Validation of Photoplethysmography Using a Mobile Phone Application for the Assessment of Heart Rate Variability in the Context of Heart Rate Variability-Biofeedback.

OBJECTIVE: Heart rate variability-biofeedback (HRV-BF) is an effective intervention to reduce stress and anxiety and requires accurate measures of real-time HRV. HRV can be measured through photoplethysmography (PPG) using the camera of a mobile phone. No studies have directly compared HRV-BF supported through PPG against classical electrocardiogram (ECG). The current study aimed to validate PPG HRV measurements during HRV-BF against ECG. METHODS: Fifty-seven healthy participants (70% women) with a mean (standard deviation) age of 26.70 (9.86) years received HRV-BF in the laboratory. Participants filled out questionnaires and performed five times a 5-minute diaphragmatic breathing exercise at different paces (range, ~6.5 to ~4.5 breaths/min). Four HRV indices obtained through PPG, using the Happitech software development kit, and ECG, using the validated NeXus apparatus, were calculated and compared: RMSSD, pNN50, LFpower, and HFpower. Resonance frequency (i.e., optimal breathing pace) was also compared between methods. RESULTS: All intraclass correlation coefficient values of the five different breathing paces were "near perfect" (>0.90) for all HRV indices: lnRMSSD, lnpNN50, lnLFpower, and lnHFpower. All Bland-Altman analyses (with just three incidental exceptions) showed good interchangeability of PPG- and ECG-derived HRV indices. No systematic evidence for proportional bias was found for any of the HRV indices. In addition, correspondence in resonance frequency detection was good with 76.6% agreement between PPG and ECG. CONCLUSIONS: PPG is a potentially reliable and valid method for the assessment of HRV. PPG is a promising replacement of ECG assessment to measure resonance frequency during HRV-BF.

Stress- and smoke free pregnancy study protocol: a randomized controlled trial of a personalized eHealth intervention including heart rate variability-biofeedback to support pregnant women quit smoking via stress reduction.

BACKGROUND: Maternal smoking and stress during pregnancy are associated with adverse health effects for women themselves and are risk factors for adverse developmental outcomes of the unborn child. Smoking and stress seem to be intertwined in various ways. First, the majority of smoking pregnant women is of lower socio-economic status, which is associated with higher levels of perceived stress. Second, smoking women often report to smoke because they feel stressed. Third, quitting smoking often increases perceived stress levels initially. Therefore, effective interventions are needed to support women with smoking cessation by reducing stress. The aim of this study is to test the effectiveness of an eHealth intervention on stress reduction and smoking cessation. METHODS/DESIGN: The Stress- and Smoke Free Start of Life (SSFSL) study is a randomized controlled trial (RCT) comparing a personalized eHealth intervention with a control condition. Inclusion criteria for the women are: (1) > 18 years of age, (2) < 28 weeks pregnant at recruitment, (3) currently smoking. Consenting participants will be randomly assigned to the intervention or control group. Participants allocated to the intervention group will receive an 8-week intervention delivered on their smartphone. The application includes psycho-education on pregnancy, stress, and smoking (cessation); stress-management training consisting of Heart Rate Variability-biofeedback; and a personalized stop-smoking-plan. Participants in the control condition will be invited to visit a webpage with information on pregnancy, stress, and smoking (cessation). Study outcomes will be collected via online questionnaires, at four timepoints: pre-intervention (baseline; t0), post-intervention (8 weeks + 1 day after t0; t1), follow up at two weeks after birth (t2), and follow up at three months after birth (t3). The primary outcome measure is self-reported smoking cessation. Secondary outcomes include daily self-reported number of cigarettes smoked, perceived stress, pregnancy experience, birth outcomes, and negative affectivity scores of the baby. Moreover, the mediating effect of stress reduction on smoking cessation will be examined, and possible moderators will be tested. DISCUSSION: If the eHealth intervention is effective in smoking cessation among pregnant smoking women, it can be implemented as a tool into the health care in the Netherlands. TRIAL REGISTRATION: Netherlands Trial Register, ID: NL8156 . Registered on 11 November 2019.

Intergenerational transmission of anxiety: linking parental anxiety to infant autonomic hyperarousal and fearful temperament.

