HPA axis and aging in depression: systematic review and meta-analysis

Associations between Depression, Depressive Symptoms, and Incidence of Dementia in Latin America: A 10/66 Dementia Research Group Study

BACKGROUND

A growing body of evidence suggests that depression is related to dementia in older adults. Previous research has been done in high-income countries and there is a lack of studies in low- and middle income countries (LMICs).

OBJECTIVE

To examine the relationship between depressive symptoms and incidence of dementia in a population-based study of older adults in Latin America.

METHODS

The study is a part of the 10/66 Dementia Research Group's population survey and includes 11,472 older adults (baseline mean age 74 years) from Cuba, Dominican Republic, Mexico, Peru, Puerto Rico, and Venezuela. The baseline examinations were done in 2003-2007 and the follow-up examinations 4 years later. Semi-structured psychiatric interviews gave information about ICD-10 depression and sub-syndromal depression (i.e., ≥4 depressive symptoms) at baseline. Information on dementia were collected at the follow-up examination. Competing risk models analyzed the associations between depression and incidence of dementia and the final model were adjusted for age, sex, education, stroke, and diabetes. Separate analyses were conducted for each site and then meta-analyzed by means of fixed effect models.

RESULTS

At baseline, the prevalence of depression was 26.0% (n = 2,980): 5.4% had ICD-10 depression and 20.6% sub-syndromal depression. During the follow-up period, 9.3% (n = 862) developed dementia and 14.3% (n = 1,329) deceased. In the pooled analyses, both ICD-10 depression (adjusted sub-hazard ratio (sHR) 1.63, 95% confidence interval (CI) 1.26-2.11) and sub-syndromal depression (adjusted sHR 1.28, 95% CI: 1.09-1.51) were associated with increased incidence of dementia. The Higging I2 tests showed a moderate heterogeneity across the study sites.

CONCLUSION

Our findings suggest that late-life depression is associated with the incidence of dementia in LMICs in Latin America, which support results from earlier studies conducted in high-income countries.

Late-life depression and the risk of dementia in 14 countries: a 10-year follow-up study from the Survey of Health, Ageing and Retirement in Europe

BACKGROUND

Depression is the most common mental health problem and often co-occurs with dementia in old age. This study investigates the influence of late-life depression on risk of dementia.

METHODS

A total of 16210 dementia-free participants aged 60+ from the Survey of Health, Aging, and Retirement in Europe were followed up for 10 years to detect incident dementia. Depression was assessed by a 12-item Europe-depression scale, dementia was determined by physician diagnosis reported by the participants and their informants. Fine and Gray model was performed to explore the association between depression and incident dementia taking into account competing risk of death.

RESULTS

During an average of 8 years follow-up, 1030 (6.35%) incident dementia were identified. Late-life depression was related to higher subdistribution hazard ratio (sHR) of dementia (sHR=1.52, 95%CI: 1.32-1.75) after adjusting for age, gender, country, education, smoking, drinking, living arrangement, BMI, chronic disease, and physical activity. Further, the risk was only existed in those below age of 80 (sHR=1.75, 95%CI: 1.47-2.07). In addition, a dose-response association was observed between the severity of depression and dementia risk (p for trend<0.001).

LIMITATION

The ascertainment of depression and dementia was based on information reported by the participants and/or their informants, which might result in information bias. The causal relationship could not be determined because limited follow-up time.

CONCLUSIONS

Late-life depression is associated with higher incidence of dementia in a dose-response fashion. Interventions targeting depression patients aged 60-79 years and those with severe depression may be effective strategies to prevent dementia.

Association of FKBP5 genotype with depressive symptoms in patients with coronary heart disease: a prospective study

Depression and coronary heart disease (CHD) are prevalent and often co-occurring disorders. Both have been associated with a dysregulated stress system. As a central element of the stress system, the FKBP5 gene has been shown to be associated with depression. In a prospective design, this study aims to investigate the association of FKBP5 with depressive symptoms in CHD patients. N = 268 hospitalized CHD patients were included. Depressive symptoms were measured using the Hospital Anxiety and Depression Scale (HADS-D) at four time points (baseline, and after 1 month, 6 months, and 12 months). The functional FKBP5 single-nucleotide polymorphism (SNP) rs1360780 was selected for genotyping. Linear regression models showed that a higher number of FKBP5 C alleles was associated with more depressive symptoms in CHD patients both at baseline (p = 0.015) and at 12-months follow-up (p = 0.025) after adjustment for confounders. Further analyses revealed that this effect was driven by an interaction of FKBP5 genotype with patients’ prior CHD course. Specifically, only in patients with a prior myocardial infarction or coronary revascularization, more depressive symptoms were associated with a higher number of C alleles (baseline: p = 0.046; 1-month: p = 0.026; 6-months: p = 0.028). Moreover, a higher number of C alleles was significantly related to a greater risk for dyslipidemia (p = .016). Our results point to a relevance of FKBP5 in the association of the two stress-related diseases depression and CHD.

Physical Activity Promotes Health and Reduces Cardiovascular Mortality in Depressed Populations: A Literature Overview

Major depression is associated with premature mortality, largely explained by heightened cardiovascular burden. This narrative review summarizes secondary literature (i.e., reviews and meta-analyses) on this topic, considering physical exercise as a potential tool to counteract this alarming phenomenon. Compared to healthy controls, individuals with depression consistently present heightened cardiovascular risk, including "classical" risk factors and dysregulation of pertinent homeostatic systems (immune system, hypothalamic-pituitary-adrenal axis and autonomic nervous system). Ultimately, both genetic background and behavioral abnormalities contribute to explain the link between depression and cardiovascular mortality. Physical inactivity is particularly common in depressed populations and may represent an elective therapeutic target to address premature mortality. Exercise-based interventions, in fact, have proven effective reducing cardiovascular risk and mortality through different mechanisms, although evidence still needs to be replicated in depressed populations. Notably, exercise also directly improves depressive symptoms. Despite its potential, however, exercise remains under-prescribed to depressed individuals. Public health may be the ideal setting to develop and disseminate initiatives that promote the prescription and delivery of exercise-based interventions, with a particular focus on their cost-effectiveness.

The symptom network structure of depressive symptoms in late-life: Results from a European population study

The network theory conceptualizes mental disorders as complex networks of symptoms influencing each other by creating feedback loops, leading to a self-sustained syndromic constellation. Symptoms central to the network have the greatest impact in sustaining the rest of symptoms. This analysis focused on the network structure of depressive symptoms in late-life because of their distinct etiologic factors, clinical presentation, and outcomes. We analyzed cross-sectional data from wave 2 of the 19 country Survey of Health, Ageing, and Retirement in Europe (SHARE) and included non-institutionalized adults aged 65 years or older (mean age 74 years, 59% females) endorsing at least one depressive symptom on the EURO-D scale for depression (N =8,557). We characterized the network structure of depressive symptoms in late-life and used indices of "strength", "betweenness", and "closeness" to identify symptoms central to the network. We used a case-dropping bootstrap procedure to assess network stability. Death wishes, depressed mood, loss of interest, and pessimism had the highest values of centrality. Insomnia, fatigue and appetite changes had lower centrality values. The identified network remained stable after dropping 74.5% of the sample. Sex or age did not significantly influence the network structure. In conclusion, death wishes, depressed mood, loss of interest, and pessimism constitute the "backbone" that sustains depressive symptoms in late-life. Symptoms central to the network of depressive symptoms may be used as targets for novel, focused interventions and in studies investigating neurobiological processes central to late-life depression.

11β-hydroxysteroid dehydrogenase type 1 inhibitor use in human disease-a systematic review and narrative synthesis

INTRODUCTION

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is an intracellular enzyme that catalyses conversion of cortisone into cortisol; correspondingly, 11β-HSD1 inhibitors inhibit this conversion. This systematic review focuses on the use of 11β-HSD1 inhibitors in diseases known to be associated with abnormalities in hypothalamic pituitary adrenal (HPA) axis function.

METHODS

The databases screened for suitable papers were: MedLine, EMBASE, Web of Science, ClinicalTrials.gov, and Cochrane Central.

