Social interaction anxiety and sleep quality in youth: Individual difference in childhood adversity and cardiac vagal control

BACKGROUND

Social interaction anxiety and sleep problems are prevalent during adolescence. Social interaction anxiety undermines sleep quality, however, little is known whether the association between social interaction anxiety and sleep quality is moderated by environmental factors such as childhood adversity and individual factors such as cardiac vagal control. This study sought to investigate the moderating effects of childhood adversity and cardiac vagal control on the link between social interaction anxiety and sleep quality.

METHOD

The Social Interaction Anxiety Scale, the Pittsburgh Sleep Quality Index and the Childhood Trauma Questionnaire were administered to 274 adolescents, who received 3-min resting ECG recording to assess respiratory sinus arrhythmia (RSA) as an index of cardiac vagal control.

RESULTS

Social interaction anxiety was negatively associated with sleep quality, and this association was moderated by childhood adversity and cardiac vagal control. In specific, social interaction anxiety was negatively associated with sleep quality among adolescents with low childhood adversity regardless of cardiac vagal control. Sleep quality was generally disrupted when adolescents exposed to high childhood adversity, but the negative association between social interaction anxiety and sleep quality among adolescents with high childhood adversity could be amortized by high cardiac vagal control.

LIMITATIONS

Cross-sectional design precluded establishing causality among variables.

CONCLUSION

These findings suggest that high cardiac vagal control reflecting better self-regulation might buffer the negative effect of social interaction anxiety on sleep quality particularly among adolescents exposed to early life stress.

Heart rate and heart rate variability in obsessive-compulsive disorder: Evidence from patients and unaffected first-degree relatives

Altered heart rate (HR) and heart rate variability (HRV) are common observations in psychiatric disorders. Yet, few studies have examined these cardiac measures in obsessive-compulsive disorder (OCD). The current study aimed to investigate HR and HRV, indexed by the root mean square of successive differences (RMSSD) and further time domain indices, as putative biological characteristics of OCD. Electrocardiogram was recorded during a five-minute resting state. Group differences between patients with OCD (n = 96), healthy participants (n = 112), and unaffected first-degree relatives of patients with OCD (n = 47) were analyzed. As potential moderators of group differences, we examined the influence of age and medication, respectively. As results indicated, patients with OCD showed higher HR and lower HRV compared to healthy participants. These group differences were not moderated by age. Importantly, subgroup analyses showed that only medicated patients displayed lower HRV compared to healthy individuals, while HR alterations were evident in unmedicated patients. Regarding unaffected first-degree relatives, group differences in HRV remained at trend level. Further, an age-moderated group differentiation showed that higher HRV distinguished relatives from healthy individuals in young adulthood, whereas at higher age lower HRV was indicative of relatives. Both the role of familial risk and medication in HRV alterations need further elucidation. Pending future studies, alterations in HR and potentially HRV might serve as useful indices to characterize the pathophysiology of OCD.

Predicting self-control capacity - Taking into account working memory capacity, motivation, and heart rate variability

The present study analyzes possible indicators for state self-control capacity (measured by a Simon task) after demanding executive function tasks as well as for trait self-control (measured by a questionnaire) by focusing on the interplay between control capacity and motivation (measured by demand-related action-state orientation; 154 students; M = 23.55 years; SD = 3.15). As possible control capacity variables, we focused on working memory capacity, based on the integrative theory of self-control, as well as on the baseline cardiac vagal control as a possible physiological index (not a resource itself) indicating control capacity based on the vagal tank theory. The vagal tank theory also focuses on within-subject changes in cardiac vagal control as a possible index of self-control capacity. Therefore, we analyzed among the first 54 participants (M = 24.61 years; SD = 2.67) baseline to post-event changes in cardiac vagal control. Following the integrative theory of self-control, the results indicated that both state and trait self-control capacity are predicted by an interplay of working memory capacity and action-state orientation. Focusing on the vagal tank theory, the results suggest that state self-control capacity can best be detected by the within-subject changes in cardiac vagal control instead of analyzing between-subject differences in cardiac vagal control. However, when focusing on trait self-control, cardiac vagal control might be an indicator, if considered without action state orientation.