BACKGROUND: Autonomic hyperarousal has been proposed as a dispositional risk factor for anxiety disorders (ADs). Therefore, we studied physiological arousal in offspring of fathers and mothers with and without ADs and whether infant hyperarousal predicts subsequent fearful temperament. METHODS: Infants (N = 128; age = 4 months) did a novel stimuli task (exposure to visual, olfactory, and acoustic stimuli and an unfamiliar male) and a habituation task (exposure to a repeated acoustic stimulus). Heart rate (HR) and heart rate variability (HRV) were measured during baseline, stimuli and post-stimuli rest. Parents' AD status and severity were measured using a diagnostic interview and their fearful temperament using a questionnaire. Child fearful temperament was measured at 4 months, 1 year and 2.5 years with observations during structured tasks. RESULTS: Parents' fearful temperament (significant in the habituation task), AD status (significant in the novel stimuli task) and AD severity (significant in both tasks) predicted a higher HR in their infants. Infants' higher HR reactivity to novel stimuli and diminished HR recovery at 4 months predicted a more fearful temperament during infancy and toddlerhood. Infants' higher HR at 4 months predicted a more fearful temperament at 2.5 years. CONCLUSIONS: Parental prenatal anxiety (disorders) predicted infants' autonomic arousal, which in turn predicted later fearful temperament in children. Outcomes suggest that autonomic hyperarousal is a dispositional risk factor of ADs.

The unique contribution of blushing to the development of social anxiety disorder symptoms: results from a longitudinal study.

BACKGROUND: Self-conscious emotional reactivity and its physiological marker - blushing has been proposed to be an etiological mechanism of social anxiety disorder (SAD), but so far, untested in longitudinal designs. This study tested, for the first time, whether self-conscious emotional reactivity (indexed as physiological blushing) contributes to the development of SAD symptoms over and above social behavioral inhibition (BI), which has been identified as the strongest predictor of SAD development in early childhood. METHODS: One hundred fifteen children (45% boys) and their mothers and fathers participated at ages 2.5, 4.5, and 7.5 years. Social BI was observed at all time points in a stranger approach task, and physiological blushing (blood volume, blood pulse amplitude, and temperature increases) was measured during a public performance (singing) and watching back the performance at ages 4.5 and 7.5. Child early social anxiety was reported by both parents at 4.5 years, and SAD symptoms were diagnosed by clinicians and reported by both parents at 7.5 years. RESULTS: Higher social BI at 2.5 and 4.5 years predicted greater social anxiety at 4.5 years, which, in turn, predicted SAD symptoms at 7.5 years. Blushing (temperature increase) at 4.5 years predicted SAD symptoms at 7.5 years over and above the influence of social BI and early social anxiety. CONCLUSIONS: That blushing uniquely contributes to the development of SAD symptoms over and above social BI suggests two pathways to childhood SAD: one that entails early high social BI and an early onset of social anxiety symptoms, and the other that consists of heightened self-conscious emotional reactivity (i.e. blushing) in early childhood.

Bumping heart and sweaty palms: physiological hyperarousal as a risk factor for child social anxiety.

BACKGROUND: Physiological hyperarousal in social situations is a characteristic of individuals with social anxiety disorder (SAD), but so far it has been rarely studied as a biological risk for SAD. Here, we investigate whether children at high risk for SAD (because of their parents' SAD) display physiological hyperarousal while interacting with a stranger. Also, we examine whether early physiological hyperarousal is related to later child social anxiety. METHOD: One hundred and seventeen children took part in the stranger-approach task when they were 2.5 and 4.5 years old. Heart rate (HR), heart rate variability (HRV), and electrodermal activity (EDA) were measured before, during, and after the conversation with a stranger. Both parents' lifetime SAD status and SAD severity were assessed before the birth of the child. Both parents and children reported on children's social anxiety symptoms when children were 7.5. RESULTS: Children of parents with the lifetime SAD diagnosis did not differ in their physiological activity from children of parents without lifetime SAD. However, children of parents with more severe SAD displayed heightened EDA throughout the task procedure. Increased HR and reduced HRV during the stranger-approach and elevated EDA throughout the task phases were linked to later child social anxiety. CONCLUSIONS: Parents' severity of SAD is related to child physiological hyperarousal early in their childhood. In addition, physiological hyperarousal in early childhood predicts later child social anxiety. Together, these findings suggest that early physiological hyperarousal in social situations may pose a risk for later child social anxiety and that physiological hyperarousal, and EDA in particular, may be a biological mechanism in the intergenerational transmission of SAD.

