Pathways to inflammation in adolescence through early adversity, childhood depressive symptoms, and body mass index: A prospective longitudinal study of Chilean infants

Inflammation and immune system pathways as biological signatures of adolescent depression-the IDEA-RiSCo study

The biological mechanisms underlying the onset of major depressive disorder (MDD) have predominantly been studied in adult populations from high-income countries, despite the onset of depression typically occurring in adolescence and the majority of the world's adolescents living in low- and middle-income countries (LMIC). Taking advantage of a unique adolescent sample in an LMIC (Brazil), this study aimed to identify biological pathways characterizing the presence and increased risk of depression in adolescence, and sex-specific differences in such biological signatures. We collected blood samples from a risk-stratified cohort of 150 Brazilian adolescents (aged 14-16 years old) comprising 50 adolescents with MDD, 50 adolescents at high risk of developing MDD but without current MDD, and 50 adolescents at low risk of developing MDD and without MDD (25 females and 25 males in each group). We conducted RNA-Seq and pathway analysis on whole blood. Inflammatory-related biological pathways, such as role of hypercytokinemia/hyperchemokinemia in the pathogenesis of influenza (z-score = 3.464, p < 0.001), interferon signaling (z-score = 2.464, p < 0.001), interferon alpha/beta signaling (z-score = 3.873, p < 0.001), and complement signaling (z-score = 2, p = 0.002) were upregulated in adolescents with MDD compared with adolescents without MDD independently from their level of risk. The up-regulation of such inflammation-related pathways was observed in females but not in males. Inflammatory-related pathways involved in the production of cytokines and in interferon and complement signaling were identified as key indicators of adolescent depression, and this effect was present only in females.

Inflammatory mediation of the relationship between early adversity and major depressive disorder: A systematic review

Early adverse experience is related to psychiatric illness that occurs decades later. The mechanisms underlying this phenomenon have not been fully identified. There is a translational and clinical literature linking early adversity with Major Depressive Disorder (MDD) and inflammation. We reviewed articles that examine whether inflammation mediates this relationship.

METHODS

Literature review of PUB MED, CINAHL and APA Psycinfo articles that explicitly examine inflammation as a mediator between early adversity and depression using ((((((((((adversity) OR (trauma)) OR (maltreatment)) OR (child abuse)) AND (inflammation)) OR (inflammatory cytokines)) OR (crp)) OR (il-6)) OR (tnf)) AND (mediates)) AND (depression))))))))) as key words.

RESULTS

2842 articles were initially identified. 1338 non-human studies were excluded and 512 more were filtered out as reviews. The remaining 992 titles and, when necessary, abstracts and manuscripts were reviewed and 956 were removed as being of other non-related phenomena. Four additional studies were added by hand searching the references of remaining studies. Out of these 40, 15 explicitly examined inflammation as a mediator of the relationship between early adversity and later depression. Approximately half (8/15) showed evidence that inflammation mediated the relationship between early adversity and depression. Sensitivity analyses showed that studies taking place in clinical populations, in youth and those that used the Adverse Childhood Events Scale to measure adversity, and IL-6 and TNF-α (as opposed to CRP) to measure inflammation were most likely to show mediation.

CONCLUSIONS

There is evidence to support the model of inflammation mediating the relationship between early adversity and depression. Certain measures in clinical populations appear more likely to support this model. Further study with more standardized, robust methods will help to answer this question more definitively and may elucidate a subtype of depression related to early adversity by alterations in immune function.

Does biological age mediate the relationship between childhood adversity and depression? Insights from the Detroit Neighborhood Health Study

