to the median levels throughout their cycle. CAR was weakly and negatively correlated with DRSP scores but strongly and positively with oestradiol (R²  = 0.300; p = 0.000) and progesterone (R²  = 0.490; p = 0.000) concentrations. Individuals with higher oestradiol and progesterone concentrations did not have high DRSP scores. In conclusion, CAR had a very high between-subject difference but had a low within-subject difference throughout the days of menstrual cycle, suggesting that CAR is a relatively stable personal trait. Moreover, the interplay between cortisol, progesterone and oestradiol appears to be important for the severity of menstrual symptoms.

Concentrations of Salivary Cortisol in Victims of Intimate Partner Violence According to the CIRCORT Database

This work analyzes the different levels of salivary cortisol in women from the southwest of Spain that were victims of intimate partner violence (IPV) with respect to a control group, assessing for the first time the different concentrations obtained in relation to a worldwide reference standard provided by the CIRCORT meta-global cortisol database. The clinical sample (N = 24) and the control group (N = 25) had an average of 39.12 years (SD = 12.31) and 39.52 years (SD = 11.74), respectively. Cortisol awakening response (CAR) was determined by defining the area under the curve (AUCi). There were no differences between the CAR data of the two populations F (1, 141) = 1.690, p = 0.196, but there was a highly significant difference in the three sampling days, where the clinical sample exceeded the cortisol levels of the CIRCORT database in the evening as compared to the control group (p = 0.004, p = 0.001 and p = 0.000). Salivary cortisol concentration samples taken in the evening were significantly higher than those standardized in the CIRCORT database, from the women victims of IPV as compared to the control group, showing its usefulness as an effective supportive tool for problems such as those triggered by IPV.

Pubertal transition with current life stress and support alters longitudinal diurnal cortisol patterns in adolescents exposed to early life adversity

Current and early life stress (ELS) are associated with diurnal cortisol patterns, which themselves are associated with mental and physical health. The pubertal recalibration hypothesis suggests that the social environment can impact dysregulated cortisol patterns for previously ELS-exposed youth as they transition through puberty. This study examined longitudinal change in cortisol awakening response (CAR) and diurnal slope (DS) across puberty as a function of ELS in infancy, current stress, and social support (N = 290, 7-17 years). The CAR and DS were examined thrice annually with an accelerated longitudinal design with nurse-assessed puberty to assess associations between diurnal cortisol and pubertal recalibration with ELS and the current social environment. Exposure to ELS was associated with less steep DS but not changes in CAR, and no evidence of pubertal calibration was found. The DS became less steep for youth in later pubertal stages and as youth progressed through puberty. The CAR was steeper for youth in later pubertal stages. Across the cohort, current life stress and support were associated with changes in the DS and the CAR through the pubertal transition. The pubertal stage and the peripubertal and pubertal social environment may have important implications for adrenocortical functioning with or without exposure to ELS.

Depression, Mindfulness, and Psilocybin: Possible Complementary Effects of Mindfulness Meditation and Psilocybin in the Treatment of Depression. A Review

Depression is a major public health problem that affects approximately 4.4% of the global population. Since conventional pharmacotherapies and psychotherapies are only partially effective, as demonstrated by the number of patients failing to achieve remission, alternative treatments are needed. Mindfulness meditation (MM) and psilocybin represent two promising novel treatments that might even have complementary therapeutic effects when combined. Since the current literature is limited to theoretical and empirical underpinnings of either treatment alone, the present review aimed to identify possible complementary effects that may be relevant to the treatment of depression. To that end, the individual effects of MM and psilocybin, and their underlying working mechanisms, were compared on a non-exhaustive selection of six prominent psychological and biological processes that are well known to show impairments in patients suffering from major depression disorder, that is mood, executive functioning, social skills, neuroplasticity, core neural networks, and neuroendocrine and neuroimmunological levels. Based on predefined search strings used in two online databases (PubMed and Google Scholar) 1129 articles were identified. After screening title and abstract for relevance related to the question, 82 articles were retained and 11 were added after reference list search, resulting in 93 articles included in the review. Findings show that MM and psilocybin exert similar effects on mood, social skills, and neuroplasticity; different effects were found on executive functioning, neural core networks, and neuroendocrine and neuroimmune system markers. Potential mechanisms of MM's effects are enhanced affective self-regulation through mental strategies, optimization of stress reactivity, and structural and functional adjustments of prefrontal and limbic areas; psilocybin's effects might be established via attenuation of cognitive associations through deep personal insights, cognitive disinhibition, and global neural network disintegration. It is suggested that, when used in combination, MM and psilocybin could exert complementary effects by potentiating or prolonging mutual positive effects, for example, MM potentially facilitating psilocybin-induced peak experiences. Future placebo-controlled double-blind randomized trials focusing on psilocybin-assisted mindfulness-based therapy will provide knowledge about whether the proposed combination of therapies maximizes their efficacy in the treatment of depression or depressive symptomatology.