RESULTS

1925 papers were identified, of which 29 were included in the final narrative synthesis. 11β-HSD1 and its inhibitors have been studied in diabetes, obesity, metabolic syndrome (MetS), and Alzheimer's disease (AD). Higher expression of 11β-HSD1 is seen in obesity and MetS, but has not yet been described in obesity or AD. Genetic studies identify 11β-HSD1 SNPs of interest in populations with diabetes, MetS, and AD. One phase II trial successfully reduced HbA1c in a diabetic population, however trials in MetS, obesity, and AD have not met primary endpoints.

CONCLUSIONS

Translation of this research from preclinical studies has proved challenging so far, however this is a growing area of research and more studies should focus on understanding the complex relationships between 11β-HSD1 and disease pathology, especially given the therapeutic potential of 11β-HSD1 inhibitors in development.

The long-term association of adverse childhood experiences with C-reactive protein and hair cortisol: Cumulative risk versus dimensions of adversity

BACKGROUND

Exposure to adverse childhood experiences (ACEs) may lead to stress-induced upregulation of inflammatory and neuroendocrine processes. However, it remains unclear whether such effects persist into later life, and which dimensions of ACEs might have the strongest impact on these biological mechanisms. Therefore, this study investigated the effects of ACEs on C-reactive protein (CRP) and hair cortisol in a large sample of older adults, distinguishing between cumulative exposure and dimensions of ACEs.

METHODS

We utilised data from the English Longitudinal Study of Ageing. ACEs were assessed through retrospective reports at wave 3(2006/07). CRP (N = 4198) was measured at waves 4(2008/09) and 6(2012/13), and hair cortisol (N = 3357) at wave 6. The effects of ACEs cumulative exposure were examined using linear and ordinal logistic regression analysis. ACEs dimensions (i.e. threat, household dysfunction, low parental bonding, and loss of an attachment figure) were identified using explorative and confirmatory factor analysis with cross-validation. All analyses were adjusted for relevant confounders.

RESULTS

Participants with three or more ACEs had higher CRP levels at wave 4 and an elevated risk of high CRP concentrations across waves 4 and 6 compared with those who did not experience any ACEs. The four ACEs dimensions were all positively associated with both CRP outcomes and had similar effect sizes. In contrast, neither the cumulative score nor the dimensions of ACEs were significantly related to hair cortisol. However, there was a positive, yet small, interaction effect between ACEs and age on hair cortisol.

CONCLUSION

Older adults who retrospectively reported three or more ACEs had chronically elevated CRP levels and exhibited a slightly steeper increase in hair cortisol with age. Different dimensions of ACEs had similar associations with the biomarkers.

Improvements to Healthspan Through Environmental Enrichment and Lifestyle Interventions: Where Are We Now?

Environmental enrichment (EE) is an experimental paradigm that is used to explore how a complex, stimulating environment can impact overall health. In laboratory animal experiments, EE housing conditions typically include larger-than-standard cages, abundant bedding, running wheels, mazes, toys, and shelters which are rearranged regularly to further increase stimulation. EE has been shown to improve multiple aspects of health, including but not limited to metabolism, learning and cognition, anxiety and depression, and immunocompetence. Recent advances in lifespan have led some researchers to consider aging as a risk factor for disease. As such, there is a pressing need to understand the processes by which healthspan can be increased. The natural and predictable changes during aging can be reversed or decreased through EE and its underlying mechanisms. Here, we review the use of EE in laboratory animals to understand mechanisms involved in aging, and comment on relative areas of strength and weakness in the current literature. We additionally address current efforts toward applying EE-like lifestyle interventions to human health to extend healthspan. Although increasing lifespan is a clear goal of medical research, improving the quality of this added time also deserves significant attention. Despite hurdles in translating experimental results toward clinical application, we argue there is great potential in using features of EE toward improving human healthy life expectancy or healthspan, especially in the context of increased global longevity.

Aging increases vulnerability to stress-induced depression via upregulation of NADPH oxidase in mice

Brain aging proceeds with cellular and molecular changes in the limbic system. Aging-dependent changes might affect emotion and stress coping, yet the underlying mechanisms remain unclear. Here, we show aged (18-month-old) mice exhibit upregulation of NADPH oxidase and oxidative stress in the hippocampus, which mirrors the changes in young (2-month-old) mice subjected to chronic stress. Aged mice that lack p47phox, a key subunit of NADPH oxidase, do not show increased oxidative stress. Aged mice exhibit depression-like behavior following weak stress that does not produce depressive behavior in young mice. Aged mice have reduced expression of the epigenetic factor SUV39H1 and its upstream regulator p-AMPK, and increased expression of Ppp2ca in the hippocampus-changes that occur in young mice exposed to chronic stress. SUV39H1 mediates stress- and aging-induced sustained upregulation of p47phox and oxidative stress. These results suggest that aging increases susceptibility to stress by upregulating NADPH oxidase in the hippocampus.

Low Circulating Levels of GR, FKBP5, and SGK1 in Medicated Patients With Depression Are Not Altered by Electroconvulsive Therapy

OBJECTIVES

Hypothalamic-pituitary-adrenal axis dysregulation is frequently observed in patients with depression, with increased levels of the glucocorticoid (GC) cortisol commonly reported. Hypothalamic-pituitary-adrenal axis dysregulation may be a consequence of impaired feedback inhibition due to GC receptor (GR) impairments or dysfunction, termed "glucocorticoid resistance." Here, our objective was to assess mRNA levels of GC-related markers (GR, FKBP5, serum glucocorticoid kinase 1 [SGK1]) in patients with depression versus controls and in patient samples after electroconvulsive therapy (ECT). We also examined the relationship between these GC-related markers and 24-item Hamilton Depression Rating Scale (HAM-D24) scores to assess the utility of using them as biological markers for depression or the therapeutic response to ECT.

METHODS

GR, FKBP5, and SGK1 mRNA levels were examined in whole blood samples from 88 medicated patients with depression pre-/post-ECT and 63 controls using quantitative real-time polymerase chain reaction. Exploratory subgroup correlational analyses were performed to determine the relationship between GR, FKBP5, and SGK1 and 24-item Hamilton Depression Rating Scale scores.

RESULTS

GR, FKBP5, and SGK1 mRNA levels were significantly lower in medicated patients with depression compared with controls (P < 0.001, P = 0.03, P < 0.001, respectively), but ECT did not alter their levels (all P > 0.05). There was no relationship between GR, FKBP5, or SGK1 and 24-item Hamilton Depression Rating Scale scores.

CONCLUSIONS

GR, FKBP5, and SGK1 do not seem to be involved in the peripheral molecular response to ECT and do not represent useful biomarkers for predicting the therapeutic response to ECT in a real-world clinical setting.

Effects of Aerobic Exercise on Cortisol Stress Reactivity in Response to the Trier Social Stress Test in Inpatients with Major Depressive Disorders: A Randomized Controlled Trial

Physical activity is associated with a favourable (blunted) cortisol stress reactivity in healthy people. However, evidence from experimental study and with psychiatric patients is missing. This study examines whether exercise training impacts on cortisol stress reactivity in inpatients with major depressive disorder (MDD). These new insights are important because the stress reactivity of healthy people and patients with severe symptoms of depression might differ. Methods: The study was designed as a randomized controlled trial (trial registration number: NCT02679053). In total, 25 patients (13 women, 12 men, mean age: 38.1 12.0 years) completed a laboratory stressor task before and after a six-week intervention period. Nine samples of salivary free cortisol were taken before and after the Trier social stress test (TSST). Fourteen participants took part in six weeks of aerobic exercise training, while 11 patients were allocated to the control condition. While the primary outcome of the study was depressive symptom severity, the focus of this paper is on one of the secondary outcomes (cortisol reactivity during the TSST). The impact of aerobic exercise training was examined with a repeated-measures analysis of variance. We also examined the association between change in depression and cortisol response via correlational analysis. Cortisol reactivity did not change from baseline to post-intervention, either in the intervention or the control group. Participation in six weeks of aerobic exercise training was not associated with participants' cortisol reactivity. Moreover, depressive symptom change was not associated with change in cortisol response. Aerobic exercise training was not associated with patients' stress reactivity in this study. Because many patients initially showed a relatively flat/blunted cortisol response curve, efforts might be needed to find out which treatments are most efficient to promote a normalization of HPA axis reactivity.

