Large-scale proteomics in the first trimester of pregnancy predict psychopathology and temperament in preschool children: an exploratory study

BACKGROUND

Understanding the prenatal origins of children's psychopathology is a fundamental goal in developmental and clinical science. Recent research suggests that inflammation during pregnancy can trigger a cascade of fetal programming changes that contribute to vulnerability for the emergence of psychopathology. Most studies, however, have focused on a handful of proinflammatory cytokines and have not explored a range of prenatal biological pathways that may be involved in increasing postnatal risk for emotional and behavioral difficulties.

METHODS

Using extreme gradient boosted machine learning models, we explored large-scale proteomics, considering over 1,000 proteins from first trimester blood samples, to predict behavior in early childhood. Mothers reported on their 3- to 5-year-old children's (N = 89, 51% female) temperament (Child Behavior Questionnaire) and psychopathology (Child Behavior Checklist).

RESULTS

We found that machine learning models of prenatal proteomics predict 5%-10% of the variance in children's sadness, perceptual sensitivity, attention problems, and emotional reactivity. Enrichment analyses identified immune function, nervous system development, and cell signaling pathways as being particularly important in predicting children's outcomes.

CONCLUSIONS

Our findings, though exploratory, suggest processes in early pregnancy that are related to functioning in early childhood. Predictive features included far more proteins than have been considered in prior work. Specifically, proteins implicated in inflammation, in the development of the central nervous system, and in key cell-signaling pathways were enriched in relation to child temperament and psychopathology measures.

Teaching or learning from baby: Inducing explicit parenting goals influences caregiver intrusiveness

Caregivers' goals influence their interactions with their children. In this preregistered study, we examined whether directing parents to teach their baby versus learn from their baby influenced the extent to which they engaged in intrusive (e.g., controlling, adult-centered rather than child-centered), sensitive, warm, or cognitively stimulating caregiving behaviors. Mothers and their 6-month-old infants (N = 66; 32 female infants) from the San Francisco Bay Area participated in a 10-min "free-play" interaction, coded in 2-min epochs for degree of parental intrusiveness. Prior to the final epoch, mothers were randomly assigned to receive instructions to focus on (a) teaching something to their infant or (b) learning something from their infant. A control group of mothers received no instructions. Analyses of within-person changes in intrusive behavior from before to after receiving these instructions indicated that mothers assigned to teach their infant increased in intrusiveness whereas mothers assigned to learn from their infant and mothers in the control group did not significantly change in intrusiveness. The study provides experimental evidence that caregivers' explicit goals to teach infants result, on average, in more controlling and adult-centered caregiving behavior. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Validation of the Assessment of Parent and Child Adversity (APCA) in Mothers and Young Children

OBJECTIVE

Advancing understanding of how early adversity arises, manifests, and contributes to health difficulties depends on accurate measurement of children's experiences. In early life, exposure to adversity is often intertwined with that of one's caregivers. We present preliminary psychometric properties of a novel measure of adversity, the Assessment of Parent and Child Adversity (APCA), which simultaneously characterizes parents' and children's adversity.

METHODS

During pregnancy, women reported their past adverse experiences. When their children were ages 3-5 years (47% female), 97 mothers (71% White, 17% Hispanic/Latinx) completed the APCA, the Childhood Trauma Questionnaire, and the Benevolent Childhood Experiences scale. They reported their current symptoms of depression and anxiety and their child's emotional and behavioral problems. Using the APCA, we distinguished between maternal adversity during different life periods and obtained metrics of child witnessing of and direct exposure to adversity.

RESULTS

The APCA demonstrated validity with other measures of maternal adverse experiences, maternal positive childhood experiences, and maternal symptoms of psychopathology. Children whose mothers experienced greater adversity, particularly in the prenatal period, had more emotional and behavioral problems, as did children who were directly exposed to greater adversity.

CONCLUSIONS

The APCA has good usability and validity. Leveraging the ability of the APCA to distinguish between adversity during different life stages and originating from different sources, our findings highlight potentially distinct effects of different aspects of maternal and child adversity on difficulties in maternal and child mental health.

A Comprehensive Multilevel Analysis of the Bucharest Early Intervention Project: Causal Effects on Recovery From Early Severe Deprivation

OBJECTIVE

The Bucharest Early Intervention Project is the first randomized controlled trial of foster care as an alternative to institutional care. The authors synthesized data from nearly 20 years of assessments of the trial to determine the overall intervention effect size across time points and developmental domains. The goal was to quantify the overall effect of the foster care intervention on children's outcomes and examine sources of variation in this effect, including domain, age, and sex assigned at birth.

METHODS

An intent-to-treat approach was used to examine the causal effects of the randomized controlled trial for 136 children residing in institutions in Bucharest, Romania (baseline age, 6-31 months) who were randomly assigned to either foster care (N=68) or care as usual (N=68). At ages 30, 42, and 54 months and 8, 12, and 16-18 years, children were assessed for IQ, physical growth, brain electrical activity (EEG), and symptoms of five types of psychopathology.

RESULTS

Participants provided 7,088 observations across follow-up waves. Children assigned to foster care had better cognitive and physical outcomes and less severe psychopathology than did those who received care as usual. The magnitude of these effect sizes remained stable across development. The foster care intervention most influenced IQ and disorders of attachment/social relatedness.

CONCLUSIONS

Young children benefit from placement in families after institutional care. The benefits of foster care for previously institutionalized children were remarkably stable across development.

Socially Stratified Epigenetic Profiles Are Associated With Cognitive Functioning in Children and Adolescents

Children's cognitive functioning and educational performance are socially stratified. Social inequality, including classism and racism, may operate partly via epigenetic mechanisms that modulate neurocognitive development. Following preregistered analyses of data from 1,183 participants, ages 8 to 19 years, from the Texas Twin Project, we found that children growing up in more socioeconomically disadvantaged families and neighborhoods and children from marginalized racial/ethnic groups exhibit DNA methylation profiles that, in previous studies of adults, were indicative of higher chronic inflammation, lower cognitive functioning, and a faster pace of biological aging. Furthermore, children's salivary DNA methylation profiles were associated with their performance on in-laboratory tests of cognitive and academic skills, including processing speed, general executive function, perceptual reasoning, verbal comprehension, reading, and math. Given that the DNA methylation measures that we examined were originally developed in adults, our results suggest that children show molecular signatures that reflect the early life social determinants of lifelong disparities in health and cognition.

Pregnancy during the pandemic: the impact of COVID-19-related stress on risk for prenatal depression

BACKGROUND

Pregnant women may be especially susceptible to negative events (i.e. adversity) related to the coronavirus disease 2019 (COVID-19) pandemic and negative affective responses to these events (i.e. stress). We examined the latent structure of stress and adversity related to the COVID-19 pandemic among pregnant women, potential antecedents of COVID-19-related stress and adversity in this population, and associations with prenatal depressive symptoms.

METHOD

We surveyed 725 pregnant women residing in the San Francisco Bay Area in March-May 2020, 343 of whom provided addresses that were geocoded and matched by census tract to measures of community-level risk. We compared their self-reported depressive symptoms to women matched on demographic factors and history of mental health difficulties who were pregnant prior to the pandemic.

RESULTS

Women who were pregnant during the pandemic were nearly twice as likely to have possible depression than were matched women who were pregnant prior to the pandemic. Individual- and community-level factors tied to socioeconomic inequality were associated with latent factors of COVID-19-related stress and adversity. Beyond objective adversity, subjective stress responses were strongly associated with depressive symptoms during the pandemic.

CONCLUSIONS

Highlighting the role of subjective responses in vulnerability to prenatal depression and factors that influence susceptibility to COVID-19-related stress, these findings inform the allocation of resources to support recovery from this pandemic and future disease outbreaks. In addition to policies that mitigate disruptions to the environment due to the pandemic, treatments that focus on cognitions about the self and the environment may help to alleviate depressive symptoms in pregnant women.