Mothers' and fathers' mind-mindedness influences physiological emotion regulation of infants across the first year of life.

The main aim of this study was to test whether mothers' (n = 116) and fathers' (n = 116) mind-mindedness predicts infants' physiological emotion regulation (heart rate variability; HRV) across the first year of life. Three hypotheses were examined: (a) parents' mind-mindedness at 4 and 12 months predicts infants' HRV at 12 months over and above infants' initial HRV levels at 4 months, (b) mothers' and fathers' mind-mindedness independently predict infant HRV, and (c) the effects of mind-mindedness on infant HRV (partially) operate via parenting behaviour. Infants' HRV was assessed during rest and a stranger approach. Mind-mindedness was assessed by calculating the proportions of appropriate and non-attuned mind-related comments during free-play interactions, and parenting quality was observed at 4 and 12 months in the same interactions. Path analyses showed that mothers' appropriate mind-related comments at 4 and 12 months predicted higher baseline HRV at 12 months, whereas mothers' non-attuned comments predicted lower baseline HRV at 12 months. Similar, but concurrent, relations were found for fathers' appropriate and non-attuned mind-related comments and infant baseline HRV at 12 months. In addition, fathers' appropriate mind-related comments showed an indirect association with infant baseline HRV at 12 months via fathers' parenting quality. With regard to infant HRV reactivity during the stranger approach, mothers' appropriate mind-related comments at 4 months and fathers' non-attuned mind-related comments at 12 months predicted a larger HRV decline during the stranger approach at 12 months. Infants' HRV at 4 months did not predict parents' later mind-mindedness. The results indicate that mothers' and fathers' appropriate and non-attuned mind-related speech uniquely impacts the development of infants' physiological emotion regulation.

Parental Expressions of Anxiety and Child Temperament in Toddlerhood Jointly Predict Preschoolers' Avoidance of Novelty.

This study investigated the link between (a) parents' social trait and state anxiety and (b) children's fear and avoidance in social referencing situations in a longitudinal design and considered the modulating role of child temperament in these links. Children were confronted with a stranger and a robot, separately with their father and mother at 1 (N = 122), at 2.5 (N = 117), and at 4.5 (N = 111) years of age. Behavioral inhibition (BI) was separately observed at 1 and 2.5 years. Parents' social anxiety disorder (SAD) severity was assessed via interviews prenatally and at 4.5 years. More expressed anxiety by parents at 4.5 years was not significantly linked to more fear or avoidance at 4.5 years. High BI children were more avoidant at 4.5 years if their parents expressed more anxiety at 2.5 years, and they were more fearful if the parents had more severe forms of lifetime SAD. More severe lifetime forms of SAD were also related to more pronounced increases in child fear and avoidance over time, whereas parents' expressions of anxiety predicted more pronounced increases in avoidance only from 2.5 to 4.5 years. High BI toddlers of parents with higher state and trait anxiety become more avoidant of novelty as preschoolers, illustrating the importance of considering child temperamental dispositions in the links between child and parent anxiety. Moreover, children of parents with more trait and state anxiety showed more pronounced increases in fear and avoidance over time, highlighting the importance of early interventions targeting parents' SAD.

The Structure of Challenging Parenting Behavior and Associations With Anxiety in Dutch and Australian Children.

Challenging parenting behavior (CPB), a novel construct involving active physical and verbal behaviors that encourage children to push their limits, has been identified as a potential buffer against child anxiety. This study aimed to (a) evaluate the measurement invariance of the Challenging Parenting Behavior Questionnaire (CPBQ4-6) across Dutch and Australian mothers and fathers of preschoolers, (b) examine differences in levels of CPB across mothers and fathers and across countries, and (c) examine whether parents' CPB predicts less child anxiety symptoms and disorders. Participants were 312 families-146 Dutch and 166 Australian-with their 3- to 4-year-old child (55.8% girls). Fathers' and mothers' CPB was measured using the CPBQ4-6, and child anxiety symptoms and presence of anxiety disorders were assessed using maternal reports. Multigroup confirmatory factor analyses revealed equivalence of factor structure and factor loadings (all significant) of the CPBQ4-6 across mothers and fathers and across countries. Evidence of partial scalar invariance indicated that the groups differed on some subscales of the CPBQ4-6. Australian mothers scored lower on the CPB factor than Australian fathers and Dutch parents. Structural equation models showed that CPB predicted fewer child anxiety symptoms and anxiety disorders for all groups. The study confirms that the CPBQ4-6 is appropriate for use with Dutch and Australian parents of preschool-age children and identifies CPB as a multifaceted and coherent construct. The negative relations between CPB and child anxiety suggest that CPB has a protective role in childhood anxiety and is important to examine in future research and interventions.

