Social niche shapes social behavior and cortisol concentrations during adolescence in female guinea pigs

Individualized social niches arise in social groups, resulting in divergent social behavior profiles among group members. During sensitive life phases, the individualized social niche can profoundly impact the development of social behavior and associated phenotypes such as hormone (e.g. cortisol) concentrations. Focusing on adolescence, we investigated the relationship between the individualized social niche, social behavior, and cortisol concentrations (baseline and responsiveness) in female guinea pigs. Females were pair-housed in early adolescence (initial social pair formation), and a social niche transition was induced after six weeks by replacing the partner with either a larger or smaller female. Regarding social behavior, dominance status was associated with aggression in both the initial social pairs and after the social niche transition, and the results suggest that aggression was rapidly and completely reshaped after the social niche transition. Meanwhile, submissive behavior was rapidly reshaped after the social niche transition, but this was incomplete. The dominance status attained in the initial social pair affected the extent of submissive behavior after the social niche transition, and this effect was still detected three weeks after the social niche transition. Regarding cortisol concentrations, higher baseline cortisol concentrations were measured in dominant females in the initial social pairs. After the social niche transition, cortisol responsiveness significantly increased for the females paired with a larger, older female relative to those paired with a smaller, younger female. These findings demonstrate that the social niche during adolescence plays a significant role in shaping behavior and hormone concentrations in females.

Cortisol reactivity to a laboratory stressor predicts increases in depressive symptoms in perinatal and nulliparous women during population-level stress

BACKGROUND

Research suggests a link between stress and depression, especially in high-risk groups. The perinatal period is known as a time of increased risk for depression and pregnancy has been associated with alterations in cortisol levels; however, limited research has assessed cortisol reactivity during pregnancy. Finally, no studies have yet examined whether cortisol reactivity predicts later depressive symptoms during a population-level stressor, such as the COVID-19 pandemic.

METHODS

The current study examined whether cortisol reactivity in perinatal and nulliparous women a year before the onset of COVID-19 predicted increases in depressive symptoms during the initial stage of the pandemic. Participants were 68 women (33 pregnant, Mage = 30.6; 35 nulliparous, Mage = 28.4) who, approximately a year before COVID-19, responded to a depressive symptoms questionnaire and completed a psychosocial stress test, during which they provided salivary cortisol samples. Shortly after the onset of pandemic-related closures (April 2020; postpartum for previously pregnant participants), participants completed follow-up questionnaires assessing current depressive symptoms.

RESULTS

Analyses showed that cortisol reactivity at baseline predicted increases in depressive symptoms at follow-up. Perinatal and nulliparous women did not differ in this association.

LIMITATIONS

The present study was limited by a moderate sample size and heterogeneity in terms of gestational week, restricting inferences about specific stages of pregnancy.

CONCLUSIONS

Our findings suggest that cortisol reactivity to a laboratory stressor is a biomarker of risk for increased depressive symptoms during ecological stress in women. Biomarkers like these increase our understanding of depression risk and may help to identify individuals in need of interventions.

Daily stress and eating behaviors in adolescents and young adults: Investigating the role of cortisol reactivity and eating styles

Stress-related eating has been well documented in previous literature. However, there is limited research investigating the role of cortisol reactivity in daily stress-eating associations in samples of adolescents and young adults. 123 participants completed a baseline questionnaire and the Trier Social Stress Test in groups. Four saliva samples were taken at - 10, + 00, + 10 and + 40 min during the stress-induction task. Following this, participants completed an online daily diary each evening for 14 consecutive days to record daily stress and between-meal snack consumption. Multilevel modelling indicated that daily stress was positively associated with daily snack intake, particularly for ego-threatening and work/academic stressors. Emotional and external eating styles were found to moderate the stress-snacking relationship. Cortisol reactivity also moderated stress-eating associations, such that as cortisol reactivity levels increased from lower to higher levels, the impact of stress on eating decreased. The current findings highlight the importance of cortisol reactivity status and eating styles in understanding the complex relationship between daily stress and eating behavior in adolescents and young adults. Future research should continue investigating stress-eating associations in these groups and explore the role of other aspects of hypothalamic-pituitary-adrenal axis functioning.