Empathy for others versus for one's child: Associations with mothers' brain activation during a social cognitive task and with their toddlers' functioning

Caregivers who are higher in dispositional empathy tend to have children with better developmental outcomes; however, few studies have considered the role of child-directed (i.e., "parental") empathy, which may be relevant for the caregiver-child relationship. We hypothesized that mothers' parental empathy during their child's infancy will be a stronger predictor of their child's social-emotional functioning as a toddler than will mothers' dispositional empathy. We further explored whether parental and dispositional empathy have shared or distinct patterns of neural activation during a social-cognitive movie-watching task. In 118 mother-infant dyads, greater parental empathy assessed when infants were 6 months old was associated with more social-emotional competencies and fewer problems in the children 1 year later, even after adjusting for dispositional empathy. In contrast, dispositional empathy was not associated with child functioning when controlling for parental empathy. In a subset of 20 mothers, insula activation was positively associated with specific facets of both dispositional and parental empathy, whereas right temporoparietal junction activation was associated only with parental empathy. Thus, dispositional and parental empathy appear to be dissociable by both brain and behavioral metrics. Parental empathy may be a viable target for interventions, especially for toddlers at risk for developing social-emotional difficulties.

Geotemporal analysis of perinatal care changes and maternal mental health: an example from the COVID-19 pandemic

Our primary objective was to document COVID-19 induced changes to perinatal care across the USA and examine the implication of these changes for maternal mental health. We performed an observational cross-sectional study with convenience sampling using direct patient reports from 1918 postpartum and 3868 pregnant individuals collected between April 2020 and December 2020 from 10 states across the USA. We leverage a subgroup of these participants who gave birth prior to March 2020 to estimate the pre-pandemic prevalence of specific birthing practices as a comparison. Our primary analyses describe the prevalence and timing of perinatal care changes, compare perinatal care changes depending on when and where individuals gave birth, and assess the linkage between perinatal care alterations and maternal anxiety and depressive symptoms. Seventy-eight percent of pregnant participants and 63% of postpartum participants reported at least one change to their perinatal care between March and August 2020. However, the prevalence and nature of specific perinatal care changes occurred unevenly over time and across geographic locations. The separation of infants and mothers immediately after birth and the cancelation of prenatal visits were associated with worsened depression and anxiety symptoms in mothers after controlling for sociodemographic factors, mental health history, number of pregnancy complications, and general stress about the COVID-19 pandemic. Our analyses reveal widespread changes to perinatal care across the US that fluctuated depending on where and when individuals gave birth. Disruptions to perinatal care may also exacerbate mental health concerns, so focused treatments that can mitigate the negative psychiatric sequelae of interrupted care are warranted.

Infants who experience more adult-initiated conversations have better expressive language in toddlerhood

To understand how infants become engaged in conversations with their caregivers, we examined who tends to initiate conversations between adults and infants, differences between the features of infant- and adult-initiated conversations, and whether individual differences in how much infants engage in infant- or adult-initiated conversations uniquely predict later language development. We analyzed naturalistic adult-infant conversations captured via passive recording of the daily environment in two samples of 6-month-old infants. In Study 1, we found that at age 6 months, infants typically engage in more adult- than infant-initiated conversations and that adult-initiated conversations are, on average, longer and contain more adult words. In Study 2, we replicated these findings and, further, found that infants who engaged in more adult-initiated conversations in infancy had better expressive language at age 18 months. This association remained significant when accounting for the number of infant-initiated conversations at 6 months. Our findings indicate that early interactions with caregivers can have a lasting impact on children's language development, and that the extent to which parents initiate interactions with their infants may be particularly important.

Maternal attachment insecurity, maltreatment history, and depressive symptoms are associated with broad DNA methylation signatures in infants

The early environment, including maternal characteristics, provides many cues to young organisms that shape their long-term physical and mental health. Identifying the earliest molecular events that precede observable developmental outcomes could help identify children in need of support prior to the onset of physical and mental health difficulties. In this study, we examined whether mothers' attachment insecurity, maltreatment history, and depressive symptoms were associated with alterations in DNA methylation patterns in their infants, and whether these correlates in the infant epigenome were associated with socioemotional and behavioral functioning in toddlerhood. We recruited 156 women oversampled for histories of depression, who completed psychiatric interviews and depression screening during pregnancy, then provided follow-up behavioral data on their children at 18 months. Buccal cell DNA was obtained from 32 of their infants for a large-scale analysis of methylation patterns across 5 × 106 individual CpG dinucleotides, using clustering-based significance criteria to control for multiple comparisons. We found that tens of thousands of individual infant CpGs were alternatively methylated in association with maternal attachment insecurity, maltreatment in childhood, and antenatal and postpartum depressive symptoms, including genes implicated in developmental patterning, cell-cell communication, hormonal regulation, immune function/inflammatory response, and neurotransmission. Density of DNA methylation at selected genes from the result set was also significantly associated with toddler socioemotional and behavioral problems. This is the first report to identify novel regions of the human infant genome at which DNA methylation patterns are associated longitudinally both with maternal characteristics and with offspring socioemotional and behavioral problems in toddlerhood.

Correlates and predictors of the severity of suicidal ideation in adolescence: an examination of brain connectomics and psychosocial characteristics

BACKGROUND

Suicidal ideation (SI) typically emerges during adolescence but is challenging to predict. Given the potentially lethal consequences of SI, it is important to identify neurobiological and psychosocial variables explaining the severity of SI in adolescents.

METHODS

In 106 participants (59 female) recruited from the community, we assessed psychosocial characteristics and obtained resting-state fMRI data in early adolescence (baseline: aged 9-13 years). Across 250 brain regions, we assessed local graph theory-based properties of interconnectedness: local efficiency, eigenvector centrality, nodal degree, within-module z-score, and participation coefficient. Four years later (follow-up: ages 13-19 years), participants self-reported their SI severity. We used least absolute shrinkage and selection operator (LASSO) regressions to identify a linear combination of psychosocial and brain-based variables that best explain the severity of SI symptoms at follow-up. Nested-cross-validation yielded model performance statistics for all LASSO models.

RESULTS

A combination of psychosocial and brain-based variables explained subsequent severity of SI (R² = .55); the strongest was internalizing and externalizing symptom severity at follow-up. Follow-up LASSO regressions of psychosocial-only and brain-based-only variables indicated that psychosocial-only variables explained 55% of the variance in SI severity; in contrast, brain-based-only variables performed worse than the null model.

CONCLUSIONS

A linear combination of baseline and follow-up psychosocial variables best explained the severity of SI. Follow-up analyses indicated that graph theory resting-state metrics did not increase the prediction of the severity of SI in adolescents. Attending to internalizing and externalizing symptoms is important in early adolescence; resting-state connectivity properties other than local graph theory metrics might yield a stronger prediction of the severity of SI.

Caregiver regulation: A modifiable target promoting resilience to early adverse experiences

BACKGROUND

Experiences of adversity in early life are associated with increased risk for negative outcomes; yet, the impact of early adversity on any given child is difficult to predict given the considerable heterogeneity in functioning found even among children with similar exposures. Thus, although early adversity is associated with increased risk for negative outcomes on average, many children are resilient. While researchers have highlighted individual differences in children's internal characteristics that may relate to risk and resilience, external characteristics of the environment that differ between children are mutable factors that are also important for understanding heterogeneity in children's outcomes.

OBJECTIVE

We propose that caregiver regulation of children's emotions is a key modifiable feature of the environment that promotes resilience to and recovery from early adversity. Specifically, given the critical role of caregiver regulation of emotions in early life for children's ability to understand and recover from adverse experiences, we highlight three levels of intervention focused on fostering healthy development in young children by targeting the availability, consistency, and quality of caregiver regulation, respectively.