The link between childhood adversity and adulthood depression is well-established; however, the underlying mechanisms are still being explored. Recent research suggests biological age may mediate the relationship between childhood adversity and depression in later life. This study examines if biological age mediates the relationship between childhood adversity and depression symptoms using an expanded set of biological age measures in an urban population-based cohort. Data from waves 1-3 of the Detroit Neighborhood Health Study (DNHS) were used in this analysis. Questions about abuse during childhood were coded to form a childhood adversity score similar to the Adverse Childhood Experience measure. Multiple dimensions of biological age, defined as latent variables, were considered, including systemic biological age (GrimAge, PhenoAge), epigenetic age (Horvath, SkinBlood), and immune age (cytomegalovirus, herpes simplex virus type 1, C-reactive protein, interleukin-6). Depression symptoms, modeled as a latent variable, were captured through the Patient Health Questionnaire-9 (PHQ-9). Models were adjusted for age, gender, race, parent education, and past depressive symptoms. Total and direct effects of childhood adversity on depression symptoms and indirect effects mediated by biological age were estimated. For total and direct effects, we observed a dose-dependent relationship between cumulative childhood adversity and depression symptoms, with emotional abuse being particularly influential. However, contrary to prior studies, in this sample, we found few direct effects of childhood adversity on biological age or biological age on depression symptoms and no evidence of mediation through the measures of biological age considered in this study. Further research is needed to understand how childhood maltreatment experiences are embodied to influence health and wellness.

Impact of social isolation during COVID-19 on anthropometric data, quality of life, baseline physical activity and aortic pulse wave parameters in children and adolescents in two independent samples

BACKGROUND

The social restrictions resulting from the COVID-19 pandemic had a great impact on the routine of children and adolescents, with important consequences such as sleep, eating, and psychological/psychiatric disorders. Even though there are no studies on the subject, it is possible that these changes in habit and routine have also affected arterial stiffness (AS) in this population, which is an important predictor of cardiovascular risk. This study aimed to assess possible changes in AS, anthropometry, and quality of life (QoL) resulting from the COVID-19 pandemic in children and adolescents.

METHODS

A controlled observational cross-sectional study was performed with 193 children and adolescents aged 9 to 19 years, allocated into two groups: before the pandemic (BPG) and one year after the pandemic (APG), matched by age and sex. Cardiovascular parameters were measured non-invasively by brachial artery oscillometry with a portable device. The main AS indices evaluated were the augmentation index (AIx) and pulse wave velocity (PWV) derived from the aortic pulse wave. QoL was assessed using the Paediatric Quality of Life Inventory version 4.0 (PedsQL 4.0).

RESULTS

Regarding QoL, the APG showed a worsening in emotional (p = 0.002) and school-related (p = 0.010) aspects. There was no statistically significant difference for most anthropometric parameters, except for the hip circumference, which was higher in the APG group (p < 0.001). The main predictor of AS in the paediatric population, AIx@75, was shown to be increased in the APG group (p < 0.001). Other cardiovascular parameters were also different, such as peripheral (p = 0.002) and central (p = 0.003) diastolic blood pressure, stroke volume (p = 0.010), and total vascular resistance (p = 0.002), which were shown to be decreased in the APG group, while the heart rate was increased (p < 0.001).

CONCLUSIONS

Our results show that routine changes resulting from the period of social isolation increased cardiovascular risk in children and adolescents, evident by the increase in AIx@75, which is considered to be an important marker of cardiovascular risk in the paediatric population.

The potential of intervening on childhood adversity to reduce socioeconomic inequities in body mass index and inflammation among Australian and UK children: A causal mediation analysis

BACKGROUND

Lower maternal education is associated with higher body mass index (BMI) and higher chronic inflammation in offspring. Childhood adversity potentially mediates these associations. We examined the extent to which addressing childhood adversity could reduce socioeconomic inequities in these outcomes.

METHODS

We analysed data from two early-life longitudinal cohorts: the Longitudinal Study of Australian Children (LSAC; n=1873) and the UK Avon Longitudinal Study of Parents and Children (ALSPAC; n=7085).

EXPOSURE

low/medium (below university degree) versus high maternal education, as a key indicator of family socioeconomic position (0-1 year).

OUTCOMES

BMI and log-transformed glycoprotein acetyls (GlycA) (LSAC: 11-12 years; ALSPAC: 15.5 years). Mediator: multiple adversities (≥2/<2) indicated by family violence, mental illness, substance abuse and harsh parenting (LSAC: 2-11 years; ALSPAC: 1-12 years). A causal mediation analysis was conducted.

RESULTS

Low/medium maternal education was associated with up to 1.03 kg/m2 higher BMI (95% CI: 0.95 to 1.10) and up to 1.69% higher GlycA (95% CI: 1.68 to 1.71) compared with high maternal education, adjusting for confounders. Causal mediation analysis estimated that decreasing the levels of multiple adversities in children with low/medium maternal education to be like their high maternal education peers could reduce BMI inequalities by up to 1.8% and up to 3.3% in GlycA.

