Autonomic reactivity and vulnerability to depression: A multi-wave study

The Predictive Potential of Heart Rate Variability for Depression

Heart rate variability (HRV),a measure of the fluctuations in the intervals between consecutive heartbeats, is an indicator of changes in the autonomic nervous system. A chronic reduction in HRV has been repeatedly linked to clinical depression. However, the chronological and mechanistic aspects of this relationship, between the neural, physiological, and psychopathological levels, remain unclear. In this review we present evidence by which changes in HRV might precede the onset of depression. We describe several pathways that can facilitate this relationship. First, we examine a theoretical model of the impact of autonomic imbalance on HRV and its role in contributing to mood dysregulation and depression. We then highlight brain regions that are regulating both HRV and emotion, suggesting these neural regions, and the Insula in particular, as potential mediators of this relationship. We also present additional possible mediating mechanisms involving the immune system and inflammation processes. Lastly, we support this model by showing evidence that modification of HRV with biofeedback leads to an improvement in some symptoms of depression. The possibility that changes in HRV precede the onset of depression is critical to put to the test, not only because it could provide insights into the mechanisms of the illness but also because it may offer a predictive anddiagnosticphysiological marker for depression. Importantly, it could also help to develop new effective clinical interventions for treating depression.

A new network analysis model in anorexia nervosa patients based on self-reported eating disorder symptoms, psychological distress, and cognitive flexibility

OBJECTIVES

Cognitive flexibility and psychological distress, such as depression and anxiety, have been implicated in the aetiology of Anorexia Nervosa (AN). Despite the known associations between eating disorder (ED) symptoms, depression, anxiety, and cognitive flexibility, the specific pathways that connect these constructs are unclear. We therefore used network analysis to examine the relationship between these symptoms in an AN sample.

METHODS

One hundred and ninety-three treatment-seeking individuals diagnosed with AN (95.6% female, M = 26.89 [SD = 9.45] years old) completed self-report measures assessing depression, anxiety, cognitive flexibility, and ED symptoms. To determine each symptom's influence in the network, we calculated the expected influence.

RESULTS

The two relationships with the greatest edges were those between (1) weight/shape concerns and eating/dietary restraint and (2) weight/shape concerns and psychological distress (a measure that combined depression and anxiety). Cognitive flexibility was not connected to weight/shape concerns but had negative partial associations with eating concerns/dietary restraint and psychological distress. There was also a slight, non-zero connection between eating concerns/dietary restraint and psychological distress.

CONCLUSIONS

The findings underscore the importance of weight/shape, eating/dietary concerns, and psychological distress in the AN network and suggest that addressing cognitive flexibility may be a useful target for eating concerns/dietary restraint and psychological distress. Future studies assessing the longitudinal course of psychopathology within the AN network structure may help in identifying whether specific symptoms function as risk factors or maintaining factors for this co-occurrence.

Individual-Specific Animated Profiles of Mental Health

How important is the timing of the pretreatment evaluation? If we consider mental health to be a relatively fixed condition, the specific timing (e.g., day, hour) of the evaluation is immaterial and often determined on the basis of technical considerations. Indeed, the fundamental assumption underlying the vast majority of psychotherapy research and practice is that mental health is a state that can be captured in a one-dimensional snapshot. If this fundamental assumption, underlying 80 years of empirical research and practice, is incorrect, it may help explain why for decades psychotherapy failed to rise above the 50% efficacy rate in the treatment of mental-health disorders, especially depression, a heterogeneous disorder and the leading cause of disability worldwide. Based on recent studies suggesting within-individual dynamics, this article proposes that mental health and its underlying therapeutic mechanisms have underlying intrinsic dynamics that manifest across dimensions. Computational psychotherapy is needed to develop individual-specific pretreatment animated profiles of mental health. Such individual-specific animated profiles are expected to improve the ability to select the optimal treatment for each patient, devise adequate treatment plans, and adjust them on the basis of ongoing evaluations of mental-health dynamics, creating a new understanding of therapeutic change as a transition toward a more adaptive animated profile.

"I was very sad, but not depressed": phenomenological differences between adjustment disorder and a major depressive episode

Introduction

Adjustment disorder (AD) is a diagnosis that must be differentiated from major depressive episode (MDE) because of the therapeutic implications. The aim of this study is to understand the experience of patients who in their lifetime have been diagnosed with AD as well as MDE to establish the characteristics of each disorder.

Methods

A descriptive phenomenological approach was used with in-depth interviews to four patients and the method proposed by Colaizzi to understand the experiences and reach the description of both disorders.

Results

Three women and one man, with advanced schooling were interviewed. The participants emphasized the existence of differences that were grouped in: the attribution made by the individual, the theme of cognitions, the variability in the course, the possibility of mood modulation, the syndrome severity, the presence of hopelessness and the perceived course.

