Lower resting cardiac autonomic balance in young adults with current major depression

Is autonomic functioning distinctly associated with anxiety and unsociability in preschoolers?

There are many benefits of peer interactions for children's social, emotional, and cognitive development, and isolation from peers may have negative consequences for children. Although biological processes may underlie social withdrawal broadly, distinct patterns may be associated with withdrawal behaviors depending on their underlying motivation (e.g., shy versus disinterested). This study investigated the role of autonomic nervous system activity, as assessed via skin conductance level (SCL) and respiratory sinus arrhythmia (RSA) in predicting changes in unsociability (e.g., lack of interest in peers) and anxious-fearfulness (e.g., discomfort among peers). Data were collected using a community sample of 92 US preschool children (45.7% female; Mage = 45.51 months, SDage = 3.81 months) at two time points one year apart. Gender differences were also explored. Baseline physiology was assessed while viewing a neutral video clip, and reactivity was assessed while viewing social exclusion and post-aggression discussion videos. For all children, coinhibition (i.e., SCL inhibition accompanied by RSA inhibition) to the post-aggression discussion video and blunted SCL activation to the exclusion video were prospectively associated with higher levels of anxious-fearfulness one year later. For boys only, baseline reciprocal sympathetic activation (i.e., SCL activation and RSA inhibition) was prospectively related to higher levels of unsociability one year later. For girls only, RSA inhibition in response to the post-aggression discussion video was prospectively related to higher levels of unsociability one year later. Findings contribute to a growing literature on autonomic reactivity in preschoolers' adjustment and suggest possible differences in the physiological processes underlying unsociability and anxious-fearfulness.

Cardiac Autonomic Balance Is Altered during the Acute Stress Response in Adolescent Major Depression-Effect of Sex

Autonomic nervous system (ANS) abnormalities are associated with major depressive disorder (MDD) already at adolescent age. The majority of studies so far evaluated parasympathetic and sympathetic branches of ANS individually, although composite indices including cardiac autonomic balance (CAB) and cardiac autonomic regulation (CAR) seem to measure ANS functioning more comprehensively and thus could provide better psychopathologies' predictors. We aimed to study CAB and CAR derived from high-frequency bands of heart rate variability and left ventricular ejection time during complex stress response (rest-Go/NoGo task-recovery) in MDD adolescents with respect to sex. We examined 85 MDD adolescents (52 girls, age: 15.7 ± 0.14 yrs.) and 80 age- and sex-matched controls. The MDD group showed significantly reduced CAB compared to controls at rest, in response to the Go/NoGo task, and in the recovery phase. Moreover, while depressed boys showed significantly lower CAB at rest and in response to the Go/NoGo task compared to control boys, depressed girls showed no significant differences in evaluated parameters compared to control girls. This study for the first time evaluated CAB and CAR indices in drug-naïve first-episode diagnosed MDD adolescents during complex stress responses, indicating an altered cardiac autonomic pattern (i.e., reciprocal sympathetic dominance associated with parasympathetic underactivity), which was predominant for depressed boys.

Child emotion lability is associated with within-task changes of autonomic activity during a mirror-tracing task

Adaptive biological and emotional stress responding are both critical for healthy human development. However, the complex associations between the two are not fully understood. The current study addresses this gap in research by studying associations of child emotion regulation and lability with within-task changes in the biological stress response during a mirror-tracing task. Participants were 59 families including two parents and a child between 5 and 12 years old (52.2% female). Parents reported on family demographics and completed the Emotion Regulation Checklist. Child skin conductance level (SCL) and respiratory sinus arrhythmia (RSA) were recorded during a baseline task and during a 3-minute mirror-tracing task. Within-task patterns of SCL and RSA during the task were estimated with multilevel modeling (measures within persons). The emotion regulation subscale was unrelated to any facet of SCL/RSA time courses. However, lower emotion lability was related to SCL patterns that changed less during the task and were overall lower. For RSA, lower emotion lability was related to higher initial RSA that significantly decreased during the task. These findings suggest that higher child emotion lability may promote increased physiological arousal of target organs during challenging activities.

