Life stress, mood disturbance, and elevated interleukin-6 in healthy older women

Chronic Stress-Associated Depressive Disorders: The Impact of HPA Axis Dysregulation and Neuroinflammation on the Hippocampus-A Mini Review

Chronic stress significantly contributes to the development of depressive disorders, with the hypothalamic-pituitary-adrenal (HPA) axis playing a central role in mediating stress responses. This review examines the neurobiological alterations in the hippocampus linked to HPA axis dysregulation in chronic stress-associated depressive disorders. The prolonged activation of the HPA axis disrupts cortisol regulation, leading to the decline of both physical and mental health. The chronic stress-induced HPA axis dysfunction interacts with inflammatory pathways and generates oxidative stress, contributing to cellular damage and neuroinflammation that further aggravates depressive symptoms. These processes result in structural and functional alterations in the hippocampus, which is essential for emotional regulation and cognitive function. Comprehending the impact of chronic stress on the HPA axis and associated neurobiological pathways is essential for formulating effective interventions for depressive disorders. This review summarises the existing findings and underscores the necessity for future investigations into intervention strategies to improve physical and psychological wellbeing targeting at HPA axis dysregulation for the betterment of psychological wellbeing and human health.

Associations between depressive and anxiety symptoms and incident kidney failure in patients with diabetic nephropathy

OBJECTIVE

This study aimed to analyze the associations between depressive and anxiety symptoms and risk of incident kidney failure in patients with biopsy-proven diabetic nephropathy (DN).

METHODS

This retrospective study enrolled 241 type 2 diabetic patients with biopsy-proven DN. Huaxi Emotional-Distress Index (HEI) was used to evaluate the depression and anxiety status of patients on admission. According to the HEI score, DN patients were divided into HEI score ≤ 8 group (without depression and anxiety) and HEI score > 8 group (with depression and anxiety). The study endpoint was defined as progression to kidney failure. The cox proportional hazard analysis was performed to investigate the risk factors for progression to kidney failure in DN patients.

RESULTS

Twenty-three patients had HEI score > 8, accounting for about 9.5% of all patients. Compared with HEI score ≤ 8 group, those with HEI score > 8 had more severe proteinuria, higher systolic blood pressure, and lower baseline eGFR and serum albumin levels. During a median follow-up of 28 months, the outcome event occurred in 89 (36.9%) of all the patients. After multivariable adjustment, HEI score > 8 (HR 1.825, 95% CI 1.050-3.172) was associated with an increased risk of progression to kidney failure.

CONCLUSION

Depressive and anxiety symptoms might be associated with an increased risk of progression to kidney failure in patients with DN, which implied psychosocial issues should be early screened, assessed and intervened to delay the progression of DN.

Differential effects of chronic unpredictable stress on behavioral and molecular (cortisol and microglia-related neurotranscriptomic) responses in adult leopard (leo) zebrafish

Stress plays a key role in mental, neurological, endocrine, and immune disorders. The zebrafish (Danio rerio) is rapidly gaining popularity as s model organism in stress physiology and neuroscience research. Although the leopard (leo) fish are a common outbred zebrafish strain, their behavioral phenotypes and stress responses remain poorly characterized. Here, we examined the effects of a 5-week chronic unpredictable stress (CUS) exposure on adult leo zebrafish behavior, cortisol levels, and brain gene expression. Compared to their unstressed control leo counterparts, CUS-exposed fish showed paradoxically lower anxiety-like, but higher whole-body cortisol levels and altered expression of multiple pro- and anti-inflammatory brain genes. Taken together, these findings suggest that behavioral and physiological (endocrine and genomic) responses to CUS do differ across zebrafish strains. These findings add further complexity to systemic effects of chronic stress in vivo and also underscore the importance of considering the genetic background of zebrafish in stress research.

The inflammatory underpinning of depression: An historical perspective

Over the last thirty years, substantial evidence has accumulated in support of the hypothesis that dysregulation of inflammatory processes plays a critical role in the pathophysiology of depression. This review traces the evolution of research supporting this link, discussing key findings from several major investigative fronts: Alterations in inflammatory markers associated with depression; Mood changes following the exogenous administration of inflammatory challenges; The anti-inflammatory properties of traditional antidepressants and the promising antidepressant effects of anti-inflammatory drugs. Additionally, it explores how inflammatory processes interact with specific brain regions and neurochemical systems to drive depressive pathology. A thorough analysis of the 100 most-cited experimental studies on the topic ensures a comprehensive, transparent and unbiased collection of references. This methodological approach offers a panoramic view of the inflammation-depression nexus, shedding light on the complexity of its mechanisms and their connections to psychiatric categorizations, symptoms, demographics, and life events. Synthesizing insights from this extensive research, the review presents an integrative model of the biological foundations of inflammation-associated depression. It posits that we have reached a critical juncture where the translation of this knowledge into personalized immunomodulatory treatments for depression is not just possible, but imperative.

Correlation between mental status and prevalence of asthenopia in Chinese college students

BACKGROUND

The purpose of this study was to identify the possible association between mental status and the risk of self-reported asthenopia among college students in China.

METHODS

Ten thousand students were randomly assessed in the study using a self-reported asthenopia questionnaire. Their demographic characteristics and mental status were recorded. Univariate analysis was performed to preliminarily select potential risk and protective factors. Then, multivariate logistic regression was used to estimate odds ratios for the selected risk factors of interest.

RESULTS

Among the 8370 students who completed the survey, the prevalence of asthenopia was 61.0%. Multivariate analysis revealed a significant relationship between asthenopia and depressive symptoms (OR 1.511 95% CI: 1.350-1.691), obsessive-compulsive symptoms (OR 1.477, 95% CI: 1.338-1.632), gender and study load. The place college students spent their off-hours (OR 0.841, 95% CI: 0.784-0.902) was found to be the strongest factor for decreasing the occurrence of asthenopia complaints.

CONCLUSION

Asthenopia appears common in Chinese college students. In addition to depressive symptoms, we should pay attention to obsessive-compulsive symptoms when considering means of preventing asthenopia. Harmonious social relationships, outdoor off-hour activities and exercising more than three times per week are crucial to relieving visual fatigue. Further study is still needed in this area.

Positive psychological effects of seated acupressure massage are associated with a rise in plasma oxytocin without affecting CGRP levels or circulating IL-6

Work-related stress is a major public health issue. Given the relationship between acute stress responses and health, finding strategies to deal with the unpleasant symptoms brought on by stress is essential. Massage therapy is a popular stress-reduction technique, but its effectiveness has yet to be shown. In that matter, this study investigates the effects of a 17-minute session of seated Amma massage on young healthy people. Subjective stress perception, anxiety and self-confidence were assessed before and after the massage using the Spielberger State Anxiety Scale (STAI-Y, Spielberger et al., 1983) and the Competitive State Anxiety Inventory (EEAC, Cury et al., 1999), together with cardiovascular parameters. Cortisol, CGRP, IL-6, and oxytocin plasma levels were measured before and after the massage to investigate its possible mode of action. This study enrolled 59 people: 33 receiving the massage, and 26 controls only seated on the massage chair. Interaction Time x Group demonstrates significant differences for all psychological measurements (STAI, EEAC) before and after the Amma massage, showing a beneficial effect of this treatment, in particular on perceived anxiety and self-confidence. No evidence was found of any correlation between cortisol plasma levels and psychological outcomes. No relationship was shown between the decrease of perceived stress and measured CGRP or IL-6 release, but the data demonstrated that heart frequency could be slightly decreased. The oxytocin plasma levels were significantly increased by the massage and could be responsible for the recovery of psychological outcomes. We conclude that seated acupressure Amma massage could be a useful tool to ameliorate quality of life at work.

SSRIs in the course of COVID-19 pneumonia: Evidence of effectiveness of antidepressants on acute inflammation. A retrospective study

INTRODUCTION

Relationships between inflammation and mood have been observed in terms of pro-inflammatory effects induced by depressive conditions and, in parallel, by an antidepressant-induced favorable effect on the recovery of inflammatory states. Selective serotonin reuptake inhibitor (SSRI) drugs were hypothesized to improve the prognosis of COVID-19 pneumonia, a typical acute inflammation, in terms of decreased mortality rate and pro-inflammatory cytokine serum levels.