How do parents' depression and anxiety, and infants' negative temperament relate to parent-infant face-to-face interactions?

The present study investigated the associations of mothers' and fathers' lifetime depression and anxiety symptoms, and of infants' negative temperament with parents' and infants' gaze, facial expressions of emotion, and synchrony. We observed infants' (age between 3.5 and 5.5 months, N = 101) and parents' gaze and facial expressions during 4-min naturalistic face-to-face interactions. Parents' lifetime symptoms of depression and anxiety were assessed with clinical interviews, and infants' negative temperament was measured with standardized observations. Parents with more depressive symptoms and their infants expressed less positive and more neutral affect. Parents' lifetime anxiety symptoms were not significantly related to parents' expressions of affect, while they were linked to longer durations of gaze to parent, and to more positive and negative affect in infants. Parents' lifetime depression or anxiety was not related to synchrony. Infants' temperament did not predict infants' or parents' interactive behavior. The study reveals that more depression symptoms in parents are linked to more neutral affect from parents and from infants during face-to-face interactions, while parents' anxiety symptoms are related to more attention to parent and less neutral affect from infants (but not from parents).

Autonomic arousal in children of parents with and without social anxiety disorder: a high-risk study.

OBJECTIVE: Autonomic hyperarousal in social situations is considered a genetic vulnerability factor for social anxiety disorder (SAD), but so far it is unstudied in children at risk for developing SAD. We examined autonomic activity during socially stressful tasks in children of mothers and fathers with and without lifetime SAD to reveal possible biological mechanisms of intergenerational transmission of SAD. METHODS: One hundred ten children aged 4.5 years were asked to sing a song in front of an audience and watch back their performance in the presence of that audience. Heart rate (HR), heart rate variability (HRV), electrodermal activity (EDA), and blushing (cheek blood flow and temperature) were measured in anticipation of, during, and after the tasks. Both parents' lifetime SAD status was assessed, and both parents reported about their own and their child's social anxiety symptoms. RESULTS: Children of parents with lifetime SAD blushed more during the socially challenging tasks than children of parents without SAD. Moreover, children of parents with more social anxiety symptoms showed increased EDA throughout the tasks. Finally, more blushing, increased EDA, and reduced HRV were associated with greater child social anxiety. CONCLUSIONS: This study adds to the current knowledge on the intergenerational transmission of SAD by providing evidence that children at risk for SAD are characterized by excessive blushing in socially challenging situations. The findings also demonstrate that heightened autonomic activity is a characteristic of social anxiety already during early childhood. Hence, autonomic hyperarousal, and blushing in particular, is likely to play an etiological role in the development of SAD.

Recovery of Work-Related Stress: Complaint Reduction and Work-Resumption are Relatively Independent Processes.

PURPOSE: The process of recovery from work-related stress, consisting of complaint reduction and work-resumption, is not yet fully understood. The aim of this study was to investigate predictors of complaint reduction and work-resumption, as well as testing complaint reduction as a mediator in the association between predictors and work-resumption. METHODS: Seventy-one patients on sickness-leave because of work-related stress complaints were followed over a period of 13 months. Predictors comprised personal (demographics, coping, cognitions), work-related (job-characteristics, social support), and illness-related (complaint duration, absence duration) variables. Dependent variables were distress complaints, burnout complaints, and work-resumption. RESULTS: Complaints reduced considerably over time to borderline clinical levels and work-resumption increased to 68% at 13 months. Predictors of stronger reduction of distress complaints were male gender, less working hours, less decision authority, more co-worker support, and shorter absence duration. Predictors of stronger reduction of burnout complaints were male gender, lower age, high education, less avoidant coping, less decision authority, more job security, and more co-worker support. Predictors of work-resumption were lower age and stronger reduction of burnout complaints. No indication for a mediating role of burnout complaints between the predictor age and work-resumption was found. CONCLUSIONS: Complaint reduction and work-resumption are relatively independent processes. Symptom reduction is influenced by individual and work-related characteristics, which holds promise for a multidisciplinary treatment approach for work-related stress.

