Current research trends in early life stress and depression: review of human studies on sensitive periods, gene-environment interactions, and epigenetics

Under the umbrella of depression and Alzheimer's disease physiopathology: Can cannabinoids be a dual-pleiotropic therapy?

Depression and Alzheimer´s disease (AD) are two disorders highly prevalent worldwide. Depression affects more than 300 million people worldwide while AD affects 60-80% of the 55 million cases of dementia. Both diseases are affected by aging with high prevalence in elderly and share not only the main brain affected areas but also several physiopathological mechanisms. Depression disease is already ascribed as a risk factor to the development of AD. Despite the wide diversity of pharmacological treatments currently available in clinical practice for depression management, they remain associated to a slow recovery process and to treatment-resistant depression. On the other hand, AD treatment is essentially based in symptomatology relieve. Thus, the need for new multi-target treatments arises. Herein, we discuss the current state-of-art regarding the contribution of the endocannabinoid system (ECS) in synaptic transmission processes, synapses plasticity and neurogenesis and consequently the use of exogenous cannabinoids in the treatment of depression and on delaying the progression of AD. Besides the well-known imbalance of neurotransmitter levels, including serotonin, noradrenaline, dopamine and glutamate, recent scientific evidence highlights aberrant spine density, neuroinflammation, dysregulation of neurotrophic factor levels and formation of amyloid beta (Aβ) peptides, as the main physiopathological mechanisms compromised in depression and AD. The contribution of the ECS in these mechanisms is herein specified as well as the pleiotropic effects of phytocannabinoids. At the end, it became evident that Cannabinol, Cannabidiol, Cannabigerol, Cannabidivarin and Cannabichromene may act in novel therapeutic targets, presenting high potential in the pharmacotherapy of both diseases.

Association of Catastrophic Health Expenditure With the Risk of Depression in Chinese Adults: Population-Based Cohort Study

BACKGROUND

Depression is one of the most common mental illnesses, and it may have a lasting effect on one's whole life. As a form of financial hardship, catastrophic health expenditure (CHE) may be associated with depression. However, current evidence about the relationship between CHE and the risk of depression is insufficient.

OBJECTIVE

This study aimed to explore the relationship between CHE and the risk of depression among Chinese adults.

METHODS

In this study, we used 3 waves of the China Family Panel Studies (CFPS) from 2012, 2016, and 2018. The CFPS are a nationally representative study covering 25 of 31 provinces in Chinese mainland and representing nearly 94.5% of the total population. We selected eligible household heads as participants, divided them into 2 groups by CHE events at baseline (exposed group: with CHE; unexposed group: without CHE), and followed them up. Households with CHE were defined as having out-of-pocket medical expenditures exceeding 40% of the total household nonfood expenditure, and people with depression were identified by the 8-item Centre for Epidemiological Studies Depression Scale (CES-D). We first described the baseline characteristics and used logistical regression to estimate their effects on CHE events. Then, we used Cox proportional hazard models to estimate adjusted hazard ratios and 95% CIs of depression among participants with CHE compared with those without CHE. Finally, we analyzed the subgroup difference in the association between CHE and depression.

RESULTS

Of a total of 13,315 households, 9629 were eligible for analysis. Among them, 6824 (70.9%) were men. The mean age was 50.15 (SD 12.84) years. Only 987 (10.3%) participants had no medical insurance. The prevalence of CHE at baseline was 12.9% (1393/9629). Participants with a higher family economic level (adjusted odds ratio [aOR] 1.15, 95% CI 1.02-1.31) and with the highest socioeconomic development level (aOR 1.18, 95% CI 1.04-1.34) had a higher prevalence of CHE than reference groups. During a median of 71 (IQR 69-72) person-months of follow-up, the depression incidence of participants with CHE (1.41 per 1000 person-months) was higher than those without CHE (0.73 per 1000 person-months). Multivariable models revealed that the adjusted hazard ratio for the incidence of depression in participants with CHE was 1.33 (95% CI 1.08-1.64), and this association appeared to be greater in participants without outpatient services (for interaction, P=.048).

CONCLUSIONS

CHE was significantly associated with increased risk of depression among Chinese adults. Concentrated work should be done to monitor CHE, and more efforts to ensure financial protection need to be made to prevent depression, especially for people with high health care needs.

Early adversity and depressive symptoms among early adolescent girls: the mediating role of exposure to recent interpersonal acute stress

Early adversity confers risk for depression in part through its association with recent (i.e., proximal) acute stress. However, it remains unresolved whether: a) early adversity predicts increases in recent acute stress over time; b) all - or only certain types - of recent events mediate the relationship between early adversity and depression; and c) early adversity places individuals at greater risk for depression via greater exposure to independent (i.e., fateful) interpersonal events or via greater generation of dependent (i.e., partially self-initiated) interpersonal events (i.e., stress generation) or both. These questions were examined in a 3-wave longitudinal study of early adolescent girls (N = 125; M = 12.35 years [SD = .77]) with no history of diagnosable depression using contextual life stress and diagnostic interviews. Path analyses indicated that increases in past-year acute interpersonal, but not non-interpersonal, stress mediated the link between early adversity and depressive symptoms. The mediating role of interpersonal events was limited to independent ones, suggesting increases in interpersonal event exposure, not interpersonal stress generation, acted as a mediator. Finally, findings support prior evidence that early adversity may not directly predict future depressive symptoms. Implications for understanding the role of recent stress in the association between early adversity and adolescent depression are discussed.

Τhe neuroprotective role of environmental enrichment against behavioral, morphological, neuroendocrine and molecular changes following chronic unpredictable mild stress: A systematic review

Environmental factors interact with biological and genetic factors influencing the development and well-being of an organism. The interest in better understanding the role of environment on behavior and physiology led to the development of animal models of environmental manipulations. Environmental enrichment (EE), an environmental condition that allows cognitive and sensory stimulation as well as social interaction, improves cognitive function, reduces anxiety and depressive-like behavior and promotes neuroplasticity. In addition, it exerts protection against neurodegenerative disorders, cognitive aging and deficits aggravated by stressful experiences. Given the beneficial effects of EE on the brain and behavior, preclinical studies have focused on its protective role as an alternative, non-invasive manipulation, to help an organism to cope better with stress. A valid, reliable and effective animal model of chronic stress that enhances anxiety and depression-like behavior is the chronic unpredictable mild stress (CUMS). The variety of stressors and the unpredictability in the time and sequence of exposure to prevent habituation, render CUMS an ethologically relevant model. CUMS has been associated with dysregulation of the hypothalamic-pituitary-adrenal axis, elevation in the basal levels of stress hormones, reduction in brain volume, dendritic atrophy and alterations in markers of synaptic plasticity. Although numerous studies have underlined the compensatory role of EE against the negative effects of various chronic stress regimens (e.g. restraint and social isolation), research concerning the interaction between EE and CUMS is sparse. The purpose of the current systematic review is to present up-to-date research findings regarding the protective role of EE against the negative effects of CUMS.

Global research trends on maternal separation paradigms as an early life stress model: A bibliometric analysis

Background

Maternal separation (MS) is an early life stress model that is often studied to determine how early life stress affects brain development and psychopathological adaptation. As society has developed, public health problems have become increasingly prominent, and this research area has attracted significant attention. However, to date, there has been no systematic bibliometric study on MS. The aim of this study was to analyze the trends and frontiers in MS using bibliometrics and provide a scientific reference to researchers in the field.

Methods

Utilizing VOSviewer, CiteSpace, and Microsoft Excel, examined data obtained from the WoSCC, which encompasses the years 2002-2021.

Results

In this bibliometric study, we analyzed 6209 articles related to MS authored by 24,174 researchers across 121 countries and regions and published in 2219 journals. The United States had the most publications (2,232, 35.95%) and both the United States and the United Kingdom had the highest h-index. Institutions in the United States and France had the most published articles and citations. Keyword clustering analysis revealed associations between MS and adverse early life experiences, the hypothalamic-pituitary-adrenal (HPA) axis, stress, gene expression, and depression.

Conclusions

This bibliometric analysis highlights the current research focus on the long-term effects of MS on emotional cognition, the HPA axis, epigenetic changes, and their links to gut microbiome imbalances. Future research may expand on these findings to investigate the underlying mechanisms and broader health and societal implications of MS. These results provide a comprehensive overview of the current research landscape in MS and offer valuable insights for researchers to guide future investigations in this field.