Vulnerability to anxiety differently predicts cortisol reactivity and state anxiety during a laboratory stressor in healthy girls and boys

BACKGROUND

Children diagnosed with anxiety disorders show altered cortisol and state anxiety reactivity to stressful situations. To date, it remains unclear whether these dysregulations emerge after the pathology or whether they are also detectable in healthy children. If the latter is true, this may provide insight into children's vulnerability to develop clinical anxiety. Various personality factors (anxiety sensitivity, intolerance of uncertainty, perseverative cognitions) increase youth's vulnerability to develop anxiety disorders. This study aimed to examine whether vulnerability to anxiety was associated with cortisol reactivity and state anxiety in healthy youth.

METHODS

114 children (8-12 y/o) were exposed to the Trier Social Stress Test for Children (TSST-C), where saliva samples were collected for cortisol quantification. State anxiety was assessed 20 min before and 10 min after the TSST-C using the state form of the State-Trait Anxiety Inventory for Children. Vulnerability to anxiety was assessed using a composite score of the Childhood Anxiety Sensitivity Index, Intolerance of Uncertainty Scale for Children, and Perseverative Thinking Questionnaire.

RESULTS

Higher vulnerability to anxiety was associated with enhanced cortisol reactivity in boys. Irrespective of vulnerability level, girls reported greater changes in state anxiety in response to the TSST.

LIMITATIONS

Given the correlational nature of this study, the directionality of the results remains to be elucidated.

CONCLUSIONS

These results indicate that endocrine patterns characterizing anxiety disorders are detectable in healthy boys who exhibit a high level of self-reported vulnerability to anxiety. These results could aid in the early identification of children at risk of developing anxiety disorders.

Cortisol reactivity and negative affect among preterm infants at 12 months during a mother-infant interaction task

The purpose of this study was to investigate correlates of preterm (PT) infant's cortisol reactivity and the association to infant negative affect, during a mother-infant interaction procedure. Participants included 48 infants born prematurely (gestational age < 37 weeks) and their mothers, assessed when infants were 12 months old corrected for prematurity. The examined variables comprised both neonatal and environmental dimensions including maternal interactive behavior. Infant negative affect and maternal interactive behavior were assessed with a standardized mother-infant interaction task. A baseline infant saliva sample was collected before the interaction began, and a second sample after the interaction episodes ended. Results revealed that decrease of infant's cortisol concentration was significantly associated with the exposure to more sensitive, and less intrusive maternal behaviors. However, once controlled for neonatal risk, family SES and maternal psychological distress, the associations were rendered non-significant. Although the association between cortisol reactivity and negative affect trended toward significance, maternal intrusiveness was the only significant predictor of observed infant negative affect. Findings suggest the importance of primary relational experiences on PT infants' early regulatory competencies.

Cortisol reactivity impairs suppression-induced forgetting

To some extent, we can shape our recollections by intentionally remembering certain experiences while trying to forget others, for example, by intentional suppression. Acute stress impairs suppression-induced forgetting of memories. It is unclear, however, whether these deficits are a direct consequence of the acute stress-induced cortisol response. The present study was designed to examine the stress-induced impairment in suppression-induced forgetting in a subgroup of cortisol responders. We exposed healthy participants to a stress (n = 55) or no-stress control (n = 32) version of the Maastricht Acute Stress Test before they performed the Think / No-Think task. Here, participants aimed to repeatedly retrieve or suppress memories of previously learned cue-target video clips to mimic the complexity of episodic memories. Results on the subsequent memory test revealed that, while the no-stress controls and cortisol non-responders demonstrated suppression-induced forgetting, this effect was absent in cortisol responders. Moreover, the magnitude of suppression-induced forgetting was negatively correlated to stress-induced cortisol increases. The current study extends findings on stress-induced impairments in suppression-induced forgetting by specifically focusing on cortisol reactivity. Furthermore, our findings show the importance of individual differences in cortisol responses as a driving mechanism behind stress-induced alterations in our capacity to actively control our memory.

