Concordance of mother-daughter diurnal cortisol production: Understanding the intergenerational transmission of risk for depression

Attention to social threat predicts diurnal cortisol dynamics during the high school transition

Adolescence is a developmental period marked by significant social shifts accompanied by concurrent changes across biological, cognitive, and emotional domains. Within adolescence, the high school transition is a pivotal time for youth that is ripe with opportunities yet has the potential to disrupt functioning. An increasingly sophisticated understanding of health and developmental biology indicates that the hypothalamic-pituitary-adrenal (HPA) axis plays an important role in transducing social experiences into physiological changes that have long-term impacts on health and wellbeing. There is reason to believe that attentional biases to social threat could impact cortisol, a steroid hormone indexing activity of the HPA axis, during the high school transition. The present study examined associations between attentional biases to socially threatening stimuli, measured using the Affective Posner paradigm, and components of the diurnal cortisol rhythm among youth across the first two days of high school. Participants included 67 youth (N = 504 saliva samples) with a mean age of 12.86 years and a relatively equal split with regard to both sex assigned at birth and gender identity (54 % male; 54 % boys). Findings build upon and extend previous work by demonstrating that greater attentional engagement bias to socially threatening stimuli is associated with a pattern of greater diurnal HPA axis reactivity across the first two days of the high school transition, as evidenced by a steeper cortisol awakening response and a steeper diurnal cortisol slope. This work extends our understanding of the mechanisms through which stress relates to wellbeing in youth by embedding biological development in the life course. Clinically, this work has the potential to inform interventions to protect youth against the biological embedding of stress by identifying a theoretically driven, socio-contextually relevant risk factor to be attenuated - namely, attentional bias to threat.

Parents' clinical depression and children's problem behaviors: A multi-level meta-analytic examination

BACKGROUND

Previous meta-analyses considering associations between parental depression (PD) and child symptoms have considered PD based primarily on self-report of depression symptoms. The present meta-analysis, in contrast, evaluated the effect of parents' clinically-diagnosed depressive disorders (PDD) on child internalizing and externalizing symptoms and considered both family- and study-level variables that influenced the strength of these effects.

METHODS

We examined 111 effect sizes nested in 40 studies including a clinical assessment of parents' major or persistent depressive disorder and measures of children's internalizing or externalizing behaviors published between 2000 and 2020. We used a multi-level meta-analytic framework to account for nesting of multiple effect sizes within studies.

RESULTS

PDD was associated with children's internalizing (weighted mean r = 0.211) and externalizing (weighted mean r = 0.204) behaviors. Family- and study-level variables moderated these relations, including the inclusion of fathers in the sample, the specific measure of internalizing behavior, reporting of diagnostic reliability, and informant for problem behaviors.

LIMITATIONS

Limitations include exclusive consideration of internalizing and externalizing symptoms (versus other symptom types or problems) and the limited number of father-only studies from which to base conclusions about the relative effect of maternal vs. paternal depression.

CONCLUSIONS

The similarity between the current findings and previous meta-analyses suggests that researchers studying the effects of PD may be able to bypass more exhaustive clinical interviews for less burdensome depression symptom inventories. Furthermore, our findings suggest that researchers and clinicians should consider how PD impacts not just child depressive symptoms, but myriad problem behaviors.

The Mood and Resilience in Offspring (MARIO) project: a longitudinal cohort study among offspring of parents with and without a mood disorder

BACKGROUND

One of the most robust risk factors for developing a mood disorder is having a parent with a mood disorder. Unfortunately, mechanisms explaining the transmission of mood disorders from one generation to the next remain largely elusive. Since timely intervention is associated with a better outcome and prognosis, early detection of intergenerational transmission of mood disorders is of paramount importance. Here, we describe the design of the Mood and Resilience in Offspring (MARIO) cohort study in which we investigate: 1. differences in clinical, biological and environmental (e.g., psychosocial factors, substance use or stressful life events) risk and resilience factors in children of parents with and without mood disorders, and 2. mechanisms of intergenerational transmission of mood disorders via clinical, biological and environmental risk and resilience factors.

METHODS

MARIO is an observational, longitudinal cohort study that aims to include 450 offspring of parents with a mood disorder (uni- or bipolar mood disorders) and 100-150 offspring of parents without a mood disorder aged 10-25 years. Power analyses indicate that this sample size is sufficient to detect small to medium sized effects. Offspring are recruited via existing Dutch studies involving patients with a mood disorder and healthy controls, for which detailed clinical, environmental and biological data of the index-parent (i.e., the initially identified parent with or without a mood disorder) is available. Over a period of three years, four assessments will take place, in which extensive clinical, biological and environmental data and data on risk and resilience are collected through e.g., blood sampling, face-to-face interviews, online questionnaires, actigraphy and Experience Sampling Method assessment. For co-parents, information on demographics, mental disorder status and a DNA-sample are collected.

DISCUSSION

The MARIO cohort study is a large longitudinal cohort study among offspring of parents with and without mood disorders. A unique aspect is the collection of granular data on clinical, biological and environmental risk and resilience factors in offspring, in addition to available parental data on many similar factors. We aim to investigate the mechanisms underlying intergenerational transmission of mood disorders, which will ultimately lead to better outcomes for offspring at high familial risk.

Dentate Gyrus Microstructure Is Associated With Resilience After Exposure to Maternal Stress Across Two Human Cohorts

BACKGROUND

Maternal stress (MS) is a well-documented risk factor for impaired emotional development in offspring. Rodent models implicate the dentate gyrus (DG) of the hippocampus in the effects of MS on offspring depressive-like behaviors, but mechanisms in humans remain unclear. Here, we tested whether MS was associated with depressive symptoms and DG micro- and macrostructural alterations in offspring across 2 independent cohorts.