RESULTS

We provide a classification system designed to guide decision making about the level of intervention needed to support a given child's needs in terms of ultimately supporting the goal of receiving effective caregiver regulation.

IMPLICATIONS

This framework may be useful for guiding the priority of treatments, as well as making clear the needed menu of options to support children following adversity, in addressing specific concerns related to ensuring effective caregiver regulation to promote resilience. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Hair cortisol concentration across the peripartum period: Documenting changes and associations with depressive symptoms and recent adversity

Women experience dramatic physiological changes during pregnancy, including changes in the production of the “stress hormone,” cortisol. Evidence has been mixed regarding whether hair cortisol concentration (HCC) can be used to accurately capture the trajectory of cortisol during this period and whether factors related to psychosocial stress are related to HCC in pregnant and postpartum women. In the current study, we collected hair samples from 85 individuals during the peripartum period (with collection occasions in pregnancy [12–37 weeks], at 3–8 weeks postpartum, and at 5–8 months postpartum) from which we derived 783 monthly observations of HCC. In addition, at each assessment individuals reported their current depressive symptoms and experiences of recent psychosocial adversity. Using piecewise mixed effects modeling, we identified significant increases in HCC across pregnancy (approximately a 2-fold rise) followed by significant decreases in HCC postpartum. Beyond these effects, however, there was substantial within-individual variability in HCC. Disaggregating between- from within-individual associations of depressive symptoms and adversity with HCC, we found that within-individual fluctuations in adversity were positively coupled with levels of HCC. Overall, the current findings suggest that measurement of cortisol in human hair captures its trajectory from conception through six months postpartum, including prenatal increases and gradual recovery of typical levels following childbirth. In addition to the overall severity of psychosocial adversity, change in women's experiences of adversity during the peripartum period merit attention.

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We analyzed monthly estimates of hair cortisol concentration (HCC) across the peripartum period.

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HCC increased across pregnancy and decreased through six months postpartum.

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There was substantial within-person variability in HCC.

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Within-person fluctuations in recent adversity were positively coupled with HCC.

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Depressive symptoms were not significantly associated with HCC.

Behavioral coping phenotypes and associated psychosocial outcomes of pregnant and postpartum women during the COVID-19 pandemic

The impact of COVID-19-related stress on perinatal women is of heightened public health concern given the established intergenerational impact of maternal stress-exposure on infants and fetuses. There is urgent need to characterize the coping styles associated with adverse psychosocial outcomes in perinatal women during the COVID-19 pandemic to help mitigate the potential for lasting sequelae on both mothers and infants. This study uses a data-driven approach to identify the patterns of behavioral coping strategies that associate with maternal psychosocial distress during the COVID-19 pandemic in a large multicenter sample of pregnant women (N = 2876) and postpartum women (N = 1536). Data was collected from 9 states across the United States from March to October 2020. Women reported behaviors they were engaging in to manage pandemic-related stress, symptoms of depression, anxiety and global psychological distress, as well as changes in energy levels, sleep quality and stress levels. Using latent profile analysis, we identified four behavioral phenotypes of coping strategies. Critically, phenotypes with high levels of passive coping strategies (increased screen time, social media, and intake of comfort foods) were associated with elevated symptoms of depression, anxiety, and global psychological distress, as well as worsening stress and energy levels, relative to other coping phenotypes. In contrast, phenotypes with high levels of active coping strategies (social support, and self-care) were associated with greater resiliency relative to other phenotypes. The identification of these widespread coping phenotypes reveals novel behavioral patterns associated with risk and resiliency to pandemic-related stress in perinatal women. These findings may contribute to early identification of women at risk for poor long-term outcomes and indicate malleable targets for interventions aimed at mitigating lasting sequelae on women and children during the COVID-19 pandemic.

Revealing the impact of lifestyle stressors on the risk of adverse pregnancy outcomes with multitask machine learning

Psychosocial and stress-related factors (PSFs), defined as internal or external stimuli that induce biological changes, are potentially modifiable factors and accessible targets for interventions that are associated with adverse pregnancy outcomes (APOs). Although individual APOs have been shown to be connected to PSFs, they are biologically interconnected, relatively infrequent, and therefore challenging to model. In this context, multi-task machine learning (MML) is an ideal tool for exploring the interconnectedness of APOs on the one hand and building on joint combinatorial outcomes to increase predictive power on the other hand. Additionally, by integrating single cell immunological profiling of underlying biological processes, the effects of stress-based therapeutics may be measurable, facilitating the development of precision medicine approaches.

OBJECTIVES

The primary objectives were to jointly model multiple APOs and their connection to stress early in pregnancy, and to explore the underlying biology to guide development of accessible and measurable interventions.

MATERIALS AND METHODS

In a prospective cohort study, PSFs were assessed during the first trimester with an extensive self-filled questionnaire for 200 women. We used MML to simultaneously model, and predict APOs (severe preeclampsia, superimposed preeclampsia, gestational diabetes and early gestational age) as well as several risk factors (BMI, diabetes, hypertension) for these patients based on PSFs. Strongly interrelated stressors were categorized to identify potential therapeutic targets. Furthermore, for a subset of 14 women, we modeled the connection of PSFs to the maternal immune system to APOs by building corresponding ML models based on an extensive single cell immune dataset generated by mass cytometry time of flight (CyTOF).

RESULTS

Jointly modeling APOs in a MML setting significantly increased modeling capabilities and yielded a highly predictive integrated model of APOs underscoring their interconnectedness. Most APOs were associated with mental health, life stress, and perceived health risks. Biologically, stressors were associated with specific immune characteristics revolving around CD4/CD8 T cells. Immune characteristics predicted based on stress were in turn found to be associated with APOs.

CONCLUSIONS

Elucidating connections among stress, multiple APOs simultaneously, and immune characteristics has the potential to facilitate the implementation of ML-based, individualized, integrative models of pregnancy in clinical decision making. The modifiable nature of stressors may enable the development of accessible interventions, with success tracked through immune characteristics.

Advancing the RDoC initiative through the assessment of caregiver social processes

The relationships infants and young children have with their caregivers are fundamental to their survival and well-being. Theorists and researchers across disciplines have attempted to describe and assess the variation in these relationships, leading to a general acceptance that caregiving is critical to understanding child functioning, including developmental psychopathology. At the same time, we lack consensus on how to assess these fundamental relationships. In the present paper, we first review research documenting the importance of the caregiver-child relationship in understanding environmental risk for psychopathology. Second, we propose that the National Institute of Mental Health's Research Domain Criteria (RDoC) initiative provides a useful framework for extending the study of children's risk for psychopathology by assessing their caregivers' social processes. Third, we describe the units of analysis for caregiver social processes, documenting how the specific subconstructs in the domain of social processes are relevant to the goal of enhancing knowledge of developmental psychopathology. Lastly, we highlight how past research can inform new directions in the study of caregiving and the parent-child relationship through this innovative extension of the RDoC initiative.

Mechanisms of neuroplasticity linking early adversity to depression: developmental considerations

Early exposure to psychosocial adversity is among the most potent predictors of depression. Because depression commonly emerges prior to adulthood, we must consider the fundamental principles of developmental neuroscience when examining how experiences of childhood adversity, including abuse and neglect, can lead to depression. Considering that both the environment and the brain are highly dynamic across the period spanning gestation through adolescence, the purpose of this review is to discuss and integrate stress-based models of depression that center developmental processes. We offer a general framework for understanding how psychosocial adversity in early life disrupts or calibrates the biobehavioral systems implicated in depression. Specifically, we propose that the sources and nature of the environmental input shaping the brain, and the mechanisms of neuroplasticity involved, change across development. We contend that the effects of adversity largely depend on the developmental stage of the organism. First, we summarize leading neurobiological models that focus on the effects of adversity on risk for mental disorders, including depression. In particular, we highlight models of allostatic load, acceleration maturation, dimensions of adversity, and sensitive or critical periods. Second, we expound on and review evidence for the formulation that distinct mechanisms of neuroplasticity are implicated depending on the timing of adverse experiences, and that inherent within certain windows of development are constraints on the sources and nature of these experiences. Finally, we consider other important facets of adverse experiences (e.g., environmental unpredictability, perceptions of one's experiences) before discussing promising research directions for the future of the field.