METHODS

The medical records of COVID-19 pneumonia inpatients at Careggi University Hospital (Florence) were analyzed for prognosis and Interleukin 6 (IL-6) after admission for over a period of 22 months. Medical records of patients treated at admission and not discontinued until discharge with an SSRI or with vortioxetine were identified. Two groups, one treated with antidepressants, the other not treated, were evaluated according to the mentioned parameters. Multiple linear regression and logistic regression were performed.

RESULTS

The entire sample composed of 1236 records (recovered patients 77.1%, deceased patients 22.9%). The treated group (n = 107) had a better prognosis than the untreated group in spite of age and comorbidity both being greater than in the untreated group. Correspondingly, IL-6 levels in the treated group were significantly lower (p < 0.01) than the levels in the untreated group, in every comparison.

CONCLUSIONS

Outcomes of this study support the hypothesis of the favorable influence of some antidepressants on the prognosis of COVID-19, possibly mediated by IL-6 modulation. Reduction in acute inflammation induced by the action of antidepressants was confirmed.

A single rapid heat stress episode does not result in prolonged elevations in salivary cortisol and C-reactive protein production in firefighters

In the present experiment, we evaluated the impact of rapid heat stress (RHS) on salivary cortisol and C-reactive protein production pre-RHS, post-RHS, and 24 and 48 h post-RHS exposure among firefighters. Previous research has demonstrated that RHS increases salivary cortisol during RHS and immediately post-RHS exposure. However, no research has evaluated the duration necessary to return to baseline cortisol levels following RHS. Additionally, no studies have analyzed the impact of RHS on inflammatory biomarkers, such as C-reactive protein. This study hypothesized that salivary cortisol and C-reactive protein levels would increase following RHS and then return to pre-RHS levels within 24 h post-exposure. Twenty-four participants performed a steady-state treadmill protocol in an environmental chamber (35 °C; 45% humidity) in full firefighter personal protective equipment until reaching either a core temperature (Tc) of 39 °C or a volitional maximum. The subjects had their saliva collected via the passive drool protocol pre-RHS, post-RHS, and 24 and 48 h post-RHS. Pre-RHS of 0.23 ± 0.03 μg/dL increased post-RHS to 0.51 ± 0.06 μg/dL (p < 0.001). This finding supports previous literature demonstrating the immediate impact of RHS. There were no changes in C-reactive protein. The novel finding of this study is that salivary cortisol levels return to baseline in the 24 h post-RHS exposure. This indicates that 24 h is recommended to recover from RHS and should be applied to prevent the chronic stress response.

Understanding the health effects of caregiving stress: New directions in molecular aging

Dementia caregiving has been linked to multiple health risks, including infectious illness, depression, anxiety, immune dysregulation, weakened vaccine responses, slow wound healing, hypertension, cardiovascular disease, metabolic syndrome, diabetes, frailty, cognitive decline, and reduced structural and functional integrity of the brain. The sustained overproduction of proinflammatory cytokines is a key pathway behind many of these risks. However, contrasting findings suggest that some forms of caregiving may have beneficial effects, such as maintaining caregivers' health and providing a sense of meaning and purpose which, in turn, may contribute to lower rates of functional decline and mortality. The current review synthesizes these disparate literatures, identifies methodological sources of discrepancy, and integrates caregiver research with work on aging biomarkers to propose a research agenda that traces the mechanistic pathways of caregivers' health trajectories with a focus on the unique stressors facing spousal caregivers as compared to other informal caregivers. Combined with a focus on psychosocial moderators and mechanisms, studies using state-of-the-art molecular aging biomarkers such as telomere length, p16INK4a, and epigenetic age could help to reconcile mixed literature on caregiving's sequelae by determining whether and under what conditions caregiving-related experiences contribute to faster aging, in part through inflammatory biology. The biomarkers predict morbidity and mortality, and each contributes non-redundant information about age-related molecular changes -together painting a more complete picture of biological aging. Indeed, assessing changes in these biopsychosocial mechanisms over time would help to clarify the dynamic relationships between caregiving experiences, psychological states, immune function, and aging.

Support-Giving Is Associated With Lower Systemic Inflammation

BACKGROUND

Support-giving has emerged as a health-relevant social behavior, such that giving more support is associated with better physical health. However, biological mechanisms by which support-giving and health are linked remain unclear. Whether support-giving uniquely relates to health relative to other psychosocial factors is also an open research question.

PURPOSE

Two studies test the hypothesis that support-giving is uniquely (over-and-above other psychosocial factors) related to lower systemic inflammation, a biological correlate of health.

METHODS

Cross-sectional associations of support-giving with markers of systemic inflammation (i.e., interleukin-6 [IL-6], C-reactive protein [CRP]) were examined in two independent samples of midlife adults (Study 1, n = 746; Study 2, n = 350).

RESULTS

Consistent with hypotheses, giving to more social targets (to family and friends, and also volunteering for various causes), but not receiving support from similar targets, was associated with lower IL-6. In conceptual replication and extension with a different measure of support-giving, higher frequency of support-giving behavior was associated with lower IL-6, even after adjusting for social network size and individual differences in social desirability. There were no associations between support-giving and CRP in either sample.

CONCLUSIONS

Future research needs to establish causality and directly test mechanistic pathways, but together, findings reaffirm the health-relevance of support-giving behavior and shed light on a promising biological mechanism by which such effects may occur.

Psychiatric aspects of ophthalmic disorders: A narrative review

Ophthalmic disorders have psychiatric aspects associated with them at various levels. Psychological factors have a well-documented role in the causation, aggravation, and maintenance of various ophthalmic conditions, including glaucoma, central serous retinopathy, dry eye disease, and retinitis pigmentosa. Many ophthalmic conditions, including blindness, have psychological manifestations as well, which need to be addressed, in addition to the ophthalmic pathology. There is also significant overlap in the treatment of the two disciplines in many ways. For instance, many ophthalmic drugs have psychiatric side effects. Even ophthalmological surgeries have psychiatric aspects associated with them, which primarily include black patch psychosis and anxiety in the operation theater. This review will be useful for psychiatrists and ophthalmologists, for their clinical practice and research. Future research should focus on this interface to give it its well-deserved attention.

Transitions to Family Caregiving and Latent Variables of Systemic Inflammation Over Time

Circulating levels of inflammatory biomarkers may be influenced by chronic psychological stressors such as those experienced by family caregivers. However, previous studies have found mostly small and inconsistent differences between caregivers and control samples on individual measures of systemic inflammation. Latent variables of inflammation were extracted from six biomarkers collected from two blood samples over 9 years apart for 502 participants in a national cohort study. One-half of these participants transitioned into a sustained family caregiving role between the blood samples. Two latent factors, termed "up-regulation" and "inhibitory feedback," were identified, and the transition to family caregiving was associated with a lower increase over time on the inhibitory feedback factor indexed by interleukin (IL)-2 and IL-10. No caregiving effect was found on the up-regulation factor indexed primarily by IL-6 and C-reactive protein. These findings illustrate the advantages of using latent variable models to study inflammation in response to caregiving stress.

Microglia as Central Protagonists in the Chronic Stress Response

Chronic stress is a major risk factor for developing psychiatric conditions. In addition to elevating the levels of stress hormones released in the body, chronic stress activates the immune system, resulting in increased levels of proinflammatory cytokines and innate immune cells in the circulation of rodents and humans. Furthermore, exposure to chronic stress alters the phenotype of microglia, a population of innate immune cells that reside in the CNS parenchyma. In rodent models, chronic stress activates microglia in defined brain regions and induces changes in their phenotype and functional properties. In this review, we discussed how microglia are activated in stressful situations. Furthermore, we described how microglia affect the CNS environment during chronic stress, through the production of cytokines, the induction of reactive oxygen species, and phagocytosis. We suggested that, due to their strategic location as immune cells within the CNS, microglia are important players in the induction of psychopathologies after chronic stress.