METHODS

We analyzed DG diffusion tensor imaging-derived mean diffusivity (DG-MD) and volume in a three-generation family risk for depression study (TGS; n = 69, mean age = 35.0 years) and in the Adolescent Brain Cognitive Development (ABCD) Study (n = 5196, mean age = 9.9 years) using generalized estimating equation models and mediation analysis. MS was assessed by the Parenting Stress Index (TGS) and a measure compiled from the Adult Response Survey from the ABCD Study. The Patient Health Questionnaire-9 and rumination scales (TGS) and the Child Behavior Checklist (ABCD Study) measured offspring depressive symptoms at follow-up. The Schedule for Affective Disorders and Schizophrenia-Lifetime interview was used to assign depression diagnoses.

RESULTS

Across cohorts, MS was associated with future symptoms and higher DG-MD (indicating disrupted microstructure) in offspring. Higher DG-MD was associated with higher symptom scores measured 5 years (in the TGS) and 1 year (in the ABCD Study) after magnetic resonance imaging. In the ABCD Study, DG-MD was increased in high-MS offspring who had depressive symptoms at follow-up, but not in offspring who remained resilient or whose mother had low MS.

CONCLUSIONS

Converging results across 2 independent samples extend previous rodent studies and suggest a role for the DG in exposure to MS and offspring depression.

Sex Differences in Depression and Anxiety

Depression and anxiety disorders carry a tremendous worldwide burden and emerge as a significant cause of disability among western societies. Both disorders are known to disproportionally affect women, as they are twice more likely to be diagnosed and moreover, they are also prone to suffer from female-specific mood disorders. Importantly, the prevalence of these affective disorders has notably risen after the COVID pandemic, especially in women. In this chapter, we describe factors that are possibly contributing to the expression of such sex differences in depression and anxiety. For this, we overview the effect of transcriptomic and genetic factors, the immune system, neuroendocrine aspects, and cognition. Furthermore, we also provide evidence of sex differences in antidepressant response and their causes. Finally, we emphasize the importance to consider sex as a biological variable in preclinical and clinical research, which may facilitate the discovery and development of new and more efficacious antidepressant and anxiolytic pharmacotherapies for both women and men.

Relationship between Borderline Personality Disorder, Emotional Availability, and Cortisol Output in Mother-Child Dyads

BACKGROUND

Mothers with borderline personality disorder (BPD) often show altered emotional availability toward their own child and heightened stress vulnerability. The aims of the present study were (1) to examine total cortisol output in saliva during mother-child interaction in mothers with BPD and their children and (2) to test whether maternal nonhostility as a subscale of emotional availability mediates the relationship between maternal BPD and child total cortisol output.

METHODS

We investigated 16 mothers with BPD and 30 healthy control mothers (HC) and 29 children of mothers with BPD and 33 children of HC mothers. Children were between 5 and 12 years old. Salivary cortisol was collected prior to and twice after an episode of a 21-min standardized play situation between mother and child. Nonhostility was rated using the emotional availability scales. Analyses of covariance were computed to test for group differences in total cortisol output (measured with area under the curve with respect to ground). Pearson's correlation was calculated to test the association between maternal and child total cortisol output. To test the second question, a mediation analysis according to Preacher and Hayes was conducted.

RESULTS

Mothers with BPD and their children had lower total cortisol output. Maternal and child total cortisol output was significantly correlated. Contrary to our hypothesis, maternal nonhostility did not mediate the relationship between BPD and child total cortisol output.

CONCLUSION

Results imply that the hormonal stress activity of mothers with BPD and their children is altered, which may reflect modified stress regulation and stress vulnerability in mother and child and may impact on mother-child interaction. The finding of a positive association between mother's and child total cortisol output could indicate an intergenerational transmission of these alterations.

Intergenerational neuroimaging study: mother-infant functional connectivity similarity and the role of infant and maternal factors

Mother and infant neural and behavioral synchrony is important for infant development during the first years of life. Recent studies also suggest that neural risk markers associated with parental psychopathology may be transmitted across generations before symptoms emerge in offspring. There is limited understanding of how early similarity in brain functioning between 2 generations emerges. In the current study, using functional magnetic resonance imaging, we examined the functional connectivity (FC) similarity between mothers and newborns during the first 3 months after the infant's birth. We found that FC similarity between mothers and infants increased as infant age increased. Furthermore, we examined whether maternal factors such as maternal socioeconomic status and prenatal maternal depressive symptoms may influence individual differences in FC similarity. For the whole-brain level, lower maternal education levels were associated with greater FC similarity. In previous literature, lower maternal education levels were associated with suboptimal cognitive and socioemotional development. Greater FC similarity may reflect that the infants develop their FC similarity prematurely, which may suboptimally influence their developmental outcomes in later ages.

Basal and reactive cortisol: A systematic literature review of offspring of parents with depressive and bipolar disorders

One of the most consistent biological findings in the study of affective disorders is that those with depression commonly show abnormal cortisol response, which suggests dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Children of parents with mood disorders offer the opportunity to explore the biological pathways that may confer risk for psychopathology. This review explores basal and reactive cortisol in the offspring of parents who are currently depressed or have had a history of a depressive or bipolar disorder. Using PRISMA guidelines, search terms yielded 2002 manuscripts. After screening, 87 of these manuscripts were included. Results from the literature suggest that while the degree and direction of dysregulation varies, offspring of a parent with depression tend to show elevations in both basal (particularly morning and evening) and reactive (tentatively for social stressors) cortisol levels. There were few studies focused on offspring of parents with bipolar disorder. This review also discusses implications and recommendations for future research regarding the HPA axis in the intergenerational transmission of depressive disorders.

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.

Emotion Regulation and Diurnal Cortisol: A Longitudinal Study of Early Adolescents

Aberrant patterns of diurnal cortisol, a marker of stress reactivity, predict adverse physical and mental health among adolescents. However, the mechanisms underlying aberrant diurnal cortisol production are poorly understood. Thus, the objective of this study was to investigate, for the first time, whether the core emotion regulation (ER) strategies of rumination (brooding, reflection), reappraisal, and suppression were prospectively associated with individual differences in diurnal cortisol during the COVID-19 pandemic, a period of significant stress. A community sample of 48 early adolescents (M_age=13.45; 60% males) was recruited from British Columbia, Canada. Participants completed ER measures before the pandemic, and diurnal cortisol was assessed by collecting eight saliva samples over two days during the first COVID-19-related lockdown in the region. As expected, brooding predicted elevated waking cortisol and a blunted cortisol awakening response (CAR), whereas reflection predicted lower waking cortisol and suppression predicted a steeper CAR. Unexpectedly, reappraisal was not associated with diurnal cortisol production. Results indicate that ER strategies may represent a mechanism underlying individual differences in biological markers of wellbeing during stress.