Youth coping and cardiac autonomic functioning: Implications for social and academic adjustment

Extending literature on youth coping and stress physiology, this two-wave longitudinal study examined independent and interactive roles of youth coping with daily stressors (i.e., peer, academic) and cardiac autonomic functioning in subsequent social and academic adjustment across the transition to middle school. Our sample consisted of 100 typically developing youth (10-12 years old at Time 1, 53 boys, 43% ethnic minorities) who reported on their coping strategies in response to peer and academic stress. Youth participated in laboratory tasks (i.e., baseline, mother-youth conversations about youth's actual peer and academic challenges) during which sympathetic and parasympathetic activities were recorded, and cardiac autonomic functioning indicators were derived. Youth, mothers, and teachers reported on various aspects of youths' social and academic adjustment at Times 1 and 2. Results revealed that, for both peer and academic domains, greater use of engagement coping strategies was prospectively linked with better adjustment 7 months later, but only among youth who exhibited higher (greater sympathetic-parasympathetic coactivation) but not lower (limited coactivation, or coinhibition) cardiac autonomic regulation at baseline. Findings suggest that a match between more engagement coping behaviors and greater cardiac autonomic capacity to coactivate the parasympathetic and sympathetic branches is linked with better social and academic adjustment.

Investigating autonomic biomarkers of sensory processing patterns in young adults

Introduction

Autonomic nervous system functioning is theorised to underpin individual differences in sensory processing, with a small amount of supporting evidence. Despite recognition of the need to measure the balance between sympathetic and parasympathetic activity, most studies have measured only one of these systems. This study investigated whether sensory processing patterns are related to autonomic balance for young adults at rest and in response to a sensory-based stressor.

Method

In this cross-sectional laboratory study, 100 young adults completed the adolescent/adult sensory profile. Heart rate variability and pre-ejection period were recorded before, during and after a coldpressor task.

Results

Relationships between sensory processing patterns and autonomic balance varied by gender. In males, low sensory thresholds were generally related to a state of reciprocal sympathetic activation. In females, low thresholds were associated with greater autonomic reactivity in response to the coldpressor.

Conclusion

This study showed, for the first time in young adults, that sensory processing patterns may be linked to patterns of autonomic balance. Therapists should be aware that young men with low sensory thresholds may be more likely than others to exhibit a resting state of sympathetic hyperarousal and further research should investigate whether this impacts their daily functioning and wellbeing.

A randomized trial of aerobic exercise for major depression: examining neural indicators of reward and cognitive control as predictors and treatment targets

BACKGROUND

Aerobic exercise has demonstrated antidepressant efficacy among adults with major depression. There is a poor understanding of the neural mechanisms associated with these effects. Deficits in reward processing and cognitive control may be two candidate targets and predictors of treatment outcome to exercise in depression.

METHODS

Sixty-six young adults aged 20.23 years (s.d. = 2.39) with major depression were randomized to 8 weeks of moderate-intensity aerobic exercise (n = 35) or light stretching (n = 31). Depressive symptoms were assessed across the intervention to track symptom reduction. Reward processing [reward positivity (RewP)] and cognitive control [error-related negativity (ERN)] were assessed before and after the intervention using event-related brain potentials.

RESULTS

Compared to stretching, aerobic exercise resulted in greater symptom reduction (gs = 0.66). Aerobic exercise had no impact on the RewP (gav = 0.08) or ERN (gav = 0.21). In the aerobic exercise group, individuals with a larger pre-treatment RewP [odds ratio (OR) = 1.45] and increased baseline depressive symptom severity (OR = 1.18) were more likely to respond to an aerobic exercise program. Pre-treatment ERN did not predict response (OR = 0.74).

CONCLUSIONS

Aerobic exercise is effective in alleviating depressive symptoms in adults with major depression, particularly for those with increased depressive symptom severity and a larger RewP at baseline. Although aerobic exercise did not modify the RewP or ERN, there is preliminary support for the utility of the RewP in predicting who is most likely to respond to exercise as a treatment for depression.

