Impaired cardiac profile in adolescents with an increasing trajectory of anxiety when confronting an acute stressor

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.

Decrements in Adolescent Cardiac Complexity During Mother-Adolescent Conflicts

The present study aimed to provide further evidence on the usefulness of non-linear cardiac measures when examining the output of the cardiac system. Scale-invariant self-similarity and entropy, in addition to heart rate variability (HRV) given by time- and frequency-domain measures were calculated in a sample of N = 55 healthy adolescents (M_age = 14.122, SD_age = 0.698) during 10-min positive (non-stressful) and negative (stressful) interactions with their mothers. We also explored sex influence in adolescents' cardiac output using both HRV measures and non-linear cardiac measures. Repeated measures MANOVA revealed a marginal within-group effect for HRV measures, F(3,51) = 2.438, p = 0.075, η²_p = 0.125), and a significant within-group effect for non-linear cardiac measures, F(6, 48) = 3.296, p = 0.009, η²_p = 0.292, showing a significant decrement in adolescents' cardiac complexity during the negative interaction. No significant effect for sex was found in either non-linear cardiac measures or HRV measures, but results suggest lower cardiac scaling in females than in males. These findings suggest a real-time scale predominance in heart rate output when adolescents face an aversive situation and support the importance of non-linear cardiac measures to gain insight into the cardiac system and its regulatory mechanisms. Further research is needed to examine sex-differences in cardiac complexity during aversive situations.

Anxiety in Early Adolescence: Heterogeneous Developmental Trajectories, Associations with Risk Factors and Depressive Symptoms

This study aimed: (1) to identify heterogeneous trajectories of anxiety symptoms in early adolescence; (2) to analyze the relationships between risk factors and identified trajectories; (3) to study the association between anxiety symptom trajectories and depression symptom course. Anxiety and depressive symptoms of 825 participants (44.40% boys; mean initial age = 13.01, SD = 0.56) was assessed every 6 months over an 18-month period. Trajectory identification relied on latent-variable approach. As a result, 2-4 trajectories were identified for social phobia (SP), generalized anxiety (GA) and panic symptoms, revealing at least a low-symptom course and a trajectory of elevated symptoms (at-risk trajectory). Being girl and sibling cohabitation were related to at-risk trajectories, and a course of low effortful control and heightened negative affectivity. Finally, SP and GA symptoms were related to heightened depressive symptom courses. Relevant implications towards tailored prevention and intervention are highlighted to promote a healthy development across adolescence.

Effects of a transdiagnostic cognitive behaviour therapy-based programme on the natural course of anxiety symptoms in adolescence

BACKGROUND

Anxiety disorders frequently have an onset during adolescence, which when left untreated could lead to a chronic course and outcome. This study aimed to examine the way in which a cognitive behaviour therapy-based programme (Super Skills for Life - adolescent version; SSL-A) could change the course of anxiety symptoms through adolescent's behavioural performance and cardiac function.

METHOD

Sixty-one adolescents at risk of developing an anxiety disorder (45.30% boys; M = 13.76 years, SD = 0.32) were randomly assigned to either an intervention (IG), placebo (PG), or a waitlist group (WG). Adolescents in the IG participated in SSL-A over an 8-week period. Adolescents in the PG participated in an 8-session school-work programme. Adolescents in the WG did not receive any intervention. Anxiety symptoms were assessed every six months, twice before the intervention, as well as at the post-intervention and six months after the intervention. Participants in the IG additionally underwent a stressful task to assess behavioural performance and cardiac adjustment.

RESULTS

Adolescents in the IG significantly reported lower levels of social phobia and generalised anxiety symptoms at the follow-up assessment compared to the adolescents in the PG and the WG. They also showed a significant improvement in vocal quality and lower discomfort during a stressful task at post-intervention, and showed attenuated cardiac recovery indexes, in terms of sample entropy.

LIMITATIONS

The study has a small sample size.

CONCLUSION

SSL-A changed the natural course of anxiety symptoms, as shown by a significant reduction in social phobia and generalised anxiety symptoms, and a significant improvement in behaviour and physiological (cardiac) function during a stressful situation.