Additive serotonergic genetic sensitivity and cortisol reactivity to lab-based social evaluative stress: Influence of severity across two samples

Prior work demonstrates that an additive serotonergic multilocus genetic profile score (MGPS) predicts amplified risk for depression following significant life stress, and that it interacts with elevations in the cortisol awakening response to predict depression. The serotonin system and HPA-axis have bidirectional influence, but whether this MGPS predicts acute cortisol reactivity, which might then serve as a mechanism for depression, is unknown. Our prior work suggests that depression risk factors predict blunted cortisol reactivity to explicit negative evaluative lab-based stress. Thus, we hypothesized that a 4-variant serotonergic MGPS (three SNPs from the original 5-variant version plus 5HTTLPR) would predict blunted cortisol reactivity to explicit negative evaluative stress versus a control. In Sample 1, growth curve modeling showed that the MGPS predicted heightened cortisol reactivity (p = 0.0001) in an explicitly negative evaluative Trier Social Stress Test variant (TSST) versus a control condition among non-depressed emerging adults (N = 152; 57% female). In Sample 2, 125 males completed the Socially Evaluative Cold Pressor Test (SECPT), an ambiguously negative evaluative manipulation; findings displayed a similar pattern but did not reach statistical significance (ps.075-.091). A participant-level meta-analysis of the two samples demonstrated a significant effect of negative evaluation severity, such that the MGPS effect size on reactivity increased linearly from control to SECPT to an explicitly negative evaluative TSST. Findings indicate that this MGPS contributes to sensitivity to social threat and that cortisol dysregulation in the context of social stress may be one mechanism by which this MGPS contributes to depression.

Interactions between genetic, prenatal, cortisol, and parenting influences on adolescent substance use and frequency: A TRAILS study

INTRODUCTION

Dynamic relations between genetic, hormone, and pre- and postnatal environments are theorized as critically important for adolescent substance use but are rarely tested in multifactorial models. This study assessed the impact of interactions of genetic risk and cortisol reactivity with prenatal and parenting influences on both any and frequency of adolescent substance use.

METHODS

Data are from the TRacking Adolescents' Individual Lives Survey (TRAILS), a prospective longitudinal, multi-rater study of 2,230 Dutch adolescents. Genetic risk was assessed via 3 substance-specific polygenic scores. Mothers retrospectively reported prenatal risk when adolescents were 11 years old. Adolescents rated their parents' warmth and hostility at age 11. Salivary cortisol reactivity was measured in response to a social stress task at age 16. Adolescents' self-reported cigarette, alcohol, and cannabis use frequency at age 16.

RESULTS

A multivariate hurdle regression model showed that polygenic risk for smoking, alcohol, and cannabis predicted any use of each substance, respectively, but predicted more frequent use only for smoking. Blunted cortisol reactivity predicted any use and more frequent use for all 3 outcomes. There were 2 interactions: blunted cortisol reactivity exacerbated the association of polygenic risk with any smoking and the association of prenatal risk with any alcohol use.

CONCLUSION

Polygenic risk seems of importance for early use but less so for frequency of use, whereas blunted cortisol reactivity was correlated with both. Blunted cortisol reactivity may also catalyze early risks for substance use, though to a limited degree. Gene-environment interactions play no role in the context of this multifactorial model.

Cortisol Reactivity as a Mediator of Peer Victimization on Child Internalizing and Externalizing Problems: The Role of Gender Differences

Children exposed to peer victimization are at increased risk for psychopathology. However, the physiological mechanisms linking peer victimization to child psychopathology and the potential gender differences in these links remain inadequately understood. The present study examined whether cortisol reactivity to acute stress mediated the associations between relational and physical victimization and internalizing and externalizing problems and whether these associations differed between boys and girls. A sample of 150 Chinese children (aged 9-13 years; M_age = 10.69 years; 51% boys) reported experiences of relational and physical victimization and participated in a standardized laboratory psychosocial stress task, during which six salivary cortisol samples were collected. Parents or primary caregivers reported their children's internalizing and externalizing problems. Overall, neither physical nor relational victimization was associated with cortisol reactivity. However, when examined separately by gender, relational victimization was associated with blunted cortisol reactivity for boys but not for girls. Further, among boys but not girls, relational victimization was indirectly associated with internalizing and externalizing problems via blunted cortisol reactivity. Our findings suggest that blunted cortisol reactivity may serve as a physiological pathway linking peer victimization to psychopathology for boys but not for girls.

