Biological embedding of stress through inflammation processes in childhood

Retrospectively reported childhood physical abuse, systemic inflammation, and resting corticolimbic connectivity in midlife adults

Childhood abuse confers risk for psychopathology and pathophysiology in midlife through intermediate pathways that remain unclear. Systemic inflammation was tested in the present study as one pathway that may link physical abuse in childhood to the adult functioning of corticolimbic brain circuits broadly implicated in risk for poor mental and physical health. Midlife adults (N = 303; 30-51 years of age; 149 women) without psychiatric, immune, or cardiovascular diagnoses provided retrospective reports of childhood physical abuse. Functional connectivity between corticolimbic brain areas (amygdala, hippocampus, ventromedial prefrontal cortex [vmPFC], anterior cingulate cortex [ACC]) was measured at rest using functional magnetic resonance imaging. Circulating levels of interleukin(IL)-6, a pro-inflammatory cytokine previously linked to childhood abuse and corticolimbic functionality, were measured via blood draw. Consistent with prior studies, retrospectively reported childhood physical abuse was associated positively with circulating IL-6, and negatively with connectivity between the amygdala and vmPFC. IL-6 was also associated negatively with several corticolimbic functional connections, including amygdala-vmPFC connectivity. Moreover, path analyses revealed an indirect effect of IL-6 that partially explained the association between childhood physical abuse and adult amygdala-vmPFC connectivity. Consistent with recent neurobiological models of early life influences on disease risk across the lifespan, associations between childhood physical abuse and adulthood corticolimbic circuit functionality may be partially explained by inflammatory processes.

Stress related disorders and subsequent risk of life threatening infections: population based sibling controlled cohort study

OBJECTIVE

To assess whether severe psychiatric reactions to trauma and other adversities are associated with subsequent risk of life threatening infections.

DESIGN

Population and sibling matched cohort study.

SETTING

Swedish population.

PARTICIPANTS

144 919 individuals with stress related disorders (post-traumatic stress disorder (PTSD), acute stress reaction, adjustment disorder, and other stress reactions) identified from 1987 to 2013 compared with 184 612 full siblings of individuals with a diagnosed stress related disorder and 1 449 190 matched individuals without such a diagnosis from the general population.

MAIN OUTCOME MEASURES

A first inpatient or outpatient visit with a primary diagnosis of severe infections with high mortality rates (ie, sepsis, endocarditis, and meningitis or other central nervous system infections) from the Swedish National Patient Register, and deaths from these infections or infections of any origin from the Cause of Death Register. After controlling for multiple confounders, Cox models were used to estimate hazard ratios of these life threatening infections.

RESULTS

The average age at diagnosis of a stress related disorder was 37 years (55 541, 38.3% men). During a mean follow-up of eight years, the incidence of life threatening infections per 1000 person years was 2.9 in individuals with a stress related disorder, 1.7 in siblings without a diagnosis, and 1.3 in matched individuals without a diagnosis. Compared with full siblings without a diagnosis of a stress related disorder, individuals with such a diagnosis were at increased risk of life threatening infections (hazard ratio for any stress related disorder was 1.47 (95% confidence intervals1.37 to 1.58) and for PTSD was 1.92 (1.46 to 2.52)). Corresponding estimates in the population based analysis were similar (1.58 (1.51 to 1.65) for any stress related disorder, P=0.09 for difference between sibling and population based comparison, and 1.95 (1.66 to 2.28) for PTSD, P=0.92 for difference). Stress related disorders were associated with all studied life threatening infections, with the highest relative risk observed for meningitis (sibling based analysis 1.63 (1.23 to 2.16)) and endocarditis (1.57 (1.08 to 2.30)). Younger age at diagnosis of a stress related disorder and the presence of psychiatric comorbidity, especially substance use disorders, were associated with higher hazard ratios, whereas use of selective serotonin reuptake inhibitors in the first year after diagnosis of a stress related disorder was associated with attenuated hazard ratios.

CONCLUSION

In the Swedish population, stress related disorders were associated with a subsequent risk of life threatening infections, after controlling for familial background and physical or psychiatric comorbidities.

Adverse childhood experiences and neuroinflammatory biomarkers-The role of sex

Despite the growing interest in adverse childhood experiences and biomarkers, less attention has been paid to multiple biomarkers as representing interrelated systems among college students. Guided by the neuroinflammatory pathway hypothesis, the current project takes the initial step in examining the link between three types of childhood adversity and biomarkers of neuroplasticity (brain-derived neurotropic factor [BDNF]) and low-grade inflammation (C-reactive protein [CRP]) in an overarching model and whether this link may differ in men and women. Undergraduate students (n = 85) were recruited through multiple departments from a state university. The participants responded to the detailed online survey questionnaire on childhood adversity and provided one blood sample via venous blood draw. Given that CRP and BDNF represent two interrelated systems, structural equation models were considered the most suitable for the analyses. The findings partially support neural and inflammatory pathways, such that childhood adversity and particularly family dysfunction have a significant positive effect on BDNF (b = 30.41, p < .01). The link between family dysfunction and CRP was stronger in female students (b = 0.57, p < .05). Results suggest that interventions for college students with family dysfunctions may need to target different physiological and behavioral outcomes for male and female students.

Pathways between early-life adversity and adolescent self-harm: the mediating role of inflammation in the Avon Longitudinal Study of Parents and Children

BACKGROUND

Adverse childhood experiences (ACEs) such as physical and emotional abuse are strongly associated with self-harm, but mechanisms underlying this relationship are unclear. Inflammation has been linked to both the experience of ACEs and self-harm or suicide in prior research. This is the first study to examine whether inflammatory markers mediate the association between exposure to ACEs and self-harm.

METHODS

Participants were 4,308 young people from the Avon Longitudinal Study of Parents and Children (ALSPAC), a population-based birth cohort in the United Kingdom. A structural equation modelling approach was used to fit a mediation model with the number of ACEs experienced between ages 0 and 9 years old (yo), levels of the inflammatory markers interleukin-6 and C-reactive protein measured at 9.5 yo, and self-harm reported at 16 yo.

RESULTS

The mean number of ACEs young people experienced was 1.41 (SE 0.03). Higher ACE scores were associated with an increased risk of self-harm at 16 yo (direct effect relative risk (RR) per additional ACE 1.11, 95% CI 1.05, 1.18, p < 0.001). We did not find evidence of an indirect effect of ACEs on self-harm via inflammation (RR 1.00, 95% CI 1.00, 1.01, p = 0.38).

CONCLUSIONS

Young people who have been exposed to ACEs are a group at high risk of self-harm. The association between ACEs and self-harm does not appear to be mediated by an inflammatory process in childhood, as indexed by peripheral levels of circulating inflammatory markers measured in childhood. Further research is needed to identify alternative psychological and biological mechanisms underlying this relationship.

Intergenerational transmission of depression: clinical observations and molecular mechanisms

Maternal mental illness can have a devastating effect during the perinatal period, and has a profound impact on the care that the baby receives and on the relationships that the baby forms. This review summarises clinical evidence showing the effects of perinatal depression on offspring physical and behavioural development, and on the transmission of psychopathology between generations. We then evaluate a number of factors which influence this relationship, such as genetic factors, the use of psychotropic medications during pregnancy, the timing within the perinatal period, the sex of the foetus, and exposure to maltreatment in childhood. Finally, we examine recent findings regarding the molecular mechanisms underpinning these clinical observations, and identify relevant epigenetic and biomarker changes in the glucocorticoid, oxytocin, oestrogen and immune systems, as key biological mediators of these clinical findings. By understanding these molecular mechanisms in more detail, we will be able to improve outcomes for both mothers and their offspring for generations.

Stressful life events, inflammation and emotional and behavioural problems in children: A population-based study

OBJECTIVE

To test the hypothesis that higher plasma levels of inflammatory markers due to exposure to adverse life events may lead to internalising and externalising symptoms in children.

