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We present new empirical data and meta-analytic evidence for the association of childhood maltreatment with reduced hippocampal volume. In Study 1, we examined the effects of maltreatment experiences reported during the Adult Attachment Interview on hippocampal volume in female twin pairs. We found that reduced hippocampal volume was related to childhood maltreatment. In addition, individuals who reported having experienced maltreatment at older ages had larger reductions in hippocampal volume compared to individuals who reported maltreatment in early childhood. In Study 2, we present the results of a meta-analysis of 49 studies (including 2,720 participants) examining hippocampal volume in relation to experiences of child maltreatment, and test the moderating role of the timing of the maltreatment, the severity of maltreatment, and the time after exposure to maltreatment. The results of the meta-analysis confirmed that experiences of childhood maltreatment are associated with a reduction in hippocampal volume and that the effects of maltreatment are more pronounced when the maltreatment occurs in middle childhood compared to early childhood or adolescence.

This longitudinal study examines links among adolescent internalizing and externalizing symptoms, the prenatal environment (e.g., nicotine exposure) and pre/perinatal maternal health, and cardiovascular risk factors. Girls (N=262) ages 11-17 reported internalizing and externalizing behaviors and mothers reported about the prenatal environment and maternal health during and 3 months post-pregnancy. Adolescent cardiovascular risk included adiposity, smoking, blood pressure, and salivary C-reactive protein. Internalizing symptoms mediated relations between prenatal exposures/maternal health and adiposity; externalizing symptoms mediated relations between prenatal exposures and adolescent smoking. Healthcare providers who attend to internalizing and externalizing symptoms in girls may ultimately influence cardiovascular health, especially among those with pre/perinatal risk factors.

Background: Tympanic membrane temperature (TMT) has been proposed as an indicator of cerebral activation and TMT asymmetry may indicate lateralization, which has been associated with specific (problem) behaviors in children and adults. The current study explored the relations between pre-adoption living arrangements, TMT, and behavior and sleep problems in a sample of adopted toddlers., Methods: Ninety-two families who had adopted a Chinese girl who had previously been placed in an institution or foster care reported on behavior problems using the Child Behavior Checklist and TMT two months (Time 1) and six months (Time 2) after adoption., Results: Structural equation modeling revealed that institutionalized children had significantly higher left than right TMTs compared with foster care children at Time 2. A higher left than right TMT was associated with increased sleep problems and total behavior problems at Time 1, but not at Time 2., Conclusions: Our findings with regard to pre-adoption living arrangements, TMT asymmetry, and sleep problems suggest that TMT is sensitive to early environmental influences and may be a biological marker of vulnerability to the development of sleep problems in children from adverse backgrounds.

We used a new interdisciplinary paradigm of social network analysis (SNA) to investigate associations between hormones and social network structures. We examine these biobehavioral processes and test hypotheses about how hormones are associated with social network structures using exponential random graph modeling (ERGM) in a cohort of first-year students (n=74; 93% female; M age=27 years) from a highly competitive, accelerated nursing program. Participants completed friendship nominations and as a group simultaneously donated saliva (later assayed for cortisol and testosterone). ERGM analyses revealed that salivary cortisol levels were inversely associated with the number of outgoing ties (i.e., network activity). By contrast, testosterone was not related to friendship network structure. Integration of SNA and salivary bioscience creates a novel approach to understanding hormone-behavior relationships within the context of human social ecologies., (Copyright © 2014 Elsevier Inc. All rights reserved.)