Intergenerational and early life associations of the gut microbiome and stress-related symptomatology among Black American mothers and children

Recent evidence suggests that maternal childhood adversity may have an intergenerational impact, with children of adversity-exposed mothers exhibiting elevated symptoms of psychopathology. At the same time, many children demonstrate resilience to these intergenerational effects. Among the variety of factors that likely contribute to resilience, the composition of the gut microbiome may play a role in buffering the negative impacts of trauma and stress. The current prospective cohort study tested the novel hypothesis that offspring gut microbiome composition is a potential moderator in the relationship between maternal exposure to childhood adversity and offspring symptomatology (i.e., internalizing, externalizing, and posttraumatic stress symptoms). Maternal childhood adversity was self-reported during pregnancy via the Childhood Trauma Questionnaire and Adverse Childhood Experiences (ACEs) survey, and offspring symptomatology was assessed with the Child Behavior Checklist/1.5-5 when offspring were 2-4 years old. Offspring fecal samples were collected between these timepoints (i.e., during 6- to 24-month follow-up visits) for microbiome sequencing. Results indicated that maternal ACEs and the relative abundances of Bifidobacterium, Lactobacillus, and Prevotella were associated with offspring symptomatology. However, there was little evidence that microbial abundance moderated the association between maternal adversity and offspring symptoms. Overall, these findings further our understanding of how the gut microbiome associates with psychopathology, and informs future studies aimed at targeting modifiable factors that may buffer the intergenerational effects of childhood adversity.

Role of optical coherence tomography in depression detection: a protocol of systematic review and meta-analysis

INTRODUCTION

Optical coherence tomography (OCT) is a non-invasive approach for detecting changes in the retinal layers, which may also reflect changes in brain structure and function. As one of the leading causes of disability worldwide, depression has been associated with alteration of brain neuroplasticity. However, the role of OCT measurements in detecting depression remains unknown. This study aims to employ a systematic review and meta-analysis approach to explore ocular biomarkers measured by OCT for detecting depression.

METHODS AND ANALYSIS

We will search studies describing the relationship between OCT and depression across seven electronic databases, and retrieve articles published from database inception to date. We will also manually search grey literature and reference lists included in the retrieved studies. Two independent reviewers will screen studies, extract data and assess risk of bias. Target outcomes will include peripapillary retinal nerve fibre layer thickness, macular ganglion cell complex thickness and macular volume, as well as other related indicators. Next, we will conduct subgroup analysis and meta-regression to explore study heterogeneity, then perform sensitivity analysis to investigate the robustness of the synthesised results. Meta-analysis will be performed using Review Manager (V.5.4.1) and STATA (V.12.0), and the certainty of evidence will be graded according to the Grading of Recommendations Assessment, Development and Evaluation system.

ETHICS AND DISSEMINATION

Ethics approval is not necessary because the data used in this systematic review and meta-analysis will be extracted from published studies. Study results will be disseminated by publishing our findings in a peer-reviewed journal.

Maternal exposure to childhood maltreatment and adverse birth outcomes

Exposure to traumatic events during pregnancy may influence pregnancy and birth outcomes. Growing evidence suggests that exposure to traumatic events well before pregnancy, such as childhood maltreatment (CM), also may influence the course of pregnancy and risk of adverse birth outcomes. We aimed to estimate associations between maternal CM exposure and small-for-gestational-age birth (SGA) and preterm birth (PTB) in a diverse US sample, and to examine whether common CM-associated health and behavioral sequelae either moderate or mediate these associations. The Measurement of Maternal Stress (MOMS) Study was a prospective cohort study that enrolled 744 healthy English-speaking participants ≥ 18 years with a singleton pregnancy, who were < 21 weeks at enrollment, between 2013 and 2015. CM was measured via the Childhood Trauma Questionnaire (CTQ) and participants above the moderate/severe cut-off for any of the five childhood abuse and neglect scales were assigned to the CM-exposed group. Common CM-associated health (obesity, depressive symptoms, hypertensive disorders) and behavioral (substance use) sequelae were obtained from standardized questionnaires and medical records. The main outcomes included PTB (gestational age < 37 weeks at birth) and SGA (birthweight < 10%ile for gestational age) abstracted from the medical record. Multivariable logisitic regression was used to test associations between CM, sequeale, and birth outcomes, and both moderation and mediation by CM-related sequelae were tested. Data were available for 657/744 participants. Any CM exposure was reported by 32% of participants. Risk for SGA birth was 61% higher among those in the CM group compared to the non-CM group (14.1% vs. 7.6%), and each subsequent form of CM that an individual was exposed to corresponded with a 27% increased risk for SGA (aOR 1.27, 95% CI 1.05, 1.53). There was no significant association between CM and PTB (9.3% vs. 13.0%, aOR 1.07, 95% CI 0.58, 1.97). Of these sequelae only hypertensive disorders were associated with both CM and SGA and hypertensive disorders of pregnancy did not mediate the association between CM and SGA. Our findings indicate that maternal CM exposure is associated with increased risk for SGA birth and highlight the importance of investigating the mechanisms whereby childhood adversity sets the trajectory for long-term and intergenerational health issues.

Stressed Microglia: Neuroendocrine-Neuroimmune Interactions in the Stress Response

Stressful life experiences are associated with the development of neuropsychiatric disorders like depression. Emerging evidence indicates that microglia, the specialized resident macrophages of the brain, may be a key mediator of the relationship between psychosocial stressor exposure and adaptive or maladaptive responses at the level of synaptic, circuit, and neuroimmune alterations. Here, we review current literature regarding how psychosocial stressor exposure changes microglial structure and function, thereby altering behavioral and brain outcomes, with a particular focus on age- and sex-dependent effects. We argue that additional emphasis should be placed in future research on investigating sex differences and the impacts of stressor exposure during sensitive periods of development, as well as going beyond traditional morphological measurements to interrogate microglial function. The bidirectional relationship between microglia and the stress response, particularly the role of microglia in the neuroendocrine control of stress-related circuits, is also an important area for future investigation. Finally, we discuss emerging themes and future directions that point to the possibility of the development of novel therapeutics for stress-related neuropsychiatric disorders.

The Individual and Societal Burden of Treatment-Resistant Depression: An Overview

Major depressive disorder is characterized by depressed mood and/or anhedonia with neurovegetative symptoms and neurocognitive changes affecting an individual's functioning in multiple aspects of life. Treatment outcomes with commonly used antidepressants remain suboptimal. Treatment-resistant depression (TRD) should be considered after inadequate improvement with two or more antidepressant treatments of adequate dose and duration. TRD has been associated with increased disease burden including higher associated costs (both socially and financially) affecting both the individual and society. Additional research is needed to better understand the long-term burden of TRD to both the individual and society.

Do Turkish mothers' emotion regulation, psychological symptoms and caregiving helplessness vary based on attachment states of mind?

Mothers' emotion regulation, mental health, and feeling of helplessness in caring for their child may vary based on maternal attachment classifications. Particularly, insecure attachment and unresolved state of mind can act as risk factors. Therefore, we examined how emotion regulation strategies of suppression and cognitive reappraisal, maternal symptoms of depression and anxiety, and caregiving helplessness differ based on maternal attachment classifications in the Adult Attachment Interview (AAI). Fifty mothers of children in the early childhood (AgeRange = 12-56 months) completed a pack of questionnaires, including Emotion Regulation Questionnaire, Brief Symptom Inventory, and Caregiving Helplessness Questionnaire. Then AAI interview protocol was administered and coded. Mothers did not vary in emotion regulation strategies, indicating emotion regulation balance. However, mothers with secure/autonomous AAIs reported less anxiety than mothers whose AAIs were judged to show unresolved loss or unresolved trauma. The mothers who provided AAIs judged to be secure/autonomous scored lower in depression and caregiving helplessness than mothers whose AAIs were judged to show unresolved loss or unresolved trauma. To our knowledge, this is one of the first studies conducting AAI in Turkish mothers. We revealed the critical role of secure attachment for mental health and caregiving helplessness that can facilitate interventions targeting maternal attachment mind state.

Maternal-infant interaction quality is associated with child NR3C1 CpG site methylation at 7 years of age

OBJECTIVE

Infancy is both a critical window for hypothalamic-pituitary-adrenal (HPA) axis development, and a sensitive period for social-emotional influences. We hypothesized that the social-emotional quality of maternal-infant interactions are associated with methylation of HPA-axis gene NR3C1 later in childhood.

METHODS

Using a subsample of 114 mother-infant pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC), linear regression models were created to predict variance in methylation of seven selected CpG sites from NR3C1 in whole blood at age 7 years, including the main predictor variable of the first principal component score of observed maternal-infant interaction quality (derived from the Thorpe Interaction Measure at 12 months of age) and covariates of cell-type proportion, maternal financial difficulties and marital status at 8 months postnatal, child birthweight, and sex.

RESULTS

CpG site cg27122725 methylation was negatively associated with warmer, more positive maternal interaction with her infant (β = 0.19, p = .02, q = 0.13). In sensitivity analyses, the second highest quartile of maternal behavior (neutral, hesitant behavior) was positively associated with cg12466613 methylation. The other five CpG sites were not significantly associated with maternal-infant interaction quality.

CONCLUSIONS

Narrow individual variation of maternal interaction with her infant is associated with childhood methylation of two CpG sites on NR3C1 that may be particularly sensitive to environmental influences. Infancy may be a sensitive period for even small influences from the social-emotional environment on the epigenetic determinants of HPA-axis function.