Physical activity, mindfulness meditation, or heart rate variability biofeedback for stress reduction: a randomized controlled trial.

In contemporary western societies stress is highly prevalent, therefore the need for stress-reducing methods is great. This randomized controlled trial compared the efficacy of self-help physical activity (PA), mindfulness meditation (MM), and heart rate variability biofeedback (HRV-BF) in reducing stress and its related symptoms. We randomly allocated 126 participants to PA, MM, or HRV-BF upon enrollment, of whom 76 agreed to participate. The interventions consisted of psycho-education and an introduction to the specific intervention techniques and 5 weeks of daily exercises at home. The PA exercises consisted of a vigorous-intensity activity of free choice. The MM exercises consisted of guided mindfulness meditation. The HRV-BF exercises consisted of slow breathing with a heart rate variability biofeedback device. Participants received daily reminders for their exercises and were contacted weekly to monitor their progress. They completed questionnaires prior to, directly after, and 6 weeks after the intervention. Results indicated an overall beneficial effect consisting of reduced stress, anxiety and depressive symptoms, and improved psychological well-being and sleep quality. No significant between-intervention effect was found, suggesting that PA, MM, and HRV-BF are equally effective in reducing stress and its related symptoms. These self-help interventions provide easily accessible help for people with stress complaints.

Parental social anxiety disorder prospectively predicts toddlers' fear/avoidance in a social referencing paradigm.

BACKGROUND: Anxiety runs in families. Observational learning of anxious behavior from parents with anxiety disorders plays an important role in the intergenerational transmission of anxiety. We investigated the link between parental anxiety (parental lifetime anxiety disorders and expressed parental anxiety) and toddler fear/avoidance during social referencing (SR) situations. METHOD: Toddlers (N = 117) participated with both parents (with lifetime social anxiety disorder, other nonsocial anxiety disorders, lifetime comorbid social and other anxiety disorders, or without anxiety disorders) in a longitudinal study. Behavioral inhibition (BI) was measured at 12 months via observational tasks. At 30 months, children were confronted with a stranger and a remote-control robot in SR situations, separately with each parent. Children's fear and avoidance, and parents' expressions of anxiety, encouragement, and overcontrol were observed. RESULTS: Toddlers of parents with lifetime social anxiety disorder (alone and comorbid with other anxiety disorders) showed more fear/avoidance in SR situations than toddlers of parents without anxiety disorders, while the effect of other anxiety disorders alone was not significant. Although expressed parental anxiety at 30 months in SR situations did not significantly predict toddlers' fear/avoidance, higher levels of expressed anxiety at 12 months in SR situations by parents with comorbid social and other anxiety disorders predicted higher levels of fear/avoidance. BI at 12 months predicted toddlers' fear/avoidance only with mothers, but not with fathers. CONCLUSIONS: Parental lifetime social anxiety disorders may be a stronger predictor of children's fear/avoidance than parents' expressions of anxiety in SR situations in toddlerhood. End of infancy may be a sensitive time for learning of anxiety from parents with comorbid lifetime social and nonsocial anxiety disorders in SR situations. Fathers are as important as mothers in the transmission of anxiety via SR. Furthermore, children may act relatively free of their early temperament in SR situations with fathers.

Smoking cessation in pregnant women: A randomized controlled trial investigating the effectiveness of an eHealth intervention including heart rate variability-biofeedback training.

BACKGROUND: Prenatal smoking and stress are associated with adverse health effects for women themselves and are risk factors for adverse outcomes of the child. Effective interventions are needed to support women with smoking cessation and reducing stress. The aims were (1) to test the effectiveness of an 8-week eHealth intervention targeting stress reduction and smoking cessation; (2) to examine whether stress reduction mediated the intervention effect on smoking behavior; (3) to test motivation to quit as a moderator; and (4) to investigate a dose-response effect of program usage. METHODS: Pregnant women were included if they were >18 years of age, < 28 weeks pregnant at recruitment, and currently smoking. In total, 156 consenting participants were randomly assigned to the intervention or active control condition. Study outcomes on smoking (yes/no, frequency, and quantity) were collected via online questionnaires at pre-intervention (baseline; t0), post-intervention (8 weeks after t0; t1), and follow up at two weeks (t2) and three months (t3) after birth. RESULTS: Smoking and stress reduced over the 8-week period in both conditions. The intervention effect on smoking was not mediated by stress reduction. Motivation to quit was found to moderate the intervention effect (smoking frequency and quantity) and a dose-response effect was found for program usage in the intervention for the reduction on smoking frequency and quantity. CONCLUSION: Program usage and motivation to quit are important for smoking reduction in pregnant women. Further research is needed to examine how the intervention could be improved to increase treatment effectiveness.