Stress- and drug-induced neuroimmune signaling as a therapeutic target for comorbid anxiety and substance use disorders

Stress and substance use disorders remain two of the most highly prevalent psychiatric conditions and are often comorbid. While individually these conditions have a debilitating impact on the patient and a high cost to society, the symptomology and treatment outcomes are further exacerbated when they occur together. As such, there are few effective treatment options for these patients, and recent investigation has sought to determine the neural processes underlying the co-occurrence of these disorders to identify novel treatment targets. One such mechanism that has been linked to stress- and addiction-related conditions is neuroimmune signaling. Increases in inflammatory factors across the brain have been heavily implicated in the etiology of these disorders, and this review seeks to determine the nature of this relationship. According to the "dual-hit" hypothesis, also referred to as neuroimmune priming, prior exposure to either stress or drugs of abuse can sensitize the neuroimmune system to be hyperresponsive when exposed to these insults in the future. This review completes an examination of the literature surrounding stress-induced increases in inflammation across clinical and preclinical studies along with a summarization of the evidence regarding drug-induced alterations in inflammatory factors. These changes in neuroimmune profiles are also discussed within the context of their impact on the neural circuitry responsible for stress responsiveness and addictive behaviors. Further, this review explores the connection between neuroimmune signaling and susceptibility to these conditions and highlights the anti-inflammatory pharmacotherapies that may be used for the treatment of stress and substance use disorders.

Impact of meibomian gland dysfunction on quality of life and mental health in a clinical sample in Ghana: a cross-sectional study

OBJECTIVES

This study aimed to determine the impact of meibomian gland dysfunction (MGD) on quality of life and psychosomatic conditions.

DESIGN

This was a clinic-based cross-sectional study.

SETTING

This study was conducted at the eye clinic of the University of Cape Coast, Ghana.

PARTICIPANTS

215 clinical subjects visiting the clinic for a comprehensive eye examination.

PRIMARY AND SECONDARY OUTCOME MEASURES

Symptomatic MGD, asymptomatic MGD, quality of life scores, depression, anxiety and stress.

RESULTS

215 clinical subjects consented to participate in the study, but 212 were included in the analysis. The mean age was 21.9 (± 3.8) years, 54 had MGD and 158 did not have MGD served as controls. There was no statistically significant difference in the mean quality of life scores between subjects with MGD and subjects without MGD (t=1.57, p=0.12). The quality of life scores (DEQS) (p=0.022) were significantly higher in the symptomatic MGD group compared with the asymptomatic MGD group. There was no significant difference in quality of life scores (DEQS) (p=0.251) in the asymptomatic MGD group compared with healthy controls. Using Pillai's trace in the MANOVA, there was a significant effect of MGD on depression, anxiety and stress (V=0.05, F(3,208)=3.76, p=0.012). Furthermore, Pillai's trace in the MANOVA showed a significant difference between asymptomatic and symptomatic MGDs for depression, anxiety and stress scores stress (V=0.24, F(3, 51)=5.24, p=0.003).

CONCLUSION

The study revealed no difference in the quality of life scores between MGD and non-MGD groups. However, the symptomatic MGD group had worse quality of life and psychosomatic symptoms than the asymptomatic MGD group and non-MGD group.

Emerging Roles of the Nervous System in Gastrointestinal Cancer Development

Simple Summary

Nerve–cancer cross-talk has increasingly become a focus of the oncology field, particularly in gastrointestinal (GI) cancers. The indispensable roles of the nervous system in GI tumorigenesis and malignancy have been dissected by epidemiological, experimental animal and mechanistic data. Herein, we review and integrate recent discoveries linking the nervous system to GI cancer initiation and progression, and focus on the molecular mechanisms by which nerves and neural receptor pathways drive GI malignancy.

Abstract

Our understanding of the fascinating connection between nervous system and gastrointestinal (GI) tumorigenesis has expanded greatly in recent years. Recent studies revealed that neurogenesis plays an active part in GI tumor initiation and progression. Tumor-driven neurogenesis, as well as neurite outgrowth of the pre-existing peripheral nervous system (PNS), may fuel GI tumor progression via facilitating cancer cell proliferation, chemoresistance, invasion and immune escape. Neurotransmitters and neuropeptides drive the activation of various oncogenic pathways downstream of neural receptors within cancer cells, underscoring the importance of neural signaling pathways in GI tumor malignancy. In addition, neural infiltration also plays an integral role in tumor microenvironments, and contributes to an environment in favor of tumor angiogenesis, immune evasion and invasion. Blockade of tumor innervation via denervation or pharmacological agents may serve as a promising therapeutic strategy against GI tumors. In this review, we summarize recent findings linking the nervous system to GI tumor progression, set the spotlight on the molecular mechanisms by which neural signaling fuels cancer aggressiveness, and highlight the importance of targeting neural mechanisms in GI tumor therapy.

Evaluation of Common Factors of Periodontitis and Cardiovascular Disease in Patients with the Acute Coronary Syndrome

Periodontitis is a multifactorial disease causing inflammatory destruction of supporting structures of the dentition and eventually leading to its loss. This study was designed to evaluate common risk factors for periodontitis and acute coronary syndrome in the study population and demonstrate the systemic impact of periodontitis on the occurrence of acute coronary syndrome. A total of 160 patients (35 female and 125 male) were enrolled in the study. Considering the age range, the largest group of patients (118 patients) was between 55 and 65 years, which accounted for 73.8% of the total study population. There were 35 patients (21.9%) in the age group of 45 to 54 years, while the youngest age group of 35 to 44 years had as many as seven patients. Medical history and physical examination, including periodontal status, were performed. API, PD, CAL, and CPITN were evaluated. Common risk factors for periodontitis and acute coronary syndrome were assessed. The study assessed risk factors such as hypertension, diabetes, dyslipidemia, general health, smoking, height, weight, and hip circumference. In light of the above-described etiopathogenesis of atherosclerotic disease and its association with periodontal disease, it is important to emphasize preventing and treating periodontitis, especially in patients in the so-called high-risk group for cardiovascular disease. Dentists' introduction of an appropriate prophylactic and therapeutic plan may constitute both primary and secondary prevention of cardiovascular diseases.

Telomere shortening and the transition to family caregiving in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study

Telomere length (TL) is widely studied as a possible biomarker for stress-related cellular aging and decreased longevity. There have been conflicting findings about the relationship between family caregiving stress and TL. Several initial cross-sectional studies have found associations between longer duration of caregiving or perceived stressfulness of caregiving and shortened TL, suggesting that caregiving poses grave risks to health. Previous reviews have suggested the need for longitudinal methods to investigate this topic. This study examined the association between the transition to family caregiving and change in TL across ~9 years. Data was utilized from the Caregiving Transitions Study, an ancillary study to the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. TL was assayed using qPCR and analyzed as the telomere-to-single copy gene ratio for each participant at baseline and follow-up. General linear models examined the association between caregiving status and the change in TL for 208 incident caregivers and 205 controls, as well as associations between perceived stress and TL among caregivers. No association was found between TL change and caregiving (p = 0.494), and fully adjusted models controlling for health and socioeconomic factors did not change the null relationship (p = 0.305). Among caregivers, no association was found between perceived caregiving stress and change in TL (p = 0.336). In contrast to earlier cross-sectional studies, this longitudinal, population-based study did not detect a significant relationship between the transition into a family caregiving role and changes in TL over time. Given the widespread citation of previous findings suggesting that caregiving shortens telomeres and places caregivers at risk of early mortality, these results demonstrate the potential need of a more balanced narrative about caregiving.

Increased Concentrations of Circulating Interleukins following Non-Invasive Vagus Nerve Stimulation: Results from a Randomized, Sham-Controlled, Crossover Study in Healthy Subjects

OBJECTIVE

The vagus nerve constitutes the main component of the parasympathetic nervous system and plays an important role in the regulation of neuro-immune responses. Invasive stimulation of the vagus nerve produces anti-inflammatory effects; however, data on humoral immune responses of transcutaneous vagus nerve stimulation (tVNS) are rare. Therefore, the present study investigated changes in serum cytokine concentrations of interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor α (TNFα) following a short-term, non-invasive stimulation of the vagus nerve.