Cortisol levels in unmedicated patients with unipolar and bipolar major depression using hair and saliva specimens

Background

Differentiating between unipolar and bipolar depression can be clinically challenging, especially at first presentation. Patterns of cortisol secretion could aid diagnostic discrimination in affective disorders although there has been little comparative research to date. In this study, we investigated acute (saliva) and chronic (hair) cortisol levels concurrently in unmedicated unipolar and bipolar disorders by using conventional diagnostic criteria and self-report measures.

Methods

Patients with unipolar and bipolar major depression and healthy controls were recruited and assessed. Cortisol levels were extracted from saliva and hair specimens. Depressive features were investigated according to diagnostic groups and with a continuous self-report measure of bipolarity using the Hypomania Checklist (HCL-33).

Results

Whilst a trend towards a reduction in the total daily salivary cortisol output—area under the curve with respect to the ground (AUCg)—was detected in depressive disorders across diagnosis, the self-administrated bipolarity index suggested that an increase in bipolarity symptoms predicted lower cortisol levels using AUCg. Chronic cortisol measurement did not discriminate unipolar from bipolar depression.

Conclusion

Results suggested that whilst a low total daily salivary cortisol output (AUCg) might be associated with depressive symptoms, a self-reported measure of bipolarity predicts lower daily cortisol output.

Melatonergic agonist regulates circadian clock genes and peripheral inflammatory and neuroplasticity markers in patients with depression and anxiety

OBJECTIVE

Circadian dysfunction is a core manifestation and a risk factor for psychiatric disorders. Ramelteon (RMT), a melatonin receptor agonist, has been shown to induce sleep phase shifts and has been used to normalize sleep onset time. RMT has been used in sleep disorders, depression and anxiety. In this study, we aimed to investigate the effects of RMT in regulating gene expression profiles of the circadian clock and peripheral markers of inflammation and neuroplasticity.

METHODS

Sixteen patients with a diagnosis of primary insomnia comorbid with depression and anxiety and ten healthy controls were recruited in an 8-week open-label trial. The patients with primary insomnia received RMT 8 mg/day. The morning expression profiles of 15 core clock genes from peripheral blood mononuclear cells (PBMCs), urine and plasma levels of melatonin and its metabolite levels, and plasma inflammatory markers and neurotrophin levels were evaluated at baseline, 4th and 8th week of RMT treatment.

RESULTS

RMT treatment was associated with significant clinical improvement in depression scores at 8th week (Hamilton depression rating scale scores (Mean ± SEM) from 21.5 ± 2.44 to 14.31 ± 2.25, p ≤ 0.05). The overall poor sleep quality (Pittsburgh sleep quality index) of the patient group significantly improved (p ≤ 0.05) following RMT treatment. The mRNA level analysis showed a significant association between RMT treatment and alterations of the nine core circadian genes (CLOCK, PER1, PER2, CRY1, CRY2, NR1D1, NR1D2, DEC1 and TIMELESS) in the patient group when compared with the control group (p ≤ 0.05). Compared with the controls, the patient group had a decrease in neurotrophins (brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor and beta-nerve growth factor; p ≤ 0.05) but an increase in pro-inflammatory cytokine levels (interleukin-6, interleukin-1b, tumour necrosis factor-alpha and interferon gamma; p ≤ 0.05); RMT treatment normalized the levels of neurotrophins and cytokine levels.

CONCLUSION

RMT treatment is able to restore phase-shifted melatonin markers, normalized the altered expression of the circadian genes, the levels of inflammatory cytokines and neurotrophins in patients with insomnia comorbid anxiety and depression.

Depressive disorders in the elderly and dementia: An update

The relationship between depressive disorders in the elderly and dementia, particularly Alzheimer’s disease (AD), is highly complex. While the nature of this relationship is still a matter of debate, differential diagnosis and treatment remain a great clinical challenge. We review recent findings on the conundrum of depressive disorders in the elderly and AD. There is a biological continuum between depressive disorders in the elderly – or at least a subgroup of them – and AD. While elderly subjects with depression and patients with AD exhibit higher circulating levels of pro-inflammatory molecules and lower BDNF than matched controls, CSF levels of Aβ42 can discriminate AD from depressive disorders in the elderly. The role of antidepressant treatment as a strategy to minimize the risk of AD remains to be established.

Risk factors for depression in adults: NR3C1 DNA methylation and lifestyle association

OBJECTIVE

The aim of this study was to verify determinant factors for depression and analyze the relationship between possible changes in HPA axis and depression, in this case NR3C1 DNA methylation and serum cortisol levels.

METHODS

349 adult volunteers were recruited to evaluate depression, socio-demographic, economic and lifestyle factors, serum cortisol levels and NR3C1 DNA methylation by pyrosequencing. Depression determinant factors were investigated using a Poisson regression model with robust variance (p < 0.05).

RESULTS

Poisson regression with robust variance adjusted by gender, tobacco use, self-perceived stress, leisure activity, suicidal ideation, low cortisol levels and NR3C1 DNA methylation was performed and predicted risk factors for depression. Furthermore, depressive volunteers showed a significant increase in NR3C1 DNA methylation when compared to healthy volunteers.

CONCLUSIONS

This findings provide a basis for understanding the role of HPA axis in depression, especially its regulation by NR3C1 DNA methylation. Furthermore, it emphasizes the stressful lifestyle risk factors (female, tobacco uso, self perceived stress, leisure activities absence and suicidal ideation) that can contribute to future research and the search for public health policies to improve quality of live, mental and general health.

Toward a New Model of Understanding, Preventing, and Treating Adolescent Depression Focusing on Exhaustion and Stress

OBJECTIVE

Adolescent depression is a heterogeneous disorder, with a wide variety of symptoms and inconsistent treatment response, and is not completely understood. A dysregulated stress system is a consistent finding, however, and exhaustion is a consistent trait in adolescent patients. The aim of this paper is to critically assess current hypotheses in adolescent depression research and reframe causes and treatment approaches.

METHODS

A mixed-method approach involved a review based on publications from PubMed, Embase and PsycInfo, and two exemplary adolescent cases.

RESULTS

Both cases show a spiral of stress and exhaustion, but with a different profile of symptoms and coping mechanisms. Reframing both cases from the perspective of coping behavior, searching for the sources of experienced stress and exhaustion, showed coping similarities. This proved essential in the successful personalized treatment and recovery process. In combination with recent evidence, both cases support the functional reframing of depression as the outcome of a stress- and exhaustion-related spiralling mechanism.

CONCLUSIONS

We propose to open up a symptom-based, mood-centered view to a model in which adolescent depression is framed as a consecutive failure of stress coping mechanisms and chronic exhaustion. Addressing exhaustion and coping primarily as a treatment strategy in adolescents and young adults might work in synergy with existing treatments and improve overall outcomes. This perspective warrants further investigation.

Disruption of Neural Homeostasis as a Model of Relapse and Recurrence in Late-Life Depression

The significant public health burden associated with late-life depression (LLD) is magnified by the high rates of recurrence. In this manuscript, we review what is known about recurrence risk factors, conceptualize recurrence within a model of homeostatic disequilibrium, and discuss the potential significance and challenges of new research into LLD recurrence. The proposed model is anchored in the allostatic load theory of stress. We review the allostatic response characterized by neural changes in network function and connectivity and physiologic changes in the hypothalamic-pituitary-adrenal axis, autonomic nervous system, immune system, and circadian rhythm. We discuss the role of neural networks' instability following treatment response as a source of downstream disequilibrium, triggering and/or amplifying abnormal stress response, cognitive dysfunction and behavioral changes, ultimately precipitating a full-blown recurrent episode of depression. We propose strategies to identify and capture early change points that signal recurrence risk through mobile technology to collect ecologically measured symptoms, accompanied by automated algorithms that monitor for state shifts (persistent worsening) and variance shifts (increased variability) relative to a patient's baseline. Identifying such change points in relevant sensor data could potentially provide an automated tool that could alert clinicians to at-risk individuals or relevant symptom changes even in a large practice.

Melancholia as Predictor of Electroconvulsive Therapy Outcome in Later Life

OBJECTIVES

In clinical practice, particularly melancholic depression benefits from electroconvulsive therapy (ECT), albeit research melancholia criteria from the Diagnostic and Statistical Manual of Mental Disorders (DSM) is not conclusive. We compared clinical characteristics and ECT outcome of melancholic and nonmelancholic depression, here defined by psychomotor symptoms.