Conclusion

Phenomenological differences were found in the subjective experience of MDE and AD. The MDE would be described as an intense state of generalized shutdown of the subject's own life, with little response to events, and the AD, as a dynamic reaction attributed to a stressful event, with high variability in the course of symptoms due to the dependence on such event, with the preserved hope that it will end.

Predicting postpartum depressive symptoms by evaluating self-report autonomic nervous system reactivity during pregnancy

OBJECTIVE

Altered self-reported autonomic reactivity is associated with worse mental health in the general population. Although dysfunctional changes in ANS during pregnancy have been investigated in relation to depressive symptoms, no studies addressed the relationship between self-report autonomic reactivity during pregnancy and depressive symptoms after the delivery. The present study aimed to assess the impact of prepartum self-reported autonomic reactivity on the development of postpartum depressive symptoms.

METHODS

In this longitudinal study, 170 women were assessed during pregnancy (i.e., second or third trimester) and after childbirth (i.e., one month after the delivery). Self-reported autonomic reactivity was assessed through the Body Perception Questionnaire - Short Form that evaluates the autonomic functions related to organs above (i.e., supradiaphragmatic reactivity) and below (i.e., subdiaphragmatic reactivity) the diaphragm. In addition, prepartum and postpartum depressive symptoms were evaluated using the Patient Health Questionnaire - 9.

RESULTS

Findings showed that higher prepartum supradiaphragmatic reactivity predicted higher depressive symptoms in the postpartum period (β = 0.112, p = 0.009) after controlling for prepartum depressive symptomatology and other potential covariates.

CONCLUSIONS

Evaluation of self-reported autonomic activity may be a useful tool to identify antenatally women at risk of postpartum depressive symptoms. Future studies are needed to evaluate the effectiveness of interventions aimed at reducing the threat-responsive autonomic reactivity at rest and improving adaptive autonomic regulation to prevent postpartum depression.

Autonomic complexity dynamically indexes affect regulation in everyday life

Affect regulation often is disrupted in depression. Understanding biomarkers of affect regulation in ecologically valid contexts is critical for identifying moments when interventions can be delivered to improve regulation and may have utility for identifying which individuals are vulnerable to psychopathology. Autonomic complexity, which includes linear and nonlinear indices of heart rate variability, has been proposed as a novel marker of neurovisceral integration. However, it is not clear how autonomic complexity tracks with regulation in everyday life, and whether low complexity serves as a marker of related psychopathology. To measure regulation phenotypes with diminished influence of current symptoms, 37 young adults with remitted major depressive disorder (rMDD) and 28 healthy comparisons (HCs) completed ambulatory assessments of autonomic complexity and affect regulation across one week in everyday life. Multilevel models indicated that in HCs, but not rMDD, autonomic complexity fluctuated in response to regulation cues, increasing in response to reappraisal and distraction and decreasing in response to negative affect. Higher complexity across the week predicted greater everyday regulation success, whereas greater variability of complexity predicted lower (and less variable) negative affect, rumination, and mind-wandering. Results suggest that ambulatory assessment of autonomic complexity can passively index dynamic aspects of real-world affect and regulation, and that dynamic physiological reactivity to regulation is restricted in rMDD. These results demonstrate how intensive sampling of dynamic, nonlinear regulatory processes can advance our understanding of potential mechanisms underlying psychopathology. Such measurements might inform how to test interventions to enhance neurovisceral complexity and affect regulation success in real time. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Utilizing Random Effects Machine Learning Algorithms for Identifying Vulnerability to Depression

Background

Reliable prediction of clinical progression over time can improve the outcomes of depression. Little work has been done integrating various risk factors for depression, to determine the combinations of factors with the greatest utility for identifying which individuals are at the greatest risk.

Materials and methods

This study demonstrates that data-driven Machine Learning (ML) methods such as Random Effects/Expectation Maximization (RE-EM) trees and Mixed Effects Random Forest (MERF) can be applied to reliably identify variables that have the greatest utility for classifying subgroups at greatest risk for depression. 185 young adults completed measures of depression risk, including rumination, worry, negative cognitive styles, cognitive and coping flexibilities and negative life events, along with symptoms of depression. We trained RE-EM trees and MERF algorithms and compared them to traditional Linear Mixed Models (LMMs) predicting depressive symptoms prospectively and concurrently with cross-validation.

Results

Our results indicated that the RE-EM tree and MERF methods model complex interactions, identify subgroups of individuals and predict depression severity comparable to LMM. Further, machine learning models determined that brooding, negative life events, negative cognitive styles, and perceived control were the most relevant predictors of future depression levels.