CONCLUSIONS

Our findings in both cohorts suggest that slight reductions in socioeconomic inequities in children's BMI and inflammation could be achieved by addressing childhood adversities. Public health and social policy efforts should help those affected by childhood adversity, but also consider underlying socioeconomic conditions that drive health inequities.

Neuroprotection in metabolic syndrome by environmental enrichment. A lifespan perspective

Metabolic syndrome (MetS) is defined by the concurrence of different metabolic conditions: obesity, hypertension, dyslipidemia, and hyperglycemia. Its incidence has been increasingly rising over the past decades and has become a global health problem. MetS has deleterious consequences on the central nervous system (CNS) and neurological development. MetS can last several years or be lifelong, affecting the CNS in different ways and treatments can help manage condition, though there is no known cure. The early childhood years are extremely important in neurodevelopment, which extends beyond, encompassing a lifetime. Neuroplastic changes take place all life through - childhood, adolescence, adulthood, and old age - are highly sensitive to environmental input. Environmental factors have an important role in the etiopathogenesis and treatment of MetS, so environmental enrichment (EE) stands as a promising non-invasive therapeutic approach. While the EE paradigm has been designed for animal housing, its principles can be and actually are applied in cognitive, sensory, social, and physical stimulation programs for humans. Here, we briefly review the central milestones in neurodevelopment at each life stage, along with the research studies carried out on how MetS affects neurodevelopment at each life stage and the contributions that EE models can provide to improve health over the lifespan.

How can early life adversity still exert an effect decades later? A question of timing, tissues and mechanisms

Exposure to any number of stressors during the first 1000 days from conception to age 2 years is important in shaping an individual's life trajectory of health and disease. Despite the expanding range of stressors as well as later-life phenotypes and outcomes, the underlying molecular mechanisms remain unclear. Our previous data strongly suggests that early-life exposure to a stressor reduces the capacity of the immune system to generate subsequent generations of naïve cells, while others have shown that, early life stress impairs the capacity of neuronal stem cells to proliferate as they age. This leads us to the "stem cell hypothesis" whereby exposure to adversity during a sensitive period acts through a common mechanism in all the cell types by programming the tissue resident progenitor cells. Furthermore, we review the mechanistic differences observed in fully differentiated cells and suggest that early life adversity (ELA) may alter mitochondria in stem cells. This may consequently alter the destiny of these cells, producing the lifelong "supply" of functionally altered fully differentiated cells.

The association between victimization and inflammation: A meta-analysis

BACKGROUND

To meta-analyze the existing studies examining the association of childhood and adulthood victimization with inflammation and to explore the moderating variables that affect these relationships.

METHODS

Relevant work published before 28th February 2021 was identified by searching five major databases. We analyzed the cross-sectional data extracted from cross-sectional and longitudinal studies using the random-effects model to estimate the correlation (r) as the pooled effect size and further conducted subgroup analyses and sensitivity analyses.

RESULTS

A total of 37 articles finally met the inclusion criteria, including studies for C-reactive protein (CRP) (k = 23; N_CRP = 11,780), interleukin-6 (IL-6) (k = 31; N_IL-6 = 8943), and tumor necrosis factor-alpha (TNF-α) (k = 14; N_TNF-α = 4125). Overall, victimization has a significantly positive association with inflammation, with a small effect size (r = 0.122). Specifically, effect sizes were the largest for TNF-a (r = 0.152), followed by IL-6 (r = 0.119), and CRP (r = 0.084). Additionally, the effect sizes for victimization against children were r = 0.145 (k = 6) for childhood victimization - childhood inflammation, and r = 0.139 (k = 27) for childhood victimization - adulthood inflammation, which appear to be larger than that of victimization against adults (r = 0.039; k = 2).

LIMITATIONS

Only a small number of studies on adult victimization were included. In addition, we only analyzed the cross-sectional relationship and did not have sufficient data to compare different types of victimization and single vs. multiple victimizations.