In the present study, we employ a longitudinal design and a generalizability framework to examine the sources of variance in the diurnal rhythm of salivary α-amylase (sAA). The sample consisted of 122 first-year law students (55% male, mean age=23.9 years), who collected five saliva samples on each of three consecutive days at each of five data collection waves. In total, over 6900 saliva samples were collected, which allowed us to examine the properties of diurnal variation in sAA in great detail. Systematic individual differences accounted for 15-29% of the variability in the awakening response and diurnal slope, and for 61-65% of the variation in overall daily levels (i.e., diurnal mean, area under the curve with respect to ground [AUCg]). Although less than 1% of the variation was due to differences between waves and between days, the generalizability analyses revealed that between 16% and 17% of the variance in the diurnal mean, slope and AUCg is due to person by wave interactions, indicating that individuals vary in their biological sensitivity to environmental influences. In sum, this study documents sufficient stability and variation in diurnal sAA to warrant future studies on the origins and consequences of alterations in the diurnal rhythm of sAA worthwhile, and proposes guidelines on obtaining reliable measures., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

We employed a social network analysis approach to examine the associations between friendship network position and cortisol levels. The sample consisted of 74 first-year students (93% female, ages 22-38 years, M = 27) from a highly competitive, accelerated Nursing program. Participants completed questionnaires online, and the entire group met at one time to complete a series of sociometric nominations and donated a saliva sample. Saliva was later assayed for cortisol. Metrics derived from directed friendship nominations indexed each student's friendship network status regarding popularity, gregariousness, and degree of interconnectedness. Results revealed that (1) individuals with lower gregariousness status (i.e., lowest number of outgoing ties) had higher cortisol levels, and (2) individuals with higher popularity status (i.e., higher numbers of incoming ties) had higher cortisol levels. Popularity and gregariousness-based network status is significantly associated with hypothalamic-pituitary-adrenal axis activity. Implications for prevailing theories of the social determinants of individual differences in biological sensitivity and susceptibility to context are discussed.

This study examined the nature, concomitants, and consequences of stress-related biological reactivity and regulation among Army nurses. Saliva was collected, heart rate (HR) and blood pressure (BP) recorded from 38 Army nurses (74% female; mean age 28.5 years [SD=6.5]) before, during, and after participation in the Combat Casualty Stress Scenario (CCSS). Saliva was assayed for cortisol and alpha-amylase (sAA). The CCSS simulates emergency combat rescue, employing two simulated combat casualties, aversive body odors, recorded battlefield sounds, and smoke in a low light environment. Participants locate and conduct preliminary assessments of the simulated patients, triage based on injury severity, initiate treatment, and coordinate medical evacuation by radio. Results revealed large magnitude increases in cortisol, sAA, HR, systolic BP and diastolic BP in response to the CCSS, followed by recovery to baseline levels 30min after the task for all physiological parameters except cortisol. Age, gender, perceived difficulty of the CCSS, and previous nursing experience were associated with individual differences in the magnitude of the physiological responses. Lower levels of performance related to triage and treatment were associated with higher levels of reactivity and slower recovery for some of the physiological measures. The findings raise important questions regarding the utility of integrating measures of the psychobiology of the stress response into training programs designed to prepare first responders to handle highly complex and chaotic rescue situations., (Published by Elsevier Ltd.)

Children vary hugely in how demanding of their caregivers they are. This creates differences in demands on parents during observation, making the comparison of sensitivity between parents difficult. It would therefore be of interest to create standard situations in which all caregivers are faced with the same level of demand. This study developed an ecologically valid but standardized setting using an infant simulator with interactive features, the Leiden Infant Simulator Sensitivity Assessment (LISSA). The infant simulator resembles a real infant in appearance and it produces crying sounds that are life-like. The simulator begins with fussing and progresses to more intense crying in case of no care or inappropriate care. It responds by being calm again if appropriate care is given. One hundred and eighty-one female participants took care of the infant simulator for two evenings and in a 30 min lab session with increasing competing demands. Sensitive parenting behavior during the lab session was coded with the Ainsworth Sensitivity Scale. Sensitivity ratings covered the whole range of the scale (1-9), and were stable across settings (free play, competing demands). Sensitivity was related to an increase of positive affect during caretaking, and insensitivity was related to intended harsh caregiving response during a computerized cry paradigm. Sensitivity was unrelated to social desirability and self-reported quality of care given to the infant simulator. We discuss the potentials of the infant simulator for research on sensitive parenting, for preventive interventions, and for clinical practices.