The impact of social disadvantage on autonomic physiology of latinx adolescents: The role of environmental risks

The experience of poverty embodies complex, multidimensional stressors that may adversely affect physiological and psychological domains of functioning. Compounded by racial/ethnic discrimination, the financial aspect of family poverty typically coincides with additional social and physical environmental risks such as pollution exposure, housing burden, elevated neighborhood unemployment, and lower neighborhood education levels. In this study, we investigated the associations of multidimensional social disadvantage throughout adolescence with autonomic nervous system (ANS) functioning at 17 years. Two hundred and twenty nine low-income Mexican-American adolescents (48.6% female) and their parents were assessed annually between the ages of 10 and 16. Participants' census tracts were matched with corresponding annual administrative data of neighborhood housing burden, education, unemployment, drinking water quality, and fine particulate matter. We combined measures of adolescents' electrodermal response and respiratory sinuses arrhythmia at rest and during a social exclusion challenge (Cyberball) to use as ANS indices of sympathetic and parasympathetic activity, respectively. Controlling for family income-to-needs, youth exposed to greater cumulative water and air pollution from ages 10-16 displayed altered patterns of autonomic functioning at rest and during the social challenge. Conversely, youth living in areas with higher housing burden displayed healthy patterns of autonomic functioning. Altogether, results suggest that toxin exposure in youths' physical environments disrupts the ANS, representing a plausible mechanism by which pollutants and social disadvantage influence later physical and mental health.

Emotion context insensitivity in depression: Toward an integrated and contextualized approach

Major depressive disorder (MDD) is characterized by pervasive mood disturbance as well as deficits in emotional processing, reactivity, and regulation. There is accumulating evidence that MDD is characterized by emotional patterns consistent with environmental disengagement, as reflected in attenuated positive and negative emotional reactivity, consistent with Emotion Context Insensitivity (ECI) theory. However, MDD individuals vary considerably in the extent to which they exhibit specific alterations in patterns of emotional responding. Emotions are complex, multicomponent processes that invoke responses across multiple functional domains and levels of analysis, including subjective experience, behavior, autonomic regulation, cognition, and neural processing. In this article, I review the current state of the literature on emotional responding and MDD from the lens of ECI. I focus on the importance of assessing emotional indices from multiple levels of analysis across development and contexts. I also discuss methodological and measurement issues that may contribute to inconsistent findings. In particular, I emphasize how psychophysiological measures can help elucidate emotional processes that underlie the pathophysiology of MDD as part of an integrated and contextualized approach.

Physiological responses to proposals during dyadic decision-making conversations

A novel conversation-analytically informed paradigm was used to examine how joint decision-making interaction, with its various types of proposal sequences, is reflected in the physiological responses of participants. Two types of dyads–dyads with one depressed and one non-depressed participant (N = 15) and dyads with two non-depressed participants (N = 15)–engaged in a series of conversational joint decision-making tasks, during which we measured their skin conductance (SC) responses. We found that the participants’ SC response rates were higher and more synchronized during proposal sequences than elsewhere in the conversation. Furthermore, SC response rates were higher when the participant was in the role of a proposal speaker (vs. a proposal recipient), and making a proposal was associated with higher SC response rates for participants with depression (vs. participants without depression). Moreover, the SC response rates in the proposal speaker were higher when the recipient accepted (vs. not accepted) the proposal. We interpret this finding with reference to accepting responses suggesting a commitment to future action, for which the proposal speaker may feel specifically responsible for. A better understanding of the physiological underpinnings of joint decision-making interaction may help improve democratic practices in contexts where certain individuals experience challenges in this regard.