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.

Low cardiac vagal control is associated with genetic liability for elevated triglycerides and risky health behaviors

Low parasympathetic regulation of cardiac activity, known as cardiac vagal control (CVC), is robustly associated with poor health outcomes. However, the etiological mechanism that undergirds this association remains largely unknown. One explanation is a causal relationship wherein health problems cause low CVC, or vice versa. However, an alternative explanation is that a common set of genetic factors contributes to both increased liability for poor health and low CVC (i.e., pleiotropy). The present study uses polygenic risk scores for a number of health-related phenotypes (physical, mental, behavioral) to test whether genetic liability for poor health has pleiotropic effects on CVC. We report evidence for shared genetic liability between low CVC and both poor physical health (elevated triglycerides) and risky health-related behaviors (increased drinking and sexual activity). The present findings are consistent with shared genetic liability explaining, at least in part, the well-documented correlation between CVC and health.

Enhancing cardiac vagal activity: Factors of interest for sport psychology

Self-regulation plays a critical role in sport performance. An objective, psychophysiological marker of self-regulation is cardiac vagal activity, the activity of the vagus nerve regulating cardiac functioning. The aim of this paper is to provide an overview of factors influencing cardiac vagal activity, which can be useful for athletes. Specifically, we organize this overview in two main domains: personal factors and environmental factors. Among the personal factors, we discuss the behavioral strategies that can be used by athletes: nutrition, non-ingestive oral habits, water immersion, body temperature reduction, sleeping habits, relaxation methods, cognitive techniques, praying, music, and exercise. Among environmental factors, we discuss those linked to the social (i.e., contact with humans and animals) and physical (i.e., aromas, lights, sounds, temperature, outdoor, altitude) environment. Future research directions are given, as well as practical implications for athletes and coaches.

Mindfulness-Based Relapse Prevention for Substance Use Disorders: Effects on Cardiac Vagal Control and Craving Under Stress

Mindfulness-based relapse prevention (MBRP) is a therapy for addictive behaviors that incorporates cognitive-behavioral relapse prevention (RP) skills with mindfulness training to increase awareness and skillful action in high-risk situations. Stress is a common reason reported for substance use relapse, and using physiological measures to measure stress engagement may help us identify mechanisms of clinical improvement. Specifically, salutatory changes in HF-HRV post-treatment may serve as a marker of treatment efficacy. We investigated tonic and phasic heart rate variability (HRV) to a cognitive stressor (i.e., arithmetic challenge) following 8 weeks of RP, MBRP, or post-detox treatment known as treatment as usual (TAU; n = 34). MBRP was related to higher levels of tonic and phasic HF-HRV, lower levels of anxiety, and lower heart rate reactivity (than TAU only) compared to RP and TAU. This suggests that those who completed MBRP are engaging with stress, but perhaps in a more adaptive, flexible manner. MBRP is associated with higher cardiac vagal control and lower stress/anxious reactivity. Given that negative emotions are an important component of relapse, these results lend further support to say that mindfulness may be helpful for those with substance use disorders.

Cardiac vagal control as a marker of emotion regulation in healthy adults: A review

In the last two decades, a growing body of theory and research has targeted the role of cardiac vagal control (CVC) in emotional responding. This research has either focused on resting CVC (also denoted as cardiac vagal tone) or phasic changes in CVC (also denoted as vagal reactivity) in response to affective stimuli. The present paper is aimed at reporting a review of the papers published between 1996 and 2016, and focused on the results of 135 papers examining cardiac vagal control as a physiological marker of emotion regulation in healthy adults. The review shows that studies have employed a wide array of methodologies and measures, often leading to conflicting results. High resting CVC has been associated with better down-regulation of negative affect, use of adaptive regulatory strategies, and more flexible emotional responding. Concerning phasic changes, research has consistently found decreased CVC in response to stress, while CVC increases have been shown to reflect either self-regulatory efforts or recovery from stress. Despite conflicting results, we conclude that existing literature supports the use of CVC as a noninvasive, objective marker of emotion regulation.

