Emotion regulation moderates the association between parent and child hair cortisol concentrations

Successful emotion regulation facilitates children's coping with everyday stress. It develops rapidly in the early preschool period. However, no work has been done to investigate the potential buffering role of emotion regulation from cumulative physiological effects of stress. In this study, we examined hair cortisol concentration (HCC), an early marker of chronic physiological stress, socioeconomic status (SES), parental sensitivity, and emotion regulation and reactivity in a sample of 3.5-year-old children (N = 86). Emotion regulation and emotional reactivity were independent of child HCC. However, emotion regulation moderated the relationship between parent and child HCC. For children with better emotion regulation, there was no association between parent and child HCC, suggesting that emotion regulation skills buffered the transgenerational effects of chronic physiological stress. Emotional reactivity moderated the relationship between SES and child HCC, and attenuated the association between parental sensitivity and child HCC. Taken together, these findings demonstrate that children who were less emotionally reactive were less susceptible to their environments. Results provide support that child emotion regulation and emotional reactivity can reduce or strengthen the relationship between established risk factors and levels of chronic physiological stress in early childhood.     

Infant emotion regulation and cortisol response during the first 2 years of life: Association with maternal parenting profiles

This study investigated the prospective associations among emotion expression, behavioral regulation, and cortisol responses in relation to different maternal parenting behaviors during the first 2 years of the infant's life, among a sample of low-income families. Participants included 1,141 mother–child pairs, assessed when the infants were 6, 15, and 24 months old. Maternal parenting behaviors were observed at the 6-month assessment, whereas infant emotion expression, orienting toward mothers, and cortisol responses were measured using a series of emotion-eliciting tasks at all time points. A latent profile analysis revealed four maternal parenting profiles: Detached, Intrusive, Average, and Engaged. Furthermore, a multiple-group path model revealed distinct patterns of emotion development for infants within different maternal parenting groups. Among children with Engaged and Average mothers, orienting behaviors tended to predict less negative emotion and cortisol responses, which was associated with more future orienting behaviors. Conversely, among children with Intrusive and Detached mothers, orienting behaviors tended to predict more negative emotion and cortisol responses, which predicted less future orienting behaviors. Findings of this study enhance current understanding of how different profiles of maternal parenting behaviors impact infant emotional development in poverty, with significant implications for intervention programs targeting early mother–infant interactions.     

Socioeconomic risk moderates the association between caregiver cortisol levels and infant cortisol reactivity to emotion induction at 24 months

Relations between maternal baseline cortisol and infant cortisol reactivity to an emotion induction procedure at child ages 7, 15, and 24 months were analyzed using data from the Family Life Project (N = 1,292). The emotion induction consisted of a series of standardized and validated tasks, including an arm restraint, toy removal, and mask presentation, intended to elicit responses of fear and frustration. Results revealed that at 7 and 15 months, maternal baseline cortisol was negatively related to child cortisol reactivity, such that children of mothers with lower cortisol exhibited steeper cortisol increases in response to the emotion induction. At 24 months, the association between mother and infant cortisol was moderated by socioeconomic risk, such that maternal baseline cortisol was associated with child cortisol reactivity only in dyads characterized by low socioeconomic risk. Furthermore, at 24 months, children of mothers with low baseline cortisol and low socioeconomic risk exhibited decreasing cortisol responses, whereas children of mothers with low baseline cortisol but high risk exhibited flat cortisol responses. Children in dyads characterized by high baseline maternal cortisol also exhibited flat cortisol responses regardless of socioeconomic risk. The role of caregiver physiology in the regulation of the child's stress response in the context of adversity is discussed.     

Longitudinal relations between child vagal tone and parenting behavior: 2 to 4 years

The longitudinal relations between physiological markers of child emotion regulation and maternal parenting practices were examined from 2 to 4 years of age. At Time 1, cardiac vagal tone was assessed for one hundred four 2-year-olds (54 females); their mothers completed an assessment of parenting styles. Two years later, at Time 2, 84 of the original participants were reassessed on measures of cardiac vagal tone and parenting style. Results indicated both baseline cardiac vagal tone and maternal parenting practices to be stable from 2 to 4 years of age. Children's cardiac vagal tone predicted specific parenting practices from the toddler to preschool years. Further, child cardiac vagal tone moderated maternal restrictive-parenting practices from 2 to 4 years of age; mothers of children who were highly or moderately physiologically dysregulated were more likely to report restrictive parenting practices at both 2 and 4 years of age.     

Innovations in biological assessments of chronic stress through hair and nail cortisol: Conceptual,developmental, and methodological issues

Much of the existing research on biological mechanisms underlying the stress experience has focused largely on moment-to-moment stress, rather than on chronic stress, an arguably more powerful predictor of long-term outcomes. Recent methodological innovations have paved the way for new lines of research on chronic stress, with promising implications for developmental researchers and for those who study health and adversity. In particular, there are increasing studies that have focused on chronic stress assessments by relying on cortisol derived from hair and nails as a biomarker for chronic stress. In this paper, we provide an overview of their use, describe how hair and nail cortisol ought to be conceptualized differently across the lifespan, how developmental factors may impact its interpretation, and the circumstances under which its use may be more methodologically sensible. The purpose of this review is to provoke further discussion and encourage careful research designs that utilize hair and nail cortisol for understanding the effects of chronic stress exposure from the early developmental period, across adverse contexts, and in association with psychological and physical health outcomes.     