Yohimbine-Induced Reactivity of Heart Rate Variability in Unmedicated Depressed Patients With and Without Adverse Childhood Experience

Stressful life events play a role in the pathogenesis of major depressive disorder (MDD) and many patients with MDD were exposed to developmental stress due to adverse childhood experiences (ACE). Furthermore, dysregulation of the autonomic nervous system and higher incidence of cardiovascular disease are found in MDD. In MDD, and independently in individuals with ACE, abnormalities in heart rate variability (HRV) have been reported. While these are often confounded, we systematically investigated them with a study which included MDD patients with/without ACE as well as healthy individuals with/without ACE. With this study, we investigated the influence of noradrenergic stimulation on HRV reactivity in unmedicated participants in a randomized, double-blind, repeated measures design. Our sample consisted of men and women with MDD and ACE (n = 25), MDD without ACE (n = 24), healthy participants with ACE (n = 27), and without ACE (n = 48). Participants received a 10 mg single dose of the alpha-2 antagonist yohimbine that increases noradrenergic activity or placebo on 2 separate days, with ECG recordings before and after drug administration at defined intervals. We found lower basal HRV in MDD and ACE: patients with MDD had reduced RMSSD whereas participants with ACE had lower LF-HRV. Contrary to our hypothesis, there was no effect of yohimbine. With this study, we were able to replicate previous findings on HRV differences in MDD and ACE. From the null effect of yohimbine, we conclude that the yohimbine-induced sympathetic activation is not a significant driver of HRV in MDD and ACE.

Acute aerobic exercise increases respiratory sinus arrythmia reactivity and recovery to a sad film among individuals at risk for depression

Cardiac vagal control (CVC), as indexed by abnormalities in resting, reactivity, and recovery levels of respiratory sinus arrythmia (RSA), has been proposed as an index of impaired self-regulatory capacity in depression. Aerobic exercise has been shown to improve positive and negative affective responses and influence autonomic function; however, it is unknown whether exercise impacts RSA reactivity and subsequent recovery to emotional challenges among individuals at risk for depression. The present study aimed to determine the effects of moderate-intensity aerobic exercise on RSA reactivity and recovery to a sad film. Using a within-subjects design, 47 individuals with variable symptoms of depression completed a 30-min session of exercise and a sedentary control condition on separate days prior to viewing a sad film. On the control day, individuals with elevated depressive symptom severity displayed less vagal withdrawal to the sad film and exhibited impaired post-film RSA recovery. Following exercise, individuals with elevated depressive symptom severity demonstrated a higher degree of vagal withdrawal to the sad film and subsequent post-film recovery that matched individuals with lower depressive symptom severity. These findings suggest that a single session aerobic exercise may be an effective approach to increase emotional and self-regulatory capacity among individual at risk for, or currently experiencing, depression.

Cross system autonomic balance and regulation: Associations with depression and anxiety symptoms

The autonomic nervous system (ANS) has demonstrated utility for identifying alterations in emotion processing associated with common psychopathology, including depression and anxiety. To date though the majority of this ANS research has several limitations. Most studies have examined parasympathetic and sympathetic branches separately, requiring activity in the other branch be inferred. This is problematic as each branch may function independently. Composite indices such as cardiac autonomic balance (CAB) and cardiac autonomic regulation (CAR) which examine the relative input between respiratory sinus arrhythmia (RSA) and pre-ejection period (PEP) should provide more comprehensive measures of autonomic functioning and thus stronger predictors of psychopathology. However, the sympathetic branch is driven by multiple neurotransmitter systems, thus PEP does not necessarily reflect overall SNS arousal. We propose two new metrics for assessing ANS functioning associated with psychopathology: parasympathetic effects on cardiac control (RSA) relative to sympathetic effects on the eccrine system (electrodermal activity, EDA), which we term cross-system autonomic balance (CSAB) and regulation (CSAR). Eighty-five women (18-37) completed a baseline physiological assessment with parasympathetic (RSA) and sympathetic indices (PEP, EDA), along with self-reported depressive and anxiety symptoms. Lower CSAB, indicating sympathetic dominance driven by cholinergic neurotransmission, was associated with higher depressive and anxiety symptoms. Lower CAB indicating sympathetic dominance driven by beta-adrenergic neurotransmission was associated specifically with depressive symptoms. CSAB was a more robust index than RSA. Results support the utility of assessing multiple composite ANS indices for identifying physiological substrates of alterations in emotion regulation associated with internalizing disorders.