Early-life exposure to permethrin affects phenotypic traits in both larval and adult mangrove rivulus Kryptolebias marmoratus

In fishes, the impacts of environmental constraints undergone during development on the behavioural response of individuals are not well understood. Obtaining more information is important since the aquatic environment is widely exposed to pollution involving neurotoxic compounds likely to cause phenotypic changes that can affect animal fitness. We explored how early exposure to the pyrethroid insecticide permethrin (PM), a compound known for its neurotoxicity, influences the phenotypic traits in both larvae and adults of the self-fertilizing fish mangrove rivulus, Kryptolebias marmoratus. First, we investigated immediate effects of PM on larvae after one-week exposure (0-7 days post-hatching): larvae exposed to high concentration (200 µg.L^-1) grew less, were less active, had negative thigmotaxis and were less likely to capture prey than control individuals and those exposed to low concentration (5 µg.L^-1). No difference was found between treatments when considering oxygen consumption rate and cortisol levels. Persistent effects of early exposure to PM on adults (147-149 days post-hatching) showed that fish previously exposed to high concentration of PM overcompensated growth, leading them to finally be longer and heavier than fish from other treatments. Moreover, we evidenced that levels of cortisol interacted with early PM exposure to affect behaviours during dyadic contests. Fish were more likely to initiate fighting behaviours and were more likely to be aggressive when they have low pre-contest levels of cortisol, but these effects were less pronounced when individuals were exposed to PM. This study shows that PM can have both immediate and persistent effects on phenotypic traits in a self-fertilizing vertebrate and suggests that a pyrethroid can interact with hormones action to affect animal behaviour.

Association of serum alkaline phosphatase and depression in US adults: a population-based cross-sectional study

Background

Depression, a serious public health disorder, is increasingly prevalent worldwide. An association between alkaline phosphatase (ALP) and neurological disorders has been reported. However, data on ALP and depression risk are scarce, which warrants attention.

Methods

We assessed the association between ALP and risk of depression in adults from the 2007-2014 National Health and Nutrition Examination Survey (NHANES). Depression was assessed using the Patient Health Questionnaire-9. Univariate and multivariate logistic regression were used to assess the association between ALP and risk of depression, and subgroup analyses were also performed.

Results

A total of 17,485 participants were included. The prevalence of depression was 9.3% (1,631/17,485) and ALP was significantly associated with the risk of depression when ALP was a categorical variable (quadratic or categorized by 79 U/L) in a multivariate logistic regression model after adjusting for confounding factors (≥79 U/L vs. <79 U/L, adjusted OR, 1.15; 95%CI, 1.02-1.29). Each 1-unit increase in ALP (log₂) was associated with a 20% increase in depression prevalence (adjusted OR, 1.20; 95%CI, 1.06-1.36) when ALP was used as a continuous variable. Subgroup analysis showed that ALP was positively associated with the risk of depression with different characteristics.

Conclusion

Our findings suggest that higher alkaline phosphatase levels, even within the normal range, are significantly associated with a higher risk of depression in US adults. Such findings require further prospective studies to provide more evidence.

Assessing the degree of urbanisation using a single-item self-report measure: a validation study

The differential impact of rural versus urban residence on mental health remains a controversial topic that requires more in-depth investigations. This calls for a valid and easy measure to assess the degree of urbanisation. The purpose of the present study was to determine the utility of a single-item self-report measure (SIDU) as a tool to classify areas along the rural-urban continuum. The validity of the SIDU was assessed by comparing its scores (1-7) to a commonly used objective surrogate measure of the degree of urbanisation (i.e. surrounding address density, SAD) in two independent older adult samples (A: N = 36, 65+; B: N = 121, 55+). SIDU scores approximated SAD scores, with r = .77 to 0.82, (A), and r = .79 to 0.83 (B). A SIDU threshold score of 6 most accurately distinguished extremely urbanised areas from other areas. Altogether, our findings suggest that SIDU scores could be used as proxy of SAD. Since self-report leaves room for the consideration of additional aspects that confer an urban settlement, this single-item scale may be even more comprehensive, and circumvents the collection and handling of highly sensitive location data when the primary goal is solely to distinguish urbanisation subgroups.

Threat versus deprivation in mother's childhood: Differential relations to hair cortisol and psychopathology in pregnancy

BACKGROUND

The negative effects of childhood maltreatment can be intergenerational, and the prenatal period may play an important role in this intergenerational transmission. Maternal hypothalamic-pituitary-adrenal (HPA) axis dysfunction and maternal psychopathology represent two mechanisms through which the effects of childhood maltreatment are hypothesized to be transmitted across generations.

OBJECTIVE

This study first sought to extend prior research on pathways of intergenerational transmission by examining whether mothers' childhood experiences of abuse versus neglect differentially relate to maternal HPA activity and to maternal psychopathology during the prenatal period. Second, exploratory analyses examined the links between maternal variables and their State Protective Service involvement as a parent, as an indicator of maladaptive caregiving.

METHODS

During the third trimester of pregnancy, 51 women reported on experiences of childhood maltreatment, on State Protective Service involvement as an adult parent, and on current depressive and post-traumatic stress symptoms, and provided a hair sample for cortisol assay.

RESULTS

Regression analyses indicated that greater severity of abuse, but not neglect, in childhood was associated with higher maternal depressive symptoms (β = 0.488, p = .020). In contrast, greater severity of neglect, but not abuse, in mothers' childhood was associated with lower maternal hair cortisol concentration (β = -0.437, p = .031). Lower maternal hair cortisol concentration, but not maternal psychopathology or severity of childhood abuse or neglect, in turn, was associated with State Protective Service involvement (β = -0.785, p < .001).

CONCLUSIONS

Findings extend prior work by suggesting that childhood abuse and neglect may have different sequelae for mothers during pregnancy and that these sequelae may have different relations to parenting.

Maternal Immune Activation and Enriched Environments Impact B2 SINE Expression in Stress Sensitive Brain Regions of Rodent Offspring

Early life stress (ELS) can have wide-spread neurodevelopmental effects with support accumulating for the idea that genomic mechanisms may induce lasting physiological and behavioral changes following stress exposure. Previous work found that a sub-family of transposable elements, SINEs, are repressed epigenetically after acute stress. This gives support to the concept that the mammalian genome may be regulating retrotransposon RNA expression allowing for adaptation in response to environmental challenges, such as maternal immune activation (MIA). Transposon (TE) RNAs are now thought to work at the epigenetic level and to have an adaptive response to environmental stressors. Abnormal expression of TEs has been linked to neuropsychiatric disorders like schizophrenia, which is also linked to maternal immune activation. Environmental enrichment (EE), a clinically utilized intervention, is understood to protect the brain, enhance cognitive performance, and attenuate responses to stress. This study examines the effects of MIA on offspring B2 SINE expression and further, the impact that EE, experienced throughout gestation and early life, may have in conjunction with MIA during development. Utilizing RT-PCR to quantify the expression of B2 SINE RNA in the juvenile brain of MIA exposed rat offspring, we found dysregulation of B2 SINE expression associated with MIA in the prefrontal cortex. For offspring experiencing EE, the prefrontal cortex exhibited an attenuation of the MIA response observed in standard housed animals. Here, the adaptive nature of B2 is observed and thought to be aiding in the animal's adaptation to stress. The present changes indicate a wide-spread stress-response system adaptation that impacts not only changes at the genomic level but potentially observable behavioral impacts throughout the lifespan, with possible translational relevance to psychotic disorders.

Connexin 43 regulates astrocyte dysfunction and cognitive deficits in early life stress-treated mice

Early life stress such as maternal separation (MS), is a major risk factor for developing psychiatric disorders in adulthood. Connexin 43 (CX43), the main type of connexins expressed in astrocytes, has been indicated to participate in depression disorders. Nevertheless, the role of CX43 in MS-induced cognitive impairment and astrocyte dysfunction is unclear. Neonatal C57BL/6 mice were exposed to MS to mimic early life stress. Adeno-associated virus carrying CX43 was inoculated into mice for CX43 overexpression. Sucrose preference test, forced swim test and Morris water maze were performed for evaluating depression-like behaviors and spatial learning and memory of mice in adulthood. Real time quantitative polymerase chain reaction was conducted to detect CX43 mRNA expression in mouse brain. Immunofluorescence staining and western blotting were used for measuring expression levels of astrocytic markers in murine hippocampal dentate gyrus. The results showed that overexpressing CX43 attenuated MS exposure-induced depression-like behaviors and decrease in spatial learning and memory in mice. Upregulating CX43 alleviated MS exposure-induced downregulation of astrocytic markers. Collectively, CX43 overexpression attenuates cognitive deficits and astrocyte dysfunction in mice exposed to MS.