METHOD

Using data from the Avon Longitudinal Study of Parents and Children, a general population birth cohort, we explored if inflammatory markers [serum C-reactive protein (CRP) and interleukin-6 (IL-6)] at age 9 years explain the longitudinal association between adverse life events (at ages 1-9 and 9-11 years) and internalising and externalising symptoms (at ages 9 and 11 years). Data (n = 4583) were analysed using cross-lagged panel modelling to take into account reciprocal associations and reverse causality, and path analyses to test for mediation. Gender, ethnicity, body mass index, maternal education, paternal social class and maternal depression were used as potential confounders.

RESULTS

CRP was not associated with adverse life events. There was evidence for partial mediation by IL-6 such that exposure to adverse life events was associated with increased levels of IL-6 later, in turn associated with later internalising symptoms. These associations were robust to adjustment for confounders. IL-6 did not explain part of the opposite association, that of earlier internalising symptoms and later life events, nor did it explain either direction of the association between life events and externalising symptoms.

CONCLUSION

Our findings suggest a pathway that may connect early psychosocial adversity and childhood internalising symptoms via higher plasma levels of inflammatory markers, such as IL-6.

The Consequences of Foster Care Versus Institutional Care in Early Childhood on Adolescent Cardiometabolic and Immune Markers: Results From a Randomized Controlled Trial

OBJECTIVE

Children exposed to institutional rearing often exhibit problems across a broad array of developmental domains. We compared the consequences of long-term, high-quality foster care versus standard institution-based care, which began in early childhood on cardiometabolic and immune markers assessed at the time of adolescence.

METHODS

The Bucharest Early Intervention Project is a longitudinal investigation of children institutionalized during early childhood (ages 6 to 30 months at baseline) who were subsequently randomized to either high-quality foster care or continued institutional care. At the age of 16 years, 127 respondents participated in a biomarker collection protocol, including 44 institutionalized children randomly assigned to receive care as usual, 41 institutionalized children randomized to be removed from institutional care and placed in high-quality foster care in infancy, and a control group of 42 demographically matched children raised in biological families. Outcomes included body mass index (BMI), systolic and diastolic blood pressure, C-reactive protein, interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor α, glycosylated hemoglobin A1c, and Epstein-Barr virus antibody titers.

RESULTS

Early institutional rearing was not associated with differences in cardiometabolic or immune markers. Randomization to foster care and age of placement into foster care were also unrelated to these markers, with the exception of BMI z-score, where children assigned to care as usual had lower BMI z-scores relative to children assigned to foster care (-0.23 versus 0.08, p = .06), and older age at placement was associated with lower BMI (β = -0.07, p = .03).

CONCLUSIONS

The impact of institutional rearing on measures of cardiometabolic health and immune system functioning is either absent or not evident until later in development. These findings provide new insights into the biological embedding of adversity and how it varies developmentally and across regulatory systems and adversity type.

CLINICAL TRIAL REGISTRATION

NCT00747396.

Preventing epigenetic traces of caregiver maltreatment: A role for HDAC inhibition

Reorganization of the brain's epigenetic landscape occurs alongside early adversity in both human and non-human animals. Whether this reorganization is simply incidental to or is a causal mechanism of the behavioral abnormalities that result from early adversity is important to understand. Using the scarcity-adversity model of low nesting resources in Long Evans rats, our lab has previously reported specific epigenetic and behavioral trajectories occurring in response to early disruption of the caregiving environment. To further probe that relationship, the current work investigates the ability of the epigenome-modifying drug sodium butyrate to prevent maltreatment-induced methylation changes when administered alongside maltreatment. Following exposure to the scarcity-adversity model, during which drug was administered prior to each caregiving session, methylation of Brain-derived Neurotrophic Factor (Bdnf) IX DNA was examined in the Prefrontal Cortex (PFC) of male and female pups at postnatal day (PN) 8. As our previous work reports, increased methylation at this exon of Bdnf in the PFC is a stable epigenetic change across the lifespan that occurs in response to early maltreatment, thus giving us a suitable starting point to investigate pharmacological prevention of maltreatment-induced epigenetic marks. Here we also examined off-target effects of sodium butyrate by assessing methylation in another region of Bdnf (exon IV) not affected in the infant brain as well as global levels of methylation in the brain region of interest. Results indicate that a 400 mg/kg (but not 300 mg/kg) dose of sodium butyrate is effective in preventing the maltreatment-induced rise in methylation at Bdnf exon IX in the PFC of male (but not female) infant pups. Administration of sodium butyrate did not affect the methylation status of Bdnf IV or overall levels of global methylation in the PFC, suggesting potential specificity of this drug. These data provide us an avenue forward for investigating whether the relationship between adversity-induced epigenetic outcomes in our model can be manipulated to improve behavioral outcomes.

Stop, think, reflect, realize-first-time mothers' views on taking part in longitudinal maternal health research

Background

Longitudinal cohort studies gather large amounts of data over time, often without direct benefit to participants. A positive experience may encourage retention in the study, and participants may benefit in unanticipated ways.

Objective

To explore first‐time mothers’ experiences of taking part in a longitudinal cohort study and completing self‐administered surveys during pregnancy and at 3, 6, 9 and 12 months’ postpartum.

Design

Content analysis of comments written by participants in the Maternal health And Maternal Morbidity in Ireland study's five self‐completion surveys, a multisite cohort study exploring women's health and health problems during and after pregnancy. This paper focuses on what women wrote about taking part in the research. Ethical approval was granted by the site hospitals and university.

Setting and participants

A total of 2174 women were recruited from two maternity hospitals in Ireland between 2012 and 2015.

Findings

A total of 1000 comments were made in the five surveys. Antenatally, barriers related to surveys being long and questions being intimate. Postpartum, barriers related to being busy with life as first‐time mothers. Benefits gained included gaining access to information, taking time to reflect, stopping to think and being prompted to seek help. Survey questions alone were described as valuable sources of information.

Discussion and conclusions

Findings suggest that survey research can “give back” to women by being a source of information and a trigger to seek professional help, even while asking sensitive questions. Understanding this can help researchers construct surveys to maximize benefits, real and potential, for participants.

Longitudinal associations between attachment quality in infancy, C-reactive protein in early childhood, and BMI in middle childhood: preliminary evidence from a CPS-referred sample

In the current pilot study, we examined whether insecure or disorganized attachment was associated with elevated inflammation (i.e. C-reactive protein [CRP]) in children with histories of child protective services (CPS) involvement, and whether early childhood CRP predicted body mass index (BMI) in middle childhood. Participants included 45 CPS-referred children and 39 low-risk comparison children, for whom we assessed levels of CRP in early childhood (Mean age = 4.9 years). For the CPS-referred children, who were drawn from an ongoing longitudinal study, we had attachment classifications (assessed during infancy with the Strange Situation) and BMI data (assessed during early and middle childhood); these data were not available for the low-risk comparison group. CPS-referred children who had insecure or disorganized attachments during infancy had higher levels of CRP in early childhood than CPS-referred children who had secure attachments, who had similar levels of CRP to low-risk comparison children. Among CPS-referred children, early childhood CRP predicted age 8 BMI, controlling for BMI at age 4. Findings offer preliminary support for the association between attachment quality and inflammation in early childhood, which may have implications for later physical health.

Old Friends, immunoregulation, and stress resilience

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

Lonely young adults in modern Britain: findings from an epidemiological cohort study

BACKGROUND

The aim of this study was to build a detailed, integrative profile of the correlates of young adults' feelings of loneliness, in terms of their current health and functioning and their childhood experiences and circumstances.