Genetic and environmental influences on cortisol reactivity to a psychosocial stressor in adolescents and young adults

Individuals vary in their response to psychological and physiological stressors, and this reactivity can be captured using measures of cortisol. Previous research suggests cortisol reactivity is under some degree of genetic control; however, the measures used have varied widely. This study (N = 524) examined potential differences in heritability across varying cortisol metrics of stress reactivity following the Trier Social Stress Test (TSST) and whether these measures are genetically or environmentally interrelated. Participants included twins aged 15-20 years (56% female). Cortisol reactivity to the TSST was assessed via serial salivary cortisol samples collected pre- and post-TSST. Modest to moderate heritability estimates (12% [95CI: 1-36%] - 45% [95CI: 16-69%]) were observed across measures purported to capture stress reactivity (peak, area under the curve [AUC], baseline-to-peak change). Findings also demonstrate both shared and unique genetic and environmental influences between baseline cortisol and cortisol reactivity. Minimal to no additional genetic innovations above and beyond the contributions of peak cortisol were found for other measures of cortisol reactivity such as AUC. This study is one of the largest twin-based samples to examine the heritability of cortisol reactivity, and results suggest that simpler measures of cortisol reactivity demonstrate higher heritability compared to more complex measurements.

A preliminary study of gut microbiome variation and HPA axis reactivity in healthy infants

The Hypothalamic Pituitary Adrenal (HPA) axis regulates hormonal responses to stress in both humans and animals and is dysregulated in a wide range of psychiatric disorders. There is strong evidence from rodent studies that gut microbial composition influences HPA axis development. In humans, variation in the gut microbiome has been associated with several psychological domains including depression and cognitive development, but studies focused on HPA axis development are still lacking. We tested whether differences in microbial composition are associated with HPA axis reactivity in a pilot study of 34 healthy human infants. HPA axis reactivity was assessed by measuring salivary cortisol in samples taken both before and after a heel stick, and 16S rRNA amplicon sequencing was used for identification and relative quantification of bacterial taxa. Subjects' alpha diversity levels showed a moderate positive association with their cortisol reactivity at one month of age. Exploratory genus-level analyses suggest that Staphylococcus, Prevotella, and genera in the order Lachnospiraceae may be related to cortisol reactivity at one month as well. The current study gives support for the endocrine pathway as a potential mediator in the microbiome-gut-brain axis during infancy, and as such provides motivation for future clinical work to support the development of stress-response systems through the manipulation of gut microbes.

Early childhood adversity and HPA axis activity in adulthood:The importance of considering minimal age at exposure

Early adversity (EA) modulates stress hormone secretion in mixed directions. The Accumulation Model suggests that the number of EA predicts patterns of cortisol dysregulations, while the Life Cycle Model of Stress highlights the importance of considering the timing at which EA began, given that brain regions sensitive to stress hormones follow distinct developmental trajectories. We aimed to test these two models in 85 healthy men and women, aged 21-40 years old who reported having been exposed to EA during childhood. Participants were grouped based on the number of EA events to which they were exposed during their lifespan (Accumulation Model) and the age of first exposure to EA (Life Cycle Model). Diurnal and stress-induced reactive cortisol secretion were measured in all participants. Results showed that although the number of EA was not associated with patterns of basal or reactive cortisol secretion, adults first exposed to EA between the ages of 3 and 7 - an important time window for amygdala development - showed greater cortisol awakening response and lower cortisol reactivity relative to those first exposed to EA before 3 or after 7. These results provide support for the Life Cycle Model of Stress and highlight the importance of considering minimal age at exposure to EA when assessing the effects of early adversity on patterns of cortisol secretion.

PTSD symptoms and cortisol stress reactivity in adolescence: Findings from a high adversity cohort in South Africa

BACKGROUND

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is implicated in the pathophysiology of post-traumatic stress disorder (PTSD). However, there has been little study of HPA stress reactivity in association with PTSD symptoms (PTSS) in children; and there is limited research on PTSD in low and middle-income countries, where trauma exposure is more common and co-occurring stressors more likely.

METHOD

We assessed the relationship between PTSS and cortisol stress reactivity in children aged 13 years (N = 291) from an impoverished South African community. HPA axis stress reactivity was indexed by salivary cortisol during the Trier Social Stress Test (TSST).