CONCLUSIONS

Victimization is associated with a heightened inflammatory response. As victimization against children may have a stronger effect than victimization against adults, prevention of victimization targeting the childhood period may be necessary. Studies with more robust methodologies (i.e., representative, longitudinal, and multi-country designs) are needed to confirm these findings and to unpack the underlying mechanisms.

Low-Grade Inflammation and Role of Anti-Inflammatory Diet in Childhood Obesity

At present, pediatric obesity is a significant public health concern. We have seen a surge of disorders that are obesity-related, e.g., insulin resistance (IR), type 2 diabetes mellitus (T2DM), high blood pressure, heart disease, stroke, cancer, non-alcoholic fatty liver disease (NAFLD), autoimmune disorders and many more. The mechanisms linking these diseases to excess body weight are related to low-grade inflammation (LGI). Although there is a limited number of studies assessing this immune process in childhood obesity, they indicate its significant importance for the health of future generations. There is a need for more research into the prevention and treatment of low-grade inflammation in childhood. The aim of this review is to present and discuss the process of "cold" inflammation, and its impact on health and anti-inflammation nutrition. A diet rich in anti-inflammatory nutrients may be the key to maintaining health, as well as recovery.

Cytokine alterations in pediatric internalizing disorders: Systematic review and exploratory multi-variate meta-analysis

Pediatric internalizing disorders are prevalent and characterized by a maladaptive cognitive, emotional response to a perceived stressor. The hypothesized effect of this response is observable changes in behavior mediated by homeostatic inflammatory cytokines. The aim of this study was to synthesize the literature and analyze the effect of cytokines on pediatric internalizing disorders. Influential moderating variables, including mean body mass index, fasting status at blood collection, participant sex, cytokine type, mean age, percentage of sample medicated, and diagnosis, were also assessed. A systematic literature search was performed in electronic databases (Medline, PubMed, and PsycINFO) from January 1, 1980 to June 15, 2022. Case-control studies of pediatric internalizing disorders, specifically anxiety and depression, were reviewed for their association with peripheral cytokine levels. Meta-analyses were performed using a random effects multi-variate model and effect sizes were calculated using Hedge's g for IL-2, CRP, IL-6, TNF-α, IL-1β, IFN-γ, and IL-10. Thirty-three studies were reviewed and 28 studies were included in the meta-analysis (n = 1322 cases and n = 3617 controls). Peripheral cytokine levels were elevated in pediatric internalizing disorders compared to controls (Hedge's g = 0.19, p < 0.001). In the moderator analyses, depression diagnosis (Hedge's g = 0.18, p = 0.009) and non-fasting blood collection (Hedge's g = 0.20, p = 0.006) were significant. The meta-analytic findings are limited by methodological variation between studies, high heterogeneity, and low statistical power. Despite this, the findings suggest that elevated peripheral cytokine levels may play a role in the etiology and/or symptom maintenance of pediatric internalizing disorders.

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Depression diagnosis and non-fasting blood collection were observed to significantly influenced peripheral cytokine levels.

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No individual peripheral cytokines tested were associated with pediatric internalizing disorders.

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Overall, elevated peripheral cytokines were observed in pediatric internalizing disorders compared to controls.

Adverse childhood experiences, bullying, inflammation and BMI in 10-year-old children: The biological embodiment