METHODS

Whole blood samples were collected before and after a short-lived application of active tVNS at the inner tragus as well as sham stimulation of the earlobe. Cytokine serum concentrations were determined in two healthy cohorts of younger (n = 20) and older participants (n = 19). Differences between active and sham conditions were analyzed using linear mixed models and post hoc F tests after applying Yeo-Johnson power transformations. This trial was part of a larger study registered on ClinicalTrials.gov (NCT05007743).

RESULTS

In the young cohort, IL-6 and IL-1β concentrations were significantly increased after active stimulation, whereas they were slightly decreased after sham stimulation (IL-6: p = 0.012; IL-1β: p = 0.012). Likewise, in the older cohort, IL-1β and IL-8 concentrations were significantly elevated after active stimulation and reduced after sham application (IL-8: p = 0.007; IL-1β: p = 0.001). In contrast, circulating TNFα concentrations did not change significantly in either group.

CONCLUSION

Our results show that active tVNS led to an immediate increase in the serum concentrations of certain pro-inflammatory cytokines such as IL-1β, IL-6, and/or IL-8 in two independent cohorts of healthy study participants.

Interleukin-10 Attenuates Behavioral, Immune and Neurotrophin Changes Induced by Chronic Central Administration of Interleukin-1β in Rats

BACKGROUND

Activated microglia can trigger pro-inflammatory cytokine releases and neuroinflammation, which may inhibit astrocytes to produce neurotrophins and anti-inflammatory factors. Both eventually lead to neuron apoptosis or death. Furthermore, effective antidepressant or anti-dementia treatments can reduce pro-inflammatory cytokines, while enhance interleukin (IL)-10 production. However, the underline mechanism by which IL-10 modulates glial cell function, hence improves cognitive impairment or depression-like behavior is unknown. This study evaluated whether and how IL-10 attenuated chronic IL-1β administration-induced behavioral changes and the possible involved mechanisms.

METHODS

Rats received intracerebroventricular injection of IL-1β and/or IL-10 for 14 days. Then animal memory and depression-like behavior, pro-inflammatory cytokines, glial activities, expression of brain-derived neurotrophic factor (BDNF), Trk B, p75, and apoptosis-related genes were studied.

RESULTS

Compared to controls, significantly increased latent time and swimming distance in the Morris-water-maze, decreased sucrose consumption, and decreased locomotor and center zone entries in the open-field were found in rats administrated with IL-1β. These changes were associated with the reduction of GFAP expression, and concentrations of BDNF and anti-inflammatory cytokine IL-10, but the increase in the expressions of CD11b, TrkB, p75, and Caspase-3, the ratio of Bax/Bcl-2, and the concentrations of IL-1β, tumor necrosis factor-α, and IL-6. IL-10 treatment markedly attenuated IL-1β-induced above changes, except for the expressions of neurotrophin receptors.

CONCLUSION

IL-10-improved behavioral changes may be through suppressing microglia activity and inflammation, while restoring astrocyte function and BDNF expression.

Association between increased inflammatory cytokine expression in the lateral habenular nucleus and depressive-like behavior induced by unpredictable chronic stress in rats

Depression induced by unpredictable chronic stress (UCS) has been widely studied using animal models. However, its underlying pathological mechanisms remain unclear. Increased inflammatory cytokines (ICs) in the central nervous system (CNS) are closely related to depressive disorder. UCS was used as an animal model in this study to investigate how UCS-induced changes in cytokine signaling lead to depression. We found that UCS could increase ICs in the CNS, especially in the habenular nucleus (Hb). UCS resulted in decreased expression of Menin in Hb and increased the activation of the NF-κB signaling pathway. Local administration of tumor necrosis factor-α in the lateral Hb (LHb) could induce depressive-like behavior in rats. The anti-inflammatory drug aspirin and the NF-κB inhibitor pyrrolidine dithiocarbamate could alleviate depressive-like behavior. This phenomenon was not observed for local administration in the dorsal raphe nucleus and paraventricular nucleus. These results indicate that LHb is the main central target for ICs to regulate depressive-like behaviors. We also found that LHb lesions could improve the inflammatory response in the hippocampus, reduce the activation of the NF-κB signaling pathway and the expression of ICs, and increase the expression of brain-derived neurotrophic factor and its receptor tropomyosin receptor kinase B, collectively improving the neuroinflammation caused by UCS. Moreover, LHb lesions improve not only hippocampal neurogenesis damage caused by UCS by activating the PI3K/mTOR signaling pathway but also hippocampal function by reducing the expression of apoptosis-related proteins, including phosphorylated p53, Bax, Bcl2, and cleaved-caspase3. In conclusion, our study sheds light on the pathogenesis of ICs-induced depression. Anti-inflammation in the CNS could be a new strategy in the treatment of depression.

Inflammation and Cognition in Depression: A Narrative Review

The authors aim to present a narrative review of research on the inflammatory aetiology of depression. Depression is a psychiatric disorder, constituting the most common reason of disability due to a health condition. It has been estimated that at least one in six people suffer from depression at some point of their lives. The aetiology of depression, although researched extensively all around the world, still remains unclear. Authors discuss the possible role of inflammation in depression, the neurodevelopmental theory of depression as well as associations between cognition and depression. Possible associations between memory dysfunction among depressive patients and inflammatory markers are included. The associations between the immune system, depression and cognition are observed. Possible mediating factors between these areas include personality traits, hormonal imbalance and functioning of the brain areas. The question as to what mediating factors are involved is still open to research.

Psychological support and its relationship with the immune system during the pandemic

The main target for this research is to know how the Coronavirus affected specially on the individual and on the society in general with anxiety and panic that resulted from the social media and communication about the severity of this virus and how quickly it spread and also fake news about the infected people and their numbers. So we try to show how it's important of the psychological support for the society generally and raise the healthy awareness between people, also as this research showed how it's necessary for people is to preoccupation in other things rather than social media like mental and physical exercises as well as reading and other useful things. From the basic things that we focused on it is the people immune and how it's get affect by the psychological anxiety, as most studies and researches have been found a relation between the psychological anxiety and the patient immune which it was an inverse relationship as in case of increase the anxiety it will cause a lower immune response and increase the probability of infection specially COVID-19. The comprehensive ban have prevent the society from the communication together to confined the virus and reduce its separation but there must be some alternatives that support people psychologically and physically. As also its important to mention that the panic cases in increase during the comprehensive ban specially in the social areas and countries, for example in Iraq the comprehensive ban was a reason that prevent the communication between relatives and that lead to the psychological fatigue for many people because the interruption that happened with the relatives and the society.

Effects of Psychosocial Interventions and Caregiving Stress on Cardiovascular Biomarkers in Family Dementia Caregivers: The UCSD Pleasant Events Program (PEP) Randomized Controlled Trial

BACKGROUND

This study examined whether biological mechanisms linking dementia caregiving with an increased risk of coronary heart disease can be modified by psychosocial interventions and which caregivers might benefit the most from an intervention.

METHODS

Spousal dementia caregivers were randomized to 12-week treatment with either a behavioral activation intervention (ie, Pleasant Events Program [PEP]; n = 60), or an active control Information and Support (IS; n = 63) condition. Indicators of caregiving stress were assessed pretreatment and circulating cardiovascular biomarkers were measured pre- and posttreatment.

RESULTS

There were no significant changes in biomarker levels from pre- to posttreatment both by treatment condition and across all caregivers. Regardless of the treatment condition, exploratory regression analysis revealed that caregivers were more likely to show significant decreases in C-reactive protein (CRP) and D-dimer when their spouse had severe functional impairment; in interleukin (IL)-6 and CRP when they had greater distress due to care recipient's problem behaviors; in tumor necrosis factor (TNF)-α when they had higher levels of negative affect; and in IL-6, CRP, TNF-α, and D-dimer when they had higher personal mastery. Within the PEP group, caregivers with higher negative affect and those with higher positive affect were more likely to show a reduction in von Willebrand factor and D-dimer, respectively. Within the IS group, caregivers whose spouse had severe functional impairment were more likely to show a decrease in IL-6.