RESULTS

In regression analyses both trauma exposure and PTSS showed small inverse associations with total cortisol output (area under the curve with respect to ground) during the TSST, but PTSS effects did not withstand correction for covariates. In addition, hierarchical linear modelling (HLM) found that PTSS were associated with alterations in the shape of the profile of cortisol reactivity that were moderated by sex. In girls, PTSS were associated with reduced linear slope but larger quadratic slopes, whereas the opposite pattern was found in boys. Thus, elevated PTSS were associated with overall blunted profiles of cortisol stress reactivity in girls, but a larger quadratic slope in boys reflects a steeper cortisol increase and decline in boys. There was no relationship between trauma exposure (with or without PTSS) and cortisol reactivity profiles in HLM analyses.

CONCLUSION

In children from a high adversity, low and middle income country context, sex specific associations were found between PTSS and cortisol responses to psychosocial stress. Further research should probe HPA axis functioning more comprehensively in such populations to understand the biological associations of PTSS.

Pain response to vaccination in newborn infants of diabetic mothers

BACKGROUND

Response to pain is altered in infants who were exposed to pain- and stressful events in the neonatal period. Infants of diabetic mothers receive several heel sticks after birth for measuring blood glucose and thus may show changes in their behavioral and physiologic response to pain. Moreover, maternal hyperglycemia may alter activity of the hypothalamic pituitary adrenal (HPA) axis reactivity.

STUDY DESIGN

In total, 43 infants of diabetic mothers and 30 control infants were included into the study. Response to pain was assessed at 3 months of age following two intramuscular injections for vaccination. We assessed behavioral (Bernese pain scale), physiologic (heart rate) and hormonal (salivary cortisol) pain response to vaccination as well as spinal sensitization (flexion withdrawal reflex).

RESULTS

Infants of diabetic mothers received a median number of 5 [4-19] painful events compared to 1 [1-3] in the control group. Heart rate reactivity differed significantly between groups. Infants of diabetic mothers had higher peaks (p = 0.002) and needed more time to recover to baseline (p < 0.001). Moreover, infants of diabetic mothers showed higher peak cortisol (p = 0.001) and a higher relative cortisol increase (p = 0.015). Flexor withdrawal reflex thresholds were significantly lower in infants of diabetic mothers (p = 0.003).

CONCLUSION

The increase of physiologic and hormonal responses to pain in infants of diabetic mothers is probably caused by repeated painful events and an altered metabolic profile.

Stress-induced cortisol reactivity as a predictor of success in treatment for affective dimensions

BACKGROUND

Response rates to first-line treatments for depression and anxiety remain unsatisfactory. Identification of predictors or moderators that can optimize treatment matching is of scientific and clinical interest. This study examined the role of prolonged laboratory-induced stress cortisol reactivity as a predictor of outcome for a treatment of affective dimensions (TAD). Patients received 15-sessions of a treatment targeting reductions in negative affect or increases in positive affect (Craske et al., 2019). A second aim was to examine whether treatment type would moderate the association between cortisol reactivity and treatment outcome.

METHODS

Thirty-five participants underwent a 36-minute intermittent stress induction task composed of a mental arithmetic task and a fear-potentiated startle task one week before treatment initiation. Cortisol was collected at five-time points with reactivity being quantified as peak during the task minus basal level of cortisol the evening before the assessment. Using multilevel modeling, we examined the associations between cortisol reactivity and slopes of symptom improvement.

RESULTS

Cortisol reactivity was related to treatment outcome, with average and higher levels of stress-induced cortisol response predicting greater decreases in symptoms throughout treatment and 6-month follow-up. Treatment condition differences (moderation) were not observed in the effect of cortisol reactivity on symptoms.

CONCLUSION

Our findings demonstrate the impact of greater cortisol stress reactivity on treatment outcome. Future studies should investigate how to enhance this therapeutic benefit through capitalizing on endogenous diurnal fluctuations or exogenous cortisol manipulation.