METHODS

One hundred ten depressed older in-patients treated with ECT were included in the Mood Disorders in Elderly treated with ECT study. The CORE was used for the assessment of psychomotor symptoms, with a score of 8 or higher defining melancholic depression. Depression severity was measured before, during, and after ECT. Characteristics were compared across melancholic and nonmelancholic patients. Regression analysis was used to assess the relation between psychomotor symptoms and remission/response, and survival analysis was used to examine the difference in time.

RESULTS

Patients with melancholic depression had higher severity, lower cognitive and overall functioning, and lower prevalence of cardiovascular disease. However, no significant relations were found between CORE scores and remission/response. Because psychotic symptoms are a positive predictor of ECT response and remission, we examined whether CORE score was a predictor of response in the nonpsychotic group (n = 49). In nonpsychotic patients, remission was 62%, and the association between CORE scores and remission almost reached significance (P = 0.057).

DISCUSSION

Although melancholically and nonmelancholically depressed patients differed significantly on several clinical characteristics, ECT outcome did not differ. Analyses may be hampered by a high prevalence of psychotic features. In nonpsychotic patients, CORE scores neared significance as predictor of remission, suggesting that CORE scores might be a distinguishing characteristic of melancholia in nonpsychotic patients and a clinical useful predictor of ECT response.

Salivary cortisol as predictor for depression characteristics and remission in electroconvulsive therapy in older persons

Objectives: Electroconvulsive therapy (ECT) is the most effective treatment for depression; however, consensus on predictors for ECT outcome is lacking. We aim to examine the relation between pre-ECT salivary cortisol values and clinical characteristics and ECT outcome in depressed, older persons.Methods: A total of 102 inpatients meeting DSM-IV criteria for depression and referred for ECT were selected. Salivary cortisol was assessed at five time points during the day, providing insight into the cortisol awakening curve to the ground (AUCg) and to the increase (AUCi) and evening cortisol level. Depression severity was assessed using the Montgomery-Asberg Depression Rating Scale (MADRS). Remission was defined as MADRS <10; response was defined as MADRS-reduction of at least 50%. Regression analysis was used to assess associations between cortisol and (1) clinical variables, including depression severity, psychomotor symptoms and presence of psychosis, and (2) ECT outcome.Results: No significant relations were found between AUCg, AUCi, evening cortisol and depression severity, psychomotor symptoms, and presence of psychosis. In addition, no significant relation was found between cortisol and response or remission.Conclusions: Our results do not support a relation between cortisol values and depression characteristics, or ECT outcome in severely depressed, older patients treated with ECT.

Cortisol is not associated with pre-treatment medial temporal lobe volume or volume changes after electroconvulsive therapy in patients with late-life depression

Accumulating evidence suggests that late-life depression is associated with reduced hippocampal volume and that cortisol might be related to this volumetric reduction. We explored whether cortisol awaking response (CAR), which is the increase in cortisol after awakening, was associated with volumetric changes in the medial temporal lobe (MTL) after electroconvulsive therapy (ECT) in 41 patients (age ≥ 55) treated for major depressive disorder (MDD) with ECT. Cortisol was measured before the start of the ECT treatment and was related to MTL volumes derived from structural T1-weighted images. The study assessed associations between CAR and pre-treatment MTL volumes, and CAR and ECT-induced MTL volumetric changes. There were no significant correlations found between CAR, operationalized as Area Under the Curve with respect to ground (AUCg) and Area Under the Curve with respect to increase (AUCi), and pre-treatment MTL volumes. Neither was there an association between AUCg or AUCi and the ECT-induced changes in MTL volumes after correction for multiple comparisons. Finally, neither AUCg or AUCi were able to predict ECT-induced volumetric changes in the MTL. Hence, we conclude that CAR is unrelated to pre-treatment hippocampus and amygdala volumes, and to the volumetric changes in the aforementioned areas following ECT.

Examining sex differences in pleiotropic effects for depression and smoking using polygenic and gene-region aggregation techniques

Sex differences in rates of depression are thought to contribute to sex differences in smoking initiation (SI) and number of cigarettes smoked per day (CPD). One hypothesis is that women smoke as a strategy to cope with anxiety and depression, and have difficulty quitting because of concomitant changes in hypothalamic-pituitary-adrenocortical (HPA) axis function during nicotine withdrawal states. Despite evidence of biological ties, research has not examined whether genetic factors that contribute to depression-smoking comorbidity differ by sex. We utilized two statistical aggregation techniques-polygenic scores (PGSs) and sequence kernel association testing-to assess the degree of pleiotropy between these behaviors and moderation by sex in the Health and Retirement Study (N = 8,086). At the genome-wide level, we observed associations between PGSs for depressive symptoms and SI, and measured SI and depressive symptoms (all p < .01). At the gene level, we found evidence of pleiotropy in FKBP5 for SI (p = .028), and sex-specific pleiotropy in females in NR3C2 (p = .030) and CHRNA5 (p = .025) for SI and CPD, respectively. Results suggest bidirectional associations between depression and smoking may be partially accounted for by shared genetic factors, and genetic variation in genes related to HPA-axis functioning and nicotine dependence may contribute to sex differences in SI and CPD.

Role of Corticotropin Releasing Factor in the Neuroimmune Mechanisms of Depression: Examination of Current Pharmaceutical and Herbal Therapies

Approximately 3% of the world population suffers from depression, which is one of the most common form of mental disorder. Recent findings suggest that an interaction between the nervous system and immune system might be behind the pathophysiology of various neurological and psychiatric disorders, including depression. Neuropeptides have been shown to play a major role in mediating response to stress and inducing immune activation or suppression. Corticotropin releasing factor (CRF) is a major regulator of the hypothalamic pituitary adrenal (HPA) axis response. CRF is a stress-related neuropeptide whose dysregulation has been associated with depression. In this review, we summarized the role of CRF in the neuroimmune mechanisms of depression, and the potential therapeutic effects of Chinese herbal medicines (CHM) as well as other agents. Studying the network of CRF and immune responses will help to enhance our understanding of the pathogenesis of depression. Additionally, targeting this important network may aid in developing novel treatments for this debilitating psychiatric disorder.

Examining HPA-axis functioning as a mediator of the relationship between depression and cognition across the adult lifespan

Altered HPA-axis functioning is a hypothesized mechanism for worsened cognition in depression. The current study examines the indirect effects of depression on processing speed, executive functioning, and memory as a function of the HPA-axis. 38 individuals with a depression diagnosis and 50 healthy controls (HCs) aged 18-86 underwent neuropsychological testing and at-home diurnal salivary cortisol collection. Depression was assessed via structured clinical interviews and rating scales. Cognitive composite scores were derived from factor analysis. Daytime cortisol exposure was estimated using area under the curve (AUC). Depression was associated with higher cortisol levels and slower processing speed . A significant suppression effect of AUC was present on the relationship between depression and processing speed. Limitations include the cross-sectional design and limited sample heterogeneity. Though poorly modulated HPA-axis is one proposed mechanism of cognitive alterations in depression, our results did not support this conclusion for processing speed. Alternative mechanisms should be considered to inform interventions to target cognitive alterations in depression.

Biological, Behavioral and Physiological Consequences of Drug-Induced Pregnancy Termination at First-Trimester Human Equivalent in an Animal Model

Given the significant physiological changes that take place during and resulting from pregnancy, as well as the relative absence of such information in relation to pregnancy termination, this study investigated the potential for developing a valid animal model to objectively assess the biological, physiological and behavioral consequences of drug-induced pregnancy termination. Female Long-Evans rats were divided into four groups (n = 19-21/group), controlling for drug [mifepristone (50 mg/kg/3 ml, i.g.)/misoprostol (0.3 mg/kg/ml, i.g.) or vehicle (1% Carboxymethylcellulose Sodium/0.2% Tween® 80 suspension, i.g.)] and pregnancy. Drug administration took place on days 12-14 of gestation (days 28-40 human gestational equivalent). Vehicle was administered to the controls on the same days. Parameters measured included rat body weight, food intake, vaginal impedance, sucrose consumption/preference, locomotor activity, forced swim test, and home-cage activity. At the termination of the study, rats were deeply anesthetized using urethane, and blood, brain, and liver were collected for biochemical analysis. Following drug/vehicle administration, only the pregnancy termination group (pregnant, drug) displayed a significant decrease in body weight, food intake, locomotor activity-related behaviors and home-cage activity relative to the control group (non-pregnant, vehicle). Additionally, the pregnancy termination group was the only group that displayed a significant reduction in sucrose consumption/preference during Treatment Week relative to Pre-Treatment Week. Vaginal impedance did not significantly decrease over time in parous rats in contrast to all other groups, including the rats in the pregnancy termination group. Biochemical analysis indicated putative drug- and pregnancy-specific influences on oxidative balance. Regression analysis indicated that pregnancy termination was a predictor variable for body weight, food intake and all locomotor activity parameters measured. Moreover, pertaining to body weight and food intake, the pregnancy termination group displayed significant changes, which were not present in a group of naturally miscarrying rats following pregnancy loss. Overall, our results appear to suggest negative biological and behavioral effects following pregnancy termination, that appear to also be distinct from natural miscarriage, and potential benefits of parity pertaining to fecundity. Thus, our findings indicate the importance for further objective investigation of the physiological and behavioral consequences of medical abortion, in order to provide further insight into the potential implications in humans.