The hierarchical basis of neurovisceral integration

The neurovisceral integration (NVI) model was originally proposed to account for observed relationships between peripheral physiology, cognitive performance, and emotional/physical health. This model has also garnered a considerable amount of empirical support, largely from studies examining cardiac vagal control. However, recent advances in functional neuroanatomy, and in computational neuroscience, have yet to be incorporated into the NVI model. Here we present an updated/expanded version of the NVI model that incorporates these advances. Based on a review of studies of structural/functional anatomy, we first describe an eight-level hierarchy of nervous system structures, and the contribution that each level plausibly makes to vagal control. Second, we review recent work on a class of computational models of brain function known as "predictive coding" models. We illustrate how the computational dynamics of these models, when implemented within our proposed vagal control hierarchy, can increase understanding of the relationship between vagal control and both cognitive performance and emotional/physical health. We conclude by discussing novel implications of this updated NVI model for future research.

The role of maternal cardiac vagal control in the association between depressive symptoms and gestational hypertension

Reduced cardiac vagal control, indexed by relatively lower high-frequency heart rate variability (HF-HRV), is implicated in depressed mood and hypertensive disorders among non-pregnant adults whereas research in pregnancy is limited. This study examined whether maternal HF-HRV during pregnancy mediates the association between depressed mood and gestational hypertension. Depressive symptoms (Edinburgh Depression Scale) and HF-HRV were measured during early (M=14.9 weeks) and late (M=32.4 weeks) pregnancy in 287 women. Gestational hypertension was determined by chart review. Depressive symptoms were associated with less HF-HRV (b=-0.02, p=.001). There was an indirect effect of depressed mood on gestational hypertension through late pregnancy HF-HRV (b=0.04, 95% CI 0.0038, 0.1028) after accounting for heart rate. These findings suggest cardiac vagal control is a possible pathway through which prenatal depressed mood is associated with gestational hypertension, though causal ordering remains uncertain.

Maternal cortisol during pregnancy is related to infant cardiac vagal control

BACKGROUND

Prenatal exposure to maternal psychological distress and glucocorticoids result in neurobiological adaptations within the fetus that increase risk for developing exaggerated emotional, behavioral, and stress responses to novelty and challenges in childhood. The current study investigated the influence of maternal depressed mood and cortisol during pregnancy on infant cardiac vagal control (CVC) to standardized laboratory challenge tasks.

METHODS

The sample comprised 194 women and their infants. Maternal reports of depressed mood and salivary cortisol were assessed at 14 and 32 weeks gestational age. Linear regression was used to examine associations between maternal measures during early and late pregnancy, and infant CVC indexed via respiratory sinus arrhythmia (RSA) at rest and in response to laboratory tasks designed to elicit frustration when infants were 6 months of age. It was hypothesized that maternal depressed mood and cortisol would be associated with lower basal RSA and smaller decreases in RSA from baseline to challenge.

RESULTS

A significant decrease in infant RSA from baseline to frustration tasks indicated that laboratory tasks elicited a reliable decrease in RSA from baseline to frustration among infants which is characterized by reduction in vagal efferent activity on the heart in response to challenge. Higher maternal cortisol, but not depressed mood, was associated with lower basal RSA and greater decrease in RSA from baseline to frustration. Associations between maternal cortisol and infant basal RSA were observed for both early and late pregnancy whereas the associations between prenatal cortisol and decrease in RSA from baseline to frustration were observed for early, but not late, pregnancy.

CONCLUSIONS

Maternal cortisol during pregnancy was associated with infant CVC at 6-months of age. Such influences may have enduring impacts on the child and important implications for the development of physical and mental health outcomes.