CONCLUSIONS

Unlike the average caregiver, caregivers high in burden/distress and resources might benefit from psychosocial interventions to improve cardiovascular risk, although these observations need confirmation.

Serum Levels of CRP are Associated with Depression in a Middle-aged and Elderly Population with Diabetes Mellitus: A Diabetes Mellitus-Stratified Analysis in a Population-Based Study

BACKGROUND

The direct relationship between inflammation and depression in patients with diabetes is still unclear. We examined the association between serum C-reactive protein (CRP) levels and the high prevalence of depression in populations (aged ≥49 years) with and without type 2 diabetes.

METHODS

Cross-sectional and longitudinal data from 3895 participants obtained from The Irish Longitudinal Study on Ageing (TILDA) were analyzed to determine the association between serum CRP levels and depression, accounting for relevant confounding factors.

RESULTS

Multivariable analyses showed a positive association between serum CRP and depression score, independent of age and gender, BMI, marital status, education, smoking status, alcohol drinking status, systolic BP, diastolic BP, physical activity, self-reported CVDs and laboratory measurements in subjects with diabetes mellitus (coefficient = 0.179, P<0.001) but not in subjects without diabetes mellitus (coefficient = 0.011, P = 0.495). Higher serum CRP levels were associated with an increased risk of depressive symptoms in subjects with diabetes mellitus (OR = 1.301, 95% CI 1.012-1.799, P = 0.011) but not in subjects without diabetes mellitus (OR = 1.004, 95% CI 0.992-1.013, P = 0.344) after adjusting for these same confounding factors. After a follow-up of 4 years, higher serum CRP levels were significantly associated with a higher possibility of depression events in subjects with diabetes mellitus.

LIMITATIONS

Time-varying confounding factors may interfere with our results.

CONCLUSION

We observed a significant positive association between serum CRP levels and the prevalence of depressive symptoms in a middle-aged and elderly population with diabetes after adjustment for a range of lifestyle factors.

Positive affect and peripheral inflammatory markers among adults: A narrative review

BACKGROUND

Previous research suggests that positive affect (PA) may promote health and longevity and that one potential mechanism involves inflammation. However, it remains unclear to what extent PA is associated with specific inflammatory markers and whether such associations are driven by main effects of PA and/or due to PA operating as a stress-buffer.

METHODS

The present narrative review incorporates studies (N = 28) that have examined the association between PA and peripheral inflammatory markers obtained using venous puncture or dried blood spots. We separate results by whether the study tested direct effects or stress-buffering, and by type of inflammatory marker [including C-reactive protein (CRP), and proinflammatory and anti-inflammatory cytokines], also paying close attention to type of PA assessment (state, aggregated state, or retrospective, the latter involving recall over one to two weeks), and study design (cross-sectional, longitudinal, and experimental).

RESULTS

Limited evidence suggests that studies were more supportive of a stress-buffering association, compared to a relatively direct association. When significant direct associations were observed, results suggested that studies using measures of state/aggregated PA exhibited more consistent associations with inflammatory markers than studies using retrospective PA. When significant, higher PA tended to be associated with lower pro- and anti-inflammatory markers, suggestive of lower overall inflammatory load.

DISCUSSION

Recommendations for the field and future research are discussed, including the value of utilizing state/aggregated PA measures and of examining stress-buffering mechanisms.

Impact of Acute and Chronic Stress on Thrombosis in Healthy Individuals and Cardiovascular Disease Patients

Psychological stress induces different alterations in the organism in order to maintain homeostasis, including changes in hematopoiesis and hemostasis. In particular, stress-induced hyper activation of the autonomic nervous system and hypothalamic–pituitary–adrenal axis can trigger cellular and molecular alterations in platelets, coagulation factors, endothelial function, redox balance, and sterile inflammatory response. For this reason, mental stress is reported to enhance the risk of cardiovascular disease (CVD). However, contrasting results are often found in the literature considering differences in the response to acute or chronic stress and the health condition of the population analyzed. Since thrombosis is the most common underlying pathology of CVDs, the comprehension of the mechanisms at the basis of the association between stress and this pathology is highly valuable. The aim of this work is to give a comprehensive review of the studies focused on the role of acute and chronic stress in both healthy individuals and CVD patients, focusing on the cellular and molecular mechanisms underlying the relationship between stress and thrombosis.

The Gut Microbiome Regulates Psychological-Stress-Induced Inflammation

Psychological stress has adverse effects on various human diseases, including those of the cardiovascular system. However, the mechanisms by which stress influences disease activity remain unclear. Here, using vaso-occlusive episodes (VOEs) of sickle cell disease as a vascular disease model, we show that stress promotes VOEs by eliciting a glucocorticoid hormonal response that augments gut permeability, leading to microbiota-dependent interleukin-17A (IL-17A) secretion from T helper 17 (Th17) cells of the lamina propria, followed by the expansion of the circulating pool of aged neutrophils that trigger VOEs. We identify segmented filamentous bacteria as the commensal essential for the stress-induced expansion of aged neutrophils that enhance VOEs in mice. Importantly, the inhibition of glucocorticoids synthesis, blockade of IL-17A, or depletion of the Th17 cell-inducing gut microbiota markedly reduces stress-induced VOEs. These results offer potential therapeutic targets to limit the impact of psychological stress on acute vascular occlusion.

Inflammation, depression, and anxiety disorder: A population-based study examining the association between Interleukin-6 and the experiencing of depressive and anxiety symptoms

The uncovering of a positive association between inflammatory cytokine levels - Interkleukin-6 (IL-6) in particular - and the experiencing of depressive and anxiety symptoms is one of the most promising and enthusiastically-discussed finding in recent years. Despite considerable ambiguity in the directionality and underpinnings of this association, anti-inflammatory drugs are already being tested on mental health patients who present no physical symptoms of inflammation, risking potential adverse side effects. Researchers have thus urgently called for more rigorous empirical elucidations of this association. Based on a large, longitudinal, nationally representative sample of middle-aged adults in the United States (N = 1255), IL-6 was observed to be significantly associated with one's present experiencing of depressive and anxiety symptoms. However, IL-6 was predictive of only prospective depressive (not anxiety) symptoms measured six years later, and only when baseline number of symptoms was not accounted for. Further, evidence for IL-6's postulated role as being either a biological cause itself (augmenting HPA stress reactivity) or a biological consequence of a psychological cause (psychological stress) for depression and anxiety was not found. These findings underscore the imperativeness of more rigorous studies to be conducted in this area, and caution practitioners against the premature consideration of IL-6 levels in clinical practice.

Is Family Caregiving Associated With Inflammation or Compromised Immunity? A Meta-Analysis

BACKGROUND AND OBJECTIVES

Family caregiving stress has been widely reported to have negative effects on circulating biomarkers of immune system function and inflammation. Our goals were to systematically review this literature and conduct a meta-analysis on the extracted effects.

RESEARCH DESIGN AND METHODS

A systematic search of published studies comparing caregivers and noncaregivers on biomarkers measured from blood samples was conducted in the PubMed, Embase, and Cochrane databases. This search identified 2,582 articles and abstracts. After removing duplicative papers and studies not meeting inclusion criteria, 30 articles were identified that reported analyses on 86 relevant biomarkers from 1,848 caregivers and 3,640 noncaregivers.

RESULTS

Random-effects models revealed an overall effect size across all biomarkers of 0.164 SD units (d). A slightly larger overall effect (d = 0.188) was found for dementia caregivers only. Immune system comparisons yielded somewhat larger differences than inflammation comparisons. Most studies used small convenience samples, and effect sizes were larger for studies with moderate or high bias ratings than for studies with low bias ratings. No significant associations were found in studies that used population-based samples.

DISCUSSION AND IMPLICATIONS

Caregivers had small but significantly reduced immune system functioning and greater inflammation than noncaregivers, but associations were generally weak and of questionable clinical significance. The absence of clear associations from low bias studies and population-based studies underscores concerns with possible selection biases in many of the convenience samples. Population-based studies that assess biomarkers before and after the onset of caregiving might add much clarity to this literature.