Conclusion

Random effects machine learning models have the potential for high clinical utility and can be leveraged for interventions to reduce vulnerability to depression.

Rethinking the risk for depression using the RDoC: A psychophysiological perspective

Considering that the classical categorical approach to mental disorders does not allow a clear identification of at-risk conditions, the dimensional approach provided by the Research Domain Criteria (RDoC) is useful in the exploration of vulnerability to psychopathology. In the RDoC era, psychophysiological models have an important role in the reconceptualization of mental disorders. Indeed, progress in the study of depression vulnerability has increasingly been informed by psychophysiological models. By adopting an RDoC lens, this narrative review focuses on how psychophysiological models can be used to advance our knowledge of the pathophysiological mechanisms underlying depression vulnerability. Findings from psychophysiological research that explored multiple RDoC domains in populations at-risk for depression are reviewed and discussed. Future directions for the application of psychophysiological research in reaching a more complete understanding of depression vulnerability and, ultimately, improving clinical utility, are presented.

Self-Reported Depression Is Associated With Aberration in Emotional Reactivity and Emotional Concept Coding

Cognitive impairment, alterations in mood, emotion dysregulation are just a few of the consequences of depression. Despite depression being reported as the most common mental disorder worldwide, examining depression or risks of depression is still challenging. Emotional reactivity has been observed to predict the risk of depression, but the results have been mixed for negative emotional reactivity (NER). To better understand the emotional response conflict, we asked our participants to describe their feeling in meaningful sentences alongside reporting their reactions to the emotionally evocative words. We presented a word on the screen and asked participants to perform two tasks, rate their feeling after reading the word using the self-assessment manikin (SAM) scale, and describe their feeling using the property generation task. The emotional content was analyzed using a novel machine-learning algorithm approach. We performed these two tasks in blocks and randomized their order across participants. Beck Depression Inventory (BDI) was used to categorize participants into self-reported non-depressed (ND) and depressed (D) groups. Compared to the ND, the D group reported reduced positive emotional reactivity when presented with extremely pleasant words regardless of their arousal levels. However, no significant difference was observed between the D and ND groups for negative emotional reactivity. In contrast, we observed increased sadness and inclination toward low negative context from descriptive content by the D compared to the ND group. The positive content analyses showed mixed results. The contrasting results between the emotional reactivity and emotional content analyses demand further examination between cohorts of self-reported depressive symptoms, no-symptoms, and MDD patients to better examine the risks of depression and help design early interventions.

Decentering predicts attenuated perseverative thought and internalizing symptoms following stress exposure: A multi-level, multi-wave study

While research identifies a growing list of risk factors for anxiety and depression, it is equally important to identify potential protective factors that may prevent or reduce vulnerability to developing internalizing psychopathology. We hypothesized that forms of perseverative thinking, such as rumination and worry, act as mechanisms linking negative life experiences and prospective symptoms of anxiety and depression. More specifically, we investigated whether decentering, the meta-cognitive capacity to adopt a distanced perspective toward one's thoughts and feelings, serves as a protective factor at various points along this mediational pathway. A sample of 181 undergraduate students were recruited and assessed at five time points over a 12-week period. Multilevel modeling indicated that decentering was associated with an attenuated impact of (1) negative events on prospective depressive symptoms; (2) negative events on prospective brooding, and (3) brooding, pondering and worry on prospective internalizing symptoms. Multilevel moderated mediation analyses provided partial support for the hypothesis that perseverative thinking would mediate the longitudinal associations between negative life events and internalizing symptoms, with decentering attenuating risk at several connections of the indirect pathways. The strongest support was provided for moderated mediation models in which decentering was associated with attenuated relationships between negative events, brooding, and symptoms of depression. This study is the first to elucidate the role of decentering as a protective factor against anxiety and depressive symptoms at different points in the path from stress to perseverative thought to internalizing symptoms. Decentering therefore may be a critical target for clinical intervention to promote resilience against anxiety and depression.

Autonomic Nervous System Activity During Positive Emotions: A Meta-Analytic Review

Autonomic nervous system (ANS) activity is a fundamental component of emotional responding. It is not clear, however, whether positive emotional states are associated with differential ANS reactivity. To address this issue, we conducted a meta-analytic review of 120 articles (686 effect sizes, total N = 6,546), measuring ANS activity during 11 elicited positive emotions, namely amusement, attachment love, awe, contentment, craving, excitement, gratitude, joy, nurturant love, pride, and sexual desire. We identified a widely dispersed collection of studies. Univariate results indicated that positive emotions produce no or weak and highly variable increases in ANS reactivity. However, the limitations of work to date – which we discuss – mean that our conclusions should be treated as empirically grounded hypotheses that future research should validate.