Attachment Security in Pregnancy Mediates the Association Between Maternal Childhood Maltreatment and Emotional and Behavioral Problems in Offspring

Attachment security may be a mechanism by which exposure to early life adversity affects subsequent generations. We used a prospective cohort design to examine this possibility in a convenience sample of 124 women (age = 23-45 years, M = 32.32 [SD = 4.83] years; 57.3% White, 22.6% Asian) who provided self-reports of attachment style during pregnancy using the Attachment Style Questionnaire, of whom 96 (age = 28-50 years, M = 36.67 [SD = 4.90] years; 60.4% White, 19.8% Asian) were reassessed when their child was preschool-age (M = 4.38 [SD = 1.29] years). Women self-reported on their own childhood maltreatment severity and their child's current emotional and behavioral problems using the Childhood Trauma Questionnaire and the Child Behavior Checklist for ages 1.5-5, respectively. Maternal childhood maltreatment severity was associated with less secure, and more avoidant and anxious attachment. Mediation analyses revealed further that less secure maternal attachment, but not avoidant or anxious attachment, mediated the associations between maternal childhood maltreatment and offspring emotional and behavioral problems. These findings suggest that improving maternal attachment security, which can be identified even prior to the child's birth, is an important target to consider for intervention efforts aimed at minimizing adverse intergenerational effects of early life adversity.

Dimensions of the language environment in infancy and symptoms of psychopathology in toddlerhood

The quality of the early environment influences the development of psychopathology. Children who are deprived of sufficient environmental enrichment in infancy may be at higher risk for developing symptoms of psychopathology in toddlerhood. In this study, we investigated the prospective association between naturalistic measures of adult language input obtained through passive monitoring of infants' daily environments and emerging psychopathology in toddlerhood. In a sample of 100 mothers and their infants recruited from the community (mean age [range] = 6.73 [5-9] months), we used the Language ENvironment Analysis (LENA) system to measure multiple dimensions of infants' language environments, including both the quantity and consistency of adult speech and conversational turns in infants' daily lives as well as the quantity of infant vocalizations. Subsequently, during toddlerhood (mean age [range] = 18.29 [17-21] months), mothers reported on their children's symptoms of psychopathology. Infants who experienced more consistent adult speech and conversational turns had lower symptoms of psychopathology in toddlerhood, independent of negative emotionality in infancy, maternal depressive symptoms, and laboratory-based measures of maternal sensitivity. These findings have implications for the measurement of environmental factors that may confer risk and resilience to emerging psychopathology.

Prenatal and postnatal depressive symptoms, infant white matter, and toddler behavioral problems

BACKGROUND

Maternal depression is prevalent during and following pregnancy and is related to adverse outcomes in offspring. Perinatal depression is associated with risk for difficulties in offspring; however, the mechanisms underlying this association are not clear. We examined whether maternal prenatal and postnatal depressive symptoms were associated with infant white matter organization and with behavioral problems in toddlerhood.

METHODS

37 mother-infant dyads (20 male; ages 5.95-7.66 months) participated in this study. We conducted diffusion MRI with infants during natural sleep. Mothers reported on their prenatal and postnatal depressive symptoms at six months postpartum. We calculated fractional anisotropy (FA), radial, axial, and mean diffusivity, and assessed offspring behavioral problems at age 18 months.

RESULTS

Prenatal depressive symptoms were associated with FA of the corpus callosum; postnatal depressive symptoms were not associated with FA of limbic tracts or corpus callosum segmentations. Higher levels of prenatal depressive symptoms were associated with higher FA and lower radial diffusivity of the corpus callosum genu; FA of this region was positively associated with behavioral problems at age 18 months.

LIMITATIONS

This study had a small sample size; therefore, findings should be replicated. Further, we used retrospective reports of maternal prenatal depression, but validated them in this study.

CONCLUSIONS

Depressive symptoms during pregnancy may affect infant corpus callosum development and, in turn, offspring behaviors. These findings suggest that early maternal stress accelerates infant neurodevelopment in a manner that may increase risk for behavioral problems. Thus, efforts to reduce maternal prenatal depression should be a public health priority.

Naturalistic Language Input is Associated with Resting-State Functional Connectivity in Infancy

The quantity and quality of the language input that infants receive from their caregivers affects their future language abilities; however, it is unclear how variation in this input relates to preverbal brain circuitry. The current study investigated the relation between naturalistic language input and the functional connectivity (FC) of language networks in human infancy using resting-state functional magnetic resonance imaging (rsfMRI). We recorded the naturalistic language environments of five- to eight-month-old male and female infants using the Linguistic ENvironment Analysis (LENA) system and measured the quantity and consistency of their exposure to adult words (AWs) and adult-infant conversational turns (CTs). Infants completed an rsfMRI scan during natural sleep, and we examined FC among regions of interest (ROIs) previously implicated in language comprehension, including the auditory cortex, the left inferior frontal gyrus (IFG), and the bilateral superior temporal gyrus (STG). Consistent with theory of the ontogeny of the cortical language network (Skeide and Friederici, 2016), we identified two subnetworks posited to have distinct developmental trajectories: a posterior temporal network involving connections of the auditory cortex and bilateral STG and a frontotemporal network involving connections of the left IFG. Independent of socioeconomic status (SES), the quantity of CTs was uniquely associated with FC of these networks. Infants who engaged in a larger number of CTs in daily life had lower connectivity in the posterior temporal language network. These results provide evidence for the role of vocal interactions with caregivers, compared with overheard adult speech, in the function of language networks in infancy.

The structure of depressive symptoms and characteristics and their relation to overall severity in major depressive disorder

Although many investigators have examined symptoms of major depressive disorder (MDD), the multivariate relations among these features of depression and their relative associations with overall severity of depression are not well understood. The present study is the first to examine the underlying factor structure of depression across a broad set of constructs and to model the multivariate association of these factors with the overall severity of depression. We conducted a large-scale factor analysis and multiple regression in a sample of participants diagnosed with MDD (N = 233) and healthy controls (N = 235). We obtained a five-factor solution composed of the following factors: (1) anxiety; (2) behavioral activation; (3) core symptoms; (4) rumination; and (5) emotional intensity. The core symptoms factor, composed primarily of DSM-5 diagnostic criteria for MDD, was the only factor that showed a consistent, significant association with overall severity of depression and functional impairment. Rumination combined with behavioral inhibition and positive and negative affect combined with each other to form coherent constructs that may be useful in examining differences among depressed individuals. These findings provide an important data-driven framework for the multidimensional symptom structure of depression and suggest several actionable ways for improving clinical assessment and treatment for individuals with MDD.