From Stress to Depression: Bringing Together Cognitive and Biological Science

One of the most consistent findings in the depression literature is that stressful life events predict the onset and course of depressive episodes. Cognitive and biological responses to life stressors have both been identified, albeit largely independently, as central to understanding the association between stress and depression. I maintain that the largest advances in the understanding of depression will come from examining the ways that cognitive and biological responses to stressors reciprocally influence one another and, in doing so, contribute to the onset and maintenance of depression. I summarize the cognitive and biological stress responses implicated in depression and then describe the reciprocal ways that they are associated with each other. Finally, I discuss the broader implications of taking this integrated approach and suggest directions and considerations for future research.

Stress Impairs Episodic Retrieval by Disrupting Hippocampal and Cortical Mechanisms of Remembering

Despite decades of science investigating the neural underpinnings of episodic memory retrieval, a critical question remains: how does stress influence remembering and the neural mechanisms of recollection in humans? Here, we used functional magnetic resonance imaging and multivariate pattern analyses to examine the effects of acute stress during retrieval. We report that stress reduced the probability of recollecting the details of past experience, and that this impairment was driven, in part, by a disruption of the relationship between hippocampal activation, cortical reinstatement, and memory performance. Moreover, even memories expressed with high confidence were less accurate under stress, and this stress-induced decline in accuracy was explained by reduced posterior hippocampal engagement despite similar levels of category-level cortical reinstatement. Finally, stress degraded the relationship between the engagement of frontoparietal control networks and retrieval decision uncertainty. Collectively, these findings demonstrate the widespread consequences of acute stress on the neural systems of remembering.

Chronic Depression Alters Mothers' DHEA and DEHA-to-Cortisol Ratio: Implications for Maternal Behavior and Child Outcomes

Maternal depression is a major public health problem that typically occurs in the period surrounding childbirth. The neurobiological mechanisms underlying maternal depression have been the focus of increasing research and studies pointed to the crucial role of the HPA axis in this disorder. However, most studies focused on cortisol expression and regulation while recent attention has shifted to include the sulfate steroids DHEA and DHEA-S. A community cohort of 1,983 women with no comorbid risk was recruited at birth and depression was assessed periodically across the first postpartum year. At 6 years, 156 families were re-visited: 46 mothers were defined as chronically-depressed and 103 controls reported no depression from birth to six years. Mothers and children were diagnosed by structured psychiatric interviews and mother-child interactions were observed. Maternal diurnal cortisol (CT) and dehydroepiandrosterone (DHEA) were assessed. Depressed mothers had lower levels of DHEA (AUCg), flattened DHEA diurnal variability (AUCi), and smaller DHEA-to-CT Ratio. Regression analysis demonstrated that maternal sensitivity during mother-child interaction was independently predicted by maternal depression, DHEA levels, child CT, and child social withdrawal. Results underscore the need for multi-level understanding of the dynamic interplay between maternal psychopathology, mother-child relationship, and pituitary-adrenal-cortex-to-medulla balance in studying the cross generational transfer of psychiatric vulnerability from depressed mothers to their children.

Stress Disrupts Human Hippocampal-Prefrontal Function during Prospective Spatial Navigation and Hinders Flexible Behavior

The ability to anticipate and flexibly plan for the future is critical for achieving goal-directed outcomes. Extant data suggest that neural and cognitive stress mechanisms may disrupt memory retrieval and restrict prospective planning, with deleterious impacts on behavior. Here, we examined whether and how acute psychological stress influences goal-directed navigational planning and efficient, flexible behavior. Our methods combined fMRI, neuroendocrinology, and machine learning with a virtual navigation planning task. Human participants were trained to navigate familiar paths in virtual environments and then (concurrent with fMRI) performed a planning and navigation task that could be most efficiently solved by taking novel shortcut paths. Strikingly, relative to non-stressed control participants, participants who performed the planning task under experimentally induced acute psychological stress demonstrated (1) disrupted neural activity critical for mnemonic retrieval and mental simulation and (2) reduced traversal of shortcuts and greater reliance on familiar paths. These neural and behavioral changes under psychological stress were tied to evidence for disrupted neural replay of memory for future locations in the spatial environment, providing mechanistic insight into why and how stress can alter planning and foster inefficient behavior.

Parent-Adolescent Dyads as Temporal Interpersonal Emotion Systems

Research on the role of parent-adolescent relationships in psychosocial adjustment needs a conceptual approach that specifies the processes by which development is nested in the relationship. I forward a new approach and emphasize the need to consider the unique elements that individuals bring to the dyadic system. I also emphasize the need to examine processes at multiple time scales. I highlight the complexity of dyadic system dynamics: Biological predispositions set the foundation for the parent-adolescent relationship and the emotion dynamics that emerge during interactions. As the system gets entrained through repeated interactions over longer time scales, real-time dynamics coalesce into psychosocial adjustment, which in turn constrains real-time dynamics. I review the evidence for each of these processes and discuss the implications.

Depression and sleep: what has the treatment research revealed and could the HPA axis be a potential mechanism?

Research indicates that insomnia improvement plays a critical role in depression symptom improvement. In line with the National Institute of Mental Health Experimental Therapeutics approach recent research focuses on identifying specific mechanisms; the present manuscript aims to review recent research on one potential mechanism, dysfunction in the HPA axis which is a shared biological substrate of both depression and insomnia. Over the past five years, research demonstrated a relationship between sleep disturbance and cortisol reactivity and recovery following a stressor. Meanwhile, research on the relationship between depression and HPA axis functioning is less consistent and is dependent on measurement of HPA axis. Experimental research that aims to determine a causal pathway between sleep, depression and HPA axis functioning is needed.