Exposure to adversity during the first years of life might already be biologically embedded well before adult life. Thus, the impact of different stressful experiences needs to be explored. This study aims to examine if the association between being victimized (adverse childhood experiences—ACEs and bullying) and (hs-) C-Reactive Protein (CRP) is explained by the influence of adversity on the body mass index (BMI) of the child. We included children from the Portuguese birth cohort Generation XXI (n = 3712) that at 10 years of age completed a questionnaire on the exposure to ACEs and bullying victimization, assessed by an adaptation from the original ACEs study and an adaptation of The Bully Scale Survey, respectively. Following an overnight fast, a venous blood sample was collected by trained nurses and hs-CRP was assayed in fresh blood samples. Weight and height were measured with the child in underwear and bare feet. Weight was measured to the nearest one-tenth of a kilogram with the use of a digital scale (Tanita), and height was measured to the nearest one-tenth of a centimetre with the use of a wall stadiometer (seca®). BMI was calculated as the value of weight (kg) over squared height (m), and computed as an age- and sex-specific BMI standard deviation (SD) score (z-score), according to the World Health Organization Child Growth Standards (5–19 years). Regression coefficients and respective 95% Confidence Interval [β(95%CI)] were computed using path analysis. We observed that ACEs had a positive total effect on hs-CRP at the age of 10 years (β = 0.06; 95%CI: -0.02; 0.15). A direct effect (β = 0.02; 95%CI: -0.01; 0.06) accounted for 66.1% of the association between ACEs and hs-CRP. A positive total effect of bullying victimization on hs-CRP (β = 0.20; 95%CI: 0.06; 0.34) was observed. A direct effect (β = 0.08; 95%CI: -0.05; 0.21) accounted for 40.0% of the association, while an indirect effect through BMI (β = 0.12; 95%CI: 0.06; 0.18) explained 60.0% of the pathway between bullying victimization and hs-CRP. Results suggest that there might be different mechanisms involved in the biological embedding of childhood experiences. BMI seems to explain a great part of the association between exposure to bullying victimization and hs-CRP at 10 years of age. Further research is still needed to better understand the mechanisms explaining the emergence and persistence of health poorer outcomes later in life for victims of abuse.

Multiple events case-control study in a prospective cohort to identify systemic, cellular, and molecular biomarkers of obesity-induced accelerated aging in 30-years-olds: the ObAGE study protocol

Background

Aging is characterized by a progressive loss of capacities linked to fundamental alterations/damage in multiple cellular and molecular pathways. It is the most significant risk factor for all non-communicable diseases (NCDs). Another contributing factor to the rise in NCDs is obesity. It has been suggested that obesity not only accelerates the onset of metabolic imbalances but also decreases lifespan and impacts cellular and molecular processes in a manner similar to aging. Obesity might accelerate the pace of aging. Guided by a lifecourse approach, we will explore how exposure to obesity in critical developmental stages disrupt homeostatic resilience mechanisms that preserve physiological integrity, inducing an early expression of aging phenotypes. Also, we will determine whether exposure to early psychosocial adversity influences vulnerability to obesity as a risk factor for accelerated aging.

Methods

Multiple events case–control study embedded in a prospective cohort of Chileans at 30-31y, 50% females, of low- to-middle socioeconomic status, who participated in nutrition research since birth. At 23y, 25% had obesity and cardiometabolic risk was high. We will use a multi-layer approach including: anthropometric assessment; DXA scan for body composition; abdominal ultrasound of the liver; stool samples collection and sequencing of the ribosomal RNA 16S gene to characterize the gut microbiome; determination of age-related pro-inflammatory cytokynes and anti-inflammatory miokynes. For the first time in Chile, we will address age-related epigenetic changes using the Horvath´s epigenetic clock. In a subset we will conduct a controlled physical challenge to characterize physical resilience (autophagy).

Discussion

ObAGE is in an excellent position to: approach aging as a process whose expression involves multiple factors from the early stages of a person's life; understand how longitudinal changes in health trajectories impact the biological mechanisms of aging; identify potential resilience mechanisms that help prevent unhealthy aging. Because SLS participants are still young, our research setting combined with advanced scientific techniques may identify individuals or groups at risk of early onset health issues. Results from ObAGE may pave the way to address the contribution of obesity to aging through lifespan from cells to systems and might be instrumental to developing interventions to improve health span in the Chilean population.

Trial registration

The proposed study does not consider any health care intervention on human participants.

Inflammation and depression in young people: a systematic review and proposed inflammatory pathways

Depression onset peaks during adolescence and young adulthood. Current treatments are only moderately effective, driving the search for novel pathophysiological mechanisms underlying youth depression. Inflammatory dysregulation has been shown in adults with depression, however, less is known about inflammation in youth depression. This systematic review identified 109 studies examining the association between inflammation and youth depression and showed subtle evidence for inflammatory dysregulation in youth depression. Longitudinal studies support the bidirectional association between inflammation and depression in youth. We hypothesise multiple inflammatory pathways contributing to depression. More research is needed on anti-inflammatory treatments, potentially tailored to individual symptom profiles.