Resistance exercise was safe for the pregnancy and offspring's development and partially protected rats against early life stress-induced effects

Promising evidence points to gestational physical exercise as the key to preventing various disorders that affect the offspring neurodevelopment, but there are no studies showing the impact of resistance exercise on offspring health. Thus, the aim of this study was to investigate whether resistance exercise during pregnancy is able to prevent or to alleviate the possible deleterious effects on offspring, caused by early life-stress (ELS). Pregnant rats performed resistance exercise throughout the gestational period:they climbed a sloping ladder with a weight attached to their tail, 3 times a week. Male and female pups, on the day of birth (P0), were divided into 4 experimental groups: 1) rats of sedentary mothers (SED group); 2) rats of exercised mothers (EXE group); 3) rats of sedentary mothers and submitted to maternal separation (ELS group) and 4) rats of exercised mothers and submitted to MS (EXE + ELS group). From P1 to P10, pups from groups 3 and 4 were separated from their mothers for 3 h/day. Maternal behavior was assessed. From P30, behavioral tests were performed and on P38 the animals were euthanized and prefrontal cortex samples were collected. Oxidative stress and tissue damage analysis by Nissl staining were performed. Our results demonstrate that male rats are more susceptible to ELS than females, showing impulsive and hyperactive behavior similar to that seen in children with ADHD. This behavior was attenuated by the gestational resistance exercise. Our results demonstrate, for the first time, that resistance exercise performed during pregnancy seems to be safe for the pregnancy and offspring's neurodevelopment and are effective in preventing ELS-induced damage only in male rats. Interestingly, resistance exercise during pregnancy improved maternal care and it is reasonable to propose that this finding may be related to the protective role on the animals neurodevelopment, observed in our study.

Understanding the relationships between physiological and psychosocial stress, cortisol and cognition

Stress is viewed as a state of real or perceived threat to homeostasis, the management of which involves the endocrine, nervous, and immune systems. These systems work independently and interactively as part of the stress response. The scientific stress literature, which spans both animal and human studies, contains heterogeneous findings about the effects of stress on the brain and the body. This review seeks to summarise and integrate literature on the relationships between these systems, examining particularly the roles of physiological and psychosocial stress, the stress hormone cortisol, as controlled by the hypothalamic-pituitary-adrenal (HPA) axis, and the effects of stress on cognitive functioning. Health conditions related to impaired HPA axis functioning and their associated neuropsychiatric symptoms will also be considered. Lastly, this review will provide suggestions of clinical applicability for endocrinologists who are uniquely placed to measure outcomes related to endocrine, nervous and immune system functioning and identify areas of intervention.

Physical and social trauma: Towards an integrative transdiagnostic perspective on psychological trauma that involves threats to status and belonging

Current theories of psychological trauma assume that posttraumatic symptoms originate from stress reactions caused by extremely adverse life experiences. Since the diagnosis of PTSD is restricted to events that involve threats to the physical or sexual integrity of a person, such as accidents and physical and sexual violence, these theories are not well suited to explain the psychopathological consequences of severe violations of one's social integrity, such as emotional abuse and bullying. However, it is evident that social threats contribute to a broad range of mental disorders and increase symptom severity in patients with posttraumatic stress disorder. The aim of the Physical and Social Trauma (PAST) framework is to extend current memory theories of psychological trauma to incorporate threats to a person's social integrity. Within this perspective, the harmful effects of events that involve social threats result from violations of core social motives such as the need for status and belonging that bring about intense affective reactions, including despair and defeat. Within associative threat structures, these emotions are tied to the stimulus characteristics of the experiences and can be re-activated in social situations. The resulting psychopathology transcends PTSD criteria and other current classifications and suggests a transdiagnostic perspective of psychological trauma. Implications for treatment and further directions for research are discussed.

Associations between epigenetic aging and childhood peer victimization, depression, and suicidal ideation in adolescence and adulthood: A study of two population-based samples

Background: Prior studies indicate that peer victimization (including bullying) is associated with higher risk for depression and suicidal ideation across the life course. However, molecular mechanisms underlying these associations remain unclear. This two-cohort study proposes to test whether epigenetic aging and pace of aging, as well as a DNA methylation marker of responsive to glucocorticoids, are associated to childhood peer victimization and later depressive symptoms, or suicidal ideation. Methods: Cohort 1: Epigenome-wide DNA methylation (EPIC array) was measured in saliva collected when participants were 10.47 years (standard deviation = 0.35) in a subsample of the Quebec Longitudinal Study of Child Development (QLSCD, n = 149 participants), with self-reported peer victimization at 6-8 years, depressive symptoms (mean symptoms, and dichotomized top 30% symptoms) and suicidal ideation at 15-17 years. Cohort 2: Epigenome-wide DNA methylation (EPIC array) was measured in blood collected from participants aged 45.13 years (standard deviation = 0.37) in a subsample of the 1958 British Birth cohort (1958BBC, n = 238 participants) with information on mother-reported peer victimization at 7-11 years, self-reported depressive symptoms at 50 years, and suicidal ideation at 45 years. Five epigenetic indices were derived: three indicators of epigenetic aging [Horvath's pan-tissue (Horvath1), Horvath's Skin-and-Blood (Horvath2), Pediatric-Buccal-Epigenetic age (PedBE)], pace of aging (DunedinPACE), and stress response reactivity (Epistress). Results: Peer victimization was not associated with the epigenetic indices in either cohort. In the QLSCD, higher PedBE epigenetic aging and a slower pace of aging as measured by DunedinPACE predicted higher depressive symptoms scores. In contrast, neither the Horvath1, or Horvath2 epigenetic age estimates, nor the Epistress score were associated with depressive symptoms in either cohort, and none of the epigenetic indices predicted suicidal ideation. Conclusion: The findings are consistent with epigenome-wide and candidate gene studies suggesting that these epigenetic indices did not relate to peer victimization, challenging the hypothesis that cumulative epigenetic aging indices could translate vulnerability to depressive symptoms and suicidal ideation following peer victimization. Since some indices of epigenetic aging and pace of aging signaled higher risk for depressive symptoms, future studies should pursue this investigation to further evaluate the robustness and generalization of these preliminary findings.

Erroneous Thought in Inpatients with Major Depressive Disorder: The Role of Psychological Trauma During Childhood and Adulthood

BACKGROUND

The pathogenic role of trauma in psychotic-like experiences has yet to be clarified. The aim of this study was to investigate the role of childhood and adulthood trauma on erroneous thoughts among patients with major depressive disorder.

MATERIALS AND METHODS

Inpatients with major depressive disorder (MDD) and healthy controls (HCs) were enrolled, and paper-and-pencil questionnaires were applied. Clinical rating and self-reported scales were used to measure levels of depression, dissociation, psychological trauma, parental maltreatment, and erroneous thoughts. Pearson's correlation analysis was conducted to explore potentially significant associations between erroneous thoughts and other independent variables, and standardized regression coefficients of hierarchical regression analysis were used to predict the significant relationships between erroneous thoughts and adulthood or childhood trauma.

RESULTS

A total of 99 participants were included into the analysis, of whom 59 were patients with MDD and 40 were HCs. After treatment, the patients with MDD showed significantly higher levels of depression, childhood maltreatment, interpersonal trauma and erroneous thoughts than the HCs. After estimating and verifying correlations with hierarchical regression among the patients with MDD, a link between adulthood betrayal trauma and higher level of conviction along with the number of erroneous thoughts was found. However, no significant association was identified between childhood trauma and erroneous thought. The concurrent level of depression significantly predicted a higher level of being preoccupied, along with the number of erroneous thoughts.

CONCLUSION

The current study fills a gap in the literature by showing a link between adulthood trauma and erroneous thoughts in non-psychotic patients. Further studies with well-controlled comparisons and prospective cohort with longer follow-up are warranted to extend the applicability and generalizability of the current study.

Exploring the role of ketone bodies in the diagnosis and treatment of psychiatric disorders

In recent times, advances in the field of metabolomics have shed greater light on the role of metabolic disturbances in neuropsychiatric conditions. The following review explores the role of ketone bodies and ketosis in both the diagnosis and treatment of three major psychiatric disorders: major depressive disorder, anxiety disorders, and schizophrenia. Distinction is made between the potential therapeutic effects of the ketogenic diet and exogenous ketone preparations, as exogenous ketones in particular offer a standardized, reproducible manner for inducing ketosis. Compelling associations between symptoms of mental distress and dysregulation in central nervous system ketone metabolism have been demonstrated in preclinical studies with putative neuroprotective effects of ketone bodies being elucidated, including effects on inflammasomes and the promotion of neurogenesis in the central nervous system. Despite emerging pre-clinical data, clinical research on ketone body effectiveness as a treatment option for psychiatric disorders remains lacking. This gap in understanding warrants further investigating, especially considering that safe and acceptable ways of inducing ketosis are readily available.

Lack of speeded disengagement from facial expressions of disgust in remitted major depressive disorder: Evidence from an eye-movement study

Acute major depression is characterized by specific abnormalities in the way emotional material is attended to. In late stages of stimulus processing, clinically depressed and dysphoric individuals show difficulties to disengage attention from emotionally negative material. It is unclear, however, whether aberrant disengagement is a transitory attentional phenomenon tied to depressive symptoms, or whether it constitutes a more stable disposition that outlast the symptomatic episode. To address this issue, the current study examined 39 currently euthymic individuals previously affected by major depression (RMD) and 40 healthy control participants reporting no lifetime psychopathology (ND). We used a gaze-contingent eye tracking paradigm designed to separately assess the attentional components of engagement and disengagement when viewing facial expressions of sadness, disgust and happiness. Never-depressed healthy participants, but not remitted euthymic individuals, showed speeded disengagement from facial expressions of disgust. We propose that the lack of this distinct acceleration in previously depressed but fully remitted individuals might reflect an attentional disposition that carries over to euthymic phases of the disease. On the other hand, a tendency to disengage quickly from areas in the visual field that convey social disdain could potentially act as a protective, possibly mood-stabilizing bias in resilient individuals.