Social Allostasis and Social Allostatic Load: A New Model for Research in Social Dynamics, Stress, and Health

Theories such as social baseline theory have argued that social groups serve a regulatory function but have not explored whether this regulatory process carries costs for the group. Allostatic load, the wear and tear on regulatory systems caused by chronic or frequent stress, is marked by diminished stress system flexibility and compromised recovery. We argue that allostatic load may develop within social groups as well and provide a model for how relationship dysfunction operates. Social allostatic load may be characterized by processes such as groups becoming locked into static patterns of interaction and may ultimately lead to up-regulation or down-regulation of a group's set point, or the optimal range of arousal or affect around which the group tends to converge. Many studies of emotional and physiological linkage within groups have reported that highly correlated states of arousal, which may reflect failure to maintain a group-level regulatory baseline, occur in the context of stress, conflict, and relationship distress. Relationship strain may also place greater demands on neurocognitive regulatory processes. Just as allostatic load may be detrimental to individual health, social allostatic load may corrode relationship quality.

Leader-employee emotional "interpersonal tuning".An EEG coherence study

Empirical management research has focused more on the investigation of important interpersonal factors that could be beneficial for a company's well-being, including emotional and empathic engagement between managers and employees. The capacity to understand and mirror others' feelings could result in a mutual adaptation that generates interpersonal tuning (IT). In the present study, we measured IT by applying a hyperscanning approach with simultaneous recording of electroencephalographic (EEG) signals from two participants interacting together. Eleven leaders and 11 employees were recruited and asked to role-play an employee performance review with a rating (R) or no rating (NR) condition. In the NR condition leaders describe by words the employee's proficiency, while in R they provided a quantitative rating. The NR condition emerged as a more engaging situation in terms of empathic responses and mirroring. This difference was detectable from the localization of neurophysiological effects over the frontopolar and frontal brain areas, and the higher synchronization of EEG delta frequency coherence. Behavioral results also revealed an increase of self-perceived emotional tuning, agreement on content, and interpersonal cooperation in the NR condition compared to R condition. These effects were present in both leaders and employees and have several implications for social and company well-being.

DNA methylation of HPA-axis genes and the onset of major depressive disorder in adolescent girls: a prospective analysis

The stress response system is disrupted in individuals with major depressive disorder (MDD) as well as in those at elevated risk for developing MDD. We examined whether DNA methylation (DNAm) levels of CpG sites within HPA-axis genes predict the onset of MDD. Seventy-seven girls, approximately half (n = 37) of whom were at familial risk for MDD, were followed longitudinally. Saliva samples were taken in adolescence (M age = 13.06 years [SD = 1.52]) when participants had no current or past MDD diagnosis. Diagnostic interviews were administered approximately every 18 months until the first onset of MDD or early adulthood (M age of last follow-up = 19.23 years [SD = 2.69]). We quantified DNAm in saliva samples using the Illumina EPIC chip and examined CpG sites within six key HPA-axis genes (NR3C1, NR3C2, CRH, CRHR1, CRHR2, FKBP5) alongside 59 genotypes for tagging SNPs capturing cis genetic variability. DNAm levels within CpG sites in NR3C1, CRH, CRHR1, and CRHR2 were associated with risk for MDD across adolescence and young adulthood. To rule out the possibility that findings were merely due to the contribution of genetic variability, we re-analyzed the data controlling for cis genetic variation within these candidate genes. Importantly, methylation levels in these CpG sites continued to significantly predict the onset of MDD, suggesting that variation in the epigenome, independent of proximal genetic variants, prospectively predicts the onset of MDD. These findings suggest that variation in the HPA axis at the level of the methylome may predict the development of MDD.

Differential neural responding to affective stimuli in 6- to 8-year old children at high familial risk for depression: Associations with behavioral reward seeking

OBJECTIVE

Children of depressed parents are at increased risk for psychopathology. One putative mechanism of risk appears to be altered processing of emotion-related stimuli. Although prior work has evaluated how adolescent offspring of depressed parents may show blunted reward processing compared to low-risk youth, there has been less attention to how young children with this familial history may differ from their peers during middle childhood, a period of critical socio-affective development METHOD: The current study evaluated 56 emotionally healthy 6-to 8-year children who were deemed at high-risk (n = 25) or low-risk (n = 31) for depression based on maternal history of depression. Children completed a behavioral reward seeking task in the laboratory and an fMRI paradigm assessing neural response to happy faces, a social reward.

RESULTS

Findings demonstrated that high-risk children showed blunted responding to happy faces in the dorsal striatum compared to low-risk children. Further, lower responding in the dorsal striatum and dorsolateral prefrontal cortex was related to lower behavioral reward seeking, but only in high-risk children.

CONCLUSION

Function within neural reward regions may be altered in high-risk offspring as young as 6- to 8-years of age. Further, neural reward responding may be linked to lower behavioral response to obtain reward in these high-risk offspring.

Socioeconomic risk moderates the association between caregiver cortisol levels and infant cortisol reactivity to emotion induction at 24 months

Relations between maternal baseline cortisol and infant cortisol reactivity to an emotion induction procedure at child ages 7, 15, and 24 months were analyzed using data from the Family Life Project (N = 1,292). The emotion induction consisted of a series of standardized and validated tasks, including an arm restraint, toy removal, and mask presentation, intended to elicit responses of fear and frustration. Results revealed that at 7 and 15 months, maternal baseline cortisol was negatively related to child cortisol reactivity, such that children of mothers with lower cortisol exhibited steeper cortisol increases in response to the emotion induction. At 24 months, the association between mother and infant cortisol was moderated by socioeconomic risk, such that maternal baseline cortisol was associated with child cortisol reactivity only in dyads characterized by low socioeconomic risk. Furthermore, at 24 months, children of mothers with low baseline cortisol and low socioeconomic risk exhibited decreasing cortisol responses, whereas children of mothers with low baseline cortisol but high risk exhibited flat cortisol responses. Children in dyads characterized by high baseline maternal cortisol also exhibited flat cortisol responses regardless of socioeconomic risk. The role of caregiver physiology in the regulation of the child's stress response in the context of adversity is discussed.