The interplay between expressed parental anxiety and infant behavioural inhibition predicts infant avoidance in a social referencing paradigm.

BACKGROUND: Anxiety aggregates in families. Environmental factors, such as modelling of anxious behaviours, are assumed to play a causal role in the development of child anxiety. We investigated the predictive value of paternal and maternal anxiety (lifetime anxiety disorders and expressed parental anxiety) on infants' fear and avoidance during encounters with social and nonsocial novel stimuli in a social referencing (SR) paradigm. METHODS: A total of 122 12-month-old infants participated in this study separately with their fathers and mothers (parents with lifetime: social anxiety disorders [n=47], other types of anxiety disorders [n=33], comorbid social and other types of anxiety disorders [n=52] and without anxiety disorders [n=112]). Infants were confronted with a stranger and a mechanical dinosaur as novel stimuli in two SR situations. Infants' avoidance as well as fear and parents' expressed anxiety were observed. Infants' behavioural inhibition (BI) was separately observed in structured tasks. RESULTS: Parental lifetime anxiety disorders did not significantly predict infant fear or avoidance. Expressed parental anxiety interacted with BI to significantly predict infant avoidance, revealing a positive association between expressed parental anxiety and infant avoidance among infants with moderate-to-high BI. The association between infant avoidance and expressed parental anxiety was not significantly different for mothers and fathers, pointing to an equally important role of fathers at this young age. Infant fear was significantly predicted by infant BI, but not by expressed parental anxiety. CONCLUSIONS: Infants with a temperamental disposition for anxiety (BI) may learn from both paternal and maternal anxious signals and become avoidant towards novelty when their parents express anxiety. This link between expressed parental anxiety and infant avoidance for moderate-to-high BI children, that seems to hold across contexts and to be independent of lifetime parental anxiety disorders, may be a mechanism explaining early intergenerational transmission of anxiety.

Just as they expected: How parents' expectations about their unborn child's characteristics provide a context for early transactions between parenting and child temperament.

Prenatal expectations about what children will be like after birth may provide a context for how parents perceive their infant's actual temperament. We examined how these expectations and perceptions are associated and together predict early parenting behavior, with parenting behavior in turn predicting changes in temperament. Reports of 125 families (N = 122 fathers; N = 123 mothers; sample 1) about their expectations of their unborn child's temperament (negative affectivity, surgency, regulation, T1), their infant's temperament at 4 and 12 months post-partum (T2 and T3), and their hostile, responsive, warm, and overprotective parenting (T2) were included. We also included data from an independent sample of 168 mothers (sample 2), with the same measures, except that mothers reported on Big Five personality traits at T1. Results indicated that in both samples, parents' expectations were positively associated with perceptions of infant temperament. Prenatal expectations and newborn temperament independently predicted parenting behavior, and maternal and paternal parenting in turn predicted infant temperament at T3, controlling for infant temperament at T2. Although overall findings indicated associations between (expectations of) a more difficult temperament and more negative/less positive parenting, significant combinations of specific traits and parenting behaviors were sample-specific-indicating that more research is necessary to draw a conclusion about specific links. Both maternal and paternal expectations about their unborn child's temperament appear to carry over into the postpartum reality and provide a context for shaping early interactions between caregivers and their children, which may further shape the developing temperament of the child.

Mothers' and fathers' mind-mindedness in infancy and toddlerhood predict their children's self-regulation at preschool age.

The ability to regulate one's emotions and behaviors is essential for adaptive functioning in society. We investigated whether parental mind-mindedness-parents' tendency to treat their children as mental agents-in infancy and toddlerhood predicts school-age children's self-regulation. The sample consisted of 125 mostly Dutch and White families. We assessed mothers' and fathers' appropriate and nonattuned mind-related comments during free play with their 12- and 30-month-old child (70 girls and 55 boys). We measured children's physiological, temperamental, and behavioral self-regulation when children were 4 1/2 years old. Fathers' appropriate mind-related comments predicted children's higher temperamental and behavioral self-regulation and mothers' and fathers' nonattuned mind-related comments predicted children's lower physiological and temperamental self-regulation. Our findings emphasize the importance of both parents' mind-mindedness in children's socioemotional development. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Hybrid models were found to be very elegant to disentangle longitudinal within- and between-subject relationships.