Psychological legacies of intergenerational trauma under South African apartheid: Prenatal stress predicts greater vulnerability to the psychological impacts of future stress exposure during late adolescence and early adulthood in Soweto, South Africa

BACKGROUND

South Africa's rates of psychiatric morbidity are among the highest in sub-Saharan Africa and are foregrounded by the country's long history of political violence during apartheid. Growing evidence suggests that in utero stress exposure is a potent developmental risk factor for future mental illness risk, yet the extent to which the psychiatric effects of prenatal stress impact the next generation are unknown. We evaluate the intergenerational effects of prenatal stress experienced during apartheid on psychiatric morbidity among children at ages 17-18 and also assess the moderating effects of maternal age, social support, and past household adversity.

METHODS

Participants come from Birth-to-Twenty, a longitudinal birth cohort study in Soweto-Johannesburg, South Africa's largest peri-urban township which was the epicentre of violent repression and resistance during the final years of the apartheid regime. Pregnant women were prospectively enrolled in 1990 and completed questionnaires assessing social experiences, and their children's psychiatric morbidity were assessed at ages 17-18.

RESULTS

Full data were available from 304 mother-child pairs in 2007-8. Maternal prenatal stress in 1990 was not directly associated greater psychiatric morbidity during at ages 17-18. Maternal age and past household adversity moderated the intergenerational mental health effects of prenatal stress such that children born to younger mothers and late adolescent/young adult children experiencing greater household adversity exhibited worse psychiatric morbidity at ages 17-18. Social support did not buffer against the long-term psychiatric impacts of prenatal stress.

CONCLUSIONS

Greater prenatal stress from apartheid predicted adverse psychiatric outcomes among children born to younger mothers and adolescents/young adults who experienced greater concurrent stress. Our findings suggest that prenatal stress may affect adolescent mental health, have stress-sensitising effects, and represent possible intergenerational effects of trauma experienced under apartheid in this sample.

Are the epigenetic changes predictive of therapeutic efficacy for psychiatric disorders? A translational approach towards novel drug targets

The etiopathogenesis of mental disorders is not fully understood and accumulating evidence support that clinical symptomatology cannot be assigned to a single gene mutation, but it involves several genetic factors. More specifically, a tight association between genes and environmental risk factors, which could be mediated by epigenetic mechanisms, may play a role in the development of mental disorders. Several data suggest that epigenetic modifications such as DNA methylation, post-translational histone modification and interference of microRNA (miRNA) or long non-coding RNA (lncRNA) may modify the severity of the disease and the outcome of the therapy. Indeed, the study of these mechanisms may help to identify patients particularly vulnerable to mental disorders and may have potential utility as biomarkers to facilitate diagnosis and treatment of psychiatric disorders. This article summarizes the most relevant preclinical and human data showing how epigenetic modifications can be central to the therapeutic efficacy of antidepressant and/or antipsychotic agents, as possible predictor of drugs response.

FAAH Inhibition Restores Early Life Stress-Induced Alterations in PFC microRNAs Associated with Depressive-Like Behavior in Male and Female Rats

Early life stress (ELS) increases predisposition to depression. We compared the effects of treatment with the fatty acid amide hydrolase (FAAH) inhibitor URB597, and the selective serotonin reuptake inhibitor paroxetine, on ELS-induced depressive-like behavior and the expression of microRNAs (miRs) associated with depression in the medial prefrontal cortex (mPFC), hippocampal CA1 area, lateral habenula and dorsal raphe in rats. We also examined the mRNA expression of serotonergic (htr1a and slc6a4) and endocannabinoid (cnr1, cnr2 and faah) targets in the mPFC following ELS and pharmacological treatment. Adult males and females exposed to the 'Limited Bedding and Nesting' ELS paradigm demonstrated a depressive-like phenotype and late-adolescence URB597 treatment, but not paroxetine, reversed this phenotype. In the mPFC, ELS downregulated miR-16 in males and miR-135a in females and URB597 treatment restored this effect. In ELS females, the increase in cnr2 and decrease in faah mRNAs in the mPFC were reversed by URB597 treatment. We show for the first time that URB597 reversed ELS-induced mPFC downregulation in specific miRs and stress-related behaviors, suggesting a novel mechanism for the beneficial effects of FAAH inhibition. The differential effects of ELS and URB597 on males and females highlight the importance of developing sex-specific treatment approaches.

Sex matters: The impact of oxytocin on healthy conditions and psychiatric disorders

Oxytocin (OT) is involved in the regulation of physiological processes and emotional states, with increasing evidence for its beneficial actions being mediated by the autonomic and immune systems. Growing evidence suggests that OT plays a role in the pathophysiology of different psychiatric disorders. Given the limited information in humans the aim of this study was to retrospectively explore plasma OT levels in psychiatric patients, particularly focusing on sex-related differences, as compared with healthy controls. The patients studied here were divided into three groups diagnosed with obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD) or major depressive disorder (MDD). Plasma OT levels were significantly different between healthy men and women, with the latter showing higher values, while none of the three psychiatric groups showed sex-related differences in the parameters measured here. The intergroup analyses showed that the OT levels were significantly higher in OCD, lower in PTSD and even more reduced in MDD patients than in healthy subjects. These differences were also confirmed when gender was considered, with the exception of PTSD men, in whom OT levels were similar to those of healthy men. The present results indicated that OT levels were higher amongst healthy women than men, while a sex difference was less apparent or reversed in psychiatric patients. Reductions in sex differences in psychopathologies may be related to differential vulnerabilities in processes associated with basic adaptive and social functions.

The Depression Prevention Initiative: Trauma as a Moderator of Prevention Outcomes

Interpersonal Psychotherapy-Adolescent Skills Training (IPT-AST) is an evidence-based indicated depression prevention program that has been shown to reduce depression symptoms. Research is needed to identify moderators of IPT-AST's effects. Although trauma history has emerged as a moderator of depression treatment outcomes, the impact of trauma on short- and long-term outcomes in the context of preventive interventions for adolescent depression is unknown. This study examines the impact of trauma on prevention outcomes in a school-based randomized controlled trial (RCT) in which 186 adolescents (mean age = 14.01 years, SD = 1.22; 67% female) were randomly assigned to IPT-AST delivered by research staff or group counseling (GC) provided by school counselors. Trauma history significantly moderated intervention outcomes during the active phase of the intervention, but not during long-term follow-up. During the active phase, youth in IPT-AST with low or no trauma exposure experienced significantly greater reductions in depression symptoms than youth in GC with low or no trauma exposure, but there were no significant differences in rates of change between the two interventions for youth with high or any trauma exposure. These findings highlight the importance of assessing trauma and investigating whether these interventions can be tailored or supplemented to enhance the effects for youth with trauma exposure.

Recognizing the role of the vagus nerve in depression from microbiota-gut brain axis

Depression is a worldwide disease causing severe disability, morbidity, and mortality. Despite abundant studies, the precise mechanisms underlying the pathophysiology of depression remain elusive. Recently, cumulate research suggests that a disturbance of microbiota-gut-brain axis may play a vital role in the etiology of depression while correcting this disturbance could alleviate depression symptoms. The vagus nerve, linking brain and gut through its afferent and efferent branches, is a critical route in the bidirectional communication of this axis. Directly or indirectly, the vagus afferent fibers can sense and relay gut microbiota signals to the brain and induce brain disorders including depression. Also, brain changes in response to stress may result in gut hyperpermeability and inflammation mediating by the vagal efferents, which may be detrimental to depression. Notably, vagus nerve stimulation owns an anti-inflammatory effect and was proved for depression treatment. Nevertheless, depression was accompanied by a low vagal tone, which may derive from response to stress and contribute to pathogenesis of depression. In this review, we aim to explore the role of the vagus nerve in depression from the perspective of the microbiota-gut-brain axis, highlighting the relationship among the vagal tone, the gut hyperpermeability, inflammation, and depression.

Assessing the Core Variables of Business Managers' Intuitive Decision Ability: A Review and Analysis

Business decisions are frequently based on informed intuition in contrast to a formal analysis. Early man used simple intuition, but through time knowledge increases allowed decision makers (DMs) to move to 'objectively informed intuition' (OII). This uses inherent and learnt cognition at both unconscious and conscious levels. A model of business OII is proposed and evaluated using as variables the managers' personal characteristics and their unique set of objectives. The resultant equation allows assessing decision quality and provides a framework for DMs to work on improvements relative to their objectives. The literature suggests OII stems from a DM's makeup (business related phenotype), training and experience in a dynamic trio leading to the defining equation. Analyses show business related phenotype is the most important determinant as well as confirming the proposed theory on the determinants of OII success. Practical methods of improving OII are reviewed, and issues worth further investigation outlined. This research is the first encompassing quantitative relationships explaining business OII quality thus enabling improving OII. Suggested further research may refine the equation and expand its core base. This work involves a range of disciplines as different aspects of human characteristics impact on how decisions are made.

