Effects of acute stress on reward processing: A comprehensive meta-analysis of rodent and human studies.

Stressors can initiate a cascade of central and peripheral changes that modulate mesocorticolimbic dopaminergic circuits and, ultimately, behavioral response to rewards. Driven by the absence of conclusive evidence on this topic and the Research Domain Criteria framework, random-effects meta-analyses were adopted to quantify the effects of acute stressors on reward responsiveness, valuation, and learning in rodent and human subjects. In rodents, acute stress reduced reward responsiveness (g = -1.43) and valuation (g = -0.32), while amplifying reward learning (g = 1.17). In humans, acute stress had marginal effects on valuation (g = 0.25), without affecting responsiveness and learning. Moderation analyses suggest that acute stress neither has unitary effects on reward processing in rodents nor in humans and that the duration of the stressor and specificity of reward experience (i.e., food vs drugs) may produce qualitatively and quantitatively different behavioral endpoints. Subgroup analyses failed to reduce heterogeneity, which, together with the presence of publication bias, pose caution on the conclusions that can be drawn and point to the need of guidelines for the conduction of future studies in the field.

From One's Heart to the Mind of Others: A Study in School-Aged Children.

Studies have shown a significant association between effective parasympathetic modulation of the heart and processes linked to social cognition. Particularly, Quintana and colleagues documented a relation between vagally-mediated heart rate variability (vmHRV) and performance on a theory of mind (ToM) task, namely, the Reading the Mind in the Eyes Test (RMET), in a sample of university students. The purpose of the present study was to test whether such result would extend to a sample of school-aged children (7-9 years old) using the child version of the RMET. In addition, the Eyes Test Revised was administered as it is more suitable to evaluate ToM during childhood. Results supported the positive association between vmHRV and ToM abilities, replicating and extending previous results obtained in young adults. The current study adds to the existing literature pointing to HRV as a putative biomarker of social cognition abilities.

Diurnal cortisol measures are distinctively associated with evaluation of neuroticism by self and others.

The link between neuroticism and the various indicators of daily cortisol fluctuations is frequently noted to be inconsistent or lacking in strength. The current study aimed to investigate the predictive capacity of both self-assessment and external evaluations of neuroticism, along with their interaction, on multiple indices of diurnal cortisol variations. This research involved the assessment of neuroticism using self-report and external evaluations among 166 working individuals, coupled with the collection of saliva samples over two consecutive workdays. Employing multilevel response surface analysis, our findings indicated that self-reported neuroticism exhibited a stronger association with cortisol indices compared to external evaluations. Additionally, the level of alignment between self-assessment and external ratings of neuroticism specifically impacted the prediction of estimates of daily cortisol production. We discuss the theoretical and practical implications of these results.

A sex-specific pathway linking early life maltreatment, vagal activity, and depressive symptoms.

Background: Experiences of early life maltreatment (ELM) are alarmingly common and represent a risk factor for the development of psychopathology, particularly depression. Research has focused on alterations in autonomic nervous system (ANS) functioning as a mediator of negative mental health outcomes associated with ELM. Early alterations in autonomic vagal activity (vmHRV) may moderate the relationship between ELM and depression, particularly when considering forms of emotional maltreatment. Recent evidence suggests that the relationships of both ELM and vmHRV with depression may be non-linear, particularly considering females.Objective: Building on and extending theoretical considerations and previous work, the present work aims to further the current understanding of the complex relationships between ELM exposure, vmHRV, and depression.Methods: This study uses an adaptive modelling approach, combining exploratory network-based analyses with linear and quadratic moderation analyses, drawing on a large sample of males and females across adolescence (total N = 213; outpatient at-risk sample and healthy controls) and adulthood (total N = 85; community-based convenience sample).Results: Exploratory network-based analyses reveal that exposure to emotional abuse is particularly central within a network of ELM subtypes, depressive symptoms, and concurrent vmHRV in both adolescents and adults. In adults, emotional neglect shows strong associations with both emotional abuse and vmHRV and is highly central as a network node, which is not observed in adolescents. Moderator analyses reveal significant interactions between emotional maltreatment and vmHRV predicting depressive symptoms in adult females. Significant quadratic relationships of emotional maltreatment and vmHRV with depression are observed in both adolescent and adult females.Conclusions: The present findings contribute to the understanding of the psychological and physiological mechanisms by which ELM acts as a risk factor for the development of depression. Ultimately, this will contribute to the development of targeted and effective intervention strategies to mitigate the detrimental effects of early adversity.