METHODS

Data were drawn from the Environmental Risk Longitudinal Twin Study, a birth cohort of 2232 individuals born in England and Wales in 1994 and 1995. Loneliness was measured when participants were aged 18. Regression analyses were used to test concurrent associations between loneliness and health and functioning in young adulthood. Longitudinal analyses were conducted to examine childhood factors associated with young adult loneliness.

RESULTS

Lonelier young adults were more likely to experience mental health problems, to engage in physical health risk behaviours, and to use more negative strategies to cope with stress. They were less confident in their employment prospects and were more likely to be out of work. Lonelier young adults were, as children, more likely to have had mental health difficulties and to have experienced bullying and social isolation. Loneliness was evenly distributed across genders and socioeconomic backgrounds.

CONCLUSIONS

Young adults' experience of loneliness co-occurs with a diverse range of problems, with potential implications for health in later life. The findings underscore the importance of early intervention to prevent lonely young adults from being trapped in loneliness as they age.

Developmental Trajectories of Early Life Stress and Trauma: A Narrative Review on Neurobiological Aspects Beyond Stress System Dysregulation

Early life stressors display a high universal prevalence and constitute a major public health problem. Prolonged psychoneurobiological alterations as sequelae of early life stress (ELS) could represent a developmental risk factor and mediate risk for disease, leading to higher physical and mental morbidity rates in later life. ELS could exert a programming effect on sensitive neuronal brain networks related to the stress response during critical periods of development and thus lead to enduring hyper- or hypo-activation of the stress system and altered glucocorticoid signaling. In addition, alterations in emotional and autonomic reactivity, circadian rhythm disruption, functional and structural changes in the brain, as well as immune and metabolic dysregulation have been lately identified as important risk factors for a chronically impaired homeostatic balance after ELS. Furthermore, human genetic background and epigenetic modifications through stress-related gene expression could interact with these alterations and explain inter-individual variation in vulnerability or resilience to stress. This narrative review presents relevant evidence from mainly human research on the ten most acknowledged neurobiological allostatic pathways exerting enduring adverse effects of ELS even decades later (hypothalamic-pituitary-adrenal axis, autonomic nervous system, immune system and inflammation, oxidative stress, cardiovascular system, gut microbiome, sleep and circadian system, genetics, epigenetics, structural, and functional brain correlates). Although most findings back a causal relation between ELS and psychobiological maladjustment in later life, the precise developmental trajectories and their temporal coincidence has not been elucidated as yet. Future studies should prospectively investigate putative mediators and their temporal sequence, while considering the potentially delayed time-frame for their phenotypical expression. Better screening strategies for ELS are needed for a better individual prevention and treatment.

Role of Inflammation in Depression and Treatment Implications

Approximately one third of depressed patients fail to respond to currently available antidepressant therapies. Therefore, new conceptual frameworks are needed to identify pathophysiologic pathways and neurobiological targets for the development of novel treatment strategies. In this regard, recent evidence suggests that inflammation may contribute to symptoms relevant to a number of psychiatric disorders and particularly depression. Numerous studies (including meta-analyses) have found elevated peripheral and central inflammatory cytokines and acute phase proteins in depression. Chronic exposure to increased inflammation is thought to drive changes in neurotransmitters and neurocircuits that lead to depressive symptoms and that may also interfere with or circumvent the efficacy of antidepressants. Indeed, patients with high inflammation have been shown to exhibit poor response to conventional antidepressant therapies. Recent developments in our ability to understand and measure the effects of inflammation on the brain in patients have opened new doors for the testing of novel treatment strategies that target the immune system or its consequences on neurotransmitter systems. Such recent developments in the field of behavioral immunology and their translational implications for the treatment of depression are discussed herein.

Inflammation, depression and cardiovascular disease in women: the role of the immune system across critical reproductive events

Women are at increased risk for developing depression and cardiovascular disease (CVD) across the lifespan and their comorbidity is associated with adverse outcomes that contribute significantly to rates of morbidity and mortality in women worldwide. Immune-system activity has been implicated in the etiology of both depression and CVD, but it is unclear how inflammation contributes to sex differences in this comorbidity. This narrative review provides an updated synthesis of research examining the association of inflammation with depression and CVD, and their comorbidity in women. Recent research provides evidence of pro-inflammatory states and sex differences associated with alterations in the hypothalamic-pituitary-adrenal axis, the renin-angiotensin-aldosterone system and the serotonin/kynurenine pathway, that likely contribute to the development of depression and CVD. Changes to inflammatory cytokines in relation to reproductive periods of hormonal fluctuation (i.e. the menstrual cycle, perinatal period and menopause) are highlighted and provide a greater understanding of the unique vulnerability women experience in developing both depressed mood and adverse cardiovascular events. Inflammatory biomarkers hold substantial promise when combined with a patient's reproductive and mental health history to aid in the prediction, identification and treatment of the women most at risk for CVD and depression. However, more research is needed to improve our understanding of the mechanisms underlying inflammation in relation to their comorbidity, and how these findings can be translated to improve women's health.

Recollections of positive early caregiving relate to sympathetic nervous system activation and chronic inflammation in subsequent generations

To understand links between early experience and biomarkers of peripheral physiology in adulthood, this study examined associations between quality of early caregiving and markers of sympathetic activation and chronic inflammation in a sample of 52 low-income mothers and their preschool-aged children. Mothers reported on levels of positive caregiving experienced during childhood using the Structural Analysis of Social Behavior-Intrex. Mother and child sympathetic activation was indexed via pre-ejection period (PEP) at rest, during a dyadic social engagement task, and for children, while interacting with an unfamiliar adult. C-reactive protein (CRP) was collected using whole blood spots to assess levels of low-grade chronic inflammation. Results showed that mothers who reported experiencing more warm guidance and support for autonomy in early childhood displayed lower resting sympathetic nervous system activation (i.e., longer PEP) and lower chronic inflammation (i.e., CRP levels). Further, lower maternal chronic inflammation levels were associated with lower sympathetic activation (i.e., longer PEP) in their children at rest, and during social interactions with mother and a female stranger.

Maternal experiences of intimate partner violence and C-reactive protein levels in young children in Tanzania

Intimate partner violence (IPV) is a critical public health issue that impacts women and children across the globe. Prior studies have documented that maternal experiences of IPV are associated with adverse psychological and physical health outcomes in children; however, research on the underlying physiological pathways linking IPV to these conditions is limited. Drawing on data from the 2010 Tanzania Demographic and Health Survey, we examined the relationship between maternal report of IPV in the past 12 months and inflammation among children ages 6 months to 5 years. Our study included 503 children who were randomly selected to provide a blood sample and had a mother who had ever been married and who had completed the Domestic Violence Module, which collected information on physical, sexual, and emotional violence. Analyses were stratified based on a threshold for acute immune activation status, defined by the threshold of CRP > 1.1 mg/L for young children in Tanzania. In bivariate analyses, healthy children whose mothers reported IPV showed a marginally elevated median CRP level compared to children whose mothers did not report IPV (0.35 vs. 0.41 mg/L; p = 0.13). Similarly, among children with active or recent infections, those whose mothers reported IPV had an elevated median CRP compared to children whose mothers did not (4.06 vs 3.09 mg/L; p = 0.03). In adjusted multiple variable regression models to account for child, mother, and household characteristics, maternal IPV was positively associated with (log) CRP in both healthy children and children with active or recent infection. Although longitudinal research with additional biomarkers of inflammation is needed, our results provide support for the hypothesis that inflammation may function as a biological pathway linking maternal IPV to poor psychological and physical health outcomes among children of mothers who are victimized-and this may extend to very young children and children in non-Western contexts.