Prefrontal cortex VAMP1 gene network moderates the effect of the early environment on cognitive flexibility in children

During development, genetic and environmental factors interact to modify specific phenotypes. Both in humans and in animal models, early adversities influence cognitive flexibility, an important brain function related to behavioral adaptation to variations in the environment. Abnormalities in cognitive functions are related to changes in synaptic connectivity in the prefrontal cortex (PFC), and altered levels of synaptic proteins. We investigated if individual variations in the expression of a network of genes co-expressed with the synaptic protein VAMP1 in the prefrontal cortex moderate the effect of early environmental quality on the performance of children in cognitive flexibility tasks. Genes overexpressed in early childhood and co-expressed with the VAMP1 gene in the PFC were selected for study. SNPs from these genes (post-clumping) were compiled in an expression-based polygenic score (PFC-ePRS-VAMP1). We evaluated cognitive performance of the 4 years-old children in two cohorts using similar cognitive flexibility tasks. In the first cohort (MAVAN) we utilized two CANTAB tasks: (a) the Intra-/Extra-dimensional Set Shift (IED) task, and (b) the Spatial Working Memory (SWM) task. In the second cohort, GUSTO, we used the Dimensional Change Card Sort (DCCS) task. The results show that in 4 years-old children, the PFC-ePRS-VAMP1 network moderates responsiveness to the effects of early adversities on the performance in attentional flexibility tests. The same result was observed for a spatial working memory task. Compared to attentional flexibility, reversal learning showed opposite effects of the environment, as moderated by the ePRS. A parallel ICA analysis was performed to identify relationships between whole-brain voxel based gray matter density and SNPs that comprise the PFC-ePRS-VAMP1. The early environment predicts differences in gray matter content in regions such as prefrontal and temporal cortices, significantly associated with a genetic component related to Wnt signaling pathways. Our data suggest that a network of genes co-expressed with VAMP1 in the PFC moderates the influence of early environment on cognitive function in children.

Annual Research Review: Social relationships and the immune system during development

A child's social relationships serve critical functions during development. The interface between a child's social world and their immune system, particularly innate immunity, which helped children survive in the face of infections, nutritional scarcity, and violence throughout human history, is the focus of this Annual Research Review. This article reviews the state of research on social relationships and innate immune inflammation during childhood. Warmth and rejection in childhood social relationships, as well as physical trauma and unpredictable social environments, were not consistently related to circulating inflammatory markers such as interleukin-6 and C-reactive protein during childhood. Instead, links between social environments and inflammation were observed in studies that focus on children with greater background risk factors, such as low family socioeconomic status, family history of mood disorders, or presence of chronic interpersonal stressors combined with acute episodic stressors. In addition, studies on worse childhood social environments and greater inflammation in adulthood were more consistent. Warmth and rejection in the social environment may be related to sensitivity of immune cells to the anti-inflammatory actions of glucocorticoids, though this is primarily observed in adolescent women at risk for depression. Additional mechanistic evidence suggests that greater warmth and less rejection are related to processes that regulate inflammation, including greater expression of the glucocorticoid receptor gene and lower expression of genes that are responsive to the pro-inflammatory transcription factor NF-kappa B. The article concludes by discussing implications of the interface between a child's social relationships and inflammation for mental health and other recent (on evolutionary timescales) health threats, as well as recommendations for future research, and recommendations for researchers interested in integrating inflammatory measures in developmental research.

Selective inflammatory propensities in adopted adolescents institutionalized as infants

This study examined whether early life adversity (ELA) limited to infancy was associated with an increase in circulating levels of proinflammatory cytokines and cellular cytokine responses to three stimulants [lipopolysaccharide (LPS), phytohemagglutinin (PHA), and phorbol myristate acetate plus ionomycin (PMA/IO)]. Participants were previously institutionalized (PI) youth (N = 45, 56 % female) who had spent their first years in institutional care (e.g., orphanages, baby homes) before being adopted into well-resourced homes (median age at adoption = 13 mos) and non-adopted comparisons (NA; N = 38, 55 % female). Their age range was 13.3-21.2 years (M = 16.3 years). This analysis followed up an earlier report on these youth (Reid et al., 2019a) that identified an increase in terminally differentiated CD8 + CD57 T cells among the PI relative to the NA youth. Cytokine levels in circulation were not highly correlated and thus examined separately. PI youth had higher circulating levels of Tumor Necrosis Factor-alpha (TNFα), but not Interleukin-1β (IL-1β) or Interleukin-6 (IL-6). Cytokine responses to in vitro activation within each stimulant condition were highly correlated and were thus combined to generate an index of the inflammatory reaction to each stimulant. Using Multivariate Analysis of Covariance, there was a highly significant multivariate effect of group, which was carried primarily by the PMA/IO condition, with PI youth exhibiting a larger inflammatory response than NA youth. Tests of mediation showed that both the early rearing effects on circulating TNFα and the composite inflammatory index of PMA/IO responsiveness were mediated in the statistical model by the percentage of CD8 + CD57+ TEMRA cells in circulation, a marker of replicative senescence in T cells. Sex differences were also found in circulating levels of IL-6 and TNFα, with males having higher levels than females.