Affective and Autonomic Reactivity During Parent-Child Interactions in Depressed and Non-Depressed Mothers and Their Adolescent Offspring

Depression presents risks that are profound and intergenerational, yet research on the association of depression with the physiological processes that might be associated with impaired mental and physical health has only recently been contextualized within the family environment. Participants in this multi-method case-control study were 180 mother-adolescent dyads (50% mothers with a history of depression treatment and current depressive symptoms). In order to examine the association between maternal depression and affective and autonomic reactivity amongst these mothers and their adolescent offspring we collected self-reported measures of positive and negative affect, as well as measures of cardiovascular and electrodermal autonomic activity, during mother-adolescent interaction tasks. Findings indicated that depressed mothers and their adolescent offspring exhibited greater self-reported negative affect reactivity during a problem-solving interaction and blunted (i.e., low) sympathetic activity as measured via skin conductance level across both interaction tasks. These effects remained significant after controlling for a range of potential covariates, including medication use, sex, age, adolescents own mental health symptoms, and behavior of the other interactant, along with correcting for multiple comparisons. Findings indicate that depressed mothers and their adolescent offspring both exhibit patterns of affect and physiology during interactions that are different from those of non-depressed mothers and their offspring, including increased negative affect reactivity during negative interactions and blunted sympathetic activity across both positive and negative interactions. These findings have potential implications for understanding the role of family processes in the intergenerational transmission of risk for depressive disorders.

From affective to cognitive processing: Functional organization of the medial frontal cortex

The medial wall of the primate frontal lobe encompasses multiple anatomical subregions. Based on distinct neurophysiological correlates and effects of lesions, individual areas are thought to play unique roles in behavior. Further, evidence suggests that dysfunction localized to specific subregions is commonly found in different neuropsychiatric disorders. The neurobiological underpinnings of these disorders, however, remain far from clear. Here, to better understand the functions of medial frontal cortex (MFC) and its role in psychiatric disease, we focus on its functional organization. We describe the emerging pattern in which more dorsal regions subserve temporally extended cognitive functions and more ventral regions predominantly subserve affective functions. We focus on two specific domains, decision-making and social cognition, that require integration across emotion and cognition. In each case, we discuss the current understanding of the functions believed to depend on subregions of MFC as a stepping-stone to speculate on how they might work in unison. We conclude with an overview of how symptoms of certain psychiatric disorders relate to our understanding of MFC functional organization and how further discovery could fuel advances in circuit-based therapies.

Adversity and Depression: The Moderating Role of Stress Reactivity among High and Low Risk Youth

Adverse life events have been causally linked to depression among youth at high risk for depression. But given that not all high-risk youth develop depression following adversity, individual differences in various processes, including physiological reactivity to stress, are likely to be at play. This longitudinal prospective study tested the hypothesis that, among high-risk youth exposed to adversities, extent of physiological reactivity to laboratory stress (indexed as respiratory sinus arrhythmia; RSA) would predict subsequent depressive symptoms. Subjects were youth at high (n = 80) and low (n = 74) familial risk for depression. At Time 1 (T1), RSA was assessed during a cognitive stress task. At Time 2 (T2) about 2 years later, parents reported on adversities experienced by their offspring during the interim. At T1 and T2, youth received a diagnostic evaluation, which included assessment of their depressive symptoms. The three-way interaction of group-X-adversities-X-RSA predicted T2 depressive symptoms (controlling for T1 depressive symptoms). This interaction was mostly driven by the moderating effect of RSA among high-risk youth, such that adversities predicted higher depressive symptoms for those who displayed greater RSA reactivity to stress. Among low-risk youth, an inverse marginal moderating effect of RSA was found, such that adversities tended to predict depressive symptoms for those who displayed blunted RSA reactivity to stress. Thus, high physiological stress reactivity appears to be an additional risk factor for depressive symptoms only among youth at elevated risk for such outcomes, and should be taken into consideration in efforts to prevent depression in these populations.

Sympathetic arousal during the processing of dysphoric affect by youths at high and low familial risk for depression

Youths at high risk for depression have been shown to have problems in repairing their own sad mood. Given that sympathetic arousal has been implicated both in the experience and regulation of affect, an atypical pattern of arousal may be one of the factors that contribute to mood repair problems. In the current study, we measured sympathetic arousal of never-depressed youths at high (n = 56) and low (n = 67) familial risk for depression during sad mood induction and instructed mood repair. Sympathetic arousal was indexed by skin conductance level (SCL) and cardiac pre-ejection period (PEP); mood repair outcome was indexed by self-rated affect. High-risk youths demonstrated increased SCL during sadness induction, which persisted during mood repair; low-risk youths evidenced increased SCL only during mood repair. Shortened PEP was evident only among high-risk youths and only during mood repair. Furthermore, shortened PEP during mood induction predicted less successful mood repair in the low-risk but not in the high-risk group. The findings suggest that: (a) depression-prone youths differ from control peers in patterns of sympathetic responses to emotional stimuli, which may impair their ability to relieve sadness, and (b) activation patterns differ across subsystems (SCL vs. PEP) of sympathetic activity, in conjunction with depression risk status.