Early exposure to chronic and severe adversity, which includes experiences of maltreatment, defined by the World Health Organization as physical, sexual, emotional abuse and/or neglect of children under the age of 18, is highly prevalent in the general population (estimated at 40­50 percent), and is a well-documented risk factor for depression.The present work combines network-based analyses with tests of different functions (i.e. linear, nonlinear quadratic) in moderator analyses to further explore the complex relationships among ELM exposure, vmHRV, and depression.The present findings contribute to the understanding of the psychological and physiological mechanisms by which early exposure to chronic and severe maltreatment acts as a risk factor for the development of depression.Ultimately, this will contribute to the development of targeted and effective intervention strategies to mitigate the detrimental effects of early adversity.

Negative emotions enhance memory-guided attention in a visual search task by increasing frontoparietal, insular, and parahippocampal cortical activity.

Previous literature demonstrated that long-term memory representations guide spatial attention during visual search in real-world pictures. However, it is currently unknown whether memory-guided visual search is affected by the emotional content of the picture. During functional magnetic resonance imaging (fMRI), participants were asked to encode the position of high-contrast targets embedded in emotional (negative or positive) or neutral pictures. At retrieval, they performed a visual search for targets presented at the same location as during encoding, but at a much lower contrast. Behaviorally, participants detected more accurately targets presented in negative pictures compared to those in positive or neutral pictures. They were also faster in detecting targets presented at encoding in emotional (negative or positive) pictures than in neutral pictures, or targets not presented during encoding (i.e., memory-guided attention effect). At the neural level, we found increased activation in a large circuit of regions involving the dorsal and ventral frontoparietal cortex, insular and parahippocampal cortex, selectively during the detection of targets presented in negative pictures during encoding. We propose that these regions might form an integrated neural circuit recruited to select and process previously encoded target locations (i.e., memory-guided attention sustained by the frontoparietal cortex) embedded in emotional contexts (i.e., emotional contexts recollection supported by the parahippocampal cortex and emotional monitoring supported by the insular cortex). Ultimately, these findings reveal that negative emotions can enhance memory-guided visual search performance by increasing neural activity in a large-scale brain circuit, contributing to disentangle the complex relationship between emotion, attention, and memory.

Daily cortisol variations are predicted proximally by self-efficacy beliefs at work and indirectly by perceived self-regulatory abilities in managing negative emotions.

In the present ecological study, we analyzed the relations of a set of self-efficacy beliefs at work to parameters of diurnal cortisol variation. Specifically, using data collected during two consecutive working days from 166 workers, we tested a mediation model positing social and work-related self-efficacy beliefs as mediators of the relations between self-regulatory emotional self-efficacy beliefs in managing negative emotions and cortisol indicators. Results from the multilevel mediation analyses supported the proposed model for work-related self-efficacy, which resulted as a significant mediator of the relation between self-regulatory emotional self-efficacy beliefs in managing negative emotions and the overall cortisol daily production indexed by computing the area under the curve with respect to the ground. Findings suggest the importance of self-efficacy beliefs for workers' physiological adjustment. Theoretical and practical contributions of the findings are discussed.

Dynamic associations of relational conflicts at work and consequent negative emotion dynamics with diurnal cortisol variations.