Challenges in researching the immune pathways between early life adversity and psychopathology

Exposure to childhood adversity is a critical risk factor for the development of psychopathology. A growing field of research examines how exposure to childhood adversity is translated into biological risk for psychopathology through alterations in immune system functioning, most notably heightened levels of inflammation biomarkers. Though our knowledge about how childhood adversity can instantiate biological risk for psychopathology is growing, there remain many challenges and gaps in the field to understand how inflammation from childhood adversity contributes to psychopathology. This paper reviews research on the inflammatory outcomes arising from childhood adversity and presents four major challenges that future research must address: (a) the measurement of childhood adversity, (b) the measurement of inflammation, (c) the identification of mediators between childhood adversity and inflammation, and (d) the identification of moderators of inflammatory outcomes following childhood adversity. We discuss synergies and inconsistencies in the literature to summarize the current understanding of the association between childhood adversity, a proinflammatory phenotype, and the biological risk for psychopathology. We discuss the clinical implications of the inflammatory links between childhood adversity and psychopathology, including possibilities for intervention. Finally, this review conclude by delineates future directions for research, including issues of how best to detect, prevent, and understand these “hidden wounds” of childhood adversity.

Risky emotional family environment in childhood and depression-related cytokines in adulthood: The protective role of compassion

BACKGROUND

Previously, compassion has been found to protect against depressive symptoms, while emotional adversities in childhood are suggested to increase inflammatory responses. The current study investigated (a) whether emotional family environment in childhood predicts levels of such cytokines in adulthood that are previously found to be elevated in depression (interleukin [IL]-2, IL-6, IL-1b, monocyte chemoattractant protein-1, interferon-gamma [IFN-γ], and tumor necrosis factor alpha [TNF-α]) and (b) whether these associations are modified by compassion in adulthood.

METHODS

The participants (N = 1,198-1,523) came from the prospective population-based Young Finns data. Emotional family environment and parental socioeconomic factors were evaluated in 1980; participants' compassion in 2001; and participants' cytokine levels and adulthood covariates in 2007.

RESULTS

Risky emotional family environment in childhood predicted higher levels of IL-2, IL-6, IFN-γ, and TNF-α in adulthood. Additionally, there were significant interaction effects between compassion and emotional risk in childhood, when predicting IL-2, IL-6, and TNF-α. Specifically, individuals who grew up in a risky emotional family environment had on average higher levels of IL-2, IL-6, and TNF-α in adulthood when combined with low compassion.

CONCLUSIONS

In individuals coming from risky emotional family environments, high compassion for others may protect against elevated levels of cytokines previously linked with depression.

Endothelial dysfunction in neuroprogressive disorders-causes and suggested treatments

BACKGROUND

Potential routes whereby systemic inflammation, oxidative stress and mitochondrial dysfunction may drive the development of endothelial dysfunction and atherosclerosis, even in an environment of low cholesterol, are examined.