To Rate or Not to Rate? Autonomic Response and Psychological Well-being of Employees During Performance Review

Organizational research started including neurosciences exploring pivotal phenomena and promoting organizational well-being. Leadership was investigated by assessing psychophysiological responses during performance review characterized by narrative or quantitative assessments and their effects on employees' well-being. As is known, rating could be perceived as threatening for employees' ranking and status perception, leading to avoidant behaviors.

DESIGN AND METHODOLOGY

Here, manager-employee dyads were assigned to 2 conditions: in the nonrate scenario, managers were asked to describe the employee's performance; in the rate one, they had to provide a quantitative rating. Skin conductance level and response and heart rate indices were continuously recorded.

FINDINGS

Dyads in nonrate condition showed higher arousal-related responses (skin conductance level and skin conductance response), perhaps highlighting an increased engagement triggered by a rewarding exchange. Conversely, in rate condition, employees showed higher heart rate, usually related to negative and stressful conditions, and avoidant behaviors.

ORIGINALITY/VALUE

Results are discussed for their possible applications to employees' well-being.

Mother-child adrenocortical synchrony: Roles of maternal overcontrol and child developmental phase

An increasing amount of empirical attention is focused on adrenocortical synchrony as an index of biobehavioral co-regulation between parent and child in the context of early child development. Working with an ethnically diverse community sample of children (N = 99, 50.5% male, ages 9-12), we collected saliva samples from mother-child dyads prior to and after a laboratory-based performance challenge task, and tested whether maternal overcontrol and child age moderated dyadic synchrony in cortisol. Results revealed that cortisol levels between mothers and children were significantly positively correlated at pretask for dyads with mean age and older children only, at 25-min post-task for all dyads, and at 45-min post-task for all dyads. Higher overcontrol/older child dyads exhibited a unique pattern of cortisol synchrony wherein at pretask, mother-child levels had the strongest positive correlation, whereas at 25 and 45 min, mother-child cortisol levels were significantly inversely correlated. These findings contribute to theory and research on parent-child relationships by examining parenting behavior, developmental stage, and adrenocortical synchrony in tandem.

Alterations in Systemic and Cognitive Glucocorticoid Sensitivity in Depression

BACKGROUND

Decades of research point to cortisol insensitivity as a biomarker of depression. Despite a vast literature on cortisol's effects on memory, the role of cortisol insensitivity in core psychological features of depression, such as emotional memory biases, is unknown.

METHODS

Sixty-five premenopausal women with varying levels of depression completed this study involving an at-home low-dose dexamethasone suppression test and four experimental sessions (i.e., two visits for memory encoding of emotionally arousing pictures, each of which was followed 48 hours later by a recall test). Participants received 20 mg of oral cortisol (CORT) or placebo prior to encoding. We tested whether systemic cortisol insensitivity measured with the dexamethasone suppression test predicted cognitive sensitivity to CORT, which was operationalized as the change in negatively biased memory formation for pictures encoded following CORT versus placebo administration.

RESULTS

Cortisol insensitivity was associated with more severe depression and flatter diurnal cortisol levels. Cortisol insensitivity predicted negative memory bias for pictures encoded during the placebo session and reduction in negative memory bias for pictures encoded during the CORT (compared with placebo) session, even after accounting for psychiatric symptomatology.

CONCLUSIONS

Our findings replicate research showing that cortisol insensitivity predicts depression severity and flatter diurnal cortisol levels. The results further suggest that systemic cortisol insensitivity is related to negative memory bias and its alleviation by cortisol administration. These novel cognitive findings tie together knowledge regarding endocrine and psychological dysfunction in depression and suggest that boosting cortisol signal may cognitively benefit individuals with cortisol insensitivity.

A systematic review of parent-child synchrony: It is more than skin deep

This manuscript provides a critical review of the literature on parent-child physiological synchrony-the matching of biological states between parents and children. All eligible studies found some evidence of physiological synchrony, though the magnitude and direction of synchrony varied according to methodological factors, including the physiological system examined (i.e., parasympathetic or sympathetic nervous system activity, adrenocortical functioning) and the statistical approach used (e.g., multilevel modeling, correlation). The review underscores the need to consider the context in which physiological synchrony occurs (e.g., family risk) to best understand its significance. Furthermore, the review delineates vital avenues for future research, including the need to assess synchrony across multiple physiological systems and the importance of documenting continuity/change in physiological synchrony across developmental periods. Such research is crucial for understanding how the parent-child relationship unfolds at a physiological level and, in turn, how this relationship can facilitate or hinder parent, child, and family adjustment.

Offspring of parents with mood disorders: time for more transgenerational research, screening and preventive intervention for this high-risk population

PURPOSE OF REVIEW

Offspring of parents with mood disorders (major depressive and bipolar disorder) are at increased risk for developing mood disorders. In this review, an overview regarding the intergenerational transmission of mood disorders, screening, and preventive intervention is given for this vulnerable group.

RECENT FINDINGS

Offspring of parents with depression have a 40% chance of developing a depression, whereas offspring of parents with bipolar disorder have a 10% chance of developing a bipolar disorder by adulthood. Studies into the intergenerational transmission of mood disorders show that children of parents with mood disorders have increased biological dysregulation and neuropsychosocial impairments. Although there is a clear need for early identification of those at the highest risk, there are few systematic attempts in mental health care to screen children of parents with mood disorders. Lastly, preventive interventions seem to be effective in reducing depressive symptoms of children of parents with depression; however, those effects are small and short-lived.

SUMMARY

Offspring of parents with mood disorders constitute a vulnerable group at high risk of mood disorders. More research needs to be conducted regarding mechanisms of the intergenerational transmission. Moreover, screening and preventive interventions for these offspring should be systematically evaluated and implemented.