Inflexible autonomic responses to sadness predict habitual and real-world rumination: A multi-level, multi-wave study

Inflexibility of the autonomic nervous system is relevant to depression vulnerability, but the downstream behavioral consequences of autonomic inflexibility are not well understood. Rumination, a perseverative thinking style that characterizes depression, is one candidate phenotype relevant to autonomic inflexibility. Undergraduates (N = 134) completed a sadness induction while respiratory sinus arrhythmia was measured, and completed four waves of follow-up over twelve weeks during which rumination, stressful events, and symptoms of depression were measured. Individuals with less autonomic flexibility had higher levels of trait rumination, and were more likely to ruminate in daily life, regardless of stress exposure, whereas individuals with more autonomic flexibility ruminated more only in the context of stress. These findings provide the first evidence that autonomic inflexibility may confer vulnerability to context-insensitive rumination. This work suggests a potential behavioral mechanism by which autonomic inflexibility leads to problems with self-regulation and depression, suggesting multiple avenues for intervention to target these markers of vulnerability.

Using ambulatory assessment to measure dynamic risk processes in affective disorders

BACKGROUND

Rapid advances in the capability and affordability of digital technology have begun to allow for the intensive monitoring of psychological and physiological processes associated with affective disorders in daily life. This technology may enable researchers to overcome some limitations of traditional methods for studying risk in affective disorders, which often (implicitly) assume that risk factors are distal and static - that they do not change over time. In contrast, ambulatory assessment (AA) is particularly suited to measure dynamic "real-world" processes and to detect fluctuations in proximal risk for outcomes of interest.

METHOD

We highlight key questions about proximal and distal risk for affective disorders that AA methods (with multilevel modeling, or fully-idiographic methods) allow researchers to evaluate.

RESULTS

Key questions include between-subject questions to understand who is at risk (e.g., are people with more affective instability at greater risk than others?) and within-subject questions to understand when risk is most acute among those who are at risk (e.g., does suicidal ideation increase when people show more sympathetic activation than usual?). We discuss practical study design and analytic strategy considerations for evaluating questions of risk in context, and the benefits and limitations of self-reported vs. passively-collected AA.

LIMITATIONS

Measurements may only be as accurate as the observation period is representative of individuals' usual life contexts. Active measurement techniques are limited by the ability and willingness to self-report.

CONCLUSIONS

We conclude by discussing how monitoring proximal risk with AA may be leveraged for translation into personalized, real-time interventions to reduce risk.

The persistence of hedonically-based mood repair among young offspring at high- and low-risk for depression

The aim of the present study was to examine whether offspring at high and low familial risk for depression differ in the immediate and more lasting behavioural and physiological effects of hedonically-based mood repair. Participants (9- to 22-year olds) included never-depressed offspring at high familial depression risk (high-risk, n = 64), offspring with similar familial background and personal depression histories (high-risk/DEP, n = 25), and never-depressed offspring at low familial risk (controls, n = 62). Offspring provided affect ratings at baseline, after sad mood induction, immediately following hedonically-based mood repair, and at subsequent, post-repair epochs. Physiological reactivity, indexed via respiratory sinus arrhythmia (RSA), was assessed during the protocol. Following mood induction and mood repair, high- and low-risk (control) offspring reported comparable changes in levels of sadness and RSA. However, sadness increased among high-risk offspring following the post-repair epoch, whereas low-risk offspring maintained mood repair benefits. High-risk/DEP offspring also reported higher levels of sadness following the post-repair epoch than did low-risk offspring. Change in RSA did not differ across the three offspring groups. Self-ratings confirm that one source of difficulty associated with depression risk is diminished ability to maintain hedonically-based mood repair gains, which were not apparent at the physiological level.