OBJECTIVES: The interpretation of a regression coefficient obtained from a longitudinal data analysis is a combination of a within-subject part and a between-subject part. The hybrid model is used to disentangle the two components. The purpose of this article was to illustrate and discuss the use of the hybrid model in epidemiologic studies. STUDY DESIGN AND SETTING: In the hybrid model the between-subject part of the relationship is obtained using the individual mean value over time, whereas the within-subject part is obtained using the deviation score, that is, the differences between the observations and the individual mean value. RESULTS: It was shown that the regression coefficient of a standard mixed model analysis is a sort of weighted average of the between- and within-subject part of the relationship. When the outcome was continuous the separate analyses to estimate the two components of a longitudinal relationship were equal to the estimation in the hybrid model. However, for dichotomous outcome, the estimations were slightly different. CONCLUSION: The hybrid model is an elegant, easy to perform method to disentangle the within- and between-subject part of a relationship in longitudinal studies.

Infant crying and the calming response: Parental versus mechanical soothing using swaddling, sound, and movement.

BACKGROUND: Frequent infant crying is associated with parental exhaustion, depression, or even infant hospitalization and shaken baby syndrome. Effective prompt soothing methods are lacking for infants under 6 months. We examined whether swaddling, sound, and movement evoked an immediate calming response (CR) when parents soothed their infants and using a smart crib, and whether infant age affected the CR. METHODS: Infants' CR was assessed in a community sample of 69 infants (0-6 months) in a counterbalanced experiment with two conditions (parent, smart crib) each composed of three two-minute phases (baseline, supine, soothing). During baseline 1, parent and infant were sitting together; in supine 1, fussiness was elicited by putting the infant suddenly supine, followed by parental soothing (shushing and jiggling of the swaddled infant). Baseline 2, supine 2, and soothing by the crib followed. Fussiness was observed and infant heart rate (HR) and heart rate variability (HRV) were recorded. The CR was operationalized as decreased fussiness and HR, and increased HRV during soothing compared to lying supine. RESULTS: Infant fussiness and HR were lower in both soothing phases compared to the supine phases. Infant HRV tended to be higher during parental soothing than during supine, but did not significantly differ between mechanical soothing and supine. Younger infants responded with a stronger CR (decreased fussiness and increased HRV) to parental soothing, but not to mechanical soothing. For HR, infants' CR was stronger in the crib than in the parent condition, whereas for HRV, infants' CR was stronger in the parent condition. For fussiness, infants' CR tended to be stronger in the parent condition. CONCLUSION: Parental and mechanical soothing using swaddling, sound, and movement promptly induced a CR in infants. This has important clinical implications for soothing fussy and crying infants. Future studies should investigate the effects of parental versus mechanical soothing in the home setting.

The Effect of Heart Rate Variability Biofeedback Training on Mental Health of Pregnant and Non-Pregnant Women: A Randomized Controlled Trial.

In this study, we examined the efficacy of heart rate variability (HRV)-biofeedback on stress and stress-related mental health problems in women. Furthermore, we examined whether the efficacy differed between pregnant and non-pregnant women. Fifty women (20 pregnant, 30 non-pregnant; mean age 31.6, SD = 5.9) were randomized into an intervention (n = 29) or a waitlist condition (n = 21). All participants completed questionnaires on stress, anxiety, depressive symptoms, sleep, and psychological well-being on three occasions with 6-week intervals. Women in the intervention condition received HRV-biofeedback training between assessment 1 and 2, and women in the waitlist condition received the intervention between assessment 2 and 3. The intervention consisted of a 5-week HRV-biofeedback training program with weekly 60⁻90 min. sessions and daily exercises at home. Results indicated a statistically significant beneficial effect of HRV-biofeedback on psychological well-being for all women, and an additional statistically significant beneficial effect on anxiety complaints for pregnant women. No significant effect was found for the other stress-related complaints. These findings support the use of HRV-biofeedback as a stress-reducing technique among women reporting stress and related complaints in clinical practice to improve their well-being. Furthermore, it supports the use of this technique for reducing anxiety during pregnancy.