Individual differences in glucocorticoid regulation: Does it relate to disease risk and resilience?

Glucocorticoid (GC) signaling varies among individuals, and this variation may relate to individual differences in health outcomes. To determine if and which aspects of signaling (basal, circadian, integrative, or reactivity) are associated with specific health outcomes, we reviewed recent studies that relate GCs to health outcomes. We identified papers through PubMed and reviewed 100 original research articles related to mental health, cardiovascular health, cancer, diabetes, obesity, pulmonary health, sleep, and fitness. Many studies reported elevated GC secretion associated with worse health, but this was only particularly true for integrative GC measures. On the other hand, accentuated cortisol awakening response and a steeper circadian rhythm were both associated with positive health outcomes. Overall, relationships between GC secretion and health outcomes were relatively weak. This systematic review of relationships between GC metrics and health outcomes highlights the importance of careful consideration when selecting methods to measure GC regulation in health research.

The effect of a service dog on salivary cortisol awakening response in a military population with posttraumatic stress disorder (PTSD)

Recent studies suggest a therapeutic effect of psychiatric service dogs for military veterans with posttraumatic stress disorder (PTSD), but are limited by self-report biases. The current study assessed the effect of PTSD service dogs on the salivary cortisol awakening response (CAR) and arousal-related functioning in a population of military veterans with PTSD. Participants included 73 post-9/11 military veterans with PTSD including 45 with a service dog and 28 on the waitlist to receive one. Saliva samples were collected on two consecutive weekday mornings at awakening and 30 min later to quantify the cortisol awakening response (CAR) and its area under the curve (AUCi) in addition to standardized survey measures of anxiety, anger, sleep quality and disturbance, and alcohol abuse. There was a significant main effect of having a service dog on both the CAR and the AUCi, with individuals with a service dog exhibiting a higher CAR and AUCi compared to those on the waitlist. Results also revealed that those with a service dog reported significantly lower anxiety, anger, and sleep disturbance as well as less alcohol abuse compared to those on the waitlist, with medium to large effect sizes. Although those with a service dog reported significantly less PTSD symptom severity, CAR was not significantly associated with PTSD symptoms within or across group. In conclusion, results indicate that the placement of a PTSD service dog may have a significant positive influence on both physiological and psychosocial indicators of wellbeing in military veterans with PTSD. Although clinical significance cannot be confirmed, a higher CAR/AUCi among those with a service dog may indicate better health and wellbeing in this population. Future within-subject, longitudinal research will be necessary to determine potential clinical significance and impact of individual differences.

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.

Psychosocial functioning and the cortisol awakening response: Meta-analysis, P-curve analysis, and evaluation of the evidential value in existing studies

Cortisol levels rise immediately after awakening and peak approximately 30-45min thereafter. Psychosocial functioning influences this cortisol awakening response (CAR), but there is considerable heterogeneity in the literature. The current study used p-curve and meta-analysis on 709 findings from 212 studies to test the evidential value and estimate effect sizes of four sets of findings: those associating worse psychosocial functioning with higher or lower cortisol increase relative to the waking period (CARi) and to the output of the waking period (AUCw). All four sets of findings demonstrated evidential value. Psychosocial predictors explained 1%-3.6% of variance in CARi and AUCw responses. Based on these effect sizes, cross-sectional studies assessing CAR would need a minimum sample size of 617-783 to detect true effects with 80% power. Depression was linked to higher AUCw and posttraumatic stress to lower AUCw, whereas inconclusive results were obtained for predictor-specific effects on CARi. Suggestions for future CAR research are discussed.