The hypothalamic-pituitary-adrenal axis in PTSD: Pathophysiology and treatment interventions

Questions of how altered functioning of the hypothalamic pituitary adrenal (HPA) axis contribute to the development and maintenance of posttraumatic stress disorder (PTSD) have been the focus of extensive animal and human research. As a rule, results have been inconsistent across studies, likely due to a variety of confounding variables that have received inadequate attention. Important confounding factors include the effects of early life stress, biological sex, and the glucocorticoid used for interventions. In this manuscript we review: 1) the literature on identified abnormalities of HPA axis function in PTSD, both in terms of basal functioning and as part of challenge paradigms; 2) the role of HPA axis function pre- and immediately post-trauma as a risk factor for PTSD development; 3) the impact of HPA axis genes' allelic variants and epigenetic modifications on PTSD risk; 4) the contributions of HPA axis components to fear learning and extinction; and 5) therapeutic manipulations of the HPA axis to both prevent and treat PTSD, including the role of glucocorticoids as part of medication enhanced psychotherapy.

Peripheral blood GILZ mRNA levels in depression and following electroconvulsive therapy

Dysregulation of the hypothalamic-pituitary-adrenocortical (HPA)-axis is commonly observed in patients with depression. The delayed feedback system that mediates inhibition of HPA-axis activation is regulated by glucocorticoid receptors (GRs) found in stress-responsive areas of the brain. Glucocorticoid-induced leucine zipper (GILZ) is a key molecule in glucocorticoid biology and is thought to mediate the downstream anti-inflammatory effects of GRs. Previous reports suggest that GILZ levels are altered in the blood and brains of patients with, and animal models of, depression. However, no study has yet investigated the effects of antidepressant treatment on GILZ. Therefore, our aim was to examine peripheral blood GILZ mRNA levels in patients with depression (n = 88) compared to age- and sex-matched healthy controls (n = 63), and in patients with depression following treatment with a course of electroconvulsive therapy (ECT). We also assessed the relationship between GILZ and mood and clinical outcomes following ECT. GILZ mRNA levels were assessed using qRT-PCR. GILZ levels were found to be significantly lower in patients with depression compared to controls (p < 0.002), and ECT further decreased GILZ levels (p = 0.05). Both of these results survived adjustment for potential covariates. However, we found no association between GILZ and mood scores. Overall, these results suggest that GILZ is involved in the pathophysiology of depression and the peripheral molecular response to ECT.

Long-term glucocorticoid levels measured in hair in patients with depressive and anxiety disorders

BACKGROUND

Depressive and anxiety disorders have been linked to a dysregulated hypothalamus-pituitary-adrenal (HPA)-axis. Hair cortisol levels (HairF) reflect integrated long-term cortisol regulation and are therefore promising endocrine markers of chronic (psychological and physical) stress. Our aim was to assess hair cortisol levels in persons with a depressive and/or anxiety disorder and to compare their levels with that of persons in remission and healthy controls.

METHODS

Data from 1166 participants of the Netherlands Study of Depression and Anxiety (NESDA) were used, including 266 participants with a recent (1-month) diagnosis of a depressive and/or anxiety disorder, 655 participants with a diagnosis in remission, and 245 healthy controls. HairF was measured in the proximal three cm of scalp hair, using LC-MS/MS.

RESULTS

Compared to the healthy controls no differences on HairF or HairE levels were found for depressive and anxiety disorders alone. However the presence of a comorbid depressive and anxiety disorder was significantly associated with increased HairF levels (β = 0.07; p = .031), as was the severity of depressive symptoms (β = 0.06; p = .029), but no differences were found on HairE nor the HairF:HairE ratio.

CONCLUSIONS

Persons with current diagnosis of comorbid depression and anxiety show moderately higher levels of cortisol than patients with only depression or anxiety, or patients in remission and healthy controls, which may be indicative of a chronic state of hyperactivation of the HPA axis.

Can physical exercise modulate cortisol level in subjects with depression? A systematic review and meta-analysis

INTRODUCTION

Major depressive disorder (MDD) is a prevalent medical illness that is associated with chronic stress. Patients with MDD can show an imbalance in cortisol levels, which can be restored with the remission of symptoms. Physical exercise training has been used as a tool to promote changes in cortisol levels in healthy individuals. However, it is unknown if exercise can produce the same results in individuals with MDD.

OBJECTIVE

To review evidence of cortisol changes after exercise training in individuals with MDD.

METHODS

We conducted a search on PubMed, SciELO, LILACS, ISI Web of Knowledge, Scopus, and PsycInfo databases. Random effects meta-analysis was performed and standardized mean difference (SMD) effect size was calculated. Analyses of forest and funnel plots was conducted using Stata v.11.0 software.

RESULTS

At first, 463 studies were obtained in the search. After completion of the selection procedure, five articles with seven analyses were included. Type of exercise, frequency of training, cortisol measurement, and type of control group were analyzed. There was a reduction of cortisol levels in the exercise group (SMD = -0.65, 95%CI 1.30-0.01). Moreover, sensitivity analysis and subgroup analyses revealed an effect of type (aerobic exercise) and frequency (five times per week) of exercise on reduction of cortisol levels. However, these results should be interpreted cautiously due to the small number of studies and a substantial heterogeneity among them.

CONCLUSION

Physical exercise promotes a reduction in cortisol levels in individuals with MDD. However, this finding can be influenced by type of exercise, weekly frequency, and type of cortisol measurement.

Glucocorticoid Negative Feedback in Regulation of the Hypothalamic-Pituitary-Adrenal Axis in Rhesus Monkeys With Various Types of Adaptive Behavior: Individual and Age-Related Differences

The study of the mechanisms underlying the increased vulnerability of the individual to stressful environmental factors in different age periods is of great relevance for prevention and effective treatment of stress-dependent diseases that are widespread in the population of aging individuals. The purpose of our study was to investigate the individual and age-related features of the glucocorticoid negative feedback in regulation of the hypothalamic-pituitary-adrenal (HPA) axis, the key adaptive neuroendocrine system, in experiments with physically healthy young and old female rhesus monkeys with administration of mineracorticoid receptor (fludrocortisone) and glucocorticoid receptor (dexamethasone) agonists. We studied the monkeys with increased trait anxiety and depression-like behavior (DAB) characterized, as previously was shown, by the increased vulnerability to acute stress and the animals with normal standard behavior (SB) as the control. The pronounced individual differences in the reaction of HPA axis to fludrocortisone and dexamethasone in young animals were found. Young animals with DAB showed a lower sensitivity of HPA axis to the inhibitory effect of both fludrocortisone and dexamethasone compared with young animals with SB. At the same time, there were no significant intergroup differences in the concentration of ACTH and cortisol in response to placebo injection, i.e., in basal conditions. The old individuals with DAB demonstrated the essential relative resistance of HPA axis to fludrocortisone test and higher basal plasma levels of cortisol and ACTH in the evening (the period of HPA axis low circadian activity) compared to old SB animals. In the same time, the intergroup differences in the response of HPA axis to dexamethasone administration were leveled due to age-related increase in sensitivity of HPA axis to dexamethasone in animals with DAB. These data testify the pronounced intergroup and age differences in the feedback regulation of HPA axis, presumably resulting from unequal individual, and age-related changes in the activity of mineralcorticoid and glucocorticoid receptors in the brain structures supporting the functions of HPA axis. The maximum age disorders in functioning of the negative feedback mechanism in the regulation of HPA axis are characteristic of animals with DAB, which, apparently, underlie the increased vulnerability of these animals to stress exposure.

