Cortisol profile and depressive symptoms in older adults residing in Brazil and in Canada

Reliability of diurnal salivary cortisol metrics: A meta-analysis and investigation in two independent samples

Stress-induced dysregulation of diurnal cortisol is a cornerstone of stress-disease theories; however, observed associations between cortisol, stress, and health have been inconsistent. The reliability of diurnal cortisol features may contribute to these equivocal findings. Our meta-analysis (5 diurnal features from 11 studies; total participant n = 3307) and investigation (15 diurnal cortisol features) in 2 independent studies (St. Louis Personality and Aging Network [SPAN] Study, n = 147, ages 61-73; Minnesota Longitudinal Study of Risk and Adaptation [MLSRA] Study, n = 90, age 37) revealed large variability in the day-to-day test-retest reliability of diurnal features derived from salivary cortisol data (i.e., ICC = 0.00-0.75). Collectively, these data indicate that some commonly used diurnal cortisol features have poor reliability that is insufficient for individual differences research (e.g., cortisol awakening response) while others (e.g., area under the curve with respect to ground) have fair-to-good reliability that could support reliable identification of associations in well-powered studies.

Long-term living in unfavorable socioeconomic conditions impairs late-life gait performance

BACKGROUND

Low socioeconomic status has been associated with individual health-related problems; however, no study has specifically investigated the impact of socioeconomic disparities on gait performance using an index that considers the population aggregation, as the Human Development Index (HDI). Thus, the aim of the present study was to assess gait parameters of older people living in cities with differences in socioeconomic conditions, identified by HDI.

METHODS

Cross-sectional design study conducted with a sample of 233 older people from two Brazilians regions: Coari, state of Amazonas, Brazil (n= 124, low-HDI-Bra) and Ribeirão Preto, state of São Paulo, Brazil (n= 109, very high-HDI-Bra). The gait performance was assessed by an electronic walkway, and the interest variables were gait speed, cadence, stride time, step length and stride width.

RESULTS

Low-HDI-Bra group presented worse gait performance as identified by slower gait speed (p = < .001), slower cadence (p = < .001), higher stride time (p = < .001), shorter step length (p = < .001), compared with the very high-HDI-Bra group. There was a positive association between HDI, and gait spend, cadence and step length, and there was a negative association between HDI and stride time and stride width.

CONCLUSIONS

Long-term exposure to socioeconomic inequalities found in low HDI cities may impair gait performance in late life. Such information may be relevant to create public politics that use the gait parameter based on the region where the people live.

Pathophysiology of Major Depression by Clinical Stages

The comprehension of the pathophysiology of the major depressive disorder (MDD) is essential to the strengthening of precision psychiatry. In order to determine the relationship between the pathophysiology of the MDD and its clinical progression, analyzed by severity of the depressive symptoms and sleep quality, we conducted a study assessing different peripheral molecular biomarkers, including the levels of plasma C-reactive protein (CRP), serum mature brain-derived neurotrophic factor (mBDNF), serum cortisol (SC), and salivary cortisol awakening response (CAR), of patients with MDD (n = 58) and a control group of healthy volunteers (n = 62). Patients with the first episode of MDD (n = 30) had significantly higher levels of CAR and SC than controls (n = 32) and similar levels of mBDNF of controls. Patients with treatment-resistant depression (TRD, n = 28) presented significantly lower levels of SC and CAR, and higher levels of mBDNF and CRP than controls (n = 30). An increased severity of depressive symptoms and worse sleep quality were correlated with levels low of SC and CAR, and with high levels of mBDNF. These results point out a strong relationship between the stages clinical of MDD and changes in a range of relevant biological markers. This can assist in the development of precision psychiatry and future research on the biological tests for depression.

Cortisol Modulation by Ayahuasca in Patients With Treatment Resistant Depression and Healthy Controls

Major depression is a highly prevalent mood disorder, affecting about 350 million people, and around 30% of the patients are resistant to currently available antidepressant medications. Recent evidence from a randomized controlled trial (RCT) supports the rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression. The aim of this study was to explore the effect of ayahuasca on plasma cortisol and awakening salivary cortisol response, in the same group of treatment-resistant patients (MD) and in healthy volunteers (C). Subjects received a single dose of ayahuasca or placebo (dosing session), and both plasma and awakening salivary cortisol response were measured at baseline (before dosing session) and 48 h after the dosing session. Baseline assessment (D0) showed blunted awakening salivary cortisol response and hypocortisolemia in patients, with respect to healthy controls. Salivary cortisol was also measured during dosing session, and we observed higher increases for both C and MD that ingested ayahuasca than placebo. After 48 h from the dosing session with ayahuasca, patients' awakening salivary cortisol response is similar to the ones detected in controls. No significant changes in plasma cortisol levels were observed 48 h after the sessions. Therefore, these findings point to new evidence on the modulation of salivary cortisol levels as a result of an ayahuasca session, both in healthy and depressive volunteers. Considering that cortisol acts in regulation of distinct physiological pathways, emotional and cognitive processes, it is assumed to be critically involved to the etiology of depression and its regulation seems to be important for the treatment and remission of major depression, ayahuasca use as antidepressant should be further investigated. Moreover, this study highlights the importance of psychedelics in the treatment of human mental disorders.

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.

Diurnal cortisol slopes and mental and physical health outcomes: A systematic review and meta-analysis

Changes in levels of the stress-sensitive hormone cortisol from morning to evening are referred to as diurnal cortisol slopes. Flatter diurnal cortisol slopes have been proposed as a mediator between chronic psychosocial stress and poor mental and physical health outcomes in past theory and research. Surprisingly, neither a systematic nor a meta-analytic review of associations between diurnal cortisol slopes and health has been conducted to date, despite extensive literature on the topic. The current systematic review and meta-analysis examined associations between diurnal cortisol slopes and physical and mental health outcomes. Analyses were based on 179 associations from 80 studies for the time period up to January 31, 2015. Results indicated a significant association between flatter diurnal cortisol slopes and poorer health across all studies (average effect size, r=0.147). Further, flatter diurnal cortisol slopes were associated with poorer health in 10 out of 12 subtypes of emotional and physical health outcomes examined. Among these subtypes, the effect size was largest for immune/inflammation outcomes (r=0.288). Potential moderators of the associations between diurnal cortisol slopes and health outcomes were examined, including type of slope measure and study quality indices. The possible roles of flatter slopes as either a marker or a mechanism for disease etiology are discussed. We argue that flatter diurnal cortisol slopes may both reflect and contribute to stress-related dysregulation of central and peripheral circadian mechanisms, with corresponding downstream effects on multiple aspects of biology, behavior, and health.