Prolonged perceived stress and saliva cortisol in a large cohort of Danish public service employees: cross-sectional and longitudinal associations

Purpose

It is well known that acute stress can lead to a transient increase in cortisol secretion, but the effects of prolonged stress on cortisol secretion are uncertain. This study examines the cross-sectional and longitudinal associations between prolonged perceived stress and salivary cortisol.

Methods

In 2007, 4467 Danish public service employees participated in a study of stress and mental health, and 3217 participated in a follow-up in 2009. Perceived stress during the past 4 weeks was assessed by Cohen’s four item perceived stress scale. Participants were asked to collect saliva 30 min after awakening and at approximately 20:00 in the evening. The cortisol dependence on perceived stress was examined in regression analyses adjusted for effects of potential confounders. We adjusted for a large variation in saliva sampling times by modelling the time trajectory of cortisol concentrations in the morning and in the evening and examined if they were influenced by perceived stress.

Results

Perceived stress had no statistically significant effects on the level or time trajectory of morning or evening cortisol, neither cross-sectionally nor longitudinally. The 1 month prevalence of frequently perceived stress was low, approximately 2.5%.

Conclusion

Our results did not support the hypothesis that prolonged perceived stress is associated with the level or time trajectory of morning or evening salivary cortisol.

Electronic supplementary material

The online version of this article (doi:10.1007/s00420-017-1241-z) contains supplementary material, which is available to authorized users.

Adolescent Life Stress and the Cortisol Awakening Response: The Moderating Roles of Attachment and Sex

This longitudinal study investigated how past versus current life stresses relate to adolescents' cortisol awakening response (CAR), an index of hypothalamic-pituitary-adrenal activity. Ninety-nine adolescents reported previous year life stress at ages 12 and 18. At the second assessment, participants also provided self-reports of parent and peer attachment and 3 days of cortisol samples. Current stress was associated with heightened CAR for both males and females, whereas past stress was associated with attenuated CAR for males. Attachment to peers buffered the relationship between past stress and attenuated CAR for all adolescents; attachment to parents was a buffer for male adolescents only. Results demonstrate the protective roles of adolescent relationships and highlight sex differences in biopsychosocial development across adolescence.

A systematic review of the effects of mindfulness interventions on cortisol

Cortisol is increasingly included in examinations of mindfulness intervention effects as an indicator of efficacy; however, the association of cortisol and mindfulness has yet to be rigorously evaluated. A systematic review of six studies examining mindfulness intervention effects on cortisol was conducted. Inconsistent results were found for mindfulness effects on cortisol. Significant changes in cortisol levels were observed in within-participants studies but not observed in randomised controlled trial designs. Mindfulness may influence cortisol, but findings are inconclusive. Mindfulness pathways and methodological differences influence variations in mindfulness effects. Robust protocols are needed to adequately examine mindfulness effects on cortisol.

Trait positive and negative emotionality differentially associate with diurnal cortisol activity

Inter-individual variability in metrics of hypothalamic-pituitary-adrenocortical (HPA) activity, such as the slope of the diurnal decline in cortisol, cortisol awakening response (CAR), and total cortisol output, have been found to associate inversely with trait ratings of extraversion and positive affect (E/PA) and positively with neuroticism and negative affect (N/NA) in some, but not all, investigations. These inconsistencies may partly reflect varied intensity of cortisol sampling among studies and reliance on self-rated traits, which are subject to reporting biases and limitations of introspection. Here, we further examined dispositional correlates of HPA activity in 490 healthy, employed midlife volunteers (M age=43 years; 54% Female; 86% white). Trait ratings were requested from participants and 2 participant-elected informants using the Positive and Negative Affect Schedule (PANAS) and Extraversion and Neuroticism dimensions of NEO personality inventories. CAR was assessed as percent increase in cortisol levels from awakening to 30min after awakening; and the diurnal slope and total output of cortisol [Area Under the Curve (AUC)] were determined from cortisol measurements taken at awakening, +4 and +9h later, and bedtime, across 3 workdays. Structural equation modeling was used to estimate multi-informant E/PA and N/NA factors. We used 3days of measurement as indicators to model each of the three latent cortisol factors (slope, CAR, and AUC). With the two latent emotionality and three latent cortisol indices included there was good fit to the data (χ(2)(200)=278.38, p=0.0002; RMSEA=0.028, 90% CI=0.02-0.04; CFI/TLI=0.97/0.96; SRMR=0.04). After controlling for covariates (age, sex, race), results showed higher latent E/PA associated with a steeper diurnal slope (Standardized β=-0.19, p=0.02) and smaller CAR (Standardized β=-0.26, p=0.004), whereas N/NA did not associate with any cortisol metric (Standardized β's=-0.12 to 0.13, p's=0.10 to 0.53). These findings suggest that positive emotionality may be more closely associated with indices of diurnal cortisol release than negative emotionality.