This study examines the predictive value of conflict and conflict-related variations in negative emotion dynamics, with respect to three cortisol indicators (cortisol awakening responses; overall cortisol output; diurnal cortisol slopes). A total of 166 workers provided momentary reports on conflict(s) with colleagues and negative emotions 10 times a day for 2 workdays and salivary cortisol samples 5 times a day. The results of latent growth curve piecewise multilevel models revealed that the occurrence of a conflict and the number of conflicts introduced significant variations in specific cortisol parameters indicating greater cortisol levels throughout the day. Moreover, the conflict-elicited negative emotion boost predicted a lower reduction of cortisol levels from morning to evening. Last, the postconflict decline in negative emotions was negatively associated with overall cortisol production. This study contributes to establishing a potential association between naturally occurring episodic conflicts at work and daily cortisol patterns, identifying within-person fluctuations in negative emotions as psychological mechanisms through which this occurs. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Modulatory effects of transcranial direct current stimulation of right insula on compassion motivation

Background: Compassion motivation is associated with increased heart rate variability (HRV), reflecting a calm and self-soothing physiological state. Recent work, however, suggests that this association is dynamic for the specific components of compassion. Objectives: The present study adopted anodal transcranial direct current stimulation (tDCS) targeting the right insula to see whether this would modulate the sensitivity to suffering and the commitment to engage in helpful actions (i.e., the components of compassion motivation). Method: Ninety-seven healthy individuals underwent 15-min anodal or sham tDCS over the frontotemporal lobe, while watching a video inducing empathic sensitivity and performing a Redistribution Game. Tonic and phasic HRV, dispositional traits, and momentary affects were assessed. Results: Compared to sham condition, anodal stimulation favored significant i) HRV reductions during the video and HRV increases during the Redistribution Game; ii) decreases in self-reported levels of negative affect and increases in positive affect during task when the latter was preceded by the video, without influencing altruistic behavior. Conclusions: Anodal tDCS over the right insula may modulate the engagement phase of compassion by intensifying the psychophysiological sensitivity to signals of distress and protecting from being subjectively overwhelmed by it. (AU)

The long-term impact of early adverse experience on adaptive functioning: a pilot study integrating measures of mental status, nonverbal communication, and heart rate variability.

Background: Childhood maltreatment (CM) can disrupt the development of behavioural and physiological systems, increasing the risk of physical and psychological adverse outcomes across the lifespan. CM may cause interpersonal dysfunctions that impair social communication and lead to dysfunctional activation of the autonomic nervous system. The present exploratory study analyzed the long-term impact of CM from an integrated perspective through the simultaneous assessment of psychological symptoms, social and behavioural communication, and physiological regulation.Methods: Participants were 55 healthy university students (9 males and 46 females; mean age ± SD = 25.26 ± 2.83 years), who filled out a battery of questionnaires to assess the presence of CM (Childhood Trauma Questionnaire) and psychopathological symptoms (Symptom Check-List-90 Item Revised). Participants were then subjected to a videotaped interview for the assessment of non-verbal behaviour (Ethological Coding System for Interviews) and measurement of tonic heart rate variability (HRV), a measure of physiological adaptability to the environment. We performed Pearson's correlation analysis to evaluate the associations between non-verbal behaviour, HRV, and CM variables. Multiple regression analysis was used to evaluate the independent associations between CM variables on HRV and nonverbal behaviour.Results: We found an association between more severe CM, increased symptoms-related distress (ps < .001), less submissive behaviour (ps < .018), and decreased tonic HRV (ps < .028). As a result of multiple regression analysis, participants with a history of emotional abuse (R² = .18, p = .002) and neglect (R² = .10, p = .03) were more likely to display decreased submissive behaviour during the dyadic interview. Moreover, early experience of emotional (R² = .21, p = .005) and sexual abuse (R² = .14, p = .04) was associated with decreased tonic HRV.Conclusion: Our preliminary findings show the utility of analyzing the long-term effects of adverse early experiences at different levels of 'adaptive functioning' (the capabilities needed to respond effectively to environmental demands).