Maternal depression and infant daytime cortisol

The effect of maternal depressive disorder on infant daytime cortisol production was studied in three groups of infants; one group with mothers with comorbid depression and anxiety (n = 19), a second group with mothers with depression only (n = 7), and a third group with non‐depressed mothers (n = 24). The infants' cortisol production pattern was measured when they were 6, 12, and 18 months old in combination with repeated measures of parenting stress and depression symptoms. Multilevel modeling analyses showed that infants of mothers with comorbid depression and anxiety had relatively higher cortisol production from morning to bedtime and higher bedtime values as compared to infants of non‐depressed mothers and infants of depressed only mothers when they were 6 and 12 months old, but not when 18 months old. The results were interpreted in light of possible changes in the infants' stress regulatory capacities or changes in maternal coping strategies at infant age 18 months. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 334–351, 2013     

Maternal hair cortisol levels as a novel predictor of neonatal abstinence syndrome severity: A pilot feasibility study

Neonatal abstinence syndrome (NAS) after in-utero opioid exposure remains a poorly understood condition with multiple factors contributing to severity. Exposure to maternal stress may be one contributing factor. Hair cortisol measurement represents a novel technique for assessing prenatal stress. In this pilot study, the association between maternal hair cortisol levels and NAS severity was examined in 70 postpartum women with opioid use disorder within 72 hr of delivery. Infants were monitored for NAS and treated according to institutional protocol. Forty-four (63%) of the infants were pharmacologically treated for NAS, with a mean length of hospital stay (LOS) for all infants of 14.2 (SD 9.0) days. The mean cortisol level in the mothers was 131.8 pg/mg (SD 124.7). In bivariate analysis, higher maternal hair cortisol levels were associated with shorter infant LOS (R = −.26, p = .03) and fewer infant opioid treatment days (R = −.28, p = .02). Results were no longer statistically significant in regression models after adjusting for maternal opioid and smoking. In conclusion, we demonstrated the feasibility of hair cortisol assaying within the first few days after delivery in mothers with opioid use disorder as a novel marker for NAS. The findings suggest that maternal stress may impact the severity of infant opioid withdrawal.     

Examining the role of socioeconomic status and temperament in the hair cortisol levels of infants

Socioeconomic status (SES) appears to be an important contextual factor in children's developmental outcomes, including their responses to stress. However, some children are more susceptible to its effects than others. Hair cortisol is a newer method of assessing the activity of the HPA axis, providing cumulative cortisol levels. The present article examined whether temperament (negative emotionality) moderates the association between an SES index and the hair cortisol concentration (HCC) of infants. Sixty infants from 6 to 15 months of age were recruited, of which 49 had sufficient hair for cortisol analysis. The SES index was calculated from the education levels of the mothers, family income, and a scale measuring the quality of the home environment. Negative emotionality was measured with the three sub‐scales of the Infant Behavior Questionnaire (falling reactivity, distress to limitations, and fear). Among infants low in negative emotionality, there was no association between SES and cortisol. In contrast, among those high in negative emotionality, a significant association was obtained. These infants showed lower levels of HCC in lower‐SES environments. The findings suggest that there are individual differences in reacting to the environment, and low levels of cortisol (not high) were found in susceptible infants in lower‐SES families.     

Hair cortisol in the perinatal period mediates associations between maternal adversity and disrupted maternal interaction in early infancy

Existing literature points to the possibility that cortisol could be one link between maternal adversity and poorer parenting quality, but most studies have examined salivary cortisol concentrations rather than hair cortisol concentrations. The current study examined hair cortisol concentration (HCC) during the third trimester of pregnancy as a mediator between maternal adversity indicators (childhood abuse, severe mental illness, symptomatic functioning) and maternal caregiving behavior at 4 months postpartum. Forty-four women participated in the study: 30 with severe mental disorders, and 14 nonclinical controls. HCC was assessed during the third trimester of pregnancy (HCC-P) and at 4 months postpartum (HCC-4M). Sexual, physical, and emotional abuse were assessed by the Adverse Childhood Experiences Study Questionnaire. Maternal disrupted interaction was reliably coded from mother–infant video interactions during a Still-Face Procedure. Mediation models indicated that maternal HCC-P and HCC-4M mediated associations between maternal psychopathology (severe mental illness, symptomatic functioning) and maternal disrupted interaction at 4 months. Maternal HCC at 4 months also mediated associations between experienced childhood abuse and overall disrupted interaction. Our findings indicate that HCC may be a potential early biomarker for future caregiving challenges among mothers with severe mental illness and histories of childhood abuse.     