Cerebral blood flow in 5- to 8-month-olds: Regional tissue maturity is associated with infant affect

Infancy is marked by rapid neural and emotional development. The relation between brain function and emotion in infancy, however, is not well understood. Methods for measuring brain function predominantly rely on the BOLD signal; however, interpretation of the BOLD signal in infancy is challenging because the neuronal-hemodynamic relation is immature. Regional cerebral blood flow (rCBF) provides a context for the infant BOLD signal and can yield insight into the developmental maturity of brain regions that may support affective behaviors. This study aims to elucidate the relations among rCBF, age, and emotion in infancy. One hundred and seven mothers reported their infants' (infant age M ± SD = 6.14 ± 0.51 months) temperament. A subsample of infants completed MRI scans, 38 of whom produced usable perfusion MRI during natural sleep to quantify rCBF. Mother-infant dyads completed the repeated Still-Face Paradigm, from which infant affect reactivity and recovery to stress were quantified. We tested associations of infant age at scan, temperament factor scores, and observed affect reactivity and recovery with voxel-wise rCBF. Infant age was positively associated with CBF in nearly all voxels, with peaks located in sensory cortices and the ventral prefrontal cortex, supporting the formulation that rCBF is an indicator of tissue maturity. Temperamental Negative Affect and recovery of positive affect following a stressor were positively associated with rCBF in several cortical and subcortical limbic regions, including the orbitofrontal cortex and inferior frontal gyrus. This finding yields insight into the nature of affective neurodevelopment during infancy. Specifically, infants with relatively increased prefrontal cortex maturity may evidence a disposition toward greater negative affect and negative reactivity in their daily lives yet show better recovery of positive affect following a social stressor.

Cross-sectional and longitudinal associations of family income-to-needs ratio with cortical and subcortical brain volume in adolescent boys and girls

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Sex-specific associations of SES with neurodevelopment may emerge in adolescence.

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We used a whole-brain approach to examine gray and white matter volume.

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Sex interacted with SES to explain variation in volume across adolescence.

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Sex is an important variable to consider in analyses of SES and brain volume.

Deviations in neurodevelopment may underlie the association between lower childhood socioeconomic status and difficulties in cognitive and socioemotional domains. Most previous investigations of the association between childhood socioeconomic status and brain morphology have used cross-sectional designs with samples that span wide age ranges, occluding effects specific to adolescence. Sex differences in the association between socioeconomic status and neurodevelopment may emerge or intensify during adolescence. In a sample representative of the San Francisco Bay Area, we used whole-brain tensor-based morphometry to examine sex differences in the cross-sectional association between variation in family income-to-needs ratio (INR) and cortical and subcortical gray and white matter volume during early adolescence (ages 9–13 years; N = 147), as well as in the longitudinal association between INR and change in volume from early to later adolescence (ages 11–16 years, N = 109). Biological sex interacted with INR to explain variation in volume in several areas cross-sectionally and longitudinally. Effects were primarily in cortical gray matter areas, including regions of the association cortex and sensorimotor processing areas. Effect sizes tended to be larger in boys than in girls. Biological sex may be an important variable to consider in analyses of the effects of family income on structural neurodevelopment during adolescence.

Associations of waking cortisol with DHEA and testosterone across the pubertal transition: Effects of threat-related early life stress

Atypical regulation of the hypothalamic-pituitary-adrenal (HPA) axis is a putative mechanism underlying the association between exposure to early life stress (ELS) and the subsequent development of mental and physical health difficulties. Recent research indicates that puberty is a period of HPA-axis plasticity during which the effects of exposure to ELS on cortisol regulation may change. In particular, increases in the sex hormones that drive pubertal maturation, including dehydroepiandrosterone (DHEA) and testosterone, may be implicated in pubertal recalibration of cortisol regulation. In the current study, we examined the associations among levels of objectively-rated threat-related ELS and salivary waking cortisol, DHEA, and testosterone in a sample of 178 adolescents (55 % female) who were in early puberty at baseline (Tanner stages 1-3; mean Tanner stage[SD] = 1.93[0.64]; mean age[SD] = 11.42[1.04]) and were followed up approximately two years later (mean Tanner stage[SD] = 3.46[0.86]; mean age[SD] = 13.38[1.06]). Using multi-level modeling, we disaggregated the effects of between-individual levels and within-individual increases in pubertal stage and sex hormones on change in cortisol. Controlling for between-individual differences in average pubertal stage, the association between levels of cortisol and DHEA was more strongly positive among adolescents who evidenced greater within-individual increases in pubertal stage across time. Both higher average levels and greater within-individual increases in DHEA and testosterone were associated with increases in cortisol across time, indicating positive coupling of developmental changes in these hormones; however, coupling was attenuated in adolescents who were exposed to more severe threat-related ELS prior to puberty. These findings advance our understanding of the development of the HPA-axis and its association with childhood environmental risk during puberty.

Early Life Stress, Frontoamygdala Connectivity, and Biological Aging in Adolescence: A Longitudinal Investigation

Early life stress (ELS) may accelerate frontoamygdala development related to socioemotional processing, serving as a potential source of resilience. Whether this circuit is associated with other proposed measures of accelerated development is unknown. In a sample of young adolescents, we examined the relations among ELS, frontoamygdala circuitry during viewing of emotional faces, cellular aging as measured by telomere shortening, and pubertal tempo. We found that greater cumulative severity of ELS was associated with stronger negative coupling between bilateral centromedial amygdala and the ventromedial prefrontal cortex, a pattern that may reflect more mature connectivity. More negative frontoamygdala coupling (for distinct amygdala subdivisions) was associated with slower telomere shortening and pubertal tempo over 2 years. These potentially protective associations of negative frontoamygdala connectivity were most pronounced in adolescents who had been exposed to higher ELS. Our findings provide support for the formulation that ELS accelerates maturation of frontoamygdala connectivity and provide novel evidence that this neural circuitry confers protection against accelerated biological aging, particularly for adolescents who have experienced higher ELS. Although negative frontoamygdala connectivity may be an adaptation to ELS, frontoamygdala connectivity, cellular aging, and pubertal tempo do not appear to be measures of the same developmental process.

Early life stress, cortisol, frontolimbic connectivity, and depressive symptoms during puberty

Early life stress (ELS) is a risk factor for the development of depression in adolescence; the mediating neurobiological mechanisms, however, are unknown. In this study, we examined in early pubertal youth the associations among ELS, cortisol stress responsivity, and white matter microstructure of the uncinate fasciculus and the fornix, two key frontolimbic tracts; we also tested whether and how these variables predicted depressive symptoms in later puberty. A total of 208 participants (117 females; M age = 11.37 years; M Tanner stage = 2.03) provided data across two or more assessment modalities: ELS; salivary cortisol levels during a psychosocial stress task; diffusion magnetic resonance imaging; and depressive symptoms. In early puberty there were significant associations between higher ELS and decreased cortisol production, and between decreased cortisol production and increased fractional anisotropy in the uncinate fasciculus. Further, increased fractional anisotropy in the uncinate fasciculus predicted higher depressive symptoms in later puberty, above and beyond earlier symptoms. In post hoc analyses, we found that sex moderated several additional associations. We discuss these findings within a broader conceptual model linking ELS, emotion dysregulation, and depression across the transition through puberty, and contend that brain circuits implicated in the control of hypothalamic-pituitary-adrenal axis function should be a focus of continued research.

Irritability and brain volume in adolescents: cross-sectional and longitudinal associations

Irritability is garnering increasing attention in psychiatric research as a transdiagnostic marker of both internalizing and externalizing disorders. These disorders often emerge during adolescence, highlighting the need to examine changes in the brain and in psychological functioning during this developmental period. Adolescents were recruited for a longitudinal study examining the effects of early life stress on the development of psychopathology. The 151 adolescents (73 M/78 F, average age = 11.5 years, standard deviation = 1.1) were scanned with a T1-weighted MRI sequence and parents completed reports of adolescent irritability using the Affective Reactivity Index. Of these 151 adolescents, 94 (46 M/48 F) returned for a second session (average interval = 1.9 years, SD = 0.4). We used tensor-based morphometry to examine cross-sectional and longitudinal associations between irritability and regional brain volume. Irritability was associated with brain volume across a number of regions. More irritable individuals had larger hippocampi, insula, medial orbitofrontal cortex and cingulum/cingulate cortex and smaller putamen and internal capsule. Across the brain, more irritable individuals also had larger volume and less volume contraction in a number of areas that typically decrease in volume over the developmental period studied here, suggesting delayed maturation. These structural changes may increase adolescents' vulnerability for internalizing and externalizing disorders.