Effects of Prior Psychosocial Trauma on Subsequent Immune Response After Experimental Thorax Trauma

Overshooting inflammation during the early phase after blunt thorax trauma promotes the development of acute respiratory distress syndrome, multiple organ failure, and subsequent mortality. Given that individuals diagnosed with stress-related disorders are characterized by chronic low-grade inflammation, we hypothesize that "psychosocial traumatic preload" poses a risk factor for the abovementioned complications after thorax trauma.Here, we used the chronic subordinate colony housing (CSC) paradigm to induce "psychosocial traumatic preload" and systemic low-grade immune activation in male mice, indicated by elevated plasma concentrations of different inflammatory mediators. Subsequent thorax trauma was induced in anaesthetized mice by a single blast wave centered on the thorax; SHAM animals were exposed to anesthesia only. Mice were killed 2, 6, and 24 h after thorax trauma or SHAM treatment.Independent of thorax trauma, CSC caused an increase in adrenal weight, and a decrease in thymus weight, indicating that the stress paradigm worked reliably. Moreover, although lung histology was not affected by prior stress, CSC exposure aggravated the early immune response after thorax trauma, indicated by elevated myeloperoxidase lung concentrations in thorax trauma-exposed CSC versus respective single-housed control (SHC) mice (2 h). Furthermore, thorax trauma caused an increase in total bronchoalveolar lavage fluid (BAL) protein (24 h), BAL C5a (2 h), BAL cell counts (24 h), and BAL keratinocyte chemoattractant (6 h and 24 h) in CSC but not SHC mice.Our data indicate that repeated psychosocial traumatization during adulthood moderately aggravates the local immune response toward thorax trauma, but overall may be considered as a rather minor risk factor in terms of thorax trauma-associated complications.

The role of parental acute psychological distress in paediatric burn re-epithelialization

OBJECTIVES

Following a paediatric burn, parents commonly experience high levels of acute psychological distress, which has been shown to increase child psychological distress as well as child procedural distress. The influence of psychological stress and perceived pain on wound healing has been demonstrated in several laboratory and medical populations. This paper investigates the influence of parental acute psychological distress and procedural behaviour on the child's rate of re-epithelialization, after controlling for child procedural distress.

DESIGN

A prospective observational study with longitudinal outcome.

METHODS

Eighty-three parents of children 1-6 years old reported acute psychological distress (post-traumatic stress symptoms [PTSS], guilt, pre-procedural fear, general anxiety/depression symptoms) in relation to their child's burn. A researcher observed parent-child behaviour at the first dressing change, and parents and nurses reported child procedural distress (pre-, peak-, and post-procedural pain and fear). These variables, along with demographic and injury information, were tested for predicting time to re-epithelialization. Date of re-epithelialization was determined by the treating consultant.

RESULTS

Days to re-epithelialization ranged from 3 to 35 days post-injury. A hierarchical multiple regression analysis found wound depth and size significantly accounted for 28% of the variance in time to re-epithelialization. In Block 2, child peak-procedural pain significantly accounted for 6% additional variance. In Block 3, parental PTSS significantly accounted for 5% additional variance.

CONCLUSIONS

Parental PTSS appears to be an important but under-recognized factor that may influence their child's burn re-epithelialization. Further investigation is required to understand the mechanisms contributing to this association. Statement of contribution What is already known on this subject? Psychological stress delays wound healing, and this relationship has been found in paediatric burn populations with procedural pain. Parental psychological stress is often present after a child's burn and is related to the child's procedural coping and distress. What does this study add? Parental post-traumatic stress is related to delayed child burn re-epithelialization. This association is in addition to procedural pain delaying re-epithelialization.

Stress and inflammation - The need to address the gap in the transition between acute and chronic stress effects

Stress responses help us navigate our environment and respond appropriately to threats. Stress systems communicate threats to the entire organism, and as such, also stimulate inflammatory mechanisms. This modulation might serve protective functions in the short term, but sustained low-grade inflammation has severe long-term health consequences. While we have reached a reasonable level of understanding of acute, as well as chronic stress effects on inflammatory mechanisms, there is a significant gap in our understanding of the transitional phase between acute and chronic stress. The purpose of this review is to first summarize current knowledge of our understanding of acute stress effects on inflammation, as well as of chronic stress effects on inflammation, and to then analyze the state of knowledge about the transitional phase between acute and chronic stress. Research discussed here shows that we are beginning to understand the early phase of repeated acute stress, but lack information on longer term exposure to repeated acute stress experiences. More research is needed to bridge this important gap und our conceptualization and understanding of the stress and health relationship.

Sleep Disorders are a Prevalent and Serious Comorbidity in Dry Eye

Purpose

Sleep is an essential life habit and closely associated with lifespan, diabetes, hypertension, and mental health. Sleep disorders are a prominent, but overlooked problem in patients with dry eye disease (DED), characterized by a poor sleep index, short sleep duration, long sleep latency, and poor subjective sleep. DED and sleep disorders are more prevalent in women than men. Moreover, sleep quality in DED is worse than in other eye diseases, including glaucoma, retinal diseases, cataract, and allergic and chronic conjunctivitis.

Methods

We reviewed the literature for studies investigating sleep and health, eyes and sleep, and DED and sleep, in terms of systemic and eye health, especially in women.

Results

Two studies reported that approximately half of patients with DED suffer from poor sleep. The severity of mood disorders, including anxiety and depression, is correlated strongly with sleep disorders in DED, and the symptoms and signs of DED, especially pain, also are correlated with sleep quality. Sleep disorders are documented in primary Sjögren's syndrome and an association with sleep apnea and depression is suggested. Primary Sjögren's syndrome includes arthritis and other rheumatic disease causing pain and fatigue; however, how sicca contributes to sleep disorders is not known.

Conclusions

Possible explanations for sleep disorders in DED may be depression, pain, and eye exposure at night. Reciprocal effects may be expected and consultation-liaison psychiatry is recommended for the management of sleep disorders in DED. Topical medication and lid heating also may be advantageous for sleep quality in DED.

HIGH-SENSITIVITY C-REACTIVE PROTEIN, POSSIBLE BIOMARKER FOR DEPRESSION IN ELDERLY POPULATION

CONTEXT

The immune system has an important role in the etiology of depression, through the pro-inflammatory cytokines and acute phase protein mechanisms. In elderly people, frequent association between depression and medical conditions leads to a difficult psychiatric diagnosis, becoming necessary to determine a specific biological marker for this category of population. C-Reactive Protein (CRP) did not prove to have a high level of validity, but higher levels of high-sensitivity C-Reactive Protein (hs-CRP) were found to be associated both with cardiovascular disease and depressive disorder, through a bidirectional relationship.

OBJECTIVES

To investigate the possible association between a major depressive episode and levels of inflammatory markers among a population of elderly.

SUBJECTS AND METHODS

A prospective study on a sample of 82 individuals aged over 65 years, who presented for laboratory evaluations in an outpatient setting. They were recorded socio-demographic and clinical data; depression and anxiety were assessed using the Hospital Anxiety and Depression Scale. Blood samples were collected and analyzed according to the protocol of the study.

RESULTS

Anxiety, identified in 57 persons, was not statistically significant correlated with the levels of inflammatory markers. For depressive disorder (37 subjects), both CRP and hs-CRP were significantly higher, with an almost medium effect size.

CONCLUSIONS

The high levels of CRP and hs-CRP are associated with the presence of depression in elderly patients, but not with the anxiety. Further and complex studies need to validate these findings on this group of age.