Substantial traumatic experiences during childhood, such as emotional abuse, emotional neglect, and sexual abuse were associated with lower heart rate variability levels in a sample of young adults.Young adults with a history of emotional abuse and neglect were more likely to display decreased submissive behaviour (ethological behaviour) during the dyadic interview.Severe childhood maltreatment was associated with increased symptoms-related distress, less submissive behaviour (ethological behaviour), and decreased tonic heart rate variability in young adults.

Beliefs in Regulating Negative Emotions and Vagally Mediated Heart Rate Variability: Does Sex Make a Difference?

OBJECTIVE: This ecological study explored the association between regulatory emotional self-efficacy beliefs in managing negative emotions (RESE-NE) and heart rate variability (HRV), a measure of parasympathetic modulation of the heart that has been positively associated with a better ability to flexibly adjust to a changing environment and regulate emotions. METHOD: To test these associations, we used data from 161 adults working in relational professions (about 40% men; mean [standard deviation] age = 40.45 [14.17] years) whose HRV was assessed continuously for 24 hours. RESULTS: Individuals high in RESE-NE showed increased HRV levels ( ß = -0.05, p = .011). However, this effect was moderated by biological sex ( ß = -0.18, p = .0001) such that RESE-NE positively and significantly predicted HRV for men ( ß = 0.18, p < .0001) but not for women ( ß = -0.001, p = .989). CONCLUSIONS: All in all, our study provides initial empirical support for the theoretical expectation derived from social cognitive theory that RESE-NE is positively correlated with a physiological indicator of adaptability to the environmental demands. This was true only for men, likely because of sex differences in physiological stress reactivity and regulation.

Momentary gustative-olfactory sensitivity and tonic heart rate variability are independently associated with motivational behavior.

Deficits in motivational functioning including impairments in reward learning or reward sensitivity are common in psychiatric disorders characterized by anhedonia. Recently, anhedonic symptoms have been exacerbated by the pandemic caused by the Coronavirus disease 2019 (COVID-19) in the general population. The present study examined the putative associations between loss of smell (anosmia) and taste (ageusia) sensitivity, irrespective of COVID-19 infection, and anhedonia, measured by a signal-detection task probing the ability to modify behavior as a function of rewards (Probabilistic Reward Task; PRT). Tonic heart rate variability (HRV) was included in the model, due to its association with both smell and taste sensitivity as well as motivational functioning. The sample included 114 healthy individuals (81 females; mean age 22.2 years), who underwent a laboratory session in which dispositional traits, resting HRV and PRT performance were assessed, followed by a 4-days ecological momentary assessment to obtain daily measures of anosmia and ageusia. Lower levels of tonic HRV and lower momentary levels of smell and taste sensitivity were associated with impaired reward responsiveness and ability to shape future behavioral choices based on prior reinforcement experiences. Overall, the current results provide initial correlational evidence that could be fruitfully used to inform future experimental investigations aimed at elucidating the disruptive worldwide mental health consequences triggered by the pandemic.

Effects of non-invasive vagus nerve stimulation on cognitive and autonomic correlates of perseverative cognition.

Perseverative cognitions can provoke psychophysiological stress in the absence of an actual stressor and are considered important transdiagnostic vulnerability factors for several (mental) health issues. These stress-related cognitive processes are reflected by both cognitive (assessed by self-reports) and autonomic inflexibility (assessed by heart rate variability; HRV), with a key role attributed to the vagus nerve. Interestingly, modulation of the afferent branches of the vagus can be achieved with transcutaneous auricular vagus nerve stimulation (taVNS), a non-invasive technique that employs a low-intensity electrical current applied to the ear. In a sample of healthy individuals, we investigated the effects of taVNS of the left concha, compared to sham (earlobe) stimulation, on the cognitive and autonomic correlates of perseverative cognition following a psychosocial stress task. Interestingly, taVNS significantly reduced cognitive rigidity, reflected by reduced subjective perseverative thinking after psychosocial stress. Although there were no direct effects on autonomic correlates of perseverative cognition, individual differences in perseverative thinking after the stressor significantly affected the effects of taVNS on HRV. Specifically, more autonomic inflexibility during the stress task (i.e., reduced HRV) was associated with increases in perseverative thinking afterward for the sham condition, but not the active taVNS condition. Additional exploratory analyses revealed no significant moderation of stimulation intensity. Overall, the study findings endorse the association between perseverative cognitions and vagus nerve functioning.