Inflammation-related epigenetic risk and child and adolescent mental health: A prospective study from pregnancy to middle adolescence

In 785 mother-child (50% male) pairs from a longitudinal epidemiological birth cohort, we investigated associations between inflammation-related epigenetic polygenic risk scores (i-ePGS), environmental exposures, cognitive function, and child and adolescent internalizing and externalizing problems. We examined prenatal and postnatal effects. For externalizing problems, one prenatal effect was found: i-ePGS at birth associated with higher externalizing problems (ages 7-15) indirectly through lower cognitive function (age 7). For internalizing problems, we identified two effects. For a prenatal effect, i-ePGS at birth associated with higher internalizing symptoms via continuity in i-ePGS at age 7. For a postnatal effect, higher postnatal adversity exposure (birth through age 7) associated with higher internalizing problems (ages 7-15) via higher i-ePGS (age 7). Hence, externalizing problems were related mainly to prenatal effects involving lower cognitive function, whereas internalizing problems appeared related to both prenatal and postnatal effects. The present study supports a link between i-ePGS and child and adolescent mental health.

Inflammation and psychopathology in children following PICU admission: an exploratory study

Background

Survivors of critical illness in childhood commonly display subsequent psychiatric symptoms including emotional and behavioural difficulties, and manifestations of post-traumatic stress disorder (PTSD). Anomalies in inflammatory profiles are an established finding in these childhood psychiatric conditions.

Objective

This exploratory study aimed to investigate whether abnormal peripheral blood inflammatory markers measured during paediatric intensive care unit (PICU) admission were associated with psychiatric symptoms after discharge.

Methods

We performed a prospective observational cohort study on 71 children with septic illness, meningoencephalitis and other critical disorders admitted to two PICUs between 2007 and 2010. 3–6 months following discharge, subjects were assessed for global psychiatric risk (ie, presence of emotional and behavioural difficulties on the parental Strengths and Difficulties Questionnaire (SDQ)), and for PTSD risk using the child-rated Impact of Events Scale (IES-8). Inflammatory and related biological markers were transcribed from PICU admission notes (white cell count, lymphocytes, neutrophils, C reactive protein (CRP), platelets, fibrinogen and lactate).

Findings

Global psychiatric risk at follow-up was associated with abnormal lymphocyte count during admission (χ²=6.757, p=0.014, n=48). In children with sepsis, partial correlation analyses controlling for age and gender highlighted associations between (i) SDQ scores and low lymphocyte count (r=−0.712; p=0.009, n=14), and (ii) IES-8 score and high CRP levels (r=0.823; p=0.006, n=11). These associations remained after correction for multiple comparisons.

Conclusion

These results support the hypothesis that acute inflammation may play a role in determining the development of psychopathology following PICU admission.

Clinical implications

If the findings are replicated, they may help to better highlight which children are at risk of post-PICU psychopathology and appropriately target follow-up.

Imaging the Role of Inflammation in Mood and Anxiety-related Disorders

Background

Studies investigating the impact of a variety of inflammatory stimuli on the brain and behavior have reported evidence that inflammation and release of inflammatory cytokines affect circuitry relevant to both reward and threat sensitivity to contribute to behavioral change. Of relevance to mood and anxiety-related disorders, biomarkers of inflammation such as inflammatory cytokines and acute-phase proteins are reliably elevated in a significant proportion of patients with major depressive disorder (MDD), bipolar disorder, anxiety disorders and post-traumatic stress disorder (PTSD).

Methods

This review summarized clinical and translational work demonstrating the impact of peripheral inflammation on brain regions and neurotransmitter systems relevant to both reward and threat sensitivity, with a focus on neuroimaging studies involving administration of inflammatory stimuli. Recent translation of these findings to further understand the role of inflammation in mood and anxiety-related disorders is also discussed.

Results

Inflammation was consistently found to affect basal ganglia and cortical reward and motor circuits to drive reduced motivation and motor activity, as well as anxiety-related brain regions including amygdala, insula and anterior cingulate cortex, which may result from cytokine effects on monoamines and glutamate. Similar relationships between inflammation and altered neurocircuitry have been observed in MDD patients with increased peripheral inflammatory markers, and such work is on the horizon for anxiety disorders and PTSD.

Conclusion

Neuroimaging effects of inflammation on reward and threat circuitry may be used as biomarkers of inflammation for future development of novel therapeutic strategies to better treat mood and anxiety-related disorders in patients with high inflammation.

Early life stress, air pollution, inflammation, and disease: An integrative review and immunologic model of social-environmental adversity and lifespan health

Socially disadvantaged individuals are at greater risk for simultaneously being exposed to adverse social and environmental conditions. Although the mechanisms underlying joint effects remain unclear, one hypothesis is that toxic social and environmental exposures have synergistic effects on inflammatory processes that underlie the development of chronic diseases, including cardiovascular disease, diabetes, depression, and certain types of cancer. In the present review, we examine how exposure to two risk factors that commonly occur with social disadvantage-early life stress and air pollution-affect health. Specifically, we identify neuroimmunologic pathways that could link early life stress, inflammation, air pollution, and poor health, and use this information to propose an integrated, multi-level model that describes how these factors may interact and cause health disparity across individuals based on social disadvantage. This model highlights the importance of interdisciplinary research considering multiple exposures across domains and the potential for synergistic, cross-domain effects on health, and may help identify factors that could potentially be targeted to reduce disease risk and improve lifespan health.

Insights into the Psychology of Trauma Should Inform the Practice of Oncology

Many cancer patients and their caretakers have histories of significant trauma, often during childhood. These experiences often affect how they respond to their diagnoses and treatment. This commentary focuses on the need for a better understanding of trauma as related to improved cancer care.

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

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

Adverse childhood experiences and adult inflammation: Findings from the 1958 British birth cohort

BACKGROUND

The relationship between adverse childhood experiences (ACE) and poorer health across the life course is well established. Increased chronic inflammation might be one mechanism through which these associations operate. The aim of this study was to explore the relationship between ACE and adult inflammation using a prospective longitudinal study. We also investigated whether associations were explained by life course socioeconomic, psychological and health behavioural factors, and whether associations differed by gender.

METHODS

Multiply imputed data on 7464 participants of the National Child Development Study (1958 British birth cohort) were used. Prospectively collected data on ACE included care placement, physical neglect, parental separation, family history of offences, mental illness, domestic conflict and alcohol misuse across childhood (0-16 years). Adult inflammation was indicated by C-reactive protein (CRP), fibrinogen and Von Willebrand factor (vWF) at age 44/45. Multivariable linear regression models were used to estimate associations between ACE and adult inflammation.

RESULTS

Graded associations for ACE with CRP and fibrinogen were observed (e.g. CRP: 1 ACE: 4.61% higher, 95% CI: -3.13, 12.97; 2+ ACE: 16.35% higher, 95% CI: 6.87, 26.66). Socioeconomic and health behavioral factors were found to particularly explain these associations. After inclusion of all covariates associations between ACE and mid-life inflammation were no longer significant. Associations did not differ for men and women.

CONCLUSIONS

ACE were associated in a graded manner with adult inflammation in a British birth cohort. The association was explained by life course socioeconomic and health behavioral factors, in particular. This study highlights the importance of protecting children from ACE and its negative health effects, and in supporting children through education and into skilled, secure work.

Maternal Systemic Interleukin-6 During Pregnancy Is Associated With Newborn Amygdala Phenotypes and Subsequent Behavior at 2 Years of Age

BACKGROUND

Maternal inflammation during pregnancy increases the risk for offspring psychiatric disorders and other adverse long-term health outcomes. The influence of inflammation on the developing fetal brain is hypothesized as one potential mechanism but has not been examined in humans.

METHODS

Participants were adult women (N = 86) who were recruited during early pregnancy and whose offspring were born after 34 weeks' gestation. A biological indicator of maternal inflammation (interleukin-6) that has been shown to influence fetal brain development in animal models was quantified serially in early, mid-, and late pregnancy. Structural and functional brain magnetic resonance imaging scans were acquired in neonates shortly after birth. Infants' amygdalae were individually segmented for measures of volume and as seeds for resting state functional connectivity. At 24 months of age, children completed a snack delay task to assess impulse control.