Regulatory Role of PFC Corticotropin-Releasing Factor System in Stress-Associated Depression Disorders: A Systematic Review

Stress has a substantial role in formation of psychiatric disorders especially depression. Meanwhile, impairment of the prefrontal cortex (PFC) is connected to the executive and cognitive deficits induced by the stress. Given the involvement of the corticotropin-releasing factor (CRF) in stress-related processes and knowing the fact that PFC hosts a lot of CRF receptors and CRF neurotransmissions, it can worth to look at the CRF as a potential treatment for the regulation of depression disorders induced by stress within PFC region. Here, for the first time we aimed to systematically review the effectiveness of intra-PFC CRF system in the modulation of depression dysfunction caused by the stress in clinical and preclinical models/studies. Qualified researches were combined utilizing a comprehensive search of six databases including Scopus, Pubmed, Web of Science, Sciencedirect, APA PsycNet, and Embase in April 2021 and were evaluated through proper methodological quality assessment tools. Results indicate that PFC has a remarkable role in the modulation for stress-induced depression and intra-PFC CRF receptors agonist and antagonist are very considerable for regulating these types of impairments. Specifically, elevation of both CRF immunoreactivity and gene expression were observed in human studies. In the animal studies, mostly immunoreactivity or excitatory/inhibitory currents of CRF within the PFC regulated depression dysfunction. In conclusion, reviewed studies show a positive attitude toward the CRF system in regulation of the stress-induced depression; however, obviously further investigations are required to get closer to the best treatment. Prefrontal cortex corticotropin-releasing factor system regulates stress-induced depression. CRFR1, Corticotropin-releasing factor receptor of type1; PFC, Prefrontal cortex; Minus (-) and Plus (+) signs, dysregulation and upregulation, respectively.

Psychosocial stress induction in vivo vs. in virtuo and the influence of a health app on the acute stress reaction in youths: a study protocol for a randomized controlled trial

BACKGROUND

Acute and everyday stress is substantial for the development of mental and physical diseases, therefore it is crucial to get a better understanding of its pathogenesis. Different methods (e.g., Ambulatory Assessment) and stress reactivity paradigms (e.g., Trier Social Stress Test / TSST) in laboratory settings are often used to investigate basic mechanisms of this process. Due to the technological progress of the last years and especially due to children and adolescents growing up with it, the application of these developments in clinical research is reasonable. The aim of this project is to successfully transfer the TSST for children and adolescents into the virtual world, which will be compared to a real TSST situation. Physiological and psychological stress reactions will be analyzed in order to assess similarities and differences. Moreover, it will be investigated whether a Heart Coherence Exercise (HCE) has a stronger influence on coping with acute stress compared to Natural Relaxation (NR).

METHODS

This single-center experimental study will examine acute and everyday stress and coping processes in eighty-four healthy children and adolescents between the ages of 11 and 17. For everyday stress, different parameters (e.g., hormonal profiles and mood ratings) as well as a history of stressful life events and utilized coping methods will be recorded and a relaxation exercise will be practiced on a smartphone over 2 days. Regarding the acute stress reaction, the participants will be confronted either with the virtual or the real version of the TSST, followed by the trained relaxation exercise (HCE vs. NR). Physiological (e.g., cortisol and heart rate) and psychological stress markers (e.g., mood and gaze behavior) will be recorded continuously.

DISCUSSION

Studies are sparse using a virtual version of the TSST in children and adolescents. A successful virtual TSST would constitute an economical variant, which would also make it easier to administer it in clinical or population-based samples. Effective ambulatory relaxation exercises would be a useful addition to clinical treatment approaches.

TRIAL REGISTRATION

The study is registered in the German Clinical Trials Register since 10 August 2020 ( DRKS00022063 ).

Association of depression with mortality in nationwide twins: The mediating role of dementia

BACKGROUND

The differential impact of depression across different periods in life on mortality remains inconclusive. We aimed to examine the association of depression that occurs at different age with all-cause mortality, and to explore the roles of dementia, as well as genetic and early-life environmental factors, in this association.

METHODS

From the Swedish Twin Registry, 44,919 twin individuals were followed for up to 18 years. Depression was ascertained using the National Patient Registry and categorized as early-life (<45 years), midlife (45-64 years), and late-life (≥65 years) depression according to the age of the first diagnosis. Deaths were identified through the Cause of Death Register. Generalized estimating equation, generalized structural equation, and conditional logistic regression were used for unmatched, mediation, and co-twin matched analyses, respectively.

RESULTS

In unmatched analyses, the multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of mortality were 1.71 (1.46-2.00) for depression at any age, 1.72 (1.36-2.17) for early-life, 1.51 (1.19-1.90) for midlife, and 4.10 (2.02-8.34) for late-life depression. Mortality was significantly higher in individuals with late-life depression than those with earlier-life depression (p < 0.05). The mediation analysis showed that 59.83% of the depression-mortality association was mediated by dementia. No significant difference in ORs between the unmatched and co-twin matched analyses was observed (p = 0.09).

CONCLUSIONS

Depression is associated with an increased risk of all-cause mortality, and dementia mediates approximately 60% of the impact of depression on mortality in late life. Genetic and early-life environmental factors may not play a significant role in the depression-mortality association.

Epigenetic and Neuronal Activity Markers Suggest the Recruitment of the Prefrontal Cortex and Hippocampus in the Three-Hit Model of Depression in Male PACAP Heterozygous Mice

Depression and its increasing prevalence challenge patients, the healthcare system, and the economy. We recently created a mouse model based on the three-hit concept of depression. As genetic predisposition (first hit), we applied pituitary adenylate cyclase-activating polypeptide heterozygous mice on CD1 background. Maternal deprivation modeled the epigenetic factor (second hit), and the chronic variable mild stress was the environmental factor (third hit). Fluoxetine treatment was applied to test the predictive validity of our model. We aimed to examine the dynamics of the epigenetic marker acetyl-lysine 9 H3 histone (H3K9ac) and the neuronal activity marker FOSB in the prefrontal cortex (PFC) and hippocampus. Fluoxetine decreased H3K9ac in PFC in non-deprived animals, but a history of maternal deprivation abolished the effect of stress and SSRI treatment on H3K9ac immunoreactivity. In the hippocampus, stress decreased, while SSRI increased H3K9ac immunosignal, unlike in the deprived mice, where the opposite effect was detected. FOSB in stress was stimulated by fluoxetine in the PFC, while it was inhibited in the hippocampus. The FOSB immunoreactivity was almost completely abolished in the hippocampus of the deprived mice. This study showed that FOSB and H3K9ac were modulated in a territory-specific manner by early life adversities and later life stress interacting with the effect of fluoxetine therapy supporting the reliability of our model.

Examining the epigenetic mechanisms of childhood adversity and sensitive periods: A gene set-based approach

BACKGROUND

Sensitive periods are developmental stages of heightened plasticity when life experiences, including exposure to childhood adversity, have the potential to exert more lasting impacts. Epigenetic mechanisms, including DNA methylation (DNAm), may provide a pathway through which adversity induces long-term biological changes. DNAm shifts may be more likely to occur during sensitive periods, especially within genes that regulate the timing of sensitive periods. Here, we investigated the possibility that childhood adversity during specific life stages is associated with DNAm changes in genes known to regulate the timing and duration of sensitive periods.

METHODS

Genome-wide DNAm profiles came from the Avon Longitudinal Study of Parents and Children (n = 785). We first used principal component analysis (PCA) to summarize DNAm variation across 530 CpG sites mapped to the promoters of 58 genes previously-identified as regulating sensitive periods. Gene-level DNAm summaries were calculated for genes regulating sensitive period opening (ngenes = 15), closing (ngenes = 36), and expression (ngenes = 8). We then performed linear discriminant analysis (LDA) to test associations between seven types of parent-reported, time-varying measures of exposure to childhood adversity and DNAm principal components. To our knowledge, this is the first time LDA has been applied to analyze functionally grouped DNAm data to characterize associations between an environmental exposure and epigenetic differences.

RESULTS

Suggestive evidence emerged for associations between sexual or physical abuse as well as financial hardship during middle childhood, and DNAm of genetic pathways regulating sensitive period opening and expression. However, no statistically significant associations were identified after multiple testing correction.

CONCLUSIONS

Our gene set-based method combining PCA and LDA complements epigenome-wide approaches. Although our results were largely null, these findings provide a proof-of-concept for studying time-varying exposures and gene- or pathway-level epigenetic modifications.