Predictors of Attrition in Longitudinal Neuroimaging Research: Inhibitory Control, Head Movement, and Resting-State Functional Connectivity

Attrition is a major problem in longitudinal neuroimaging studies, as it may lead to unreliable estimates of the stability of trait-like processes over time, of the identification of risk factors for clinical outcomes, and of the effects of treatment. Identification of characteristics associated with attrition has implications for participant recruitment and participant retention to achieve representative longitudinal samples. We investigated inhibitory control deficits, head motion, and resting-state functional connectivity within the cognitive control network (CCN) as predictors of attrition. Ninety-seven individuals with remitted major depressive disorder or healthy controls completed a functional magnetic resonance imaging scan, which included a go/no-go task and resting-state functional connectivity. Approximately 2 months later, participants were contacted and invited to return for a second scan. Seventeen individuals were lost to follow-up or declined to participate in the follow-up scan. Worse inhibitory control was correlated with greater movement within the scanner, and each predicted a greater likelihood of attrition, with movement mediating the effects of inhibitory control on attrition. Individuals who dropped out of the study exhibited greater movement than nondropouts across 9 of the 14 runs of the scan, with medium-to-large effect sizes. Finally, exploratory analyses suggested that attenuated resting-state connectivity with the CCN (particularly in bilateral dorsolateral prefrontal cortex) was associated with greater likelihood of attrition after accounting for head motion at several levels of analysis. Inhibitory control and movement within the scanner are associated with attrition, and should be considered for strategic oversampling and participant retention strategies to ensure generalizability of results in longitudinal studies.

Sleep disturbance and physiological regulation among young adults with prior depression

Sleep disturbance and respiratory sinus arrhythmia (RSA) are well-known to be independently associated with depression. Yet, it remains unclear how sleep disturbance and impaired physiological regulation (indexed by RSA) may synergistically contribute to depression risk. The current study examined the relationship between sleep disturbance (duration, insomnia) on daily depressive symptoms, and whether RSA moderated this relationship in a sample of young adults with a history of depression. To examine hypotheses, participants (N = 102, ages 18-22) completed a laboratory socio-evaluative stressor task to assess RSA at rest and reactivity. Participants then completed daily measures of sleep duration, insomnia symptoms, and depressive symptoms for two weeks. For main effects, multilevel modeling indicated that shorter overall sleep duration (but not insomnia) predicted higher depressive symptoms, and individual fluctuations in insomnia symptoms (but not sleep duration) predicted higher levels of next-day depressive symptoms. Lower resting RSA, but not reactivity, potentiated these relationships. Individual differences in sleep disturbance (duration and insomnia) predicted prospective levels of depressive symptoms among individuals with lower physiological regulation (indexed by lower RSA), who were particularly vulnerable to the daily effects of sleep disturbance on depressed mood. These results suggest the need to examine both daily sleep disturbance and physiological regulation to understand who may be at greatest risk for depression.

Reactive Heart Rate Variability and Cardiac Entropy in Children with Internalizing Disorder and Healthy Controls

Atypical vagal reactivity has been linked to internalizing psychopathology and less adaptive emotion regulation, but reactive cardiac entropy is largely unexplored. Therefore, this study investigated reactive vagally-mediated heart-rate variability (vmHRV) and cardiac entropy in relation to emotion regulation. Electrocardiograms of 32 children (9-13 years) with internalizing difficulties and 25 healthy controls were recorded during a baseline and a sad film. Reactivity-measures were calculated from the root mean square of successive differences (RMSSD) and sample entropy (SampEn). Emotion regulation was assessed using the emotion regulation checklist (ERC). Determinants of reactive SampEn and RMSSD were analyzed with marginal and generalized linear models. The study also modeled the relationship between cardiac reactivity and emotion regulation while controlling for psychopathology. The two groups differed significantly in vmHRV-reactivity, with seemingly higher vagal-withdrawal in the control group. SampEn increased significantly during the film, but less in subjects with higher psychopathology. Higher reactive entropy was a significant predictor of better emotion regulation as measured by the ERC. Internalizing subjects and controls showed significantly different vmHRV-reactivity. Higher reactive cardiac entropy was associated with lower internalizing psychopathology and better emotion regulation and may reflect on organizational features of the neurovisceral system relevant for adaptive emotion regulation.

Associations between depression, anxious arousal and manifestations of psychological inflexibility

BACKGROUND AND OBJECTIVES

Psychological inflexibility exhibits across multiple facets of functioning, including thinking styles, personality, cognitive shifting, emotion, and physiology, with many of these manifestations showing associations with depression. As such, these facets might be part of an overarching latent construct of psychological inflexibility that explains associations with depression. We predicted that (1) five facets of inflexibility (perseverative thinking, personality rigidity, attention-shifting, negative emotional inertia, and low respiratory sinus arrhythmia reactivity) would load onto a unique latent construct of psychological inflexibility. Further, we hypothesized this latent construct of psychological inflexibility would be (2) significantly associated with higher depression; and (3) associated with depression to a greater extent than anxious arousal.

METHODS

Seventy-five adult community participants completed measures assessing the five indices of inflexibility and self-report measures of depression and anxious arousal.

RESULTS

Structural equation modeling identified a latent inflexibility construct reflected by perseverative thinking, personality rigidity, and emotional inertia, but did not include attention-shifting or RSA reactivity. The inflexibility construct was positively associated with depression and anxious arousal, but more strongly associated with depression than with anxious arousal.