RESULTS

Higher average maternal interleukin-6 concentration during pregnancy was prospectively associated with larger right amygdala volume and stronger bilateral amygdala connectivity to brain regions involved in sensory processing and integration (fusiform, somatosensory cortex, and thalamus), salience detection (anterior insula), and learning and memory (caudate and parahippocampal gyrus). Larger newborn right amygdala volume and stronger left amygdala connectivity were in turn associated with lower impulse control at 24 months of age, and mediated the association between higher maternal interleukin-6 concentrations and lower impulse control.

CONCLUSIONS

These findings provide new evidence in humans linking maternal inflammation during pregnancy with newborn brain and emerging behavioral phenotypes relevant for psychiatric disorders. A better understanding of intrauterine conditions that influence offspring disease susceptibility is warranted to inform targeted early intervention and prevention efforts.

Childhood victimization and inflammation in young adulthood: A genetically sensitive cohort study

OBJECTIVE

Childhood victimization is an important risk factor for later immune-related disorders. Previous evidence has demonstrated that childhood victimization is associated with elevated levels of inflammation biomarkers measured decades after exposure. However, it is unclear whether this association is (1) already detectable in young people, (2) different in males and females, and (3) confounded by genetic liability to inflammation. Here we sought to address these questions.

METHOD

Participants were 2232 children followed from birth to age 18years as part of the Environmental Risk (E-Risk) Longitudinal Twin Study. Childhood victimization was measured prospectively from birth to age 12years. Inflammation was measured through C-reactive protein (CRP) levels in dried blood spots at age 18years. Latent genetic liability for high inflammation levels was assessed through a twin-based method.

RESULTS

Greater exposure to childhood victimization was associated with higher CRP levels at age 18 (serum-equivalent means were 0.65 in non-victimized Study members, 0.74 in those exposed to one victimization type, and 0.81 in those exposed to poly-victimization; p=0.018). However, this association was driven by a significant association in females (serum-equivalent means were 0.75 in non-victimized females, 0.87 in those exposed to one type of victimization, and 1.19 in those exposed to poly-victimization; p=0.010), while no significant association was observed in males (p=0.19). Victimized females showed elevated CRP levels independent of latent genetic influence, as well as childhood socioeconomic status, and waist-hip ratio and body temperature at the time of CRP assessment.

CONCLUSION

Childhood victimization is associated with elevated CRP levels in young women, independent of latent genetic influences and other key risk factors. These results strengthen causal inference about the effects of childhood victimization on inflammation levels in females by accounting for potential genetic confounding.

Neuroimmune Impacts of Early-Life Stress on Development and Psychopathology

Maltreatment and trauma in childhood, termed early-life stress (ELS), has long-term effects on the immune system. ELS impacts immune signaling at the time of exposure but also disrupts the developmental trajectory of certain immunological processes, both in the periphery and in the brain. One consequence of these early alterations is a heightened immune response to stressors later in life. However, chronic and sustained inflammatory response can also lead to excitotoxicity and prevent typical brain development. In this chapter, we discuss current progress toward understanding the contribution of neuroimmune signaling to ELS-attributable dysfunction or maladaptation with a focus on postnatal experiences. To do so we first present an operational definition of ELS. Then, we offer a brief overview of the immune system and neuroimmune development, followed by a section discussing the interaction between immunity, childhood trauma, and mental disorders in humans. We present evidence from animal models about immune alterations after ELS and discuss the ways in which ELS-induced immune changes ultimately affect brain and behavior, as well as the importance of individual differences and future directions in this field. Taken together, we submit that when encountered with ELS, some core brain circuits could develop differently via various mechanisms involving dysfunctional immune reprograming. However, given the remarkable plasticity of both the brain and the immune system, many of the deleterious effects of ELS may be mitigated with interventions that account for sex and target neuroimmune interactions over the lifespan.

Association Between Early Life Adversity and Risk for Poor Emotional and Physical Health in Adolescence: A Putative Mechanistic Neurodevelopmental Pathway

IMPORTANCE

Adverse childhood experiences (ACEs) have been associated with poor mental and physical health outcomes. However, the mechanism of this effect, critical to enhancing public health, remains poorly understood.

OBJECTIVE

To investigate the neurodevelopmental trajectory of the association between early ACEs and adolescent general and emotional health outcomes.

DESIGN, SETTING, AND PARTICIPANTS

A prospective longitudinal study that began when patients were aged 3 to 6 years who underwent neuroimaging later at ages 7 to 12 years and whose mental and physical health outcomes were observed at ages 9 to 15 years. Sequential mediation models were used to investigate associations between early ACEs and brain structure, emotion development, and health outcomes longitudinally. Children were recruited from an academic medical center research unit.

EXPOSURE

Early life adversity.

MAIN OUTCOMES AND MEASURES

Early ACEs in children aged 3 to 7 years; volume of a subregion of the prefrontal cortex, the inferior frontal gyrus, in children aged 6 to 12 years; and emotional awareness, depression severity, and general health outcomes in children and adolescents aged 9 to 15 years.

RESULTS

The mean (SD) age of 119 patients was 9.65 (1.31) years at the time of scan. The mean (SD) ACE score was 5.44 (3.46). The mean (SD) depression severity scores were 2.61 (1.78) at preschool, 1.77 (1.58) at time 2, and 2.16 (1.64) at time 3. The mean (SD) global physical health scores at time 2 and time 3 were 0.30 (0.38) and 0.33 (0.42), respectively. Sequential mediation in the association between high early ACEs and emotional and physical health outcomes were found. Smaller inferior frontal gyrus volumes and poor emotional awareness sequentially mediated the association between early ACEs and poor general health (model parameter estimate = 0.002; 95% CI, 0.0002-0.056) and higher depression severity (model parameter estimate = 0.007; 95% CI, 0.001-0.021) in adolescence. An increase from 0 to 3 early ACEs was associated with 15% and 25% increases in depression severity and physical health problems, respectively.

CONCLUSIONS AND RELEVANCE

Study findings highlight 1 putative neurodevelopmental mechanism by which the association between early ACEs and later poor mental and physical health outcomes may operate. This identified risk trajectory may be useful to target preventive interventions.

Effects of early-life adversity on immune function are mediated by prenatal environment: Role of prenatal alcohol exposure

The contribution of the early postnatal environment to the pervasive effects of prenatal alcohol exposure (PAE) is poorly understood. Moreover, PAE often carries increased risk of exposure to adversity/stress during early life. Dysregulation of immune function may play a role in how pre- and/or postnatal adversity/stress alters brain development. Here, we combine two animal models to examine whether PAE differentially increases vulnerability to immune dysregulation in response to early-life adversity. PAE and control litters were exposed to either limited bedding (postnatal day [PN] 8-12) to model early-life adversity or normal bedding, and maternal behavior and pup vocalizations were recorded. Peripheral (serum) and central (amygdala) immune (cytokines and C-reactive protein - CRP) responses of PAE animals to early-life adversity were evaluated at PN12. Insufficient bedding increased negative maternal behavior in both groups. Early-life adversity increased vocalization in all animals; however, PAE pups vocalized less than controls. Early-life adversity reduced serum TNF-α, KC/GRO, and IL-10 levels in control but not PAE animals. PAE increased serum CRP, and levels were even higher in pups exposed to adversity. Finally, PAE reduced KC/GRO and increased IL-10 levels in the amygdala. Our results indicate that PAE alters immune system development and both behavioral and immune responses to early-life adversity, which could have subsequent consequences for brain development and later life health.