Ingestion of Bifidobacterium longum subspecies infantis strain CCFM687 regulated emotional behavior and the central BDNF pathway in chronic stress-induced depressive mice through reshaping the gut microbiota

Probiotics which enhance the biosynthesis of 5-hydroxytryptamine in enterochromaffin cells could alleviate depression symptoms through regulating the CREB-BDNF pathway in the brain.

Hypothalamic-pituitary-adrenal axis functioning in borderline personality disorder: A meta-analysis

Borderline Personality Disorder (BPD) has been associated with altered hypothalamic-pituitary-adrenal (HPA) axis functioning. However, evidence is inconsistent. Therefore, the present series of meta-analyses aimed to quantify HPA axis functioning in BPD patients based on singular and continuous cortisol assessments and measures of reactivity to pharmacological and psychosocial stress. Case-control studies comparing adult BPD patients and healthy and clinical controls were considered for inclusion. The search resulted in 804 publications, of which 37 studies (k = 81; BPD n = 803, controls n = 1092) were included. Analyses were based on random effect models using standardized mean differences. BPD patients displayed elevated continuous cortisol output and blunted cortisol following psychosocial challenges. Singular cortisol assessments and cortisol after pharmacological challenges were not significantly different. Meta-analyses were limited by inconsistent reporting in individual studies and small samples for some comparisons. Due to the debilitating nature of stress-related symptoms in BPD, more research on elevated continuous cortisol output and blunted cortisol responses to psychosocial stress is warranted.

The Role of Physical Exercise and Omega-3 Fatty Acids in Depressive Illness in the Elderly

Background:

In adulthood, depression is the most common type of mental illness and will be the second leading cause of disease by 2020. Major depression dramatically affects the function of the central nervous system and degrades the quality of life, especially in old age.

Several mechanisms underlie the pathophysiology of depressive illness, since it has a multifactorial etiology. Human and an-imal studies have demonstrated that depression is mainly associated with imbalances in neurotransmitters and neurotrophins, hypothalamic-pituitary-adrenal axis alterations, brain volume changes, neurogenesis dysfunction, and dysregulation of in-flammatory pathways. Also the gut microbiota may influence mental health outcomes.

Although depression is not a consequence of normal aging, depressive disorders are common in later life, even if often undi-agnosed or mis-diagnosed in old age. When untreated, depression reduces life expectancy, worsens medical illnesses, en-hances health care costs and is the primary cause of suicide among older people. To date, the underpinnings of depression in the elderly are still to be understood, and the pharmacological treatment is the most commonly used therapy.

Objective:

Since a sedentary lifestyle and poor eating habits have recently emerged as crucial contributors to the genesis and course of depression, in the present review, we have focused on the effects of physical activity and omega-3 fatty acids on depressive illness in the elderly.

Results:

A growing literature indicates that both exercise and dietary interventions can promote mental health throughout one’s lifespan.

Conclusion:

There thus emerges the awareness that an active lifestyle and a balanced diet may constitute valid low-cost pre-vention strategies to counteract depressive illness in the elderly.

The influence of childhood abuse on cortisol levels and the cortisol awakening response in depressed and nondepressed older adults

OBJECTIVES

Childhood abuse has been associated with depression in later life. This may be related to hypothalamic-pituitary-adrenal (HPA) axis functioning. Therefore we aimed to examine the impact of childhood abuse and its interaction with depression on cortisol levels in older adults.

METHODS

Data from 418 participants (mean age 70.8 years) in the Netherlands Study of Depression in Older Persons (NESDO) were used; 187 participants experienced childhood abuse; 309 participants had a diagnosis of depression. Diurnal cortisol levels were determined using six saliva samples from every participant. Multiple regression analyses were performed.

RESULTS

Significant negative associations between childhood abuse and morning cortisol levels were found. In nondepressed persons, both psychological and sexual abuse were associated with greater dynamics of the HPA axis in response to awakening.

CONCLUSIONS

Childhood abuse is associated with lower basal cortisol levels at awakening irrespective of major depressive disorder (MDD). Higher reactivity of the HPA axis during the hour after awakening was found in nondepressed participants only, which might suggest that late-life depression modifies the effect of childhood abuse on the HPA axis. Older adults with a history of childhood abuse may be more negatively affected by stress or stressful events and this is reflected in dysregulation of the HPA axis.

Apelin-13 Upregulates BDNF Against Chronic Stress-induced Depression-like Phenotypes by Ameliorating HPA Axis and Hippocampal Glucocorticoid Receptor Dysfunctions

Localization of apelin and its receptor APJ in limbic structures such as the hippocampus suggests potential involvement of apelin/APJ signaling in stress-related emotional responses. We have recently reported that apelin-13 exerts antidepressant-like actions in acute stressed rats, and that the hippocampus is a critical brain region mediating its actions. However, the neural mechanism underling antidepressant-like actions of apelin-13 is still largely unknown. The aim of the present study is to determine whether apelin-13 ameliorates chronic water-immersion restraint stress (CWIRS)-induced depression-like phenotypes and its neural mechanism in rats. Here, we report that CWIRS exposure leaded to upregulation of apelin/APJ signaling in the hippocampus. Apelin-13 ameliorated CWIRS-induced depression-like phenotypes including hedonic-like deficit and behavioral despairs. Moreover, apelin-13 ameliorated hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, and hippocampal BDNF expression deficit and glucocorticoid receptor (GR) nucleus translocation hypoactivity in chronic stressed rats. Finally, apelin-13-mediated effects were blocked by the selective TrkB receptor antagonist ANA-12. These results suggest that apelin-13 upregulates BDNF against chronic stress-induced depression-like phenotypes by ameliorating HPA axis and hippocampal GR dysfunctions.

Antidepressant and anxiolytic effects of the proprietary Chinese medicine Shexiang Baoxin pill in mice with chronic unpredictable mild stress

Depression and anxiety often co-occur with cardiac diseases. The Shexiang Baoxin pill (SBP) is a proprietary Chinese medicine initially used to treat cardiac conditions. This study explored whether SBP has antidepressant and anxiolytic effects in addition to hormonal and psychotropic mechanisms. Mice underwent 6 weeks of chronic unpredictable mild stress (CUMS) to induce depression- and anxiety-like behavior. During the 6-week experiment, mice received SBP at intragastric doses of 20.25 mg/kg or 40.5 mg/kg daily. Animals were then tested for depression in sucrose preference, forced-swimming, and tail suspension paradigms, and for anxiety in open field and elevated plus maze tests. Both SBP doses significantly reduced anhedonic behavior in the sucrose preference test; the high SBP dose also increased the number of entries into the central zone of the open field. SBP-treated mice had markedly lower blood levels of corticotrophin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) than stressed mice treated with vehicle. Either low- or high-dose SBP reversed stress-induced reductions of norepinephrine (NE) and dopamine (DA) metabolites and the expression levels of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and glial cell-derived neurotrophic factor (GDNF) in related brain regions. These results suggest that SBP could prevent and alleviate prolonged stress-induced anhedonia and anxiety in association with its suppression of the hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, modulation of brain monoamine neurotransmitter metabolism and neurotrophins. SBP may be particularly suitable for the management of depressive and anxiety disorders in patients with cardiac conditions.

Inflammatory markers and cortisol parameters across depressive subtypes in an older cohort

BACKGROUND

There is growing evidence that inflammatory and cortisol dysregulation are underlying pathophysiological mechanisms in the aetiology of major depressive disorder, particularly in younger adults. However, findings of biological disturbances in late-life depression have been divergent, probably due to the even greater heterogeneity of depression in older adults with aging processes influencing biological factors. Using empirically derived subtypes may enable the identification of biological disturbances underlying depression in older adults.

METHODS

Data were used from the Netherlands Study of Depression in Older Persons (NESDO) of 359 persons aged 60 years or older, with a current diagnosis of major depressive disorder (MDD). Depressive subtypes (severe atypical, severe melancholic, and moderate severe subtype) that were previously identified through latent class analysis (LCA), were examined on differences in inflammatory markers including C-reactive protein (CRP), interleukin-6 (IL-6), and neutrophil gelatinase-associated lipocalin (NGAL), as well as cortisol parameters.