MAIN TEXT

Key molecular players involved in the regulation of endothelial cell function are described, including PECAM-1, VE-cadherin, VEGFRs, SFK, Rho GEF TRIO, RAC-1, ITAM, SHP-2, MAPK/ERK, STAT-3, NF-κB, PI3K/AKT, eNOS, nitric oxide, miRNAs, KLF-4 and KLF-2. The key roles of platelet activation, xanthene oxidase and myeloperoxidase in the genesis of endothelial cell dysfunction and activation are detailed. The following roles of circulating reactive oxygen species (ROS), reactive nitrogen species and pro-inflammatory cytokines in the development of endothelial cell dysfunction are then described: paracrine signalling by circulating hydrogen peroxide, inhibition of eNOS and increased levels of mitochondrial ROS, including compromised mitochondrial dynamics, loss of calcium ion homeostasis and inactivation of SIRT-1-mediated signalling pathways. Next, loss of cellular redox homeostasis is considered, including further aspects of the roles of hydrogen peroxide signalling, the pathological consequences of elevated NF-κB, compromised S-nitrosylation and the development of hypernitrosylation and increased transcription of atherogenic miRNAs. These molecular aspects are then applied to neuroprogressive disorders by considering the following potential generators of endothelial dysfunction and activation in major depressive disorder, bipolar disorder and schizophrenia: NF-κB; platelet activation; atherogenic miRs; myeloperoxidase; xanthene oxidase and uric acid; and inflammation, oxidative stress, nitrosative stress and mitochondrial dysfunction.

CONCLUSIONS

Finally, on the basis of the above molecular mechanisms, details are given of potential treatment options for mitigating endothelial cell dysfunction and activation in neuroprogressive disorders.

Social Safety Theory: A Biologically Based Evolutionary Perspective on Life Stress, Health, and Behavior

Social Safety Theory hypothesizes that developing and maintaining friendly social bonds is a fundamental organizing principle of human behavior and that threats to social safety are a critical feature of psychological stressors that increase risk for disease. Central to this formulation is the fact that the human brain and immune system are principally designed to keep the body biologically safe, which they do by continually monitoring and responding to social, physical, and microbial threats in the environment. Because situations involving social conflict, isolation, devaluation, rejection, and exclusion historically increased risk for physical injury and infection, anticipatory neural-immune reactivity to social threat was likely highly conserved. This neurocognitive and immunologic ability for humans to symbolically represent and respond to potentially dangerous social situations is ultimately critical for survival. When sustained, however, this multilevel biological threat response can increase individuals' risk for viral infections and several inflammation-related disease conditions that dominate present-day morbidity and mortality.

Youth Depression Alleviation with Anti-inflammatory Agents (YoDA-A): a randomised clinical trial of rosuvastatin and aspirin

BACKGROUND

Inflammation contributes to the pathophysiology of major depressive disorder (MDD), and anti-inflammatory strategies might therefore have therapeutic potential. This trial aimed to determine whether adjunctive aspirin or rosuvastatin, compared with placebo, reduced depressive symptoms in young people (15-25 years).

METHODS

YoDA-A, Youth Depression Alleviation with Anti-inflammatory Agents, was a 12-week triple-blind, randomised, controlled trial. Participants were young people (aged 15-25 years) with moderate to severe MDD (MADRS mean at baseline 32.5 ± 6.0; N = 130; age 20.2 ± 2.6; 60% female), recruited between June 2013 and June 2017 across six sites in Victoria, Australia. In addition to treatment as usual, participants were randomised to receive aspirin (n = 40), rosuvastatin (n = 48), or placebo (n = 42), with assessments at baseline and weeks 4, 8, 12, and 26. The primary outcome was change in the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to week 12.

RESULTS

At the a priori primary endpoint of MADRS differential change from baseline at week 12, there was no significant difference between aspirin and placebo (1.9, 95% CI (- 2.8, 6.6), p = 0.433), or rosuvastatin and placebo (- 4.2, 95% CI (- 9.1, 0.6), p = 0.089). For rosuvastatin, secondary outcomes on self-rated depression and global impression, quality of life, functioning, and mania were not significantly different from placebo. Aspirin was inferior to placebo on the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q-SF) at week 12. Statins were superior to aspirin on the MADRS, the Clinical Global Impressions Severity Scale (CGI-S), and the Negative Problem Orientation Questionnaire scale (NPOQ) at week 12.

CONCLUSIONS

The addition of either aspirin or rosuvastatin did not to confer any beneficial effect over and above routine treatment for depression in young people. Exploratory comparisons of secondary outcomes provide limited support for a potential therapeutic role for adjunctive rosuvastatin, but not for aspirin, in youth depression.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12613000112763. Registered on 30/01/2013.