Racial/ethnic disparities in cortisol diurnal patterns and affect in adolescence.

Racial/ethnic minorities are more vulnerable to mental and physical health problems, but we know little about the psychobiological underpinnings of these disparities. In this study, we examined racial/ethnic differences in cortisol diurnal patterns and affect as initial steps toward elucidating long-term health disparities. A racially/ethnically diverse (39.5% White, 60.5% minority) sample of 370 adolescents (57.3% female) between the ages of 11.9 and 18 years (M = 14.65 years, SD = 1.39) participated in this study. These adolescents provided 16 cortisol samples (4 samples per day across 4 days), allowing the computation of diurnal cortisol slopes, the cortisol awakening response, and diurnal cortisol output (area under the curve), as well as daily diary ratings of high-arousal and low-arousal positive and negative affect. Consistent with prior research, we found that racial/ethnic minorities (particularly African American and Latino youth) exhibited flatter diurnal cortisol slopes compared to White youth, F (1, 344.7) = 5.26, p = .02, effect size g = 0.25. Furthermore, African American and Asian American youth reported lower levels of positive affect (both high arousal and low arousal) compared to White youth. Racial/ethnic differences in affect did not explain differences in cortisol patterns, suggesting a need to refine our models of relations between affect and hypothalamic-pituitary-adrenocortical activity. We conclude by proposing that a deeper understanding of cultural development may help elucidate the complex associations between affect and hypothalamic-pituitary-adrenocortical functioning and how they explain racial/ethnic differences in both affect and stress biology

The impacts of social support and early life stress on stress reactivity in children and adolescents

University of Minnesota Ph.D. dissertation. August 2013. Major:Child Psychology. Advisor:Megan R. Gunnar, Ph.D. 1 computer file (PDF); v, 115 pages.The goal of the present study was to investigate the impacts of social support and early life stress on individual differences in HPA axis reactivity in children (ages 9-10) and adolescents (ages 15-16). The primary aims were: 1) to experimentally manipulate the provision of social support in the laboratory and examine its effect on levels of salivary cortisol in response to the Trier Social Stress Test for Children; 2) to investigate parenting quality variables that may moderate the social buffering effect based on coding of videotaped parent-child interactions; 3) to analyze the role of early life stress (orphanage-rearing versus birth family rearing) and current social network characteristics in predicting the cortisol response; and 4) to explore age and sex differences in stress reactivity and the social buffering of stress. A sample of 162 participants was recruited, roughly equally divided between the two age groups, experimental conditions (half were exposed to a parent support condition before the stress task, whereas half received support from a stranger), early life experience (adopted or non-adopted) and by gender. Analyses of cortisol stress responses revealed that in the non-adopted group parent support provided in the laboratory significantly dampened stress reactivity in children but not in adolescents when compared to the stranger support condition. Additionally, participants reared in orphanages showed atypical patterns of HPA reactivity and of responses to social support provided before the stressor. Implications and future directions are discussed

Heart rate variability and circulating inflammatory markers in midlife

Theoretical perspectives and empirical evidence suggest that the parasympathetic nervous system engages in active monitoring and moderating of inflammatory processes. A clearer understanding of the bidirectional communication between the parasympathetic nervous system and the immune system could lead to novel clinical interventions for inflammatory illnesses. The current study used a large (N = 836) nationally representative sample of adults in the United States to investigate the relations between resting parasympathetic modulation of the heart, indexed through both high frequency heart rate variability (HF-HRV) and low frequency heart rate variability (LF-HRV), and six markers of circulating inflammation. Statistical analyses revealed robust inverse relations between HF-HRV and interleukin-6 (IL6), C-reactive protein (CRP), and fibrinogen, with or without covariate adjustment. Similar inverse relations were observed between LF-HRV and IL6 and CRP. No significant relations were observed between HRV and either inflammatory adhesion molecules (E-selectin, intracellular adhesion molecule-1) or soluble IL6 receptor. Results are consistent with the cholinergic anti-inflammatory pathway and suggest that parasympathetic modulation of inflammation through the vagus nerve may act on specific inflammatory molecules more than others

Psychosocial Functioning and the Cortisol Awakening Response: Meta-Analysis, \u3cem\u3eP\u3c/em\u3e-Curve Analysis, and Evaluation of the Evidential Value in Existing Studies

Cortisol levels rise immediately after awakening and peak approximately 30-45 minutes thereafter. Psychosocial functioning influences this cortisol awakening response (CAR), but there is considerable heterogeneity in the literature. The current study used p-curve and metaanalysis on 709 findings from 212 studies to test the evidential value and estimate effect sizes of four sets of findings: those associating worse psychosocial functioning with higher or lower cortisol increase relative to the waking period (CARi) and to the output of the waking period (AUCw). All four sets of findings demonstrated evidential value. Psychosocial predictors explained 1%-3.6% of variance in CARi and AUCw responses. Based on these effect sizes, cross-sectional studies assessing CAR would need a minimum sample size of 617-783 to detect true effects with 80% power. Depression was linked to higher AUCw and posttraumatic stress to lower AUCw, whereas inconclusive results were obtained for predictor-specific effects on CARi. Suggestions for future CAR research are discussed

Interactive effects of early and recent exposure to stressful contexts on cortisol reactivity in middle childhood