RESULTS

No differences in measures for inflammation and cortisol across subtypes were observed in uncorrected or for putative confounders corrected models.

LIMITATIONS

Several subjects had missing cortisol and inflammatory data, decreasing the power. However, results did not change after imputation analysis.

DISCUSSION

In this cohort of depressed older adults, no differences in inflammation and cortisol measures between depression subtypes were observed. This is probably due to the many (patho)physiological processes that are involved in aging, thereby clouding the results.

Midday and nadir salivary cortisol appear superior to cortisol awakening response in burnout assessment and monitoring

Burnout and work-related stress symptoms of anxiety disorder and depression cause prolonged work absenteeism and early retirement. Hence, reliable identification of patients under risk and monitoring of treatment success is highly warranted. We aimed to evaluate stress-specific biomarkers in a population-based, “real-world” cohort (burnouts: n = 40, healthy controls: n = 26), recruited at a preventive care ward, at baseline and after a four-month follow up, during which patients received medical and psychological treatment. At baseline, significantly higher levels of salivary cortisol were observed in the burnout group compared to the control group. This was even more pronounced in midday- (p < 0.001) and nadir samples (p < 0.001) than for total morning cortisol secretion (p < 0.01). The treatment program resulted in a significant reduction of stress, anxiety, and depression scores (all p < 0.001), with 60% of patients showing a clinically relevant improvement. This was accompanied by a ~30% drop in midday cortisol levels (p < 0.001), as well as a ~25% decrease in cortisol nadir (p < 0.05), although not directly correlating with score declines. Our data emphasize the potential usefulness of midday and nadir salivary cortisol as markers in the assessment and biomonitoring of burnout.

Honokiol Exerts Antidepressant Effects in Rats Exposed to Chronic Unpredictable Mild Stress by Regulating Brain Derived Neurotrophic Factor Level and Hypothalamus-Pituitary-Adrenal Axis Activity

Honokiol (HNK), the main active component of Magnolia officinalis, has shown a variety of pharmacological activities. In the present study, we measured the antidepressant-like effects of HNK in a rat model of chronic unpredictable mild stress (CUMS) and explored its possible mechanisms. The antidepressant-like effects of HNK were assessed in rats by an open field test (OFT), sucrose preference test (SPT) and forced swimming test (FST). Then, serum levels of corticotrophin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) and hippocampal brain-derived neurotrophic factor (BDNF) and glucocorticoid receptor α (GRα) levels were assessed to explore the possible mechanisms. We identified that HNK treatment (2, 4, and 8 mg/kg) alleviated the CUMS-induced behavioural deficits. Treatment with HNK also normalized the CUMS-induced hyperactivity of the limbic hypothalamic-pituitary-adrenal (HPA) axis, as indicated by reduced CRH, ACTH and CORT serum levels. In addition, HNK increased the expression of GRα (mRNA and protein) and BDNF (mRNA and protein) in the hippocampus. These data confirmed the antidepressant-like effects of HNK, which may be related to its normalizing the function of the HPA axis and increasing the BDNF level in the hippocampus.

Suggested Biomarkers for Major Depressive Disorder

Currently, the diagnosis of major depressive disorder (MDD) mainly relies on clinical examination and subjective evaluation of depressive symptoms. There is no non-invasive, quantitative test available today for the diagnosis of MDD. In MDD, exploration of biomarkers will be helpful in diagnosing the disorder as well as in choosing a treatment, and predicting the treatment response. In this article, it is aimed to review the findings of suggested biomarkers such as growth factors, cytokines and other inflammatory markers, oxidative stress markers, endocrine markers, energy balance hormones, genetic and epigenetic features, and neuroimaging in MDD and to evaluate how these findings contribute to the pathophysiology of MDD, the prediction of treatment response, severity of the disorder, and identification of subtypes. Among these, the findings related to the brain-derived neurotrophic factor, the hypothalamo-pituitary-adrenal axis, cytokines, and neuroimaging may be strong candidates for being biomarkers MDD, and may provide critical information in understanding biological etiology of depression. Although the findings are not sufficient yet, we think that the results of epigenetic studies will also provide very important contributions to the biomarker research in MDD. The availability of biomarkers in MDD will be an advancement that will facilitate the diagnosis of the disorder, treatment choices in the early stages, and prediction of the course of the disorder.

How to measure glucocorticoid receptor's sensitivity in patients with stress-related psychiatric disorders

Stress is a state of derailed homeostasis and a main environmental risk factor for psychiatric diseases. Chronic or uncontrollable stress may lead to a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which is a common feature of stress-related psychiatric disorders. One of the key mechanisms underlying a disturbed HPA axis is an impaired function of the glucocorticoid receptor (GR) with an enhanced or reduced feedback sensitivity for glucocorticoids and subsequently altered concentrations of peripheral cortisol. GR function is regulated by a multiprotein complex including the different expression of the hsp90 co-chaperone FK 506 binding protein 51 (FKBP5) that may be genetically determined or acquired in response to stressful stimuli. Specific patterns of a dysregulation of the HPA axis and GR function are found in different stress-related psychiatric entities e.g. major depression, job-related exhaustion or posttraumatic stress disorder. GR challenge tests like the dexamethasone-suppression test (DST), the dexamethasone-corticotropin-releasing hormone (dex-CRH) test or most recently the analysis of the dexamethasone-induced gene expression are employed to sensitively measure HPA axis activity in these disorders. They provide information for a stratification of phenotypic similar but neurobiological diverse psychiatric disorders. In this review we present a synopsis of GR challenge tests with a focus on the application of the DST, the CRH test and the dex-CRH test as well as the dexamethasone-induced gene expression in stress-related psychiatric entities.

Hypothalamus-Pituitary-Adrenal-axis activity and cognitive functioning in older adults

Inconsistent results are found in the involvement of the Hypothalamus-Pituitary-Adrenal (HPA)-axis in cognitive functioning. This study examined the association between various saliva cortisol measures (the 1-h awakening cortisol, evening cortisol, diurnal change, and cortisol suppression) and cognitive functioning (episodic memory, processing speed, interference control, and working memory). Participants were older adults, between 60 and 93 years with (N = 328) and without (N = 119) a depressive disorder from the Netherlands Study of Depression in Older adults. No significant associations between cortisol and cognitive functioning were observed in the total sample. Only in non-depressed older adults, higher total cortisol secretion over the first hour after awakening and worse episodic memory, higher cortisol levels at awakening and better working memory, and higher diurnal change and better processing speed were significantly associated. Cortisol was not associated with cognitive functioning in depressed older adults. In older adults, the association between depression and cognitive functioning is likely the consequence of other biological or psychological mechanisms.

Cranial electrotherapy stimulation affects mood state but not levels of peripheral neurotrophic factors or hypothalamic- pituitary-adrenal axis regulation

Cranial electrotherapy stimulation (CES) is reported to aid in relieving symptoms of depression and anxiety, though the mechanism underlying this effect remains unclear. Therefore, the present study aimed to evaluate changes in the hypothalamic-pituitary-adrenal (HPA) axis response and levels of neurotrophic factors, as well as changes in mood state, in patients undergoing CES therapy. Fifty healthy postmenopausal women were randomly assigned to either a Sham CES group (n = 25) or an Active CES group (n = 25). CES treatment was conducted in 20-minute sessions, three times per week for 8 weeks, using a micro current cranial electrotherapy stimulator. Blood samples were collected prior to and following the 8-week treatment period for measurement of cortisol, adrenocorticotropic hormone (ACTH), brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) levels. Changes in mood state were also examined at the time of blood collection using the Profile of Mood States (POMS). No significant differences in cortisol, ACTH, BDNF, or NGF were observed between the two participant groups (p > 0.05) following the treatment period. However, those in the Active CES group exhibited significantly decreased Tension-Anxiety and Depression-Dejection scores on the POMS relative to pre-treatment scores (p < 0.05). Furthermore, Depression-Dejection scores following treatment were significantly lower in the Active CES group than in the Sham CES group (p < 0.05). No significant differences were observed in any other POMS scores such as Anger-Hostility, Vigor-Activity, Fatigue-Inertia, and Confusion-Bewilderment (p > 0.05). These results suggest that 8 weeks of CES treatment does not induce changes in blood levels of neurotrophic factors or HPA-axis-related hormones, though such treatment may be effective in treating symptoms of anxiety and depression.