Modulatory effects of transcranial direct current stimulation of right insula on compassion motivation.

Background: Compassion motivation is associated with increased heart rate variability (HRV), reflecting a calm and self-soothing physiological state. Recent work, however, suggests that this association is dynamic for the specific components of compassion. Objectives: The present study adopted anodal transcranial direct current stimulation (tDCS) targeting the right insula to see whether this would modulate the sensitivity to suffering and the commitment to engage in helpful actions (i.e., the components of compassion motivation). Method: Ninety-seven healthy individuals underwent 15-min anodal or sham tDCS over the frontotemporal lobe, while watching a video inducing empathic sensitivity and performing a Redistribution Game. Tonic and phasic HRV, dispositional traits, and momentary affects were assessed. Results: Compared to sham condition, anodal stimulation favored significant i) HRV reductions during the video and HRV increases during the Redistribution Game; ii) decreases in self-reported levels of negative affect and increases in positive affect during task when the latter was preceded by the video, without influencing altruistic behavior. Conclusions: Anodal tDCS over the right insula may modulate the engagement phase of compassion by intensifying the psychophysiological sensitivity to signals of distress and protecting from being subjectively overwhelmed by it.

The association of self-esteem variability with diurnal cortisol patterns in a sample of adult workers.

This study explored the relationships between self-esteem level and self-esteem variability at work with parameters of diurnal cortisol rhythm, using intensive longitudinal data collected during two consecutive working days from N = 166 workers. Participants self-reported measures of sex, height, weight, self-esteem, neuroticism, and negative events at T0. Then, they answered a single item of self-esteem 4 times per day. Self-esteem variability was assessed by means of the relative variability index approach proposed by Mestdagh et al. (2018). Further, participants collected salivary samples at specific time points for analysis of diurnal cortisol patterns. Self-esteem average levels and a specific form of self-esteem variability were associated with diurnal cortisol parameters. In particular, results showed a relationship between low self-esteem and blunted cortisol awakening response, specifically when low self-esteem levels were stable over time. Moreover, self-esteem variability predicted a lower diurnal cortisol decline and a smaller magnitude of overall cortisol production. Present findings highlight the neuroendocrine correlates of self-esteem level and variation at work, suggesting potential pathways by which short-term variability in self-esteem states may impact hypothalamic-pituitary-adrenal axis functioning and long-term workers' health and well-being.

Perseverative Cognition as a Mediator Between Perceived Stress and Sleep Disturbance: A Structural Equation Modeling Meta-analysis (meta-SEM).

BACKGROUND: According to the perseverative cognition (PC) hypothesis, the repetitive chronic activation of the cognitive representations of stressors are associated with a concomitant prolonged and sustained physiological stress response, including sleep disruption. PURPOSE: We conducted a systematic review and structural equation modeling meta-analysis (meta-SEM) on PC as mediator of the association between perceived stress and subjective sleep disturbance (i.e., difficulties falling asleep or maintaining sleep). METHODS: PubMed, Scopus, Medline, CINAHL, and PsycInfo were searched up to September 2021. To test mediation, only longitudinal studies assessing the predictor (perceived stress) at T0, the mediator (PC) at T1, and the outcome (sleep disturbance) at T2, were eligible. RESULTS: Findings on 3,733 individuals (k = 8) showed a significant component effect of perceived stress on PC (ß = 0.340, p < .001), which in turn was related to sleep disturbance (ß = 0.258, p < .001). The direct effect of stress on sleep disturbance was significant (ß = 0.133, p < .001). Lastly, the indirect effect between stress and sleep disturbance via PC supported the mediation hypothesis (ß = 0.09, 95% CI 0.078-0.100). The mediation path remained significant (ß = 0.03, 95% CI 0.020-0.036) after adjusting for baseline sleep disturbance. Further leave-one-out sensitivity and control analyses confirmed that all direct and indirect effects were not driven by any single study included in the meta-analysis, as well as their robustness when controlling for sex and age, respectively. CONCLUSIONS: Overall, results of this meta-analysis indicate that PC may be one of the mechanisms explaining how perceived stressful experiences lead to subjective sleep disturbance.