This is the first study on adults' physiological reactivity to infant cry sounds and the association with intended harsh parenting using salivary α-amylase (sAA) as a novel and noninvasive marker of autonomic nervous system activity. The sample consisted of 184 adult twin pairs. In an experimental design, cry sounds were presented and adults' perception and their intended caregiving responses were measured. Saliva samples were collected after each cry sound. For the majority of the sample, a decrease in sAA across the cry paradigm was observed. However, adults who indicated that they would respond in a harsh way to the crying infant were significantly less likely to show a decrease in sAA. Consistent with previous studies on physiological hyperreactivity in abusive parents, these findings suggest that failure to habituate to repeated infant crying may be one of the mediating mechanisms through which excessive, inconsolable, and high-pitched infant crying triggers less optimal caregiving.

Analytes and biomarkers present in saliva may provide insight into individual differences in environmental chemical exposures, variation in reproductive hormones, therapeutic and illegal substance use, changes in stress-related physiology, and the immunologic footprints of infectious disease. The wealth of information provided by salivary analytes has the potential to enrich biobehavioral nursing research by enabling researchers to measure these individual differences in the clinic as well as in patients' and participants' everyday social worlds. In this article, the authors provide a roadmap for researchers new to this area who would like to learn more about integrating salivary biospecimens into the next generation of health research. In addition, the authors highlight best practices and strategies to avoid common pitfalls for researchers already engaged in this field.

The characterization of the salivary proteome and advances in biotechnology create an opportunity for developmental scientists to measure multi-level components of biological systems in oral fluids and identify relationships with developmental processes and behavioral and social forces. The implications for developmental science are profound because from a single oral fluid specimen, information can be obtained about a broad array of biological systems and the genetic polymorphisms related to their function. The purpose of this review is to provide a conceptual and tactical roadmap for investigators interested in integrating these measurement tools into research on adolescent health and development., (Copyright © 2012 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.)

This study evaluated individual differences in levels of C-reactive protein (CRP) measured in saliva, cross-sectionally and prospectively, in relation to systemic inflammation and risk for cardiovascular disease (CVD). Plasma and saliva samples, later assayed for CRP, were collected multiple times from an ethnically diverse group of women seeking help from domestic violence crisis shelters-agencies (N=107; mean age at study start=34 years). Plasma and saliva CRP levels were moderately associated cross-sectionally and across two years. There were indications that saliva CRP levels were, on average, higher in the morning than evening. Higher levels of saliva and plasma CRP were associated with a higher body mass index, but did not differ between women who did and did not smoke. Salivary CRP reliably discriminated between high and low levels of plasma CRP, using a clinically relevant cutoff point of 3mg/L, recommended by the American Heart Association. Results build upon an emerging literature suggesting that under specific conditions levels of CRP in saliva may reflect low-grade inflammation and have the potential to serve as a screen for CVD risk status., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Current research found that adult attachment representations influence neural, emotional, and behavioral responses to infant crying, thus validating the Berkeley Adult Attachment Interview with functional Magnetic Resonance Imaging. This study examined amygdala activation, feelings of irritation, and the use of excessive force as indicated by grip strength using a handgrip dynamometer during exposure to infant crying and scrambled control sounds in 21 women without children. Individuals with insecure attachment representations showed heightened amygdala activation when exposed to infant crying compared to individuals with secure attachment representations. In addition, insecure individuals experienced more irritation during infant crying and used more excessive force than individuals with a secure representation. Amygdala hyperactivity might be one of the mechanisms underlying the experience of negative emotions during exposure to infant crying in insecure individuals and might explain why insecure parents respond inconsistently to infant signals or reject their infants' attachment behavior.