Mothers' postpartum sleep disturbance is associated with the ability to sustain sensitivity toward infants

BACKGROUND/OBJECTIVE

Infancy is a period of rapid development when the quality of caregiving behavior may be particularly consequential for children's long-term functioning. During this critical period for caregiving behavior, parents experience changes in their sleep that may affect their ability to provide sensitive care. The current study investigated the association of mothers' sleep disturbance with both levels and trajectories of maternal sensitivity during interactions with their infants.

METHODS

At 18 weeks postpartum, mothers and their infants were observed during a home-based 10-minute "free play" interaction. Mothers' nighttime sleep was objectively measured using actigraphy and subjectively measured using sleep diaries. Maternal sensitivity was coded in two-minute intervals in order to characterize changes in sensitivity across the free play interaction. We used exploratory factor analysis to reduce the dimensionality of the objective and subjective measures of mothers' sleep, identifying a subjective sleep disturbance and an objective sleep continuity factor.

RESULTS

Using multi-level modeling, we found that mothers with poorer objective sleep continuity evidenced decreasing sensitivity toward their infants across the interaction. Mothers' self-reports of sleep disturbance were not associated with maternal sensitivity.

CONCLUSIONS

Although future research is necessary to identify the mechanisms that may explain the observed association between poor sleep continuity and the inability to sustain sensitivity toward infants, mothers' postpartum sleep continuity may be one factor to consider when designing interventions to improve the quality of caregiving.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, NCT01846585.

A person-centered approach to the assessment of early life stress: Associations with the volume of stress-sensitive brain regions in early adolescence

Researchers are becoming increasingly interested in linking specific forms of early life stress (ELS) to specific neurobiological markers, including alterations in the morphology of stress-sensitive brain regions. We used a person-centered, multi-informant approach to investigate the associations of specific constellations of ELS with hippocampal and amygdala volume in a community sample of 211 9- to 13-year-old early adolescents. Further, we compared this approach to a cumulative risk model of ELS, in which ELS was quantified by the total number of stressors reported. Using latent class analysis, we identified three classes of ELS (labeled typical/low, family instability, and direct victimization) that were distinguished by experiences of family instability and victimization. Adolescents in the direct victimization class had significantly smaller hippocampal volume than did adolescents in the typical/low class; ELS classes were not significantly associated with amygdala volume. The cumulative risk model of ELS had a poorer fit than did the person-centered model; moreover, cumulative ELS was not significantly associated with hippocampal or amygdala volume. Our results underscore the utility of taking a person-centered approach to identify alterations in stress-sensitive brain regions based on constellations of ELS, and suggest victimization is specifically associated with hippocampal hypotrophy observed in early adolescence.

Stressful Life Events, ADHD Symptoms, and Brain Structure in Early Adolescence

Despite a growing understanding that early adversity in childhood broadly affects risk for psychopathology, the contribution of stressful life events to the development of symptoms of attention-deficit/hyperactivity disorder (ADHD) is not clear. In the present study, we examined the association between number of stressful life events experienced and ADHD symptoms, assessed using the Attention Problems subscale of the Child Behavior Checklist, in a sample of 214 children (43% male) ages 9.11-13.98 years (M = 11.38, SD = 1.05). In addition, we examined whether the timing of the events (i.e., onset through age 5 years or after age 6 years) was associated with ADHD symptoms. Finally, we examined variation in brain structure to determine whether stressful life events were associated with volume in brain regions that were found to vary as a function of symptoms of ADHD. We found a small to moderate association between number of stressful life events and ADHD symptoms. Although the strength of the associations between number of events and ADHD symptoms did not differ as a function of the age of occurrence of stressful experiences, different brain regions were implicated in the association between stressors and ADHD symptoms in the two age periods during which stressful life events occurred. These findings support the hypothesis that early adversity is associated with ADHD symptoms, and provide insight into possible brain-based mediators of this association.

Associations Among Early Life Stress, Rumination, Symptoms of Psychopathology, and Sex in Youth in the Early Stages of Puberty: a Moderated Mediation Analysis

Despite the high prevalence and substantial costs of early life stress (ELS), the mechanisms through which ELS confers risk for psychopathology are poorly understood, particularly among youth who are in an earlier stage of the transition through puberty. We sought to advance our understanding of the link between ELS and psychopathology by testing whether rumination mediates the relation between ELS and symptoms of psychopathology in youth in the early stages of puberty, and whether sex moderates this mediation. We assessed levels of ELS, both brooding and reflection subtypes of rumination, and internalizing and externalizing symptoms in 170 youth in the early stages of puberty (56% girls) ages 9-13 years. Brooding, but not reflection, mediated the relation between ELS and both internalizing and externalizing symptoms. Importantly, however, sex moderated the relation among ELS, brooding, and symptoms. Specifically, brooding mediated the relation between ELS and both internalizing and externalizing symptoms for girls, but not for boys. Findings support the formulation that brooding is a mechanism linking ELS to multiple forms of behavioral and emotional problems exclusively in girls in the early stages of puberty.

Evidence for a sensitive period in the effects of early life stress on hippocampal volume

Exposure to stress has been causally linked to changes in hippocampal volume (HV). Given that the hippocampus undergoes rapid changes in the first years of life, stressful experiences during this period may be particularly important in understanding individual differences in the development of the hippocampus. One hundred seventy-eight early adolescents (ages 9-13 years; 43% male) were interviewed regarding exposure to and age of onset of experiences of stress; the severity of each stressful event was rated by an objective panel. All participants underwent structural magnetic resonance imaging, from which HVs were automatically segmented. Without considering the age of onset for stressful experiences, there was a small but statistically significant negative association of stress severity with bilateral HV. When considering the age of onset, there was a moderate and significant negative association between stress severity during early childhood (through 5 years of age) and HV; there was no association between stress severity during later childhood (age 6 years and older) and HV. We provide evidence of a sensitive period through 5 years of age for the effects of life stress on HV in adolescence. It will be important in future research to elucidate how reduced HV stemming from early life stress may contribute to stress-related health outcomes.

Maternal depressive symptoms, self-focus, and caregiving behavior

BACKGROUND

Parent-child interactions set the stage for child mental health and development. Given that maternal depressive symptoms are associated with poorer observed caregiving behaviors, examining potential cognitive mediators is important for identifying mechanisms underlying the intergenerational transmission of risk and possible targets for intervention.

METHODS

We assessed depressive symptoms and levels of self-focus and psychological distancing from infant-centered verbal narratives obtained from 54 mothers, and examined caregiving behaviors in a structured interaction with their six-month-old infants.

RESULTS

Higher depressive symptoms were associated with pronoun use in narratives (i.e., greater "I" and reduced "we" use), reflecting increased self-focus and psychological distancing. Further, increased self-focus was associated with lower levels of caregiver warmth, and mediated the association between depressive symptoms and caregiving warmth.

LIMITATIONS

This observational study does not allow for causal interpretations.

CONCLUSION

These findings suggest that the cognitive styles associated with depression interfere with the caregiving relationship, affecting behavior in parent-child interactions that may increase the risk for the intergenerational transmission of depression.