The role of week(end)-day and awakening time on cortisol and alpha-amylase awakening responses

Awakening responses in salivary cortisol (CAR) and alpha-amylase (AAR) constitute proxies of morning activation patterns of the hypothalamic-pituitary-adrenal axis and autonomic nervous system, respectively. Previous studies suggest that the CAR is decreased at weekends and at late awakening. However, it is insufficiently studied (a) whether this also applies to the AAR and (b) whether week(end)-day and awakening time interact with each other. Using an ecological momentary assessment design, 48 healthy young adults (60% women) were investigated over a 7-d period (Study 1), and 27 chronic pain patients diagnosed with fibromyalgia syndrome were examined over a 14-d period (Study 2). For the assessment of the CAR and AAR, participants provided saliva samples each morning (upon awakening, 30 min after awakening). Preprogrammed electronic diary devices were used to track week(end)-day and exact time of saliva sampling (awakening time). In Study 1, CAR was unrelated to weekend, awakening time, or their interaction, whereas only early awakening time was positively associated with AAR. In Study 2, week-days as well as early awakening times on week-days predicted increased CAR. AARs were not predicted by week(end)-day, awakening times, or their interaction. These findings suggest that time-related factors may influence awakening responses, particularly the impact of week(end)-day on the CAR and the impact of awakening times on the AAR. Since week(end)-day and awakening times may negatively affect awakening responses, these potential confounding factors should be assessed and controlled for, particularly in studies assessing both CAR and AAR.

Happiness and its relation to psychological well-being of adolescents

In the present decade, adolescents' mental problems are known as critical problems which have many destructive consequences. This study aimed to measure students' happiness and psychological well-being status in a sample of high school students. The cross sectional study consisted of 403 randomly selected high school students in Tabriz, Iran. Numerous variables including general health status, happiness, self-efficacy, perceived stress, hopefulness and life satisfaction were measured by using self-reported written questionnaires. Significant relation observed between happiness and psychological well-being (r=0.48). Those students with good relationship and those who had reported to enjoy attending social events indicated better mental health status. No causal inferences were investigated due to the non-experimental nature of the study. The findings also revealed that students with higher happiness score have a better school performance. Integration of happiness promotion initiatives into the comprehensive school health programs is recommended to have pleasant environments for a healthy population of adolescents.

Post awakening salivary cortisol secretion and trait well-being: The importance of sample timing accuracy

Indices of post awakening cortisol secretion (PACS), include the rise in cortisol (cortisol awakening response: CAR) and overall cortisol concentrations (e.g., area under the curve with reference to ground: AUCg) in the first 30-45 min. Both are commonly investigated in relation to psychosocial variables. Although sampling within the domestic setting is ecologically valid, participant non-adherence to the required timing protocol results in erroneous measurement of PACS and this may explain discrepancies in the literature linking these measures to trait well-being (TWB). We have previously shown that delays of little over 5 min (between awakening and the start of sampling) to result in erroneous CAR estimates. In this study, we report for the first time on the negative impact of sample timing inaccuracy (verified by electronic-monitoring) on the efficacy to detect significant relationships between PACS and TWB when measured in the domestic setting. Healthy females (N=49, 20.5±2.8 years) selected for differences in TWB collected saliva samples (S1-4) on 4 days at 0, 15, 30, 45 min post awakening, to determine PACS. Adherence to the sampling protocol was objectively monitored using a combination of electronic estimates of awakening (actigraphy) and sampling times (track caps). Relationships between PACS and TWB were found to depend on sample timing accuracy. Lower TWB was associated with higher post awakening cortisol AUCg in proportion to the mean sample timing accuracy (p<.005). There was no association between TWB and the CAR even taking into account sample timing accuracy. These results highlight the importance of careful electronic monitoring of participant adherence for measurement of PACS in the domestic setting. Mean sample timing inaccuracy, mainly associated with delays of >5 min between awakening and collection of sample 1 (median=8 min delay), negatively impacts on the sensitivity of analysis to detect associations between PACS and TWB.