Sex differences on the response to antidepressants and psychobiotics following early life stress in rats

Major depressive disorder (MDD) is the most prevalent mood disorder globally. Most antidepressants available for the treatment of MDD increase the concentration of monoamines in the synaptic cleft. However, such drugs have a high latency time to obtain benefits. Thus, new antidepressants with fast action and robust efficacy are very important. This study evaluated the effects of escitalopram, ketamine, and probiotic Bifidobacterium infantis in rats submitted to the maternal deprivation (MD). MD rats received saline, escitalopram, ketamine, or probiotic for 10, 30, or 50 days, depending on the postnatal day (PND):21, 41, and 61. Following behavior, this study examined the integrity of the blood-brain barrier (BBB) and oxidative stress markers. MD induced depressive-like behavior in females with PND21 and males with PND61. All treatments reversed depressive-like behavior in females and escitalopram and ketamine in males. MD induced an increase in the permeability of the BBB, an imbalance between oxidative stress and antioxidant defenses. Treatments regulated the oxidative damage and the integrity of the BBB induced by MD. The treatment with escitalopram, ketamine, or probiotics may prevent behavioral and neurochemical changes associated with MDD, depending on the developmental period and gender.

Early life stress, systemic inflammation, and neural correlates of implicit emotion regulation in adolescents

Exposure to early life stress (ELS) increases the risk for developing psychopathology; however, the mechanisms underlying this association are not clear. In this study we examined systemic inflammation as a pathway that may link exposure to stress to altered neural correlates of implicit emotion regulation in adolescents with varying levels of exposure to ELS (n = 83; 52 females, 31 males; 15.63 ± 1.10 years). We measured ventrolateral prefrontal cortex (vlPFC) activation and functional connectivity (FC) between the bilateral amygdala and the vlPFC as adolescents completed an affect labeling task in the scanner and assessed concentrations of C-reactive protein (CRP) using a dried blood spot protocol. We found that CRP levels were negatively associated with vlPFC activation during implicit regulation of negatively-valenced stimuli, and that cumulative severity of ELS exposure moderated this neuroimmune association. Severity of ELS also significantly moderated the association between CRP levels and FC between the bilateral amygdala and l-vlPFC during implicit emotion regulation: in adolescents who had been exposed to more severe ELS, higher CRP was associated with more negative frontoamygdala FC during implicit regulation of negatively-valenced stimuli. Thus, ELS may disrupt the normative association between the immune system and the neural processes that underlie socioemotional functioning potentially increasing adolescents' risk for maladaptive outcomes.

Decreased functional coupling within default mode network in major depressive disorder with childhood trauma

OBJECTIVE

Childhood trauma (CT) has been supported to be a high-risk factor for major depressive disorder (MDD), but the neural mechanism linking CT and depression remains unclear. The aim of this study is to deepen our understanding of this issue by establishing the neuroimaging correlations between CT and depression.

METHODS

A sample of 123 MDD patients (91 with moderate-to-severe CT and 32 with no or low CT) and 79 healthy controls (HC, 33 with moderate-to-severe CT and 46 with no or low CT) participated. All participants completed assessments of depression level, anxiety, recent perceived stress, and resting-state functional MRI scan.

RESULTS

Participants with moderate-to-severe CT showed elevated depression level and trait anxiety, and reduced spontaneous neural activity in left inferior temporal gyrus (ITG). Abnormalities of seed-based functional connectivity (FC) of left ITG - bilateral precuneus/posterior cingulate cortex (PCC), left middle temporal gyrus (MTG), left medial orbitofrontal cortex (mOFC), and bilateral medial prefrontal cortex (mPFC)/anterior cingulate cortex (ACC) were observed. CT was associated with decreased FCs in MDD, but with increased FCs in HC. The total altered FCs of left ITG - bilateral precuneus/PCC and left mOFC mediated relationship between CT and depression in MDD, and total altered FCs and trait anxiety have a significant chain mediation effect in the association between CT and depression in HC.

CONCLUSION

These findings highlight the changes of default mode network (DMN) functions and trait anxiety as targets of CT. The decreased functional coupling within DMN may be involved in the mechanism of MDD following CT.

Fluoxetine treatment supports predictive validity of the three hit model of depression in male PACAP heterozygous mice and underpins the impact of early life adversity on therapeutic efficacy

According to the three hit concept of depression, interaction of genetic predisposition altered epigenetic programming and environmental stress factors contribute to the disease. Earlier we demonstrated the construct and face validity of our three hit concept-based mouse model. In the present work, we aimed to examine the predictive validity of our model, the third willnerian criterion. Fluoxetine treatment was applied in chronic variable mild stress (CVMS)-exposed (environmental hit) CD1 mice carrying one mutated allele of pituitary adenylate cyclase-activating polypeptide gene (genetic hit) that were previously exposed to maternal deprivation (epigenetic hit) vs. controls. Fluoxetine reduced the anxiety level in CVMS-exposed mice in marble burying test, and decreased the depression level in tail suspension test if mice were not deprived maternally. History of maternal deprivation caused fundamental functional-morphological changes in response to CVMS and fluoxetine treatment in the corticotropin-releasing hormone-producing cells of the bed nucleus of the stria terminalis and central amygdala, in tyrosine-hydroxylase content of ventral tegmental area, in urocortin 1-expressing cells of the centrally projecting Edinger-Westphal nucleus, and serotonergic cells of the dorsal raphe nucleus. The epigenetic background of alterations was approved by altered acetylation of histone H3. Our findings further support the validity of both the three hit concept and that of our animal model. Reversal of behavioral and functional-morphological anomalies by fluoxetine treatment supports the predictive validity of the model. This study highlights that early life stress does not only interact with the genetic and environmental factors, but has strong influence also on therapeutic efficacy.

Investigating the Effects of Maternal Separation on Hypothalamic-Pituitary-Adrenal Axis and Glucose Homeostasis under Chronic Social Defeat Stress in Young Adult Male Rat Offspring

INTRODUCTION

Given the suggested metabolic regulatory effects of stress-responsive genes and based on the impacts of early-life stress on HPA axis development, this study aimed to characterize the maternal separation (MS) impact on the communication between glucose metabolism and HPA axis dysregulations under chronic social defeat stress (CSDS).

METHODS

During the first 2 weeks of life, male Wistar rats were either exposed to MS or left undisturbed with their mothers (Std). Starting on postnatal day 50, the animals of each group were either left undisturbed in the standard group housing (Con) or underwent CSDS for 3 weeks. There were four groups (n = 10/group): Std-Con, MS-Con, Std-CSDS, and MS-CSDS.

RESULTS

Early and/or adult life adversity reduced β-cell number, muscular FK506-binding protein 51 (FKBP51) content, and BMI in adulthood. The reduction of β-cell number and BMI in the MS-CSDS rats were more profound than MS-Con group. CSDS either alone or in combination with MS reduced locomotor activity and increased and decreased corticotropin-releasing factor type 1 receptor (CRFR1) content, respectively, in hypothalamus and pancreas. Although, under CSDS, MS intensified HPA axis overactivity and reduced isolated islets' insulin secretion, it could promote resilience to depression symptoms. No differences were observed in hypothalamic Fkbp5 gene DNA methylation and glucose tolerance among groups.

CONCLUSION

MS exacerbated HPA axis overactivity and the endocrine pancreas dysfunctions under CSDS. The intensified corticosterone secretion and the diminished content of pancreatic CRFR1 protein could be involved in the reduced β-cell number and islets' insulin secretion under CSDS. The decreased muscular FKBP51 content might be a homeostatic response to slow down insulin resistance development under chronic stress.

Immediate impact of child maltreatment on mental, developmental, and physical health trajectories

OBJECTIVE

The immediate impact of child maltreatment on health and developmental trajectories over time is unknown. Longitudinal studies starting in the direct aftermath of exposure with repeated follow-up are needed.

METHOD

We assessed health and developmental outcomes in 6-month intervals over 2 years in 173 children, aged 3-5 years at study entry, including 86 children with exposure to emotional and physical abuse or neglect within 6 months and 87 nonmaltreated children. Assessments included clinician-administered, self- and parent-report measures of psychiatric and behavioral symptoms, development, and physical health. Linear mixed models and latent growth curve analyses were used to contrast trajectories between groups and to investigate the impact of maltreatment features on trajectories.

RESULTS

Maltreated children exhibited greater numbers of psychiatric diagnoses (b = 1.998, p < .001), externalizing (b = 13.29, p < .001) and internalizing (b = 11.70, p < .001) symptoms, impairments in cognitive (b = -11.586, p < .001), verbal (b = -10.687, p < .001), and motor development (b = -7.904, p = .006), and greater numbers of medical symptoms (b = 1.021, p < .001) compared to nonmaltreated children across all time-points. Lifetime maltreatment severity and/or age at earliest maltreatment exposure predicted adverse outcomes over time.

CONCLUSION

The profound, immediate, and stable impact of maltreatment on health and developmental trajectories supports a biological embedding model and provides foundation to scrutinize the precise underlying mechanisms. Such knowledge will enable the development of early risk markers and mechanism-driven interventions that mitigate adverse trajectories in maltreated children.