Heart rate variability: Can it serve as a marker of mental health resilience?: Special Section on "Translational and Neuroscience Studies in Affective Disorders" Section Editor, Maria Nobile MD, PhD

BACKGROUND

Stress resilience influences mental well-being and vulnerability to psychiatric disorders. Usually, measurement of resilience is based on subjective reports, susceptible to biases. It justifies the need for objective biological/physiological biomarkers of resilience. One promising candidate as biomarker of mental health resilience (MHR) is heart rate variability (HRV). The evidence for its use was reviewed in this study.

METHODS

We focused on the relationship between HRV (as measured through decomposition of RR intervals from electrocardiogram) and responses to laboratory stressors in individuals without medical and psychiatric diseases. We conducted a bibliographic search of publications in the PubMed for January 2010-September 2018.

RESULTS

Eight studies were included. High vagally mediated HRV before and/or during stressful laboratory tasks was associated with enhanced cognitive resilience to competitive/self-control challenges, appropriate emotional regulation during emotional tasks, and better modulation of cortisol, cardiovascular and inflammatory responses during psychosocial/mental tasks.

LIMITATIONS

All studies were cross-sectional, restricting conclusions that can be made. Most studies included only young participants, with some samples of only males or females, and a limited array of HRV indexes. Ecological validity of stressful laboratory tasks remains unclear.

CONCLUSIONS

Vagally mediated HRV may serve as a global index of an individual's flexibility and adaptability to stressors. This supports the idea of HRV as a plausible, noninvasive, and easily applicable biomarker of MHR. In future longitudinal studies, the implementation of wearable health devices, able to record HRV in naturalistic contexts of real-life, may be a valuable strategy to gain more reliable insight into this topic.

Sex differences in adolescents' cardiac reactivity and recovery under acute stress: The importance of nonlinear measures

How well adolescents can self-regulate in the face of stressors has considerable implications for long-term well-being and risk of psychopathology. This study investigated sex differences in adolescents' cardiac reactivity and recovery during a stressful task. Measures of cardiac variability (linear) and complexity (nonlinear) were obtained from N = 92 adolescents, 41 males (M age = 13.28, SD = 0.69; BMI = 21.9) and 51 females (M age = 13.36, SD = 0.67; BMI = 21.5). The adolescents underwent the Trier Social Stress Test, consisting of five conditions: baseline, anticipation, social exposure, math task, and recovery. Repeated measures ANOVAs revealed that female in comparison to male adolescents showed lower cardiac complexity revealed by higher short-term scaling exponent at baseline (p = .006) and math (p = .013) and lower entropy at exposure (p = .013) and math (p = .012). A marginal between-groups effect was found for Higuchi's fractal dimension, F(1, 90) = 3.67, p = .059, η_p ²  = .041, with females showing lower fractal dimension than males in math (p = .037). Linear measures did not reveal sex-related differences. Results suggest that adolescent females show lower cardiac complexity during stress. These findings support the importance of nonlinear cardiac measures for understanding cardiac reactivity during stress. Further research is needed to test the hypothesis that cardiac complexity is useful to detect an increased risk of emotional disorders, disorders that are more prevalent in women.

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.

Negative cognitive emotion regulation as a predictor of adolescent heart rate variability and entropy under social stress

BACKGROUND AND OBJECTIVES

Negative cognitive emotion regulation (ER) strategies are particularly important within the framework of anxiety problems amongst youths and how they cope with stressful events. The aim of this study was to examine the associations between both negative and positive ER style and cardiac regulation under stressful conditions.

DESIGN

Eighty-nine adolescents (M = 13.31 years, SD = 0.68, 44.94% girls) were exposed to a socially relevant stress induction protocol.

METHODS

Participants' emotion regulation strategies were assessed and their cardiac function was recorded.

RESULTS

A negative ER style predicted heart rate (HR) entropy at the stressful stage after controlling for anxiety scores. In addition, heart rate variability reactivity and recovery and HR entropy recovery were larger (p < .05) in the low negative ER style group (n = 16) than in the high negative ER style group (n = 23).

CONCLUSIONS

Results suggest that individuals with a highly negative ER style have diminished autonomic flexibility.