The cortisol awakening response and major depression: examining the evidence

A vast body of literature has revealed that dysregulation of the hypothalamic-pituitary-adrenal (HPA) stress axis is associated with etiology of major depressive disorder (MDD). There are many ways that the dysregulation of the HPA axis can be assessed: by sampling diurnal basal secretion and/or in response to a stress task, pharmacological challenge, and awakening. Here, we focus on the association between cortisol awakening response (CAR), as one index of HPA axis function, and MDD, given that the nature of this association is particularly unclear. Indeed, in the following selective review, we attempt to reconcile sometimes-divergent evidence of the role of CAR in the pathway to depression. We first examine association of CAR with psychological factors that have been linked with increased vulnerability to develop depression. Then, we summarize the findings regarding the CAR profile in those with current depression, and evaluate evidence for the role of CAR following depression resolution and continued vulnerability. Finally, we showcase longitudinal studies showing the role of CAR in predicting depression onset and recurrence. Overall, the studies reveal an important, but complex, association between CAR and vulnerability to depression.

Day-to-day dynamics of associations between sleep, napping, fatigue, and the cortisol diurnal rhythm in women diagnosed as having breast cancer

OBJECTIVES

To examine whether day-to-day variations in sleep behaviors, ongoing sleep disturbance, and fatigue predict the cortisol diurnal rhythm in women recently diagnosed as having early-stage breast cancer.

METHODS

Women (N = 130, mean [standard deviation] age = 55.6 [9.4] years) collected saliva 5×/day/2 days for cortisol. Diaries were used to assess prior-day nap duration, nocturnal awakenings, sleep latency, and morning restfulness. Ongoing fatigue and sleep disturbance were measured using the Multidimensional Fatigue Symptom Inventory and the Pittsburg Sleep Quality Inventory. Data were analyzed using a multilevel growth curve modeling.

RESULTS

Greater ongoing fatigue (b = 0.035, p = .032), or sleep disturbance (b = 0.026, p = .006) predicted a slower cortisol decline. Greater ongoing fatigue also predicted higher awakening cortisol (b = 0.154, p = .030) and lower cortisol awakening response (CAR; b = -0.146, p = .005). Longer prior-day naps predicted higher CAR (b = 0.042, p = .050) and a steeper cortisol decline (b = -0.035, p = .003). Longer sleep latency predicted both a greater cortisol linear decline (b = -0.013, p < .001) and a greater quadratic slope curvature (b = 0.0007, p < .001). Feeling less rested in the morning predicted lower awakening cortisol (b = -0.187, p = .004), higher CAR (b = 0.124, p = .016), and a slower cortisol decline (b = 0.023, p = .042).

CONCLUSIONS

Both daily variations in sleep behaviors and ongoing sleep disturbance and fatigue are associated with a disrupted cortisol rhythm. In contrast, prior-day napping is associated with a more robust cortisol rhythm. These findings are particularly relevant to women with breast cancer who often experience sleep disturbance and fatigue. Additional research is needed to determine causal pathways between sleep disturbance and dysregulation of the hypothalamic-pituitary-adrenal axis in patients with breast cancer.

Health-related determinants of happiness in Korean adults

OBJECTIVES

Happiness has been associated with a range of favorable health outcomes. The aim of this study was to examine the relationships between happiness and health behaviors, stress, and environmental aspects of exercise in a Korean national representative sample.

METHODS

This cross-sectional study was conducted using multiple-stratified random sampling on the Korea Census of 2005. In October 2009, investigators conducted 15-min face-to-face interviews with 1,530 South Korean volunteers aged between 30 and 69 years. The questionnaire included questions about sociodemographic factors, perceived stress, smoking, drinking, healthy diet, exercise, exercise environment, and happiness levels.