Neurobiological Mechanisms of Stress Resilience and Implications for the Aged Population

BACKGROUND

Stress is a common reaction to an environmental adversity, but a dysregulation of the stress response can lead to psychiatric illnesses such as major depressive disorder (MDD), post-traumatic stress disorder (PTSD), and anxiety disorders. Yet, not all individuals exposed to stress will develop psychiatric disorders; those with enhanced stress resilience mechanisms have the ability to adapt successfully to stress without developing persistent psychopathology. Notably, the potential to enhance stress resilience in at-risk populations may prevent the onset of stress-induced psychiatric disorders. This novel idea has prompted a number of studies probing the mechanisms of stress resilience and how it can be manipulated.

METHODS

Here, we review the neurobiological factors underlying stress resilience, with particular focus on the serotoninergic (5-HT), glutamatergic, and γ-Aminobutyric acid (GABA) systems, as well as the hypothalamic-pituitary axis (HPA) in rodents and in humans. Finally, we discuss stress resiliency in the context of aging, as the likelihood of mood disorders increases in older adults.

RESULTS

Interestingly, increased resiliency has been shown to slow aging and improved overall health and quality of life. Research in the neurobiology of stress resilience, particularly throughout the aging process, is a nascent, yet, burgeoning field.

CONCLUSION

Overall, we consider the possible methods that may be used to induce resilient phenotypes, prophylactically in at-risk populations, such as in military personnel or in older MDD patients. Research in the mechanisms of stress resilience may not only elucidate novel targets for antidepressant treatments, but also provide novel insight about how to prevent these debilitating disorders from developing.

Of Microbes and Minds: A Narrative Review on the Second Brain Aging

In recent years, an extensive body of literature focused on the gut-brain axis and the possible role played by the gut microbiota in modulating brain morphology and function from birth to old age. Gut microbiota has been proposed as a relevant player during the early phases of neurodevelopment, with possible long-standing effects in later life. The reduction in gut microbiota diversity has also become one of the hallmarks of aging, and disturbances in its composition are associated with several (age-related) neurological conditions, including depression, Alzheimer's disease, and Parkinson's disease. Several pathways have been evoked for gut microbiota-brain communication, including neural connections (vagus nerve), circulating mediators derived by host-bacteria cometabolism, as well as the influence exerted by gut microbiota on host gut function, metabolism, and immune system. Although the most provoking data emerged from animal studies and despite the huge debate around the possible epiphenomenal nature of those findings, the gut microbiota-brain axis still remains a fascinating target to be exploited to attenuate some of the most burdensome consequences of aging.

Testosterone, DHEA and DHEA-S in patients with schizophrenia: A systematic review and meta-analysis

Neuroactive steroids, including testosterone, dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S) might play an important role in the pathophysiology of schizophrenia. Therefore, we performed a systematic review and meta-analysis of studies comparing the levels of testosterone, DHEA and DHEA-S in patients with schizophrenia and healthy controls. We searched electronic databases from their inception until Oct 29, 2017. Effect size (ES) estimates were calculated as Hedges' g. Data analysis was performed using random-effects models. Our analysis included 34 eligible studies, representing 1742 patients and 1604 controls. Main analysis revealed elevated DHEA-S levels in the whole group of patients (ES = 0.75, 95%CI: 0.23-1.28, p = 0.005). In subgroup analyses, patients with first-episode psychosis (FEP) had significantly higher levels of free testosterone (ES = 1.21, 95%CI: 0.30-2.12, p = 0.009) and DHEA-S (ES = 1.19, 95%CI: 0.66-1.71, p < 0.001). Acutely relapsed schizophrenia patients presented significantly higher levels of total testosterone (ES = 0.50, 95%CI: 0.21-0.70, p < 0.001). Total testosterone levels were also elevated in stable multi-episode schizophrenia (sMES) females (ES = 0.56, 95%CI: 0.33-0.80, p < 0.001) and reduced in sMES males (ES = -0.62, 95%CI: -1.07 to 0.18, p = 0.006). Increased levels of biologically active, free testosterone and DHEA-S in FEP suggest that these alterations might appear as a response to stress that becomes blunted during subsequent exacerbations of schizophrenia. Differential changes in total testosterone levels in male and female sMES patients might represent medication effects related to prolactin-releasing effects of antipsychotics.

Age-related differences in stress responsiveness of the hypothalamic-pituitary-adrenal axis of nonhuman primates with various types of adaptive behavior

Aging is characterized by disturbances in the functioning of the hypothalamic-pituitary-adrenal (HPA) axis, associated with disturbances in the adaptation processes and increase of the probability of the onset of post-stress syndrome. However, the individual features of age-related disorders stress reactivity of HPA axis have not been studied. The purpose was to study individual characteristics of the HPA axis responsiveness to acute psycho-emotional stress exposure (restraint, ASE) at different age periods on the model of the young adult and old physically healthy female rhesus monkeys that differ in their behavioral responses to stress, i.e., with depression-like and anxiety-like behavior (DAB) on the one hand and healthy standard (control) adaptive behavior (SB) on the other hand. No significant intergroup differences were observed in HPA axis responses to ASE in young animals. During aging the monkeys with SB showed reduced ACTH response to the ASE, whereas the monkeys with DAB demonstrated its increase. The old animals with DAB in response to ASE demonstrated the most pronounced HPA axis disorders, such as the highest levels of corticotrophin (ACTH), the lowest levels of dehydroepiandrosterone sulfate (DHEAS), reduced cortisol (F) levels and the highest values of the F/DHEAS molar ratio. The ratio F/DHEAS positively correlates with the malondialdehyde concentration in erythrocytes that is considered as the biomarker of oxidative stress. Thus, these data allow us to consider the old monkeys with DAB as individuals with higher vulnerability to the adverse effects of ASE. In addition, depression-like and anxiety-like behavior of aged primates under mild/moderate stress along with reduced DHEAS plasma concentration and increased values of F/DHEAS ratio can be used to identify individuals with increased vulnerability to ASE and accelerated aging.

Antidepressant Outcomes Predicted by Genetic Variation in Corticotropin-Releasing Hormone Binding Protein

OBJECTIVE

Genetic variation within the hypothalamic-pituitary-adrenal (HPA) axis has been linked to risk for depression and antidepressant response. However, these associations have yet to produce clinical gains that inform treatment decisions. The authors investigated whether variation within HPA axis genes predicts antidepressant outcomes within two large clinical trials.

METHOD

The test sample comprised 636 patients from the International Study to Predict Optimized Treatment in Depression (iSPOT-D) who completed baseline and 8-week follow-up visits and for whom complete genotyping data were available. The authors tested the relationship between genotype at 16 candidate HPA axis single-nucleotide polymorphisms (SNPs) and treatment outcomes for three commonly used antidepressants (escitalopram, sertraline, and extended-release venlafaxine), using multivariable linear and logistic regression with Bonferroni correction. Response and remission were defined using the Hamilton Depression Rating Scale. Findings were then validated using the Predictors of Remission in Depression to Individual and Combined Treatments (PReDICT) study of outcome predictors in treatment-naive patients with major depression.

RESULTS

The authors found that the rs28365143 variant within the corticotropin-releasing hormone binding protein (CRHBP) gene predicted antidepressant outcomes for remission, response, and symptom change. Patients homozygous for the G allele of rs28365143 had greater remission rates, response rates, and symptom reductions. These effects were specific to drug class. Patients homozygous for the G allele responded significantly better to the selective serotonin reuptake inhibitors escitalopram and sertraline than did A allele carriers. In contrast, rs28365143 genotype was not associated with treatment outcomes for the serotonin norepinephrine reuptake inhibitor venlafaxine. When patients were stratified by race, the overall effect of genotype on treatment response remained. In the validation sample, the GG genotype was again associated with favorable antidepressant outcomes, with comparable effect sizes.

CONCLUSIONS

These findings suggest that a specific CRHBP SNP, rs28365143, may have a role in predicting which patients will improve with antidepressants and which type of antidepressant may be most effective. The results add to the foundational knowledge needed to advance a precision approach to personalized antidepressant choices.