Like mother like daughter: putamen activation as a mechanism underlying intergenerational risk for depression

Having a depressed mother is one of the strongest predictors for developing depression in adolescence. Given the role of aberrant reward processing in the onset and maintenance of depression, we examined the association between mothers’ and their daughters’ neural response to the anticipation of reward and loss. Fifteen non-depressed mothers with a history of recurrent depression and their never-disordered daughters, and 23 mothers without past or current depression and their never-disordered daughters, underwent functional magnetic resonance imaging while performing the monetary incentive delay task. To assess mother-daughter concordance, we first identified ROIs involved in the anticipation of reward and loss across all mother-daughter pairs. Within each of these ROIs, we examined the association between mothers’ and daughters’ neural response, and the interaction between group status and mothers’ neural response in predicting daughters’ neural response. We found a significant association between mothers’ and daughters’ putamen response to the anticipation of loss, regardless of mother’s depression history. Furthermore, pubertal stage moderated the association between mother-daughter putamen concordance. Our findings suggest a unique role of the putamen in the maternal transmission of reward learning and have important implications for understanding disorders characterized by disturbances in reward learning and processing, such as major depression.

Maternal exercise increases but concurrent maternal fluoxetine prevents the increase in hippocampal neurogenesis of adult offspring

Treating postpartum depression (PPD) with pharmacological antidepressants like fluoxetine (FLX) is complicated because these drugs can remain active in breast milk and potentially affect infant development. Alternatively, non-pharmacological treatments such as exercise are associated with beneficial effects on infant development but its potential ability to counter the effects of PPD are largely unknown. To investigate this, we treated dams with corticosterone (CORT) or vehicle (sesame oil) from postpartum days 2-25 to model PPD. Within oil and CORT treatments, dams were also assigned to one of these treatments: 1) exercise (voluntary running wheel) + FLX (10 mg/kg, i.p.), 2) exercise + saline (vehicle for FLX), 3) no exercise + FLX, 4) no exercise + saline. Both male and female offspring were analyzed, and this generated a total of 16 experimental groups for this study. Adult male and female offspring (125 d old) of these dams were tested for anxiety-like behavior in the novelty suppressed feeding test and stress reactivity in the dexamethasone suppression test. Hippocampal tissue was processed for doublecortin, a protein expressed in immature neurons. Regardless of sex, maternal exercise increased neurogenesis in the dorsal hippocampus of adult offspring, but concurrent exposure to maternal fluoxetine prevented this effect. Exposure to either maternal exercise or maternal FLX facilitated HPA negative feedback in adult males but not females. Maternal postpartum CORT also facilitated HPA feedback in adult offspring of both sexes. Collectively, these data indicate that maternal exercise increased dorsal hippocampal neurogenesis in both sexes but differentially affected offspring HPA axis based on sex. Alternatively, maternal postpartum FLX facilitated HPA axis negative feedback only in males. These findings indicate that different types of maternal interventions bear long-term effects on offspring outcome with implications for treating PPD.

Annual Research Review: Early adversity, the hypothalamic-pituitary-adrenocortical axis, and child psychopathology

BACKGROUND

Research on early adversity, stress biology, and child development has grown exponentially in recent years.

FINDINGS

We review the current evidence for the hypothalamic-pituitary-adrenocortical (HPA) axis as a stress-mediating mechanism between various forms of childhood adversity and psychopathology. We begin with a review of the neurobiology of the axis and evidence for relations between early adversity-HPA axis activity and HPA axis activity-psychopathology, as well as discuss the role of regulatory mechanisms and sensitive periods in development.

CONCLUSIONS

We call attention to critical gaps in the literature to highlight next steps in this research including focus on developmental timing, sex differences, stress buffering, and epigenetic regulation. A better understanding of individual differences in the adversity-HPA axis-psychopathology associations will require continued work addressing how multiple biological and behavioral systems work in concert to shape development.

Link between children's hair cortisol and psychopathology or quality of life moderated by childhood adversity risk

The hypothalamus-pituitary-adrenal axis (HPAA) and its end product, the glucocorticoid cortisol, has been shown to be associated with psychopathology. Determining cortisol concentrations in hair (HCC) allows the investigation of long-term HPAA-activity. There is a significant scarcity of studies investigating the link between HCC and psychopathology and quality of life in child and adolescent samples. In addition, as the HPAA constitutes a feedback system enabling adaption to environmental demands, it is important to consider the socio-environmental context that the children grow up in. We therefore investigated the associations between child HCC and psychopathology/quality of life and compared these links in two groups of five to 12-year-olds: children living with mothers who report experiences of early life maltreatment (ELM) (high-risk group) and children whose mothers did not report any ELM (low-risk group). We expected that, under conditions of a high-risk environment, elevated HPAA-functioning would be associated with low levels of psychopathology and high levels of quality of life in children. Under low-risk conditions, elevated HPAA-functioning would be associated with high levels of psychopathology and low levels of quality of life in children. For the complete sample of N = 130 children, three-months HCC did not significantly predict child psychopathology or quality of life. However, there was a significant moderating effect of group membership: In the high-risk group, high levels of HCC were significantly associated with high levels of self-reported quality of life. In the low-risk group, there was no association between HCC and self-reported quality of life. For child psychopathology, in the low-risk group, high levels of HCC were significantly associated with high levels of teacher reported behavior problems, whereas in the high-risk group, the association did not reach significance. Our results underline the importance of accounting for the social environment children grow up in when investigating the link between HCC and child psychopathology and quality of life.

Maternal Depressive Symptoms and Child Behavior among Mexican Women and Their Children

Over 50% of mothers in rural Mexico have high depressive symptoms, and their children's health and development are likely to be negatively affected. A critical question is whether children vary in their vulnerability to the effects of high maternal depressive symptoms according to their indigenous ethnicity, maternal education, or household wealth. Our sample included 4442 mothers and 5503 children from an evaluation of Mexico's social welfare program. Maternal depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) Scale, and child behavior was measured using an adapted version of the Behavior Problems Index (BPI). Multiple linear regression models were used to explore the associations between maternal depressive symptoms and child behavior problems, and the heterogeneity of associations by indigenous ethnicity, maternal education, and household assets. We found that having greater maternal depressive symptoms was significantly associated with having a child with more behavior problems (β = 0.114, p < 0.0001, [95% CI 0.101, 0.127]), in adjusted models. In tests of heterogeneity, the association between maternal depressive symptoms and child behavior problems was strongest in households with indigenous ethnicity, low maternal education, or in households with fewer assets. These results strengthen the case for effective mental health interventions in low- and middle-income countries, particularly among the most vulnerable families where mothers and children appear to be at the greatest risk.