RESULTS

The multivariate analysis revealed that middle-aged participants were less likely to be happy than younger and older participants, and higher happiness was associated with being part of a couple, higher income, lower stress, healthy diet, exercise, and certain exercise environments (e.g., mountain trails).

CONCLUSIONS

Besides individual-level sociodemographic conditions, such as income or psychological status, community-level conditions, such as environment, should be considered when national and community public welfare policy is established.

The relation of the cortisol awakening response and prospective memory functioning in young children

Recent research suggests that the cortisol awakening response (CAR) is linked to cognitive functions depending on hippocampal and frontal cortex circuits and may possibly be modulated by prospective memory (PM). However, the link between the CAR and PM abilities has not been investigated so far. Addressing this open issue, we report data from 97 children aged 37-87 months. Salivary cortisol levels were assessed 0 and 30 min post-awakening over three study days. Thereby a valid CAR measurement was ensured by using objective measures of awakening and sampling times. A game-like task served as behavioral measure of PM performance. Bayesian analysis revealed a positive association between children's PM performance and the CAR, with better PM performance being related to a greater CAR. This association persisted after controlling for age. Overall, the current finding supports the prediction that PM functioning may be linked to the CAR, possibly as both the CAR and PM rely on a common neurophysiological basis.

Positive psychological characteristics in diabetes: a review

Positive psychological characteristics, such as optimism, self-efficacy, and resilience, have been increasingly associated with improved outcomes in medically ill individuals. However, there has been minimal systematic review of these characteristics and their associations with outcomes in people with diabetes. We aim to review these associations, their potential mediating mechanisms, and the evidence supporting interventions targeting these qualities. In people with diabetes, positive psychological characteristics are significantly associated with improved glycemic control, fewer complications, and reduced rates of mortality. Potential mechanisms mediating these associations include behavioral factors (e.g., improved treatment adherence), reduced inflammation, and improved neuroendocrine and autonomic functioning. Most psychosocial treatments in this population have focused on improving self-efficacy and resilience; such interventions may improve quality of life, well-being, and diabetes self-care. While untested in diabetes, interventions to boost other positive characteristics have been effective in other medically ill patients and may warrant further study in this cohort.

State variation in the cortisol awakening response

The cortisol awakening response (CAR) is a much studied but poorly understood aspect of the circadian pattern of cortisol secretion. A Scopus search of "cortisol" and "awakening" reveals 666 publications in this area since 1997 when it was first identified by Pruessner and colleagues as a "reliable biomarker of adrenocortical activity". The primary focus of the majority of these studies is centered on its utility as a biomarker associated with a range of psychosocial, physical and mental health variables. Such studies typically examine differences in the CAR (studied on 1 or 2 days) between healthy participants and other comparator groups of interest. Fewer studies (25 in our estimation) have examined correlates of day-to-day variation in the CAR in healthy participants, informing its role and regulation within the healthy circadian pattern of cortisol secretion. This is the first review to examine these studies which, although limited in number, offer a relatively coherent emerging story about state factors that influence the CAR and the impact of the CAR on daily functioning. Greater understanding of these issues helps illuminate the utility of the CAR as a promising biomarker in psychophysiological and epidemiological research. The review also highlights areas that require greater clarification and points to potentially fruitful areas of further research.

Daily life stress and the cortisol awakening response: testing the anticipation hypothesis

The cortisol awakening response (CAR) is a distinct facet of the circadian cortisol rhythm associated with various health conditions and risk factors. It has repeatedly been suggested that the CAR could be a result of the anticipated demands of the upcoming day (stress anticipation) and could support coping with daily life stress. In a sample of 23 healthy participants CARs were assessed on two consecutive days by measures of salivary cortisol upon awakening (S1) and 30 and 45 minutes later, which were aggregated to the area under the curve increase (AUCI). Stress anticipation was assessed immediately after awakening. On the same days, daily life stress and distress were assessed six times per day based on a quasi-randomized design using handheld computers. Associations were tested by day using regression analysis and standard multilevel/mixed effects models for longitudinal data. The CAR AUCI moderated the effect of daily life stress on distress; higher CAR increases were associated with attenuated distress responses to daily life stress on both days (day 1: p = .039; day 2: p = .004) adjusted for age, gender, sleep quality, time of awakening and oral contraceptive use. Lagged-effects and redundancy models showed that this effect was not due to prior-day CAR increases but specific for same day CARs. On day 2, associations between daily life stress and distress were stronger when individuals showed a higher S1 cortisol level, but this effect was similar for S1 on day 1, and the day 2 effect of S1 became non-significant when S1 on day 1 was controlled. No associations were found between stress anticipation and CARs. Findings indicate that the CAR increase is associated with successful coping with same-day daily life stress.