The repetitive chronic activation of the cognitive representations of stressors, known as perseverative cognition (PC), is associated with a concomitant prolonged and sustained physiological stress response, with may include sleep disturbance. This study investigates the mediating role of PC in the association between perceived stress and subjective indices of sleep disturbance using structural equation modeling meta-analysis (meta-SEM). PubMed, Scopus, Medline, CINAHL, and PsycInfo were searched up to September 2021. Findings on eight studies (n = 3,733 individuals) showed a significant component effect of perceived stress on PC, which in turn was related to sleep disturbance. The direct effect of stress on sleep disturbance was significant. Finally, the indirect effect between stress and sleep disturbance via PC supported the mediation hypothesis. Results of this meta-analysis suggest that PC may be one of the mechanisms explaining how perceived stressful experiences lead to subjective sleep disturbance.

From skinner box to daily life: Sign-tracker phenotype co-segregates with impulsivity, compulsivity, and addiction tendencies in humans.

Pavlovian conditioning holds the potential to incentivize environmental cues, leading to approach behavior toward them, even outside our awareness. Animal models suggest that this is particularly true for the so-called sign-tracker (ST) phenotype, which is considered to reflect a predisposition toward developing addiction-related behaviours. Despite its potential clinical relevance, few studies have demonstrated the translational validity of this model, likely due to difficulties in studying Pavlovian processes in humans. To fill this gap, we combined an ecological momentary assessment with ambulatory peripheral autonomic monitoring to test the hypothesis that traits associated with ST in preclinical studies would be associated with attribution of high incentive salience to reward-related cues. Several times for 2 days, participants were asked to rate the attractiveness of several preselected ecological rewards (e.g., coffee) and the preceding cues (the smell of coffee) while their electrocardiogram was recorded. While no absolute difference in subjective and physiological measures of motivational approach to daily cues compared with rewards emerged, individuals with high levels of impulsivity, obsessive-compulsive, and addiction-prone behaviors rated as more attractive and showed a greater increase in sympathetic arousal to cues versus rewards. The opposite pattern emerged for those with low levels in those dispositional traits, who responded more (both subjectively and physiologically) to rewards compared with their preceding cues. This study represents an attempt to answer the call to parcel complex behaviors into smaller constructs, improving the early detection of those who are vulnerable to develop psychopathological disorders, particularly in the domain of impulse control such as addiction.

Sleep disturbance, neuro-immune markers, and depressive symptoms in older age: Conditional process analysis from the English Longitudinal Study of Aging (ELSA).

This study aimed to investigate the long-term association between subjective sleep disturbance and depressive symptoms in older adults, and ascertain whether this association is partially mediated by neuro-immune markers, while testing the moderation of sex using conditional process analyses, i.e., combinations of mediation and moderation analyses. We analysed data of 2124 participants aged 50 and above from the English Longitudinal Study of Ageing (ELSA) across three waves of data collection. Sleep disturbance was assessed in 2008/9, serum levels of high sensitivity C-reactive protein (hs-CRP), insulin like growth factor-1 (IGF-1), white blood cell (WBC) count in 2012/2013, and self-reported depressive symptoms in 2016/2017. After accounting for health-related and psychosocial confounders, results showed that sleep disturbance significantly predicted depressive symptoms at follow-up in the whole sample and hs-CRP in women, but not in men. Hs-CRP also predicted depressive symptoms only in women. Moreover, hs-CRP significantly mediated the association between sleep disturbance and depressive symptoms in women, but not in men. The association between sleep disturbance and IFG-1was marginal, and the latter did not mediate the association between sleep and depressive symptoms neither in women nor in men. Results on WBC count were all non-significant. In conclusion, sleep disturbance resulted significantly associated with depressive symptoms in a long-term follow-up. Moreover, ELSA data provide preliminary evidence that increased inflammation may mediate this association in women. Future longitudinal studies may advance the knowledge in the field considering the mediating role of proinflammatory cytokines such as interleukin-6.