Affective Synchrony and Autonomic Coupling during Cooperation: A Hyperscanning Study

Previous research highlighted that during social interactions people shape each other's emotional states by resonance mechanisms and synchronized autonomic patterns. Starting from the idea that joint actions create shared emotional experiences, in the present study a social bond was experimentally induced by making subjects cooperate with each other. Participants' autonomic system activity (electrodermal: skin conductance level and response: SCL, SCR; cardiovascular indices: heart rate: HR) was continuously monitored during an attentional couple game. The cooperative motivation was induced by presenting feedback which reinforced the positive outcomes of the intersubjective exchange. 24 participants coupled in 12 dyads were recruited. Intrasubject analyses revealed higher HR in the first part of the task, connoted by increased cognitive demand and arousing social dynamic, while intersubject analysis showed increased synchrony in electrodermal activity after the feedback. Such results encourage the use of hyperscanning techniques to assess emotional coupling in ecological and real-time paradigms.

Physiological attunement in mother–infant dyads at clinical high risk: The influence of maternal depression and positive parenting

A growing number of research studies have examined the intradyadic coregulation (or attunement) of hypothalamus–pituitary–adrenal axis functioning in mothers and their children. However, it is unclear how early this coregulation may be present in dyads at clinical high risk and whether certain factors, such as maternal depression or positive parenting, are associated with the strength of this coregulation. The present study examined cortisol attunement within mother–infant dyads in a high-risk sample of 233 mothers who received treatment for psychiatric illness during pregnancy and whose infants were 6 months old at the study visit. Results showed that maternal and infant cortisol covaried across four time points that included a stressor paradigm and a mother–infant interaction task. Greater maternal positive affect, but not depression, predicted stronger cortisol attunement. In addition, infants’ cortisol level following separation from the mother predicted mothers’ cortisol level at the next time point. Mothers’ cortisol level following the separation and the laboratory stress paradigm predicted infants’ cortisol levels at each successive time point, over and above infants’ own cortisol at the previous time point. These findings suggest that maternal and infant cortisol levels influence one another in a bidirectional fashion that may be temporally and context dependent.

The effect of a maternal history of childhood abuse on adrenocortical attunement in mothers and their toddlers

We investigated circadian mother-child adrenocortical attunement in the context of a maternal history of childhood abuse (HoA). Mothers were screened after birth using the Childhood Trauma Questionnaire. Women reporting moderate or severe abuse formed the HoA group (n = 37; HoAG) and were compared with a non-maltreated comparison group (n = 45; CG). Three years later, cortisol awakening response (CAR) and diurnal slope (DSL) were assessed. Mother-child interaction was coded using the Emotional Availability Scales at 12 months of age. For the CAR, we found adrenocortical attunement only in the HoAG (2-way interaction: p = .004), particularly if mothers scored low on structuring (3-way interaction: p = .042) and children scored low on responsiveness (3-way interaction: p = .044). DSL-attunement was dependent on maternal sensitivity (3-way interaction: p = .012) and child involvement (3-way interaction: p = .012). In the context of a maternal HoA, it seems possible for mother-child-dyads to show less optimal interactional quality but be stronger attuned to each other biologically.

Sex-dependent effects of maternal corticosterone and SSRI treatment on hippocampal neurogenesis across development

Background

Postpartum depression affects approximately 15% of mothers and represents a form of early life adversity for developing offspring. Postpartum depression can be treated with prescription antidepressants like fluoxetine (FLX). However, FLX can remain active in breast milk, raising concerns about the consequences of neonatal FLX exposure. The hippocampus is highly sensitive to developmental stress, and males and females respond differently to stress at many endpoints, including hippocampal plasticity. However, it is unclear how developmental exposure to FLX alters the trajectory of hippocampal development. The goal of this study was to examine the long-term effects of maternal postpartum corticosterone (CORT, a model of postpartum depression) and concurrent FLX on hippocampal neurogenesis in male and female offspring.

Methods

Female Sprague-Dawley rat dams were treated daily with either CORT or oil and FLX or saline from postpartum days 2–23. Offspring were perfused on postnatal day 31 (pre-adolescent), postnatal day 42 (adolescent), and postnatal day 69 (adult). Tissue was processed for doublecortin (DCX), an endogenous marker of immature neurons, in the dorsal and ventral hippocampus.

Results

Maternal postpartum CORT reduced density of DCX-expressing cells in the dorsal hippocampus of pre-adolescent males and increased it in adolescent males, suggesting that postpartum CORT exposure disrupted the typical progression of the density of DCX-expressing cells. Further, among offspring of oil-treated dams, pre-adolescent males had greater density of DCX-expressing cells than pre-adolescent females, and maternal postpartum CORT prevented this sex difference. In pre-adolescent females, maternal postpartum FLX decreased the density of DCX-expressing cells in the dorsal hippocampus compared to saline. As expected, maternal CORT reduced the density of DCX-expressing cells in adult female, but not male, offspring. The combination of maternal postpartum CORT/FLX diminished density of DCX-expressing cells in dorsal hippocampus regardless of sex or age.

Conclusions

These findings reveal how modeling treatment of postpartum depression with FLX alters hippocampal neurogenesis in developing offspring differently depending on sex, predominantly in the dorsal dentate gyrus and earlier in life.

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.