Cortisol levels in children with attention-deficit/hyperactivity disorder

Regulation of the Hypothalamus-Pituitary-Adrenal axis (HPA-axis) and its end product cortisol differs among persons with certain psychiatric disorders when compared with controls. Some reports concern Attention-Deficit/Hyperactivity Disorder (ADHD) but findings are inconclusive. In this study we collected four saliva samples during a regular weekday in children, 6-17 years old, with ADHD (n = 201) and non-affected comparisons (n = 221). Saliva cortisol was measured with radioimmunoassay technique. Clinical data were collected for diagnostic information. Subtypes and severity of symptoms were determined using parental rating scales. Children with ADHD had lower saliva cortisol levels than comparisons at waking up Median = 9.1 versus 12.7 nmol/L (p < .001), 30 min later Median = 15.8 versus 20.1 nmol/L (p < .001) and before going to bed Median = 0.8 versus 1.0 nmol/L (p = .015). No difference was found for the afternoon sample. When the study group was split into three different age groups similar results were found only for children above 10 years of age. Subtype of ADHD or co-occurring symptoms did not affect the cortisol levels. Degree of severity of ADHD symptoms was not associated with cortisol levels in the study group, other than a weak negative correlation between the afternoon sample and hyperactivity symptoms. The low cortisol levels in children with ADHD may indicate a dysregulation of the HPA-axis, for instance a down-regulation or a phase delay of the diurnal curve. The low levels may be related to the under-arousal possibly underlying several of the core symptoms of ADHD.

Salivary cortisol measurement in developmental research: where do we go from here?

Salivary cortisol has been measured extensively in developmental research over the last three decades. The purpose of this article is to summarize the contributions to and limitations of salivary cortisol measurement in developmental research and propose future directions for research that includes salivary cortisol measurement. The properties of cortisol, the history of its burgeoning popularity, and the utility and limitations of (a) cortisol as a biological indicator, (b) saliva as a source of cortisol, and (c) various saliva collection methodologies are described. The current state of understanding about what is and is not reliably predictable from cortisol is summarized and the value of salivary cortisol measurement in developmental research is discussed, addressing whether methodology could be driving research design. Recommendations are made for streamlining study design and reporting within developmental research.

Stressful life events and daily stressors affect awakening cortisol level in midlife mothers of individuals with autism spectrum disorders

OBJECTIVES

The current study examines the awakening cortisol level in midlife mothers (M = 51.4 years old, SD = 8.4) of individuals (M = 22.1 years old, SD = 7.1) with autism spectrum disorders (ASD) under stressful conditions that are not specific to their son or daughter's ASD symptoms.

METHODS

In addition to completing a set of questionnaires and in-home interviews, 82 mothers from the Adolescents and Adults with Autism Study (AAA) participated in a Daily Diary Study.

RESULTS

Findings from the multilevel models indicated that mothers who previously were exposed to no negative life events in the previous period had an increased awakening cortisol level on days following a greater number and more severe stressors, a normative stress response. In contrast, we observed a flatter cortisol level of daily stressors in mothers who experienced a greater number of negative life events in the previous period.

CONCLUSION

These findings highlight the sustained toll that global and everyday stressors have on awakening cortisol level of midlife and aging mothers of individuals with ASD.

Happiness and health behaviours in Chilean college students: a cross-sectional survey

Background

Happiness has been associated with a range of favourable health outcomes through two pathways: its relationship with favourable biological responses to stress and with healthy lifestyles and prudent health behaviours. There are a substantial number of cross-cultural studies about happiness, but none of them has studied the association of happiness with perceived stress and health behaviours in Latin American samples. Therefore, the aim of this study was to examine the association between general happiness and these variables in a Latin American sample.