LIMITATIONS

Limitations included a small sample size, cross-sectional approach, and dimensional measures of depression and anxious arousal.

CONCLUSIONS

Findings provide preliminary support that multiple facets of inflexibility may emerge from a broader overarching vulnerability for internalizing psychopathology. This overarching inflexibility construct may have stronger associations with depression than with anxious arousal.

Depressive Symptoms, Rumination, and Emotion Reactivity Among Youth: Moderation by Gender

The emotion context-insensitivity hypothesis (ECI; Rottenberg et al., 2005) posits that depressive symptoms are associated with blunted emotional reactivity and is supported by the results of a meta-analysis (Bylsma et al., 2008). Yet it remains unclear how strongly ECI holds across emotional response domains, whether ECI operates similarly in male and female individuals, and whether this pattern of underreactivity is observed in youth. In contrast, rumination, a cognitive style strongly associated with depressive symptoms, may be associated with heightened reactivity. We assessed the effects of youth's depressive symptoms and rumination on subjective and physiological emotion reactivity (N = 160; M_age = 12.67, SD_age = 1.12; 48% female; 94% non-Hispanic). State sadness and respiratory sinus arrhythmia were assessed during a baseline activity (nature video) and a sad mood induction. As hypothesized, depressive symptoms predicted less subjective emotional reactivity, whereas rumination predicted more subjective reactivity. Exploratory analyses revealed that associations for physiological reactivity differed by child gender. ECI may be stronger in terms of subjective rather than physiological emotional reactivity.

School-Aged Children's Cognitive Interdependence as a Prospective Link Between Their Depressive Symptoms and Physiological Stress Reactivity

Associations between children's depressive symptoms and physiological stress reactivity have been identified across many investigations. Similarly, a large body of literature explores the cognitive correlates of depressive symptomatology in childhood. To date, few studies conducted with children have integrated these approaches. In the present study, we examine a well-documented correlate of depression in adults; low cognitive interdependence (as measured via pronoun use, or we-ratio), in a child population. We explore the relation of low cognitive interdependence to children's concurrent depressive symptoms as well as their concurrent and later stress reactivity. At Time 1, we assessed school-aged children's (N = 60) depressive symptoms and children's we-ratio from an interview about their school experiences. Two weeks later (Time 2), children provided salivary cortisol samples before and after a stressor task. At Time 3 (1.5 years later), children provided cortisol samples before and after completing a different stressor task. Children's depressive symptoms were concurrently associated with lower we-ratio, which in turn was prospectively, but not concurrently, associated with higher cortisol reactivity, acting as an indirect effect between depression and later reactivity. These findings suggest that low levels of cognitive interdependence may be one mechanism by which children's depressive symptoms forecast heightened reactivity to stress.

Neural Response to Pleasant Pictures Moderates Prospective Relationship Between Stress and Depressive Symptoms in Adolescent Girls

Adolescent girls are at increased risk for depression, which is thought to result from the interaction of biological vulnerabilities and life stressors common to adolescent girls. A blunted late positive potential (LPP) to emotional stimuli (i.e., pleasant and unpleasant) has been associated with depressive symptoms and risk. The current study of adolescent girls examines the moderating effects of the LPP, a candidate biomarker of depression, of the link between life stress and increases in depressive symptoms over 1 year. We measured LPP to pleasant and unpleasant pictures from the International Affective Picture Set among 143 predominantly Caucasian adolescent girls ages 8 to 14, who also reported on the frequency of common life stressors. Self-reported depressive symptoms were assessed both at baseline and 1 year after the initial lab visit. The LPP to pleasant pictures moderated the relationship between baseline life stressors and the change in depressive symptoms. Specifically, life stress was associated with increases in depressive symptoms when the LPP to pleasant pictures was blunted, whereas life stress was associated with decreases in depressive symptoms when the LPP to pleasant pictures was potentiated. These effects showed some specificity to family and school-related stressors and to anhedonic and efficacy-related depressive symptoms. A similar pattern, though not statistically significant, was found for the LPP to unpleasant pictures. Together, these findings suggest that the LPP to pleasant pictures may represent a useful biomarker in identifying individuals at greatest risk of experiencing depressive symptoms following stress.

Inflexibility as a Vulnerability to Depression: A Systematic Qualitative Review

The study of vulnerabilities to depression typically identifies factors that are thought to be universally maladaptive or adaptive. In contrast, researchers recently have theorized that the ability to flexibly engage in different thoughts and behaviors that fit situational demands may be most indicative of psychological health. We review empirical evidence from 147 studies reporting associations between five components of flexibility (set-shifting, affective set-shifting, cardiac vagal control, explanatory flexibility, and coping flexibility) and depression and classify studies according to strength of study design. Evidence from correlational and case-controlled studies suggests cross-sectional relationships, but few prospective studies have been conducted. We discuss limitations of existing studies, identify new directions for programmatic research, and discuss implications that flexibility has for the prevention and treatment of depression.