Breathing out dental fear: A feasibility crossover study on the effectiveness of diaphragmatic breathing in children sitting on the dentist's chair.

BACKGROUND: Anxiety related to the dental context is a clinically significant challenge. In children, dental fear is often accompanied by disruptive and uncooperative behaviours that can render treatment difficult. Although techniques to reduce children's anxiety exist, many have not been formally evaluated. DESIGN: Diaphragmatic breathing has been shown to reduce fear and anxiety, but few investigations have evaluated whether it can reduce dental anxiety in children. This crossover study tested the effectiveness and feasibility of diaphragmatic breathing in twenty children undergoing dental care. RESULTS: Compared with the treatment as usual, such a simple technique had significant benefits on mood, self-reported pain and autonomic balance, thus reducing sympathetic activation. CONCLUSION: Diaphragmatic breathing is a low-cost, easy-to-implement technique suitable for daily dental practice, and is a promising tool for reducing negative effect and physiological distress in children with dental anxiety that results in more cooperative behaviours and reduced visit time.

Safe in my heart: resting heart rate variability longitudinally predicts emotion regulation, worry, and sense of safeness during COVID-19 lockdown.

Resting heart rate variability (HRV), a surrogate index of cardiac vagal modulation, is considered a putative biomarker of stress resilience as it reflects the ability to effectively regulate emotions in a changing environment. However, most studies are cross-sectional, precluding longitudinal inferences. The high degree of uncertainty and fear at a global level that characterizes the COVID-19 pandemic offers a unique opportunity to explore the utility of HRV measures as longitudinal predictors of stress resilience. This study examined whether resting measures of HRV prior to the COVID-19 outbreak (i.e. nearly 2 years before; Time 0) could predict emotion regulation strategies and daily affect in healthy adults during the May 2020 lockdown (Time 1). Moreover, we evaluated the association between HRV measures, emotion regulation strategies, subjective perception of COVID-19 risk, and self-reported depressive symptoms at Time 1. Higher resting HRV at Time 0 predicted a stronger engagement in more functional emotion regulation strategies, as well as of higher daily feelings of safeness and reduced daily worry at Time 1. Moreover, depressive symptoms negatively correlated with HRV and positively correlated with the subjective perception of COVID-19 risk at Time 1. Current data support the view that HRV might not only be a marker but also a precursor of resilience under stressful times.

Combining top-down and bottom-up interventions targeting the vagus nerve to increase resilience.

Chronic stress has dramatically increased over the last years and is one of the major health concerns of the 21st century. Targeted interventions are traditionally based on inducing cognitive changes and enhancing control with the aim to promote adaptive emotion regulation, ultimately enhancing stress resilience. Crucially, bodily functions have received little attention in this quest, despite increasing evidence on the impact of mind-body interactions on resilience. An exemplary model is constituted by accumulating empirical support on the vagus nerve, which enables two-way communication between heart and brain, allowing to engage in an adaptive stress response in a context-appropriate manner. Yet, research on such bidirectional communication is mainly correlational. We propose to consider resonance breathing (bottom-up approach, heart > brain), and neuromodulation (top-down approach, brain > heart) as evidence-based ways to increase vagal nerve inhibitory control and hence increase stress resilience. These promising, likely cost-effective and easily employable techniques can be used alone or in combination, harnessing neurobiological scientific advances to select treatment options with the greatest likelihood of success.