This is the first behavior genetic study of salivary α-amylase (sAA), focusing on genetic and environmental influences on stability and change in sAA during baseline and exposure to infant crying. The sample consisted of 184 adult twin pairs. Although there was significant variation between individuals in basal levels of sAA and in responsivity to infant crying, strong stability in sAA concentrations across conditions was found. Similar genetic mechanisms influenced sAA at baseline and in response to cry sounds (explained variance: 51-62%), accounting for part of the stability in sAA. Unique environmental factors explained the remaining variance in sAA, some of them only emerging in response to the cry sounds, explaining individual differences in the pattern of reactivity. These findings confirm that sAA is sensitive to the effects of potentially stressful stimuli (state variance) and at the same time demonstrate its relative robustness and stability across time and conditions (trait variance)., (Copyright © 2011 Elsevier B.V. All rights reserved.)

We evaluated the role of the serotonin transporter gene promoter polymorphism (5-HTTLPR) in the etiology of dissociation. Adult twin pairs (N = 184 pairs; mean age 33.0 years, SD = 10.8) completed measures for dissociation and trauma. The DNA samples were genotyped for 5-HTTLPR adjusted for rs25531 alleles. Behavioral genetic analyses showed that genetic factors explained 45% of the variance in dissociative symptoms, while 55% of the variance was explained by unique environment and measurement error. Participants with the SS genotype of 5-HTTLPR reported more dissociative symptoms compared to participants with the other genotypes (p = .02), and they showed more pathological dissociative symptoms than the other participants (p = .04) when they reported more depressive symptoms and when they had experienced trauma., (Copyright © 2011 International Society for Traumatic Stress Studies.)

Both the oxytocin receptor (OXTR) gene and depressive symptoms have been associated with parenting behaviour. The OXTR GG genotype has been suggested to be related to more sensitive parenting, whereas depressive symptoms may affect sensitivity negatively. We examined the role of OXTR and the influence of depressive symptoms in explaining differences in physiological reactivity to infant crying. Heart rate responses of 40 healthy females without children (age 19-47 years, randomly selected half of twin pairs) were measured during the presentation of three episodes of infant cry sounds. Participants with the presumably more efficient variant of the oxytonergic system gene (OXTR GG) had more pronounced physiological reactivity to repeated cry sounds, except when they showed more symptoms of depression. Results were replicated in the second half of the twin sample. This is the first study to suggest effects of OXTR genotype on physiological reactivity to infant crying. Depressive symptoms may however suppress the effect of the OXTR GG genotype.

Objective: To examine the underlying mechanisms of adults' intended caregiving responses to cry sounds in a behavioral genetic design and to investigate the role of cry pitch and perceived urgency in sensitive and harsh caregiving responses., Methods: The sample consisted of 184 adult twin pairs (18-69 years), including males and females, parents and nonparents. In an experimental design we presented cry sounds varying in pitch and measured adults' perception and their intended caregiving responses. Cry stimuli were based on a 10-second cry sample of a 2-day-old infant with a fundamental frequency averaging 500 Hz. Two additional cry sounds were created by digitally increasing the fundamental frequency to 700 and 900 Hz., Results: Individual differences in the perceived urgency of infant crying and intended sensitive caregiving responses were explained by genetic factors (38% and 39%, respectively), while the variance in harsh caregiving responses was due to shared (31%) and unique (69%) environmental influences. Adults were more likely to indicate sensitive caregiving responses to higher-pitched cry sounds and when they perceived the cries as more urgent, while high-pitched cry sounds were also directly associated with harsh caregiving responses., Conclusions: The influence of genetic factors on intended caregiving responses to infant crying is substantial for normal variations in sensitive caregiving, but absent for harsh caregiving responses. The findings suggest that the perception of infant crying as urgent paves the way for more immediate and affectionate caregiving responses, while an extreme increase in cry pitch may present a direct risk factor for more irritated, negative and even harsh parenting., Practice Implications: Infants who display abnormal cry acoustics such as extreme increases in pitch may be at risk for harsh parenting. Interventions should promote parental sensitive response to distress vocalizations to prevent harsh parenting in case of at-risk infants., (Copyright © 2010. Published by Elsevier Ltd.)