Sleep, biological stress, and health among toddlers living in socioeconomically disadvantaged homes: A research protocol

Healthy sleep is important to behavioral, neurobiological, and physiologic health. In older children and adults, stress biomarkers, such as cortisol and C-reactive protein, increase when they do not practice healthy sleep habits. However, little is known about the relationships among sleep health, stress, and health outcomes among very young children living with socioeconomic adversity, a group that is particularly at risk for poor future health. The NIH-funded study described in this protocol addresses this scientific gap to improve understanding of these relationships during a critical developmental period in children's lives-toddlerhood. We will use a longitudinal design with repeated measures to prospectively examine the relationships among sleep health, stress, and toddlers' health from age 12 to 24 months, to address the following aims: i) examine changes in subjective and objective sleep health measures; ii) examine changes in stress biomarkers; iii) examine the cross-sectional and longitudinal relationships between sleep health measures and stress response; and iv) examine the cross-sectional and longitudinal relationships between sleep health measures, stress biomarkers, and toddlers' behavioral health. The sample will include 113 toddlers and their caregivers. We are collecting subjective and objective data on sleep health, multi-systemic biomarkers of stress, and toddlers' behavioral health. Generalized linear models will be used in the data analyses. Results from this study will be used to support development and testing of interventions, such as those that may improve sleep, among young children at risk for toxic stress.

Childhood maltreatment and the medical morbidity in bipolar disorder: a case-control study

Background

Childhood maltreatment (abuse and neglect) can have long-term deleterious consequences, including increased risk for medical and psychiatric illnesses, such as bipolar disorder in adulthood. Emerging evidence suggests that a history of childhood maltreatment is linked to the comorbidity between medical illnesses and mood disorders. However, existing studies on bipolar disorder have not yet explored the specific influence of child neglect and have not included comparisons with individuals without mood disorders (controls). This study aimed to extend the existing literature by examining the differential influence of child abuse and child neglect on medical morbidity in a sample of bipolar cases and controls.

Methods

The study included 72 participants with bipolar disorder and 354 psychiatrically healthy controls (average age of both groups was 48 years), who completed the Childhood Trauma Questionnaire, and were interviewed regarding various medical disorders.

Results

A history of any type of childhood maltreatment was significantly associated with a diagnosis of any medical illness (adjusted OR = 6.28, 95% confidence intervals 1.70–23.12, p = 0.006) and an increased number of medical illnesses (adjusted OR = 3.77, 95% confidence intervals 1.34–10.57, p = 0.012) among adults with bipolar disorder. Exposure to child abuse was more strongly associated with medical disorders than child neglect. No association between childhood maltreatment and medical morbidity was detected among controls.

Conclusions

To summarise, individuals with bipolar disorder who reported experiencing maltreatment during childhood, especially abuse, were at increased risk of suffering from medical illnesses and warrant greater clinical attention.

Developmental psychoneuroendocrine and psychoneuroimmune pathways from childhood adversity to disease

Childhood adversity has been repeatedly and robustly linked to physical and mental illness across the lifespan. Yet, the biological pathways through which this occurs remain unclear. Functioning of the inflammatory arm of the immune system and the hypothalamic-pituitary-adrenal (HPA)-axis are both hypothesized pathways through which childhood adversity leads to disease. This review provides a novel developmental framework for examining the role of adversity type and timing in inflammatory and HPA-axis functioning. In particular, we identify elements of childhood adversity that are salient to the developing organism: physical threat, disrupted caregiving, and unpredictable environmental conditions. We propose that existing, well-characterized animal models may be useful in differentiating the effects of these adversity elements and review both the animal and human literature that supports these ideas. To support these hypotheses, we also provide a detailed description of the development and structure of both the HPA-axis and the inflammatory arm of the immune system, as well as recent methodological advances in their measurement. Recommendations for future basic, developmental, translational, and clinical research are discussed.

Childhood Psychological Distress as a Mediator in the Relationship Between Early-Life Social Disadvantage and Adult Cardiometabolic Risk: Evidence From the 1958 British Birth Cohort

OBJECTIVES

Prior research on the relationship between early adversity and adult chronic disease has often relied on retrospective reports of a limited range of exposures and has not considered childhood psychological distress as a mediator. We investigate whether distress in childhood is one pathway by which early social disadvantage leads to greater cardiometabolic risk in middle adulthood.

METHODS

Data are from the 1958 British Birth Cohort study (sample n = 6027). We created an early social disadvantage index based on 16 exposures related to family and socioeconomic hardship from birth to age 7. Childhood psychological distress was ascertained from internalizing and externalizing symptoms at ages 7, 11, and 16 years. Cardiometabolic risk was assessed with a Z-standardized score derived from 9 immune, cardiovascular, and metabolic biomarkers measured at age 45. We used linear regression models and formal tests of mediation to assess relationships between disadvantage, distress, and subsequent cardiometabolic risk.

RESULTS

Higher social disadvantage predicted increased adult cardiometabolic risk (β = 0.05; 95% CI = 0.03-0.07). Mediation analyses revealed a significant direct (path c'; β = 0.03; 95% CI = 0.01-0.05) and indirect (path ab; β = 0.02; 95% CI = 0.01-0.02) effect of social disadvantage on cardiometabolic risk, adjusting for potential confounders. Child psychological distress accounted for 37% (95% CI = 34-46%) of the observed association.

CONCLUSIONS

Results suggest childhood distress may be one factor on the pathway linking early disadvantage to higher risk of developing cardiometabolic diseases. Such results may point to the importance of blocking the translation of psychosocial to biological risk during a potentially sensitive developmental window.

Timeline of Intergenerational Child Maltreatment: the Mind-Brain-Body Interplay

PURPOSE OF REVIEW

Still obscure mechanisms of intergenerational child maltreatment (ITCM) have been investigated partially, from various psychological and biological perspectives and from various time perspectives. This review is aimed at integrating the findings on different temporal ITCM pathways, emphasizing the mind-brain-body interplay.

RECENT FINDINGS

Psychological mediators of ITCM involve attachment, mentalization, dissociation, social information processing, personality traits, and psychiatric disorders. Neurobiological findings mostly refer to the neural correlates of caregiving and attachment behaviors, affected by several physiological systems (stress-response, immune, oxytocin), which also affect physical health. The latest research clusters around the epigenetic pathways of ITCM, suggesting the additional, prenatal, and preconception forms of transmission. Data suggest that ITCM needs to be conceptualized as a longitudinal process, with various interrelated psychological, neurodevelopmental, and somatic paths. Future research and prevention should take into account both, each path and each phase of ITCM, in an integrative way.

A Theory of Mental Health and Optimal Service Delivery for Homeless Children

Homeless children are a vulnerable group with high risk for developing mental health disorders. The pathways to disorders among homeless children have not been fully elucidated, with significant logistical and measurement issues challenging accurate and thorough assessment of need. The environments of homeless children are uniquely chaotic, marked by frequent moves, family structure changes, household and neighborhood disorder, parenting distress, and lack of continuous services. Despite high rates of service use, mental health outcomes remain poor. This paper reviews the literature on homeless children's mental health, as well as prior theoretical explorations. Finally, the paper proposes a theoretical model that explains elevated rates of mental health problems among homeless children as consequences of harmful stress reactions triggered by chronic household instability along with repeated service disruptions. This model draws upon existing conceptual frameworks of child development, family poverty, health services utilization, and the biology of stress to clarify the role of environmental chaos in the development of child emotional and behavioral problems. Potential strategies to mitigate the risk for mental health disorders among homeless children and future research directions are discussed.

The relations of child adiposity with parent-to-child and parent-to-parent hostility

OBJECTIVE

Investigate (1) the association of child adiposity with parent-to-child and parent-to-parent hostility, (2) the mediation of these associations by dietary behaviours and (3) moderation by gender.

DESIGN

One hundred thirty-five couples with 6- to 14-year-old children completed measures of emotional and physical aggression, overreactive discipline and child diet. Parent-to-parent hostility was also coded from laboratory observations.