Maternal prenatal cortisol and the interaction of income and pre-pregnancy body mass index are independently associated with newborn cortisol

While extensive research has supported the developmental programming hypothesis regarding contributions of prenatal psychosocial or nutritional adversity to offspring stress physiology, fewer studies consider both exposures together with maternal stress physiology. This study examined newborn cortisol output during a stressor as a function of maternal pre-pregnancy health status and nutritional history (pre-pregnancy body mass index [PPBMI]), economic resources (household income), and maternal cortisol awakening response (mCAR) in late pregnancy. Participants were 102 mother-infant pairs from an economically and racial/ethnically diverse sample. Offspring salivary cortisol response to a neurobehavioral exam was assessed at 1 month. Income and maternal PPBMI were positively associated with mCAR in late pregnancy. mCAR was positively related to 1-month newborn cortisol response. The interaction of income and PPBMI was positively associated with newborn cortisol output during an exam at 1-month. Mothers with the highest PPBMI and lowest income had offspring with higher cortisol responses than offspring of mothers with higher income and lower PPBMI. There was no evidence of indirect mediation effects of predictors (PPBMI, income, and interaction) on infant cortisol via mCAR. The differential effects of the interaction of PPBMI and income suggest that these exposures influence infant cortisol output in the context of one another, independent of maternal pregnancy cortisol.     

Fetal motor activity and maternal cortisol

The contemporaneous association between maternal salivary cortisol and fetal motor activity was examined at 32 and 36 weeks gestation. Higher maternal cortisol was positively associated with the amplitude of fetal motor activity at 32 weeks, r(48) = .39, p < .01, and 36 weeks, r(77) = .27, p < .05, and the amount of time fetuses spent moving at 32 weeks during the 50 min observation period, r(48) = 33, p < .05. Observation of periods of unusually intense fetal motor activity were more common in fetuses of women with higher cortisol, Mann–Whitney U = 58.5. There were no sex differences in fetal motor activity, but the associations between maternal cortisol and fetal motor amplitude and overall movement were significantly stronger for male than female fetuses. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 505–512, 2009     

Emotion regulation and cortisol reactivity during a social evaluative stressor: A study of post-institutionalized youth

In the current study, we compared emotion regulation abilities between post-institutionalized (PI; N = 124) and never-institutionalized non-adopted (NA; N = 172) children and adolescents (7–15 years). We assessed cortisol reactivity and coded emotion regulation during the speech portion of Trier Social Stress Test (TSST-M). Parents reported on their children's social, academic, and behavioral adjustment. Results suggest that emotion regulation abilities increased with age, but this increase was greater for NA than PI youth. With regard to cortisol, piecewise growth modeling revealed that at higher levels of emotion regulation PI youth had greater baseline values (after a period of time allowing for acclimation to the laboratory) and had steeper recovery slopes than NA youth. There was also a main effect of emotion regulation on the reactivity slope suggesting that for both groups, as emotion regulation increased, the cortisol reactivity slope decreased. Finally, greater emotion regulation predicted fewer internalizing behavior problems for PI youth but not for NA youth.     

Cortisol secretion moderates the association between mother–infant attachment at 17 months and child behavior at age 5 years

This study examined infant cortisol secretion as a moderator of the association between mother–infant attachment security at age 17 months and child behavior at age 5 years. A longitudinal community sample of 96 mother–child dyads participated in the strange situation procedure (SSP) at age 17 months. Cortisol was collected at baseline, and at 20 and 40 min post-SSP. Maternal reports of child behavior were collected at age 5 years. Results revealed that the associations between nonsecure mother–infant attachment and higher total, internalizing, and externalizing behavior were stronger for infants with high cortisol secretion, relative to infants with low cortisol secretion. The model of interaction differed depending on the outcome, with diathesis-stress explaining variance in total as well as internalizing behavior, and with differential susceptibility explaining variance in externalizing behavior. These findings augment our understanding of risk and resilience to the impact of the early rearing environment on later psychopathology.     

The relation between maternal emotional support and child physiological regulation across the preschool years

Trajectories of baseline RSA (respiratory sinus arrhythmia), an index of reactivity, and vagal withdrawal, an index of regulation, across the preschool period were examined. In addition, maternal emotional support was investigated as a potential time‐varying predictor of these trajectories. Physiological measures were obtained during frustration tasks, and a maternal emotional support measure was assessed via maternal report and direct observation. Children's baseline RSA and vagal withdrawal scores were moderately stable across the preschool period. Growth models indicated that children's baseline RSA scores changed linearly over the preschool years, and there was significant variability in withdrawal trajectories. Greater maternal emotional support predicted higher initial withdrawal levels and lower emotional support was associated with the greatest increase in withdrawal over time. This suggests that children of higher emotionally supportive mothers reached higher levels of physiological regulation earlier in development and therefore did not show the same increase across preschool as children of less supportive mothers. Maternal emotional support was not significantly related to trajectories of baseline RSA. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 382–394, 2013