Mother-child adrenocortical synchrony; Moderation by dyadic relational behavior

Mother-child adrenocortical synchrony, the coupling of cortisol (CT) secretion in mother and child, has been associated with shared parent-child experiences and maladaptive familial contexts. Yet, few studies tested adrenocortical synchrony in diurnal CT patterns. Guided by the bio-behavioral synchrony model, we examined whether mother-child relational behavior and maternal psychopathology may moderate the degree of concordance between mother and child's diurnal CT. Ninety-seven mothers and their six-year old children participated in two groups; mothers diagnosed with major depression disorder (N=28) and non-depressed controls (N=69). Mother-child interactions were observed and coded for dyadic reciprocity and dyadic tension and diurnal cortisol was collected from mother and child over two consecutive weekend days. Concordance between maternal and child's diurnal CT was found, significant above and beyond time of measurement. Maternal depression, while associated with attenuated child diurnal CT variability, was unrelated to adrenocortical synchrony. Higher child diurnal CT production predicted a stronger linkage between maternal and child's diurnal CT, suggesting that greater child physiological stress is associated with increased susceptibility to the influences of maternal stress physiology. Mother-child reciprocity was related to lower adrenocortical synchrony. Findings suggest that higher adrenocortical synchrony is associated with greater physiological stress and less adaptive dyadic relational patterns. Results raise the possibility that diurnal adrenocortical synchrony taps a unique aspect of HPA-axis functioning whose role in the cross-generational transfer of stress physiology requires further research.

Etiologic specificity of waking Cortisol: Links with maternal history of depression and anxiety in adolescent girls

BACKGROUND

Many previous studies have indicated that individuals who are depressed or at risk for depression are characterized by increased levels of morning cortisol and a greater cortisol awakening response (CAR). However, despite the high comorbidity between depressive and anxiety disorders, fewer studies have examined whether these diurnal cortisol abnormalities are also characteristic of anxiety or risk for anxiety.

METHODS

In the present study we examined cortisol in a community sample of 476 female adolescents and related it to maternal history of depression and/or anxiety disorders. Salivary cortisol was collected at waking, 30min post waking, and in the evening on three weekdays.

RESULTS

Contrary to prior results, offspring at risk for depression did not have increased morning cortisol or CAR. However, offspring at risk for anxiety disorders had elevated 30min cortisol and total cortisol produced throughout the day; this effect was primarily driven by offspring of mothers with panic disorder or agoraphobia. Additionally, levels of cortisol were highest among offspring of mothers with multiple anxiety diagnoses.

LIMITATIONS

The study is limited to female adolescents and maternal diagnostic history. Additionally, some diagnoses could not be examined as a result of too few cases (e.g. GAD).

CONCLUSIONS

Overall, these results underscore the importance of considering anxiety when examining the association of diurnal cortisol abnormalities with risk for psychopathology, as it may have influenced prior observations of elevated morning cortisol in depression.

Understanding the epigenetic basis of sex differences in depression

Epigenetics refers to potentially heritable processes that can mediate both lasting and transient changes in gene expression in the absence of genome sequence alterations. The field of epigenetics has introduced a novel understanding of the mechanisms through which the environment can shape an individual and potentially its offspring. This Mini-Review examines the current literature exploring the role of epigenetics in the development of mood disorders such as depression. Depression is twofold more common in females, yet the majority of preclinical research has been conducted exclusively in male subjects. Here we discuss what is known about sex differences in epigenetic regulation and function and how this may contribute to the etiology and onset of mood disorders. © 2016 Wiley Periodicals, Inc.

Concordant Patterns of Brain Structure in Mothers with Recurrent Depression and Their Never-Depressed Daughters

BACKGROUND

A growing body of research has demonstrated that having a mother with a history of major depressive disorder (MDD) is one of the strongest predictors of depression in adolescent offspring. Few studies, however, have assessed neural markers of this increased risk for depression, or examined whether risk-related anomalies in adolescents at maternal risk for depression are related to neural abnormalities in their depressed mothers. We addressed these questions by examining concordance in brain structure in two groups of participants: mothers with a history of depression and their never-depressed daughters, and never-depressed mothers and their never-depressed daughters.

METHOD

We scanned mothers with (remitted; RMD) and without (control; CTL) a history of recurrent episodes of depression and their never-depressed daughters, computed cortical gray matter thickness, and tested whether mothers' thickness predicted daughters' thickness.

RESULTS

Both RMD mothers and their high-risk daughters exhibited focal areas of thinner cortical gray matter compared with their CTL/low-risk counterparts. Importantly, the extent of thickness anomalies in RMD mothers predicted analogous abnormalities in their daughters; this pattern was not present in CTL/low-risk dyads.

CONCLUSIONS

We identified neuroanatomical risk factors that may underlie the intergenerational transmission of risk for MDD. Our findings suggest that there is concordance in brain structure in dyads that is affected by maternal depression, and that the location, direction, and extent of neural anomalies in high-risk offspring mirror those of their recurrent depressed mothers.

Maternal and pediatric health and disease: integrating biopsychosocial models and epigenetics

The concepts of allostasis (stability through adaptation) and accumulated life stress (McEwen's allostatic load) aim to understand childhood and adult outcomes. Chronic malnutrition, changes in social condition, and adverse early-life experiences may program phenotypes and contribute to long-lasting disease risk. However, integration of life course approaches, social and economic contexts, and comparison among different biopsychosocial models has not generally been explored. This review critically examines the literature and evaluates recent insights into how environmental stress can alter lifelong hypothalamic-pituitary-adrenal axis and immune system responsiveness and induce metabolic and neurodevelopmental maladaptation. Models of biopsychosocial stress overlap but may consider different conditions. Concepts include allostasis, which incorporates hormonal responses to predictable environmental changes, and Geronimus's "weathering," which aims to explain how socially structured, repeated stress can accumulate and increase disease vulnerability. Weathering emphasizes roles of internalized/interpersonal racism in outcomes disparities. For Mexican immigrants and Mexican Americans, the "acculturation" framework has proven especially useful to explore disparities, including preterm birth and neuropsychiatric risks in childhood. Complexities of stress assessments and recent research into epigenetic mechanisms mediating effects of physical, nutritional, psychological, and social stress are reviewed.