- Background: Given mixed findings as to whether stressful experiences and relationships are associated with increases or decreases in children's cortisol reactivity, we tested whether a child's developmental history of risk exposure explained variation in cortisol reactivity to an experimentally induced task. We also tested whether the relationship between cortisol reactivity and children's internalizing and externalizing problems varied as a function of their developmental history of stressful experiences and relationships. - Method: Participants included 400 children (M = 9.99 years, SD = 0.74 years) from the Children's Experiences and Development Study. Early risk exposure was measured by children's experiences of harsh, nonresponsive parenting at 3 years. Recent risk exposure was measured by children's exposure to traumatic events in the past year. Children's cortisol reactivity was measured in response to a social provocation task and parents and teachers described children's internalizing and externalizing problems. - Results: The effect of recent exposure to traumatic events was partially dependent upon a child's early experiences of harsh, nonresponsive parenting: the more traumatic events children had recently experienced, the greater their cortisol reactivity if they had experienced lower (but not higher) levels of harsh, nonresponsive parenting at age 3. The lowest levels of cortisol reactivity were observed among children who had experienced the most traumatic events in the past year and higher (vs. lower) levels of harsh, nonresponsive parenting in early childhood. Among youth who experienced harsh, nonresponsive parent–child relationships in early childhood and later traumatic events, lower levels of cortisol reactivity were associated with higher levels of internalizing and externalizing problems. - Conclusions: Hypothalamic–pituitary–adrenal (HPA) axis reactivity to psychological stressors and the relationship between HPA axis reactivity and children's internalizing and externalizing problems vary as a function of a child's developmental history of exposure to stressful relationships and experiences

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 = 55.3 years, 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

Compassion Focused Approaches to Working With Distressing Voices

This paper presents an outline of voice-hearing phenomenology in the context of evolutionary mechanisms for self- and social- monitoring. Special attention is given to evolved systems for monitoring dominant-subordinate social roles and relationships. These provide information relating to the interpersonal motivation of others, such as neutral, friendly or hostile, and thus the interpersonal threat, versus safe, social location. Individuals who perceive themselves as subordinate and dominants as hostile are highly vigilant to down-rank threat and use submissive displays and social spacing as basic defenses. We suggest these defense mechanisms are especially attuned in some individuals with voices, in which this fearful-subordinate – hostile-dominant relationship is played out. Given the evolved motivational system in which voice-hearers can be trapped, one therapeutic solution is to help them switch into different motivational systems, particularly those linked to social caring and support, rather than hostile competition. Compassion focused therapy (CFT) seeks to produce such motivational shifts. Compassion focused therapy aims to help voice-hearers, (i) notice their threat-based (dominant-subordinate) motivational systems when they arise, (ii) understand their function in the context of their lives, and (iii) shift into different motivational patterns that are orientated around safeness and compassion. Voice-hearers are supported to engage with biopsychosocial components of compassionate mind training, which are briefly summarized, and to cultivate an embodied sense of a compassionate self-identity. They are invited to consider, and practice, how they might wish to relate to themselves, their voices, and other people, from the position of their compassionate self. This paper proposes, in line with the broader science of compassion and CFT, that repeated practice of creating internal patterns of safeness and compassion can provide an optimum biopsychosocial environment for affect-regulation, emotional conflict-resolution, and therapeutic change. Examples of specific therapeutic techniques, such as chair-work and talking with voices, are described to illustrate how these might be incorporated in one-to-one sessions of CFT.CH-M was supported by a Medical Research Council Clinical Research Training Fellowship (MR/L01677X/1) to investigate Compassion Focused Therapy for Psychosis

Genome-wide DNA methylation levels and altered cortisol stress reactivity following childhood trauma in humans

DNA methylation likely plays a role in the regulation of human stress reactivity. Here we show that in a genome-wide analysis of blood DNA methylation in 85 healthy individuals, a locus in the Kit ligand gene (KITLG; cg27512205) showed the strongest association with cortisol stress reactivity (P=5.8 � 10?6). Replication was obtained in two independent samples using either blood (N=45, P=0.001) or buccal cells (N=255, P=0.004). KITLG methylation strongly mediates the relationship between childhood trauma and cortisol stress reactivity in the discovery sample (32% mediation). Its genomic location, a CpG island shore within an H3K27ac enhancer mark, and the correlation between methylation in the blood and prefrontal cortex provide further evidence that KITLG methylation is functionally relevant for the programming of stress reactivity in the human brain. Our results extend preclinical evidence for epigenetic regulation of stress reactivity to humans and provide leads to enhance our understanding of the neurobiological pathways underlying stress vulnerability

Neural Circuits Underlying Rodent Sociality: A Comparative Approach

All mammals begin life in social groups, but for some species, social relationships persist and develop throughout the course of an individual’s life. Research in multiple rodent species provides evidence of relatively conserved circuitry underlying social behaviors and processes such as social recognition and memory, social reward, and social approach/avoidance. Species exhibiting different complex social behaviors and social systems (such as social monogamy or familiarity preferences) can be characterized in part by when and how they display specific social behaviors. Prairie and meadow voles are closely related species that exhibit similarly selective peer preferences but different mating systems, aiding direct comparison of the mechanisms underlying affiliative behavior. This chapter draws on research in voles as well as other rodents to explore the mechanisms involved in individual social behavior processes, as well as specific complex social patterns. Contrasts between vole species exemplify how the laboratory study of diverse species improves our understanding of the mechanisms underlying social behavior. We identify several additional rodent species whose interesting social structures and available ecological and behavioral field data make them good candidates for study. New techniques and integration across laboratory and field settings will provide exciting opportunities for future mechanistic work in non-model species