PreBötzinger complex neurons drive respiratory modulation of blood pressure and heart rate

Heart rate and blood pressure oscillate in phase with respiratory activity. A component of these oscillations is generated centrally, with respiratory neurons entraining the activity of pre-sympathetic and parasympathetic cardiovascular neurons. Using a combination of optogenetic inhibition and excitation in vivo and in situ in rats, as well as neuronal tracing, we demonstrate that preBötzinger Complex (preBötC) neurons, which form the kernel for inspiratory rhythm generation, directly modulate cardiovascular activity. Specifically, inhibitory preBötC neurons modulate cardiac parasympathetic neuron activity whilst excitatory preBötC neurons modulate sympathetic vasomotor neuron activity, generating heart rate and blood pressure oscillations in phase with respiration. Our data reveal yet more functions entrained to the activity of the preBötC, with a role in generating cardiorespiratory oscillations. The findings have implications for cardiovascular pathologies, such as hypertension and heart failure, where respiratory entrainment of heart rate is diminished and respiratory entrainment of blood pressure exaggerated.

Diverse Autonomic Nervous System Stress Response Patterns in Childhood Sensory Modulation

The specific role of the autonomic nervous system (ANS) in emotional and behavioral regulation—particularly in relation to automatic processes—has gained increased attention in the sensory modulation literature. This mini-review article summarizes current knowledge about the role of the ANS in sensory modulation, with a focus on the integrated functions of the ANS and the hypothalamic-pituitary-adrenal (HPA) axis and their measurement. Research from the past decade illustrates that sympathetic and parasympathetic interactions are more complex than previously assumed. Patterns of ANS activation vary across individuals, with distinct physiological response profiles influencing the reactivity underlying automatic behavioral responses. This review article advances a deeper understanding of stress and the complex stress patterns within the ANS and HPA axis that contribute to allostatic load (AL). We argue that using multiple physiological measurements to capture individual ANS response variation is critical for effectively treating children with sensory modulation disorder (SMD) and sensory differences. We consider the relative contributions of automatic vs. deliberately controlled processes across large-scale neural networks in the development of sensorimotor function and their associated links with arousal patterns and sensory over- and under-responsivity.

Depression, stress and vascular function from childhood to adolescence: A longitudinal investigation

BACKGROUND

Psychological distress is associated with risk markers for cardiovascular disease, including increased arterial stiffness and high blood pressure, but it's unclear when these first manifest. This study aims to investigate the effect of psychosocial stress and depression on arterial stiffness and blood pressure in a cohort study of Australian children followed through to adolescence.

METHOD

Depression and psychosocial stress in 520 young people (265 boys; M age = 11.6 y) were assessed via the Children's Depression Inventory and Children's Stress Questionnaire respectively. Carotid-femoral pulse wave velocity was assessed using applanation tonometry, with further assessments of supine brachial blood pressure and percent body fat (dual x-ray absorptiometry). All measures were repeated four years later at age 16-years.

RESULTS

We found no cross-sectional or longitudinal evidence that children self-reporting higher levels of psychosocial stress or depressive symptoms had greater arterial stiffness. Children reporting an increase in depressive symptoms had an increase in diastolic blood pressure and mean arterial pressure over time. An effect was also evident for pulse pressure, where higher pulse pressure was found in children with lower psychosocial stress at baseline and in children self-reporting a decrease in stress between baseline and follow-up.

CONCLUSIONS

Findings from the current study contribute to the scant paediatric literature but only provide limited support for any influence of psychological factors on blood pressure. Depressive symptoms in apparently healthy adolescents may exert some influence on later risk for cardiovascular disease via increases in diastolic blood pressure and mean arterial pressure, but these effects were small.