Chronic social instability stress down-regulates IL-10 and up-regulates CX3CR1 in tumor-bearing and non-tumor-bearing female mice

Extensive literature has reported a link between stress and tumor progression, and between both of these factors and mental health. Despite the higher incidence of affective disorders in females and the neurochemical differences according to sex, female populations have been understudied. The aim of this study was therefore to analyze the effect of stress on tumor development in female OF1 mice. For this purpose, subjects were inoculated with B16F10 melanoma cells and exposed to the Chronic Social Instability Stress (CSIS) model. Behavioral, neurochemical and neuroendocrine parameters were analyzed. Female mice exposed to CSIS exhibited reduced body weight and increased arousal, but there was no evidence of depressive behavior or anxiety. Exposure to CSIS did not affect either corticosterone levels or tumor development, although it did provoke an imbalance in cerebral inflammatory cytokines, decreasing IL-10 expression (IL-6/IL-10 and TNF-α/IL-10); chemokines, increasing CX3CR1 expression (CX3CL1/CX3CR1); and glucocorticoid receptors, decreasing GR expression (MR/GR). In contrast, tumor development did not alter body weight and, although it did alter behavior, it did so to a much lesser extent. Tumor inoculation did not affect corticosterone levels, but increased the MR/GR ratio in the hippocampus and provoked an imbalance in cerebral inflammatory cytokines and chemokines, although differently from stress. These results underscore the need for experimental approaches that allow us to take sex differences into account when exploring this issue, since these results appear to indicate that the female response to stress is mediated by mechanisms different from those often proposed in relation to male mice.

Neurocognitive functioning in adolescents with non-suicidal self-injury

BACKGROUND

Non-suicidal self-injury (NSSI) is a highly prevalent transdiagnostic psychiatric symptom in adolescents. Research in adults has begun to investigate neurocognitive processes associated with NSSI as potential underlying phenotypes. However, research on neurocognitive function in adolescent patients with NSSI is scarce.

METHODS

In this study, we examined neurocognitive functioning in the domains of processing speed, attention, learning, working memory, and executive function in a relatively large sample of n = 240 adolescent patients engaging in NSSI and n = 49 healthy controls. Further, associations between neurocognitive performance and clinical characteristics in the patient group were examined.

RESULTS

While conventional regression analyses showed somewhat weaker neurocognition in the NSSI group in several domains, propensity score matching for IQ showed little evidence that patients engaging in NSSI showed worse neurocognition when general intelligence was considered. Further, a random forest machine learning algorithm was not able to classify NSSI vs. control groups based on neurocognitive features. Within the patient group, linear regression and latent class analyses yielded little evidence that neurocognitive performance was related with clinical characteristics or phenotypes.

LIMITATIONS

As the study did not include a clinical control group, findings might not be specific to NSSI.

CONCLUSIONS

Our findings challenge the importance of specific neurocognitive measures related to the presence or severity of NSSI in adolescents. Future studies should consider general intelligence as an important confounding factor and should focus on domains of affective cognition. Finally, longitudinal studies are needed to determine whether low neurocognitive performance serves to inform prognosis of NSSI or psychopathology in general.

Rodent models of early adversity: Impacts on developing social behavior circuitry and clinical implications

Flexible and context-appropriate social functioning is key for survival across species. This flexibility also renders social behavior highly plastic, particularly during early development when attachment to caregiver can provide a template for future social processing. As a result, early caregiving adversity can have unique and lasting impacts on social behavior and even confer vulnerability to psychiatric disorders. However, the neural circuit mechanisms translating experience to outcome remain poorly understood. Here, we consider social behavior scaffolding through the lens of reward and threat processing. We begin by surveying several complementary rodent models of early adversity, which together have highlighted impacts on neural circuits processing social cues. We next explore these circuits underlying perturbed social functioning with focus on dopamine (DA) and its role in regions implicated in social and threat processing such as the prefrontal cortex (PFC), basolateral amygdala (BLA) and the lateral habenula (LHb). Finally, we turn to human populations once more to examine how altered DA signaling and LHb dysfunction may play a role in social anhedonia, a common feature in diagnoses such as schizophrenia and major depressive disorder (MDD). We argue that this translational focus is critical for identifying specific features of adversity that confer heightened vulnerability for clinical outcomes involving social cue processing.

Time Dimension of Childhood Adversities and Externalizing Behavior Among Children of Teen Mothers: Sensitive Period Hypothesis vs. Accumulation Hypothesis

Childhood adversities are associated with compromised behavioral health later in life. However, less attention has been paid to how time contributes to the damaging effects of adversity exposure. In addition, the differential impact of childhood maltreatment and household dysfunction has been understudied. The current study tested (a) the sensitive period hypothesis regarding timing of childhood adversity on externalizing behavior, (b) the accumulation hypothesis regarding the associations between the duration of childhood adversity and externalizing behavior, and (c) the domain-specific impact of childhood adversity on externalizing behavior. Data came from the Young Women and Child Development Study (N = 240). Childhood adversity was measured at seven periods (age range: 5.5-16), which were used to test the sensitive period hypothesis. Childhood adversity at each time period was summed across seven time periods to test the accumulation measure representing the duration of childhood adversity. Least angle and multiple regression analyses were conducted. Results supported the sensitive period hypothesis-the effect of childhood adversity was the most prominent at age 11.5, whereas the accumulation of childhood adversity time periods was not a significant predictor of later externalizing behavior. Probing childhood adversity by subdomains revealed maltreatment primarily accounted for externalizing behavior (p < .05). Findings suggest intervention efforts for children of teen mothers during early adolescence to prevent externalizing behavior in later adolescence. Unpacking childhood adversity may illuminate key areas of vulnerability to externalizing behavior.

Associations between lifetime stress exposure and the error-related negativity (ERN) differ based on stressor characteristics and exposure timing in young adults

Life stress increases risk for multiple forms of psychopathology, in part by altering neural processes involved in performance monitoring. However, the ways in which these stress-cognition effects are influenced by the specific timing and types of life stressors experienced remains poorly understood. To address this gap, we examined how different social-psychological characteristics and developmental timing of stressors are related to the error-related negativity (ERN), a negative-going deflection in the event-related potential (ERP) waveform that is observed from 0 to 100 ms following error commission. A sample of 203 emerging adults performed an ERN-eliciting arrow flanker task and completed an interview-based measure of lifetime stress exposure. Adjusting for stress severity during other developmental periods, there was a small-to-medium effect of stress on performance monitoring, such that more severe total stress exposure, as well as more severe social-evaluative stress in particular, experienced during early adolescence significantly predicted an enhanced ERN. These results suggest that early adolescence may be a sensitive developmental period during which stress exposure may result in lasting adaptations to neural networks implicated in performance monitoring.

The interaction of early life factors and depression-associated loci affecting the age at onset of the depression

Multiple previous studies explored the associations between early life factors and the age at onset of the depression. However, they only focused on the influence of environmental or genetic factors, without considering the interactions between them. Based on previous genome-wide association study (GWAS) data, we first calculated polygenic risk score (PRS) for depression. Regression analyses were conducted to assess the interacting effects of depression PRS and 5 early life factors, including felt hated by family member (N = 40,112), physically abused by family (N = 40,464), felt loved (N = 35633), and sexually molested (N = 41,595) in childhood and maternal smoking during pregnancy (N = 38,309), on the age at onset of the depression. Genome-wide environment interaction studies (GWEIS) were then performed to identify the genes interacting with early life factors for the age at onset of the depression. In regression analyses, we observed significant interacting effects of felt loved as a child and depression PRS on the age at onset of depression in total sample (β = 0.708, P = 5.03 × 10^-3) and males (β = 1.421, P = 7.64 × 10^-4). GWEIS identified a novel candidate loci interacting with felt loved as a child at GSAP (rs2068031, P = 4.24 × 10^-8) and detected several genes with suggestive significance association, such as CMYA5 (rs7343, P = 2.03 × 10^-6) and KIRREL3 (rs535603, P = 4.84 × 10^-6) in males. Our results indicate emotional care in childhood may affect the age at onset of depression, especially in males, and GSAP plays an important role in their interaction.

Brain-immune interaction mechanisms: Implications for cognitive dysfunction in psychiatric disorders

Objectives

Cognitive dysfunction has been identified as a major symptom of a series of psychiatric disorders. Multidisciplinary studies have shown that cognitive dysfunction is monitored by a two‐way interaction between the neural and immune systems. However, the specific mechanisms of cognitive dysfunction in immune response and brain immune remain unclear.

Materials and methods

In this review, we summarized the relevant research to uncover our comprehension of the brain–immune interaction mechanisms underlying cognitive decline.

Results

The pathophysiological mechanisms of brain‐immune interactions in psychiatric‐based cognitive dysfunction involve several specific immune molecules and their associated signaling pathways, impairments in neural and synaptic plasticity, and the potential neuro‐immunological mechanism of stress.

Conclusions

Therefore, this review may provide a better theoretical basis for integrative therapeutic considerations for psychiatric disorders associated with cognitive dysfunction.