MAIN OUTCOME MEASURE

Child adiposity was a combination of body mass index and waist-to-hip ratio.

RESULTS

Mother-to-child hostility was associated with child adiposity. This association was concentrated in boys and was not significantly explained by child dietary factors. Mother-to-father hostility was not significantly associated with boys' or girls' adiposity. Girls' adiposity was not significantly associated with family hostility. Fathers' hostility was not linked to child adiposity.

CONCLUSION

This is the first study to take a family-level approach to understanding the relation of hostility to child adiposity by examining relations among adiposity and both mothers' and fathers' hostility directed toward one another and toward their children. Our findings highlight the potential role played by mothers' emotional hostility in boys' adiposity and suggest that, if this role is further substantiated, mother-son emotional hostility may be a promising target for the prevention of child obesity.

Why are depressed patients inflamed? A reflection on 20 years of research on depression, glucocorticoid resistance and inflammation

Studies over the last 20 years have demonstrated that increased inflammation and hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis are two of the most consistent biological findings in major depression and are often associated: but the molecular and clinical mechanisms underlying these abnormalities are still unclear. These findings are particularly enigmatic, especially considering the accepted notion that high levels of cortisol have an anti-inflammatory action, and therefore the coexistence of inflammation and hypercortisolemia in the same diagnostic group appears counter-intuitive. To celebrate the 2015 Anna-Monika Foundation Award to our laboratory, this review will discuss our own 20 years of research on the clinical and molecular evidence underlying the increased inflammation in depression, especially in the context of a hyperactive HPA axis, and discuss its implications for the pathogenesis and treatment of this disorder.

Biomarkers for depression: recent insights, current challenges and future prospects

A plethora of research has implicated hundreds of putative biomarkers for depression, but has not yet fully elucidated their roles in depressive illness or established what is abnormal in which patients and how biologic information can be used to enhance diagnosis, treatment and prognosis. This lack of progress is partially due to the nature and heterogeneity of depression, in conjunction with methodological heterogeneity within the research literature and the large array of biomarkers with potential, the expression of which often varies according to many factors. We review the available literature, which indicates that markers involved in inflammatory, neurotrophic and metabolic processes, as well as neurotransmitter and neuroendocrine system components, represent highly promising candidates. These may be measured through genetic and epigenetic, transcriptomic and proteomic, metabolomic and neuroimaging assessments. The use of novel approaches and systematic research programs is now required to determine whether, and which, biomarkers can be used to predict response to treatment, stratify patients to specific treatments and develop targets for new interventions. We conclude that there is much promise for reducing the burden of depression through further developing and expanding these research avenues.

Disparities in Anxiety and its Disorders

Much of the scientific work addressing the enigmas of anxiety and its disorders has been conducted among European Americans. This work has led to great progress into the nature of anxiety psychopathology, including etiologic, maintenance, and relapse processes. Moreover, evidenced-based treatments for anxiety and its disorders have arguably been among the best in the field of psychopathology for well over two decades. Yet, the progress thus far attained on the nature and treatment of anxiety disorders has not benefited all members of society equally. In fact, there are striking gaps of inequalities in anxiety disorder research and practice. The population in the United States (U.S.) and many parts of the industrialized world is rapidly changing in terms of diversity, and gaps between segments of society are growing in many instances (e.g., financial inequity). Health disparities in anxiety disorders are not a generic issue, but rather, reflect a systematic difference disproportionately affecting groups often not afforded a high social status ranking. We developed this Special Issue in the Journal of Anxiety Disorders to call attention to matters of inequality in anxiety disorders. The present special issue is designed to contextualize contemporary health disparity work on anxiety and its disorders. The special issue highlights three domains of study that are starting to guide research and practice in this arena, including sociocultural and contextual influences on anxiety and its disorders; intra-individual transdiagnostic mechanisms underpinning the expression and etiology/maintenance of anxiety psychopathology; and the close interconnection between anxiety processes and health status and health compromising behaviors. By covering a range of issues interconnected by their focus on understanding health disparity issues, it is hoped that this issue will: alert readers to the significance of this work at different levels of analysis; illustrate the many domains currently being explored via innovative approaches; and identify fecund areas for future systematic study.

A bidirectional relationship between depression and the autoimmune disorders - New perspectives from the National Child Development Study

Background

Depression and the autoimmune disorders are comorbid—the two classes of disorders overlap in the same individuals at a higher frequency than chance. The immune system may influence the pathological processes underlying depression; understanding the origins of this comorbidity may contribute to dissecting the mechanisms underlying these disorders.

Method

We used population cohort data from the 1958 British birth cohort study (the National Child Development Study) to investigate the ages at onset of depression and 23 autoimmune disorders. We used self-report data to ascertain life-time history of depression, autoimmune disorders and their ages at onset. We modelled the effect of depression onset on subsequent autoimmune disorder onset, and vice versa, and incorporated polygenic risk scores for depression and autoimmune disorder risk.

Results

In our analytic sample of 8174 individuals, 315 reported ever being diagnosed with an autoimmune disorder (3.9%), 1499 reported ever experiencing depression (18.3%). There was significant comorbidity between depression and the autoimmune disorders (OR = 1.66, 95% CI = 1.27–2.15). Autoimmune disorder onset associated with increased subsequent hazard of depression onset (HR = 1.39, 95% CI = 1.11–1.74, P = 0.0037), independently of depression genetic risk. Finally, depression increased subsequent hazard of autoimmune disorder onset (HR = 1.40, 95% CI = 1.09–1.80, P = 0.0095), independently of autoimmune disorder genetic risk.

Discussion

Our results point to a bidirectional relationship between depression and the autoimmune disorders. This suggests that shared risk factors may contribute to this relationship, including both common environmental exposures that increase baseline inflammation levels, and shared genetic factors.

Anxiety symptoms and disorders among adults living with HIV and AIDS: A critical review and integrative synthesis of the empirical literature

There are over 35 million people worldwide infected with the Human Immunodeficiency Virus (HIV) and its progression to Acquired Immunodeficiency Syndrome (AIDS; WHO, 2014). With the advent of combined antiretroviral therapy (i.e., cART) in 1996, persons living with HIV/AIDS (PLWHA) now have much longer life expectancies. However, living with HIV remains challenging, as it is associated with a number of significant and recurrent (chronic) stressors including physical pain, side effects of cART, social stigma, and discrimination, among other social stressors. Presumably, as a result of these types of stressors, a disproportionately high number of PLWHA struggle with clinically-significant psychiatric symptoms and disorders. Although much scientific and clinical attention has focused on depressed mood and psychopathology among PLWHA, there has been comparably less focus on anxiety and its disorders. The paucity of work in this area is concerning from a public health perspective, as anxiety symptoms and disorders are the most common class of psychiatric disorders and often maintain a large negative impact on life functioning.

Future Directions in the Study of Early-Life Stress and Physical and Emotional Health: Implications of the Neuroimmune Network Hypothesis

Early-life stress is associated with increased vulnerability to physical and emotional health problems across the lifespan. The recently developed neuroimmune network hypothesis proposes that one of the underlying mechanisms for these associations is that early-life stress amplifies bidirectional crosstalk between the brain and the immune system, contributing to several mental and physical health conditions that have inflammatory underpinnings, such as depression and coronary heart disease. Neuroimmune crosstalk is thought to perpetuate inflammation and neural alterations linked to early-life stress exposure, and also foster behaviors that can further compromise health, such as smoking, drug abuse and consumption of high-fat diets. The goal of the present review is to briefly summarize the neuroimmune network hypothesis and use it as a starting point for generating new questions about the role of early-life stress in establishing a dysregulated relationship between neural and immune signaling, with consequences for lifespan physical and emotional health. Specifically, we aim to discuss implications and future directions for theory and empirical research on early-life stress, as well as for interventions that may improve the health and well-being of children and adolescents living in adverse conditions.