Social support and verbal interaction are differentially associated with cognitive function in midlife and older age

Social engagement is associated with healthy aging and preserved cognition. Two dimensions of engagement, verbal interactions and perceived support, likely impact cognition via distinct mechanistic pathways. We explored the cognitive benefit of each construct among enrollees (N = 1,052, mean age = 60.2 years) in the Wisconsin Registry for Alzheimer's Prevention study, who provide neuropsychological and sociobehavioral data at two-year intervals. Outcomes included six cognitive factor scores representing key domains of executive function and memory. Key predictors included self-reported perceived social support and weekly verbal interaction. Results indicated that after adjusting for lifestyle covariates, social support was positively associated with Speed and Flexibility and that verbal interactions were associated with Verbal Learning and Memory. These findings suggest that support, which may buffer stress, and verbal interaction, an accessible, aging-friendly form of environmental enrichment, are uniquely beneficial. Both are integral in the design of clinical and community interventions and programs that promote successful aging.

Functions of reminiscence in later life: Predicting change in the physical and mental health of older adults over time

OBJECTIVE

Research has repeatedly shown that reminiscence affects the mental health and well-being of older adults contemporaneously and over time. Cross-sectional research also points to a link between reminiscence and physical health. The direction of this relationship is unclear, however. Does physical health affect how and why older adults think of themselves in the past? Or conversely, do various functions of reminiscence affect both mental and physical health now, and in future?

METHODS

Online responses were collected from a primarily Canadian sample of 411 older adults at three time points, separated by eight months on average. Participants responded to the Reminiscence Functions Scale at baseline and reported their health conditions, perceived state of health, life satisfaction, and psychological distress at subsequent points of measurement. A structural equation model was computed to identify direct and indirect associations between reminiscence functions and health over time.

RESULTS

Self-negative reminiscence functions at baseline (T1) predicted physical health 8 months later (T2), whereas self-positive reminiscence functions at T1 predicted both physical health and psychological distress at T2. The associations among self-positive functions and subsequent physical and mental health were maintained over time. Additionally, longitudinal crossover was observed in which psychological distress at T2 predicted physical health at T3, controlling for physical and mental health at T2.

CONCLUSIONS

Findings confirm longitudinal associations among reminiscence functions and subsequent indicators of health. For older adults, this extends to both physical and mental health. Future research should examine the physiological mechanisms by which autobiographical memory affects health over time.

Old Friends, immunoregulation, and stress resilience

There is a considerable body of evidence indicating that chronic adverse experience, especially chronic psychosocial stress/trauma, represents a major risk factor for the development of many somatic and affective disorders, including inflammatory bowel disease (IBD) and posttraumatic stress disorder (PTSD). However, the mechanisms underlying the development of chronic stress-associated disorders are still in large part unknown, and current treatment and prevention strategies lack efficacy and reliability. A greater understanding of mechanisms involved in the development and persistence of chronic stress-induced disorders may lead to novel approaches to prevention and treatment of these disorders. In this review, we provide evidence indicating that increases in immune (re-)activity and inflammation, potentially promoted by a reduced exposure to immunoregulatory microorganisms ("Old Friends") in today's modern society, may be causal factors in mediating the vulnerability to development and persistence of stress-related pathologies. Moreover, we discuss strategies to increase immunoregulatory processes and attenuate inflammation, as for instance contact with immunoregulatory Old Friends, which appears to be a promising strategy to promote stress resilience and to prevent/treat chronic stress-related disorders.

Alzheimers' disease and caregiving: a meta-analytic review comparing the mental health of primary carers to controls

OBJECTIVES

To quantitatively review the literature comparing depressed mood, anxiety and psychological distress in caregivers (CGs) of older adults with Alzheimer's disease (AD) with non-caregivers (NCGs) Methods: Eighteen independent studies comparing AD CGs (N = 2378) with NCGs (N = 70,035) were evaluated in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Standardised mean differences (Hedges' g) with associated 95% confidence intervals and p-values were calculated using a random-effects model.

RESULTS

Studies generally conformed to STROBE criteria in terms of their methodological and procedural detail, although data management issues that may contribute to methodological bias were identified. Pooled effect estimates revealed medium to large group differences in depression (g_w = 1.01 [CI: 0.73, 1.29] p < 0.01) and anxiety (g_w = 0.64 [CI: 0.39, 0.89] p < 0.01): AD caregivers reported higher symptom severity. Gender was a significant moderator: female caregivers experienced poor self-reported mood (g_w = 1.58 [CI: 1.11, 2.05], p < 0.01), although this analysis was limited in power given the small number of contributing studies.

DISCUSSION

Caregivers of patients with AD experience poor mental health in comparison to the general population, with female caregivers being disproportionately affected. Further exploration of the psychosocial variables that contribute to these group differences is needed to inform effective support services and, in turn, help caregivers manage the emotional demands of AD.

The body remembers: Adolescent conflict struggles predict adult interleukin-6 levels

Struggles managing conflict and hostility in adolescent social relationships were examined as long-term predictors of immune-mediated inflammation in adulthood that has been linked to long-term health outcomes. Circulating levels of interleukin-6 (IL-6), a marker of immune system dysfunction when chronically elevated, were assessed at age 28 in a community sample of 127 individuals followed via multiple methods and reporters from ages 13 to 28. Adult serum IL-6 levels were predicted across periods as long as 15 years by adolescents' inability to defuse peer aggression and poor peer-rated conflict resolution skills, and by independently observed romantic partner hostility in late adolescence. Adult relationship difficulties also predicted higher IL-6 levels but did not mediate predictions from adolescent-era conflict struggles. Predictions were also not mediated by adult trait hostility or aggressive behavior, suggesting the unique role of struggles with conflict and hostility from others during adolescence. The implications for understanding the import of adolescent peer relationships for life span physical health outcomes are considered.

A conceptual model of social networks and mechanisms of cancer mortality, and potential strategies to improve survival

Women with larger personal social networks have better breast cancer survival and a lower risk of mortality. However, little work has examined the mechanisms through which social networks influence breast cancer outcomes and cancer outcomes more generally, potentially limiting the development of feasible, clinically effective interventions. In fact, much of the emphasis in cancer research regarding the influence of social relationships on cancer outcomes has focused on the benefits of the provision of social support to patients, especially through peer support groups, and only more recently through patient navigation. Though critically important, there are other ways through which social relationships might influence outcomes, around which interventions might be developed. In addition to social support, these include social resources, social norms, social contagion, social roles, and social burdens and obligations. This narrative review addresses how social networks may influence cancer outcomes and discusses potential strategies for improving outcomes given these relationships. The paper (a) describes background and limitations of previous research, (b) outlines terms and provides a conceptual model that describes interrelationships between social networks and relevant variables and their hypothesized influence on cancer outcomes, (c) clarifies social and psychosocial mechanisms through which social networks affect downstream factors, (d) describes downstream behavioral, treatment, and physiological factors through which these subsequently influence recurrence and mortality, and (e) describes needed research and potential opportunities to enhance translation. Though most literature in this area pertains to breast cancer, this review has substantial relevance for cancer outcomes generally. Further clarification and research regarding potential mechanisms are needed to translate epidemiological findings on social networks into clinical and community strategies to improve cancer outcomes.

Weathering the storm; a review of pre-pregnancy stress and risk of spontaneous abortion

The Weathering Effect is a theory that links stress exposure, over the life-course, with racial disparities in reproductive outcomes, through the effects of social adversity on a woman's body. The concept of maternal "weathering" captures cumulative somatic and psychological adversities that can exacerbate the effects of aging. Much of the evidence for weathering comes from observational studies linking self-report measures with reproductive outcomes. The purpose of this review is to explore biological mechanisms that underlie these observations. We focus on spontaneous abortion because this event is understudied despite evidence of racial disparities in this outcome. Spontaneous abortion is the most common pregnancy failure, and it happens early in pregnancy. Early pregnancy is a time most susceptible to the harmful effects of immune dysregulation that may, in part, result from adversities experienced before pregnancy begins. In exploring these mechanisms, we draw on well-defined signaling processes observed in the stressor-depression relationship. Pro-inflammatory dysregulation, for example, has particular relevance to immunological control occurring early in pregnancy. Early pregnancy immunologic changes affect the trajectories of pregnancy via control of trophoblastic invasion. Within the first few weeks of pregnancy, uterine derived cytokines operate within cytokine networks and play a critical role in this invasion. Programming for pro-inflammatory dysregulation can occur before conception. This dysregulation, brought into early pregnancy, has implications for viability and success of the index pregnancy. These patterns suggest early pregnancy health is susceptible to stress processing pathways that influence this immunologic control in the first six to eight weeks of pregnancy. In this review, we discuss the known mediating role of immune factors in the stressor-depression relationship. We also discuss how adversity experienced before the index pregnancy, or "pre-pregnancy" may influence these pathways, and subsequently influence early pregnancy health. There is a need to understand adversity, experienced before pregnancy, and mechanisms driving the effects of these experiences on pregnancy outcomes. This approach is a useful entry point for understanding racial inequities in pregnancy health through an understanding of differences in exposures to adversity. We hypothesize that spontaneous abortion involves cyclical changes within a woman's reproductive tract in response to stressors that are established well before a woman enters into pregnancy. Furthermore, we propose mechanisms that potentially drive weathering processes relevant to reproductive disparities. We also examine what is known about pre-pregnancy stress exposures associated with race, inequity, and adversity, and their potential impact on neuroendocrine and immune changes affecting early pregnancy risk.