Perseverate or decenter? Differential effects of metacognition on the relationship between parasympathetic inflexibility and symptoms of depression in a multi-wave study

Depression often is characterized by inflexible autonomic and metacognitive processes that interfere with effective self-regulation. However, few studies have integrated these factors to improve the prediction of which individuals are at greatest risk for depression. Among 134 undergraduates, we evaluated whether parasympathetic inflexibility (a lack of reduction in respiratory sinus arrhythmia) in response to a sadness induction involving loss would prospectively predict symptoms of depression across four waves of follow-up over twelve weeks. Furthermore, we evaluated whether metacognitive components of perseverative cognition (PC) and decentering (identified by a principal component analysis) would moderate this relationship in opposite directions. Multilevel modeling demonstrated that the relationship between parasympathetic inflexibility and prospective symptoms of depression was exacerbated by PC, but attenuated by decentering. Furthermore, individuals with parasympathetic inflexibility, PC, and low decentering were at greatest risk for symptoms of depression across follow-up. These results support the utility of integrating autonomic and metacognitive risk factors to identify individuals at risk for depression.

Brain-behavioral adaptability predicts response to cognitive behavioral therapy for emotional disorders: A person-centered event-related potential study

Single-trial-level analyses afford the ability to link neural indices of elaborative attention (such as the late positive potential [LPP], an event-related potential) with downstream markers of attentional processing (such as reaction time [RT]). This approach can provide useful information about individual differences in information processing, such as the ability to adapt behavior based on attentional demands ("brain-behavioral adaptability"). Anxiety and depression are associated with maladaptive information processing implicating aberrant cognition-emotion interactions, but whether brain-behavioral adaptability predicts response to psychotherapy is not known. We used a novel person-centered, trial-level analysis approach to link neural indices of stimulus processing to behavioral responses and to predict treatment outcome. Thirty-nine patients with anxiety and/or depression received 12 weeks of cognitive behavioral therapy (CBT). Prior to treatment, patients performed a speeded reaction-time task involving briefly-presented pairs of aversive and neutral pictures while electroencephalography was recorded. Multilevel modeling demonstrated that larger LPPs predicted slower responses on subsequent trials, suggesting that increased attention to the task-irrelevant nature of pictures interfered with reaction time on subsequent trials. Whereas using LPP and RT averages did not distinguish CBT responders from nonresponders, in trial-level analyses individuals who demonstrated greater ability to benefit behaviorally (i.e., faster RT) from smaller LPPs on the previous trial (greater brain-behavioral adaptability) were more likely to respond to treatment and showed greater improvements in depressive symptoms. These results highlight the utility of trial-level analyses to elucidate variability in within-subjects, brain-behavioral attentional coupling in the context of emotion processing, in predicting response to CBT for emotional disorders.

Flexible parasympathetic responses to sadness facilitate spontaneous affect regulation

The ability of the parasympathetic nervous system to flexibly adapt to changes in environmental context is thought to serve as a physiological indicator of self-regulatory capacity, and deficits in parasympathetic flexibility appear to characterize affective disorders such as depression. However, whether parasympathetic flexibility (vagal withdrawal to emotional or environmental challenges such as sadness, and vagal augmentation during recovery from sadness) could facilitate the effectiveness of adaptive affect regulation strategies is not known. In a study of 178 undergraduate students, we evaluated whether parasympathetic flexibility in response to a sad film involving loss would enhance the effectiveness of regulatory strategies (reappraisal, distraction, and suppression) spontaneously employed to reduce negative affect during a 2-min uninstructed recovery period following the induction. Parasympathetic reactivity and recovery were indexed by fluctuations in respiratory sinus arrhythmia and high-frequency heart rate variability. Cognitive reappraisal and distraction were more effective in attenuating negative affect among individuals with more parasympathetic flexibility, particularly greater vagal augmentation during recovery, relative to individuals with less parasympathetic flexibility. In contrast, suppression was associated with less attenuation of negative affect, but only among individuals who also had less vagal withdrawal during the sad film. Alternative models provided partial support for reversed directionality, with reappraisal predicting greater parasympathetic recovery, but only when individuals also experienced greater reductions in negative affect. These results suggest that contextually appropriate parasympathetic reactivity and recovery may facilitate the success of affect regulation. Impairments in parasympathetic flexibility could confer risk for affective disorders due to attenuated capacity for effective self-regulation.