Frontal brain asymmetry, childhood maltreatment, and low-grade inflammation at midlife

Frontal EEG asymmetry is thought to reflect variations in affective style, such that greater relative right frontal activity at rest predicts enhanced emotional responding to threatening or negative stimuli, and risk of depression and anxiety disorders. A diathesis-stress model has been proposed to explain how this neuro-affective style might predispose to psychopathology, with greater right frontal activity being a vulnerability factor especially under stressful conditions. Less is known about the extent to which greater relative right frontal activity at rest might be associated with or be a diathesis for deleterious physical health outcomes. The present study examined the association between resting frontal EEG asymmetry and systemic, low-grade inflammation and tested the diathesis-stress model by examining whether childhood maltreatment exposure interacts with resting frontal asymmetry in explaining inflammation. Resting EEG, serum inflammatory biomarkers (interleukin-6, C-reactive protein, and fibrinogen) and self-reported psychological measures were available for 314 middle-aged adults (age M=55.3years, SD=11.2, 55.7% female). Analyses supported the diathesis-stress model and revealed that resting frontal EEG asymmetry was significantly associated with inflammation, but only in individuals who had experienced moderate to severe levels of childhood maltreatment. These findings suggest that, in the context of severe adversity, a trait-like tendency towards greater relative right prefrontal activity may predispose to low-grade inflammation, a risk factor for conditions with inflammatory underpinnings such as coronary heart disease.

Inflammation Effects on Motivation and Motor Activity: Role of Dopamine

Motivational and motor deficits are common in patients with depression and other psychiatric disorders, and are related to symptoms of anhedonia and motor retardation. These deficits in motivation and motor function are associated with alterations in corticostriatal neurocircuitry, which may reflect abnormalities in mesolimbic and mesostriatal dopamine (DA). One pathophysiologic pathway that may drive changes in DAergic corticostriatal circuitry is inflammation. Biomarkers of inflammation such as inflammatory cytokines and acute-phase proteins are reliably elevated in a significant proportion of psychiatric patients. A variety of inflammatory stimuli have been found to preferentially target basal ganglia function to lead to impaired motivation and motor activity. Findings have included inflammation-associated reductions in ventral striatal neural responses to reward anticipation, decreased DA and DA metabolites in cerebrospinal fluid, and decreased availability, and release of striatal DA, all of which correlated with symptoms of reduced motivation and/or motor retardation. Importantly, inflammation-associated symptoms are often difficult to treat, and evidence suggests that inflammation may decrease DA synthesis and availability, thus circumventing the efficacy of standard pharmacotherapies. This review will highlight the impact of administration of inflammatory stimuli on the brain in relation to motivation and motor function. Recent data demonstrating similar relationships between increased inflammation and altered DAergic corticostriatal circuitry and behavior in patients with major depressive disorder will also be presented. Finally, we will discuss the mechanisms by which inflammation affects DA neurotransmission and relevance to novel therapeutic strategies to treat reduced motivation and motor symptoms in patients with high inflammation.

Psychoneuroimmunology of Early-Life Stress: The Hidden Wounds of Childhood Trauma?

The brain and the immune system are not fully formed at birth, but rather continue to mature in response to the postnatal environment. The two-way interaction between the brain and the immune system makes it possible for childhood psychosocial stressors to affect immune system development, which in turn can affect brain development and its long-term functioning. Drawing from experimental animal models and observational human studies, we propose that the psychoneuroimmunology of early-life stress can offer an innovative framework to understand and treat psychopathology linked to childhood trauma. Early-life stress predicts later inflammation, and there are striking analogies between the neurobiological correlates of early-life stress and of inflammation. Furthermore, there are overlapping trans-diagnostic patterns of association of childhood trauma and inflammation with clinical outcomes. These findings suggest new strategies to remediate the effect of childhood trauma before the onset of clinical symptoms, such as anti-inflammatory interventions and potentiation of adaptive immunity. Similar strategies might be used to ameliorate the unfavorable treatment response described in psychiatric patients with a history of childhood trauma.

Epigenetic signatures of childhood abuse and neglect: Implications for psychiatric vulnerability

Childhood maltreatment is a key risk factor for poor mental and physical health. Recently, variation in epigenetic processes, such as DNA methylation, has emerged as a potential pathway mediating this association; yet, the extent to which different forms of maltreatment may be characterized by unique vs shared epigenetic signatures is currently unknown. In this study, we quantified DNA methylation across the genome in buccal epithelial cell samples from a high-risk sample of inner-city youth (n = 124; age = 16-24; 53% female), 68% of whom reported experiencing at least one form of maltreatment while growing up. Our analyses aimed to identify methylomic variation associated with exposure to five major types of childhood maltreatment. We found that: (i) maltreatment types differ in the extent to which they associate with methylomic variation, with physical exposures showing the strongest associations; (ii) many of the identified loci are annotated to genes previously implicated in stress-related outcomes, including psychiatric and physical disorders (e.g. GABBR1, GRIN2D, CACNA2D4, PSEN2); and (iii) based on gene ontology analyses, maltreatment types not only show unique methylation patterns enriched for specific biological processes (e.g. physical abuse and cardiovascular function), but also share a 'common' epigenetic signature enriched for biological processes related to neural development and organismal growth. A stringent set of sensitivity analyses were also run to identify high-confidence associations. Together, findings lend novel insights into epigenetic signatures of childhood abuse and neglect, point to novel potential biomarkers for future investigation and support a molecular link between maltreatment and poor health outcomes. Nevertheless, it will be important in future to replicate findings, as the use of cross-sectional data and high rates of polyvictimization in our study make it difficult to fully disentangle the shared vs unique epigenetic signatures of maltreatment types. Furthermore, studies will be needed to test the role of potential moderators in the identified associations, including age of onset and chronicity of maltreatment exposure.

Home sweet home? Home physical environment and inflammation in children

The home environment includes important social and physical contexts within which children develop. Poor physical home environments may be a potential source of stress for children through difficult daily experiences. Using a sub-sample from the Los Angeles Family and Neighborhood Survey (N = 425), we consider how the home physical environment affects stress-related immune system dysregulation in children ages 3-18 years. Results indicated that children in poorer quality homes had higher inflammation (measured by C-reactive protein). The associations were particularly strong for younger children. We also found that part of the home physical environment association with CRP worked through increased risk of obesity for children living in low-quality homes. Future research should assess how home physical environments could be improved to reduce stress and improve health outcomes in children.

Biological embedding: evaluation and analysis of an emerging concept for nursing scholarship

AIM

The purpose of this paper was to report the analysis of the concept of biological embedding.

BACKGROUND

Research that incorporates a life course perspective is becoming increasingly prominent in the health sciences. Biological embedding is a central concept in life course theory and may be important for nursing theories to enhance our understanding of health states in individuals and populations. Before the concept of biological embedding can be used in nursing theory and research, an analysis of the concept is required to advance it towards full maturity.

DESIGN

Concept analysis.

DATA SOURCES

PubMed, CINAHL and PsycINFO were searched for publications using the term 'biological embedding' or 'biological programming' and published through 2015.

METHODS

An evaluation of the concept was first conducted to determine the concept's level of maturity and was followed by a concept comparison, using the methods for concept evaluation and comparison described by Morse.

RESULTS

A consistent definition of biological embedding - the process by which early life experience alters biological processes to affect adult health outcomes - was found throughout the literature. The concept has been used in several theories that describe the mechanisms through which biological embedding might occur and highlight its role in the development of health trajectories. Biological embedding is a partially mature concept, requiring concept comparison with an overlapping concept - biological programming - to more clearly establish the boundaries of biological embedding.

CONCLUSIONS

Biological embedding has significant potential for theory development and application in multiple academic disciplines, including nursing.