Interleukin-6 Level among Shift and Night Workers in Japan: Cross-Sectional Analysis of the J-HOPE Study

Aim: Shift workers have a high risk of cardiovascular disease (CVD). Systemic inflammation measured has been associated with the risk of CVD onset, in addition to classical risk factors. However, the association between work schedule and inflammatory cytokine levels remains unclear. The purpose of this study was to examine the association between work schedule and interleukin-6 (IL-6)/high-sensitivity C-reactive protein (hs-CRP) levels among Japanese workers.

Methods: The present cross-sectional study was a part of the Japanese Study of Health, Occupation and Psychosocial Factors Related Equity (J-HOPE). A total of 5259 persons who measured inflammatory cytokine were analyzed in this study. One-way analysis of variance was used to test log-transformed IL-6/hs-CRP differences by work schedule. Multiple regression analysis was used to examine the difference adjusted for other possible CVD risk factors.

Results: There were 3660 participants who had a regular work schedule; the remaining schedules were shift work without night work for 181 participants, shift work with night work for 1276 participants, and only night work for 142 participants. The unadjusted model showed that only night workers were significantly related to high levels of IL-6 compared with regular workers. Even in the multiple regression analysis, the higher level of IL-6 among only night workers remained significant (β = 0.058, P = 0.01). On the contrary, hs-CRP was not.

Conclusion: The present study revealed that only night shift work is significantly associated with high levels of IL-6 in Japanese workers. These observations help us understand the mechanism for the association between work schedule and CVD onset.

Effect of Aerobic Exercise Training on Mood in People With Traumatic Brain Injury: A Pilot Study

BACKGROUND

Exercise training is associated with elevations in mood in patients with various chronic illnesses and disabilities. However, little is known regarding the effect of exercise training on short and long-term mood changes in those with traumatic brain injury (TBI).

OBJECTIVE

The purpose of this study was to examine the time course of mood alterations in response to a vigorous, 12-week aerobic exercise training regimen in ambulatory individuals with chronic TBI (>6 months postinjury).

METHODS

Short and long-term mood changes were measured using the Profile of Mood States-Short Form, before and after specific aerobic exercise bouts performed during the 12-week training regimen.

RESULTS

Ten subjects with nonpenetrating TBI (6.6 ± 6.8 years after injury) completed the training regimen. A significant improvement in overall mood was observed following 12 weeks of aerobic exercise training (P = .04), with moderate to large effect sizes observed for short-term mood improvements following individual bouts of exercise.

CONCLUSIONS

Specific improvements in long-term mood state and short-term mood responses following individual exercise sessions were observed in these individuals with TBI. The largest improvement in overall mood was observed at 12 weeks of exercise training, with improvements emerging as early as 4 weeks into the training regimen.

Mechanisms of Mitochondrial Redox Signaling in Psychosocial Stress-Responsive Systems: New Insights into an Old Story

SIGNIFICANCE

Psychosocial stress is associated with alterations in serum glucocorticoids and cytokines, such as interleukin-6 (IL-6) and IL-1β, which functionally interact. However, the molecular mechanisms and physiological relationship between the two systems within the context of stress exposure are not well characterized. Recent Advances: Extracellular IL-6, which stimulates the release of cortisol from the zona fasciculata of the adrenal cortex, mediates its intracellular effects by tyrosine phosphorylation of the transcription factor signal transducer and activator of transcription 3 (STAT3). Mitochondrial electron transfer reactions are involved in both STAT3-driven ATP production in oxidative respiration and adrenocortical steroid biosynthesis.

CRITICAL ISSUES

The role of STAT3 in oxidative respiration and steroidogenesis suggests that it integrates both nuclear and mitochondrial actions, thereby preserving main steps of glucocorticoid biosynthesis in the adrenal gland under psychosocial stress. This review discusses the notion that these two pathways are together simultaneously involved in protection against chronic stressors.

FUTURE DIRECTIONS

Linking the function of cytokines and main components of the hypothalamic-pituitary-adrenal (HPA) axis to molecular mechanisms of mitochondrial redox signaling will be essential for a better understanding of the relevant stress-responsive systems engaged in stress vulnerability. Antioxid. Redox Signal. 28, 760-772.

Development of glucocorticoid resistance over one year among mothers of children newly diagnosed with cancer

Chronic distress associates with peripheral release of cortisol and a parallel upregulation of innate inflammation. Typically, cortisol functions to down-regulate inflammatory processes. However, in the context of chronic stress, it is hypothesized that glucocorticoid receptors within immune cells become less sensitive to the anti-inflammatory effects of cortisol, resulting in increased systemic inflammation. Caring for a child newly diagnosed with cancer is a particularly provocative chronic stressor. Here, we examine evidence for the development of cellular resistance to glucocorticoids among 120 mothers (Aged 18-56 years; 86% Caucasian) across the 12 months following their child's new diagnosis with cancer. Measures of psychological distress, interleukin (IL)-6, and glucocorticoid resistance (GCR) were assessed 1, 6, and 12 months after the diagnosis. A latent factor for distress was derived from the covariation among symptoms of anxiety, depression, and post-traumatic stress. Latent change score models revealed a significant positive association between change in distress and change in GCR from 0 to 6 months, and 6 months-1 year. This finding provides initial evidence for a longitudinal association between change in maternal distress and change in GCR from the onset of a chronic stressor through one year. Although levels of IL-6 increased during the first six months after the child's diagnosis, the magnitude of this change was not related to change in distress or change in GCR. Given the possible health consequences of reduced immune sensitivity to glucocorticoids, future work should further explore this stress response and its clinical significance.

Impact of caregiving for older people and pro-inflammatory biomarkers among caregivers: a systematic review

INTRODUCTION

Evidence suggests that providing care for an older loved one may present a risk to the health of the caregiver. To understand the link between the psychosocial stress of caregiving and damage to the health of caregivers, numerous studies have assessed the presence of inflammatory biomarkers among caregivers. These biomarkers are measured to understand the relationships between the social stress of caregiving and the health of caregivers.

OBJECTIVE

To provide a complete summary of the current literature regarding the most clinically relevant pro-inflammatory biomarkers associated with caregiving.

METHODS

We searched articles in MEDLINE and EMBASE from January 1980 to 30 April 2016 for all studies that assessed biomarkers (cortisol, interleukin-6 and c-reactive protein) among caregivers of community-dwelling older persons. The quality of the selected studies was assessed by two reviewers using the STROBE or CONSORT checklist.

RESULTS

Twenty-four studies were included. Most of the studies were cross-sectional and focused on dementia caregiving. Increases in biomarkers were associated with problems such as disturbed sleep, burden or pain and caregiving characteristics, including daily stressors and the duration of caregiving. Cognitive-behavioural therapy and participation in leisure activities were associated with significantly lower levels of cortisol and IL-6, respectively.

DISCUSSION

We found little evidence concerning the association between caregiving status and biomarkers of stress and inflammation. We discuss potential sources of bias and suggest some directions for further research. This stress model can be expanded by taking into account the positive aspects of caregiving and the potential resources of caregivers.