Self-reported neglect, amygdala volume, and symptoms of anxiety in adolescent boys

Experiences of psychosocial neglect affect the developing brain and may place individuals at increased risk for anxiety. The majority of research in this area has focused on children who have experienced severe psychosocial deprivation; it is not clear whether typical variation in neglect experienced in community samples would have the same neurobiological consequences as those documented in extreme samples. The present study examined the associations among self-reported childhood neglect, amygdala volume, and anxiety symptoms in a community sample of 138 adolescents ages 9-15 years (43% male). Linear mixed modeling yielded a three-way interaction of neglect, sex, and brain hemisphere, reflecting a significant positive association between neglect and right amygdala volume in boys. Additional analyses indicated that right amygdala volume significantly mediated the association between neglect and anxiety symptoms in boys. These findings are consistent with previous reports of larger amygdala volumes in previously institutionalized children, and with documented associations between caregiving deprivation and anxiety symptoms. The results suggest that the effects of childhood neglect on limbic structures are sex-specific and lateralized, and provide support for a neural mechanism relating childhood neglect to later difficulties in emotional functioning.

Effects of sensitivity to life stress on uncinate fasciculus segments in early adolescence

Previous research suggests that exposure to early life stress (ELS) affects the structural integrity of the uncinate fasciculus (UF), a frontolimbic white matter tract that undergoes protracted development throughout adolescence. Adolescence is an important transitional period characterized by the emergence of internalizing psychopathology such as anxiety, particularly in individuals with high levels of stress sensitivity. We examined the relations among sensitivity to ELS, structural integrity of the UF, and anxiety symptoms in 104 early adolescents. We conducted structured interviews to assess exposure to ELS and obtained subjective and objective ratings of stress severity, from which we derived an index of ELS sensitivity. We also acquired diffusion MRI and conducted deterministic tractography to visualize UF trajectories and to compute measures of structural integrity from three distinct segments of the UF: frontal, insular, temporal. We found that higher sensitivity to ELS predicted both reduced fractional anisotropy in right frontal UF and higher levels of anxiety symptoms. These findings suggest that fibers in frontal UF, which are still developing throughout adolescence, are most vulnerable to the effects of heightened sensitivity to ELS, and that reduced structural integrity of frontal UF may underlie the relation between early stress and subsequent internalizing psychopathology.

The impact of the severity of early life stress on diurnal cortisol: The role of puberty

Researchers have documented dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in children and adolescents who experienced early life stress (ELS). The precise nature of this dysregulation, however, has been difficult to discern. In fact, both elevated and blunted patterns of diurnal cortisol regulation have been reported in children and adolescents exposed to greater ELS, including both reduced and heightened cortisol levels and change in cortisol across the day. These divergent findings may be due to developmental changes in the relation between ELS and HPA-axis functioning. The present study was designed to examine the role of puberty in the impact of the severity of ELS on the regulation of diurnal cortisol. Boys and girls (N=145) ages 9-13 years recruited from lower-risk communities completed an interview about their ELS experiences and at-home collection of diurnal cortisol. ELS experiences were objectively coded for severity, and children's level of pubertal development was measured using Tanner Staging. Multi-level piecewise mixed-effects models tested the effects of ELS severity and pubertal stage on cortisol levels at waking, the cortisol awakening response (CAR), and the daytime cortisol slope. While we found no significant interactive effects of pubertal stage and ELS severity on cortisol levels at waking or the daytime cortisol slope, findings indicated that pubertal stage interacted with ELS severity to predict the cortisol awakening response (CAR). Specifically, in earlier puberty, higher ELS was associated with a blunted CAR compared to lower ELS; in contrast, in later puberty, higher ELS was associated with a heightened CAR compared to lower ELS. Differences in the relation between ELS severity and the CAR were uniquely determined by puberty, and not by age. By considering and examining the role of puberty, the current study provides a developmental explanation for previous divergent findings of both blunted and heightened patterns of diurnal cortisol following ELS. These results indicate that careful attention should be given to children's pubertal status before drawing conclusions concerning the nature of diurnal cortisol dysregulation.

Enhanced resolution of experimental ARDS through IL-4-mediated lung macrophage reprogramming

Despite intense investigation, acute respiratory distress syndrome (ARDS) remains an enormous clinical problem for which no specific therapies currently exist. In this study, we used intratracheal lipopolysaccharide or Pseudomonas bacteria administration to model experimental acute lung injury (ALI) and to further understand mediators of the resolution phase of ARDS. Recent work demonstrates macrophages transition from a predominant proinflammatory M1 phenotype during acute inflammation to an anti-inflammatory M2 phenotype with ALI resolution. We tested the hypothesis that IL-4, a potent inducer of M2-specific protein expression, would accelerate ALI resolution and lung repair through reprogramming of endogenous inflammatory macrophages. In fact, IL-4 treatment was found to offer dramatic benefits following delayed administration to mice subjected to experimental ALI, including increased survival, accelerated resolution of lung injury, and improved lung function. Expression of the M2 proteins Arg1, FIZZ1, and Ym1 was increased in lung tissues following IL-4 treatment, and among macrophages, FIZZ1 was most prominently upregulated in the interstitial subpopulation. A similar trend was observed for the expression of macrophage mannose receptor (MMR) and Dectin-1 on the surface of alveolar macrophages following IL-4 administration. Macrophage depletion or STAT6 deficiency abrogated the therapeutic effect of IL-4. Collectively, these data demonstrate that IL-4-mediated therapeutic macrophage reprogramming can accelerate resolution and lung repair despite delayed use following experimental ALI. IL-4 or other therapies that target late-phase, proresolution pathways may hold promise for the treatment of human ARDS.

Trajectories of post-traumatic stress disorder symptoms among youth exposed to both natural and technological disasters

BACKGROUND

Theorists and researchers have demonstrated multiple trajectories of symptoms following disasters (Ecology and Society, 13, 2008, 9), highlighting the importance of obtaining more knowledge about exposed youth who demonstrate resilience as well as those who suffer chronic difficulties. This paper examines trajectories of post-traumatic stress disorder (PTSD) symptoms following exposure to hurricanes and the Deepwater Horizon Oil Spill to increase understanding of resilience and chronic reactions to both natural and technological disasters.

METHODS

A multiwave longitudinal design was used to follow N = 4,619 youth who were evaluated for PTSD symptoms, hurricane exposure, and oil spill exposure/stress at four time points over a period of 4 years. Trajectories were identified with cluster analyses and multilevel modeling.

RESULTS

Individual trajectories were statistically identified consistent with theory. The largest group exhibited stable-low symptoms (52%), a second group showed steep declines following initial symptoms (21%), a third group exhibited increasing symptoms (18%), and a fourth group showed stable-high symptoms (9%). Both hurricane exposure and oil spill stress predicted trajectories and overall levels of PTSD symptoms.

CONCLUSIONS

Results identified an effect of oil spill stress and hurricane exposure on symptom levels and trajectories of exposed youth. Results provide prospective data to support theories of multiple symptom trajectories following disasters and reinforce the importance of research that utilizes a developmental perspective to consider the long-term effects of disasters in youth. Findings highlight the importance of identifying symptoms and predictors of resilience as well as factors that contribute to resilience.

STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : VI. FACILITATION OF INFECTION IN THE MOUSE

50 per cent glycerine injected intraperitoneally, intramuscularly, or intravenously, greatly enhances the activity of equine encephalomyelitis virus injected intramuscularly, increasing its virulence up to 100-fold. The same effect is produced by very concentrated sodium chloride. The result appears due to dehydration of the nervous system, suddenly produced. Gradual withdrawal of body fluids, produced by depriving animals of drinking water, results in sharp concentration of the blood, equal to that produced by glycerine or salt. But such deprivation of water alone does not result in significant dehydration of the brain, nor does it have any effect on virus action. The facilitation effect is not produced by drastic procedures involving shifts of electrolytes without loss of total water from the brain. Glycerine has no facilitating action when the virus is administered intranasally or intraocularly, suggesting a fundamental difference in pathogenesis between these routes and the intramuscular.

STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : III. INTRAOCULAR INFECTION WITH FIXED VIRUS IN THE GUINEA PIG

The behavior of a fixed strain of Eastern equine encephalomyelitis virus was studied in guinea pigs after intraocular inoculation. Such inoculation concerns the central and not the peripheral nervous system. The susceptibility to intraocular injection lies midway between the highly virulent intracerebral and the quite avirulent peripheral routes. The virus must act for 10 to 13 hours in order to induce a fatal infection. Removal of the inoculated eyeball before this interval almost always prevents fatality although it may allow immunity to develop. The virus, at suitable intervals after injection into the eye, may be recovered from successive and appropriate optic centers before it is demonstrable in non-optic portions. Approximately 24 hours are required for the virus to reach a significant concentration in the contralateral geniculate body, 36 hours in the contralateral visual cortex. Significant amounts of virus may be present in the optic chiasm and tract prior to involvement of the higher centers. Virus placed in contact with the retina produces an insignificant, essentially non-specific reaction comparable to that produced at the site of direct intracerebral inoculation. In the retina there is no ganglion cell necrosis unless there is a complicating intraocular infection. In the cerebral visual centers the first reaction is inflammatory and interstitial, and may appear in the lateral geniculate body as early as 24 hours after injection. Neuronal necrosis is not the primary action of the virus on the nervous system in these experiments. The distribution of lesions in the brain is in excellent agreement with the method of direct testing for virus content, and is far more accurate than the latter. The virus in its primary distribution through the nervous system follows the nerve pathways of the optic system. This occurs within the central nervous system, where presumably there is first an involvement of the nerve cell body and then a spread along the cell process or axone.

ENCEPHALOPATHY FOLLOWING INJECTIONS OF BONE MARROW EXTRACT

Monkey bone marrow extract when injected intracerebrally into guinea pigs or rabbits produces a distinctive encephalopathy. The Purkinje cells are severely affected, especially those at the periphery of the cerebellum. Nuclear alterations first appear, with well marked intranuclear acidophilic inclusion bodies. Similar inclusions appear at a little later stage in the ectodermal glia. The affected cells later become necrotic and usually disappear. The reaction is essentially glial and non-inflammatory, and hence is called encephalopathy rather than encephalitis. A hyaline necrosis of cerebral blood vessels, especially at the base of the brain, is described. Small areas of softening may appear in the cerebellum as a result, but this is considered a secondary process, independent of the Purkinje cell loss. There may also inconstantly be found a loss of cerebellar granule cells and a selective necrosis of the hippocampal pyramidal cells. Secondary and reparative reactions are described. Similar changes are produced by extracts of lymph nodes from Hodgkin's disease, and by leucocytic cream of human blood. A tentative explanation of the pathogenesis is suggested, and similarities to certain virus diseases are pointed out.

EXPERIMENTAL ENCEPHALITIS : SOME FACTORS AFFECTING INFECTION WITH CERTAIN NEUROTROPIC VIRUSES

The action on mice of several neurotropic viruses was studied with reference to factors which influence infection. With pseudorabies virus, section of the sciatic nerve with inoculation into the ipsilateral foot pad significantly retarded the speed of infection. The virus ascended other nerves of the leg, but at a slower rate. It would appear that the number of nerve fibers available for passage may play a rôle in the speed with which infection occurs with this virus. When pseudorabies virus was inoculated into an area of inflammation its effects were markedly lessened. Similar experiments with unmodified equine encephalomyelitis virus which, unlike pseudorabies, does not ascend along local nerves, showed no impedance of infection. Brain trauma did not change the rate of infection with the viruses of St. Louis encephalitis, herpes, or pseudorabies. But intraperitoneal injection of glycerine, followed by intramuscular inoculation of St. Louis virus, resulted in marked facilitation of infection, as already remarked of fixed equine encephalomyelitis virus. This phenomenon did not occur with pseudorabies or herpes. In contrast to certain other viruses, pseudorabies and herpes viruses were only slightly more effective in young mice than in adults. With St. Louis virus, as with fixed equine encephalomyelitis viruses, inoculation into the eye or nose was far more effective than other peripheral routes. This was not the case with pseudorabies. Herpes, however, also showed greater sensitivity of the intraocular route. After injection into the eye, St. Louis and fixed equine encephalomyelitis viruses invaded the optic pathway, while herpes and pseudorabies avoided the optic fibers and attacked the trigeminal nerve. These phenomena are discussed in the light of cellufugal and cellupetal progression of viruses. The similarities in the action of fixed equine encephalomyelitis and St. Louis encephalitis viruses are discussed and contrasted with herpes and pseudorabies.

STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : I. HISTOPATHOLOGY OF THE NERVOUS SYSTEM IN THE GUINEA PIG

The action of the virus of equine encephalomyelitis in the guinea pig brain has been studied, and various histological changes have been described in detail. After peripheral inoculation (as in the pad) the earliest detectable pathologic change in the nervous system is the accumulation of leucocytes within the lumen of blood vessels, and the proliferation of the vascular adventitia. This precedes the appearance of any significant perivascular cuffing, and may or may not be accompanied by a few polymorphonuclear leucocytes in the tissue. The typical lesion is a fairly well circumscribed focus of polymorphonuclear leucocytes accompanying the blood vessel changes described above. The leucocytes may be numerous or sparse, and may or may not be accompanied by neuronal destruction. In early cases, before the onset of symptoms, such circumscribed lesions appear in small number irregularly scattered through the gray matter. The neo- and olfactory cortices are the principal sites of predilection, although basal ganglia, thalamus, cerebellum, and lower olfactory centers may also be involved. The hippocampus is much less affected than other parts of the brain. A rough distinction is made between inflammatory and degenerative lesions, a distinction which depends on the relationship between the neuronal destruction and the exudative changes in any given site. These two types are described, and their significance is discussed. After intracerebral inoculation, the inflammatory changes are much less marked than after peripheral inoculation. This is due not to insufficient time for the development of lesions but to a different type of pathological process. Following intracerebral inoculation, there is primary destruction of neurones, involving especially the hippocampus, and also large areas of the neo-cortex. This change, similar to ischemic necrosis, is regarded in part as a non-specific reaction of especially vulnerable tissue.

STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : II. PATHOGENESIS OF THE DISEASE IN THE GUINEA PIG

After inoculation with equine encephalomyelitis virus by various routes, guinea pigs were sacrificed at early stages, before symptoms were apparent. The brains were studied histologically, with serial sections; all lesions were noted, and subjected to topographical analysis. Nine cases are presented in detail. With any given mode of inoculation the distribution of lesions varied very widely from one instance to another. In some cases, affected regions bore a striking and definite anatomical relationship to each other. These distributions can be explained only by the assumption that the anatomical pathways played some rôle in the spread of the virus. In other instances lesions were present in areas, the anatomical connections of which were entirely normal. Attention is called to the frequency of lesions in the neocortex, with intact subcortical centers. Such distribution is held to render nerve spread extremely improbable. The only satisfactory explanation of such random distributions is by direct passage of virus from the blood stream into the brain tissue. There is no histological difference between lesions which result from blood spread and those resulting from nerve spread.

STUDIES ON EASTERN EQUINE ENCEPHALOMYELITIS : V. HISTOPATHOLOGY IN THE MOUSE

In mice affected with equine encephalomyelitis, the first pathological disturbance in infant animals is an inflammatory reaction, which is usually less pronounced in adult animals. A characteristic type of parenchymal damage appears to be independent of the inflammation. In such foci of injury there is initially a vacuolation of intercellular tissue. Neurones in such areas are at first intact, later show cytoplasmic changes, and finally nuclear alterations. Complete disintegration of tissue and all its elements may be the end result.