Methods

We conducted a survey to examine the status of 3461 students aged between 17 and 24 years old (mean age = 19.89; SD = 1.73) who attended University of Santiago de Chile during 2009. The healthy behaviours indexes assessed were the frequency of daily physical exercise, fruits/vegetables intake, breakfast and lunch intake, smoking, alcohol and other drugs consumption. We also included the assessment of perceived stress and Body Mass Index. All of them were evaluated using a self-report questionnaire.

Results

The univariate and multivariate binary logistic regression analyses showed that being female and younger was related to a higher happiness, as well as that people self-reporting daily physical activity, having lunch and fruits and vegetables each day had a higher likelihood (OR between 1.33 and 1.40) of being classified as "very happy". Those who informed felt stressed in normal circumstances and during tests situations showed a lower likelihood (0.73 and 0.82, respectively) of being considered "very happy". Regarding drug consumption, taking tranquilizers under prescription was negative related to "subjective happiness" (OR = 0.62), whereas smoking was positive associated (OR = 1.20).

Conclusions

The findings of this study mainly support the relationship between happiness and health outcomes through the two pathways previously mentioned. They also underscore the importance of that some healthy behaviours and person's cognitive appraisal of stress are integrated into their lifestyle for college students. Additionally, highlight the importance of taking into account these variables in the design of strategies to promote health education in university setting.

Cortisol awakening response and hippocampal volume: vulnerability for major depressive disorder?

BACKGROUND

Major depressive disorder is associated with dysregulated basal cortisol levels and small hippocampal (HC) volume. However, it is still debated whether these phenomena are a consequence of the illness or whether they may represent a vulnerability marker existing before the illness onset. Here, we aimed to examine this notion of vulnerability by assessing whether abnormalities in basal cortisol secretion and HC volumes are already present in a sample of healthy young adults who showed varying levels of depressive tendencies, but at subclinical levels.

METHODS

We recruited healthy young men and women from the local university. On the basis of depression scores derived from standard questionnaires, three groups were formed: a control group (n = 27), a subclinical group (n = 23), and a high-risk subclinical group (n = 9). The participants underwent a magnetic resonance imaging scan and collected saliva samples for the assessment of diurnal cortisol levels.

RESULTS

Both the subclinical and the high-risk subclinical group failed to show a significant increase in cortisol levels after awakening. The high-risk subclinical group also showed a lower area-under-the-curve increase of cortisol levels after awakening compared with control subjects. In addition, this group also had smaller total HC volume compared with control subjects.

CONCLUSIONS

The findings from this subclinical sample suggest that dysregulated cortisol awakening response and small HC volume may constitute vulnerability factors for major depressive disorder. Further investigations are needed to discern the mechanisms that may underlie these phenomena.

Overnight changes of immune parameters and catecholamines are associated with mood and stress

OBJECTIVES

To test the hypothesis that a nocturnal decrease of secretion of inflammation markers and catecholamines would be associated with mood and stress variables even after controlling for objective sleep variables.

METHODS

A total of 130 healthy volunteers participated in this study, spending 2 nights in the Gillin Laboratory of Sleep and Chronobiology at the University of California, San Diego, General Clinical Research Center. Blood samples were obtained before sleep (10:30 PM) and after awakening (6:30 AM) on the first day, and these samples were assayed for inflammatory biomarkers and catecholamines. On the second night, polysomnographic records were scored for objective sleep variables, e.g., total sleep time and wake after sleep onset. Self-rating scales for mood, stress, depression, and daily hassles were administered the second day.

RESULTS

The nocturnal decrease in interleukin-6 was smaller in people who reported more negative mood or fatigue and greater in those who reported more uplift events (e.g., with Profile of Mood States fatigue r(p) = -.25 to -.30). People with high stress or high depression levels had smaller nocturnal decreases of epinephrine. That relationship was even stronger when partial correlations were used to control for morning level and sleep variables. The associations between nocturnal changes of C-reactive protein, soluble tumor necrosis factor-receptor I, and norepinephrine with psychological states were nonremarkable.

CONCLUSIONS

The analyses of nocturnal change scores (difference scores) add substantial information compared with the traditional analyses of morning levels of immune variables and catecholamines alone. Subjective well-being is significantly associated with a greater nocturnal decrease of interleukin-6 and epinephrine. More research on nocturnal adaptation processes is warranted.