Stress, cortisol and suicide risk

Suicide is a global health issue accounting for at least 800,000 deaths per annum. Numerous models have been proposed that differ in their emphasis on the role of psychological, social, psychiatric and neurobiological factors in explaining suicide risk. Central to many models is a stress-diathesis component which states that suicidal behavior is the result of an interaction between acutely stressful events and a susceptibility to suicidal behavior (a diathesis). This article presents an overview of studies that demonstrate that stress and dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, are important additional risk factors for suicide. Evidence for other putative stress-related suicide risk factors including childhood trauma, impaired executive function, impulsivity and disrupted sleep are considered together with the impact of family history of suicide, perinatal and epigenetic influences on suicide risk.

Violence exposure and social deprivation is associated with cortisol reactivity in urban adolescents

The present study tested how two different dimensions of childhood adversity, violence exposure and social deprivation, were associated with the cortisol response to the Socially Evaluated Cold-Pressor task in a sample of 222 adolescents (n = 117 girls, n = 167 African American). Participants were part of the Fragile Families and Child Wellbeing Study, a probability sample of births in large US cities (>200,000) between 1998 and 2000. Our subsample includes births in three cities: Detroit, Toledo, and Chicago. The study design called for an oversampling of births to unmarried parents (3:1) which led to a large number of minority and economically disadvantaged adolescents. When children were ages 3, 5, and 9, mothers reported on exposures to violence and social deprivation that occurred in the past year. Exposures from the three waves were averaged to reflect violence exposure and social deprivation during childhood. Greater levels of violence exposure from ages 3 to 9 were associated with a blunted cortisol response to stress at age 15, even after controlling for social deprivation and other factors known to influence cortisol reactivity. Social deprivation from ages 3 to 9 was not associated with the cortisol response to stress; though in an exploratory analysis, social deprivation moderated the association between violence exposure and cortisol peak activation. In line with the Dimensional Model of Adversity and Psychopathology, these findings suggest that experiences of violence, but not social deprivation, during childhood may contribute to cortisol blunting that has been previously reported in samples with high levels of social deprivation. Findings from the present longitudinal study on a relatively large sample of under-represented minority youth provide insight into the ways two different dimensions of childhood adversity impact the cortisol response to stress.

Developmental Pathways from Genetic, Prenatal, Parenting and Emotional/Behavioral Risk to Cortisol Reactivity and Adolescent Substance Use: A TRAILS Study

Cortisol reactivity is a frequently studied biomarker of substance use, though infrequently examined in adolescence. However, past research provides evidence that multiple developmental influences, including genetics and both prenatal and postnatal environmental influences, contribute both to cortisol reactivity and adolescent substance use. The aim of this study was to assess the impact of these earlier developmental influences on cortisol reactivity to a social stress challenge and adolescent substance use (smoking, alcohol, and marijuana use frequency assessed at age 16 years), using data from the TRacking Adolescents' Individual Lives Survey (TRAILS; N= 2230 adolescents, 51% female). Developmental pathways included polygenic risk, prenatal stress, warm parenting (age 11), and internalizing and externalizing problems (intercepts and change from 11-16 years). Cortisol reactivity was associated with smoking but not alcohol or marijuana use. Externalizing problems were the stronger predictor of adolescent substance use, but internalizing problems also had an important role. Prenatal stress and middle childhood parenting operated via middle childhood externalizing problems, and parenting also operated via trajectories of growth of externalizing problems in predicting adolescent substance use outcomes. Further, there were protective effects of internalizing problems for alcohol and marijuana use in the context of a more comprehensive model. These developmental influences did not attenuate the association of cortisol reactivity and smoking. These findings suggest a need to understand the broader developmental context regarding the impact of internalizing pathways to substance use, and that it is unlikely that cortisol reactivity and smoking are associated solely because of common developmental influences.

Lasting effects of stress physiology on the brain: Cortisol reactivity during preschool predicts hippocampal functional connectivity at school age

Prolonged exposure to glucocorticoid stress hormones, such as cortisol in humans, has been associated with structural and functional changes in the hippocampus. The majority of research demonstrating these associations in humans has been conducted in adult, clinical, or severely maltreated populations, with little research investigating these effects in young or more typically developing populations. The present study sought to address this gap by investigating longitudinal associations between preschool (3−5 years) and concurrent (5–9 years) cortisol reactivity to a laboratory stressor and hippocampal functional connectivity during a passive viewing fMRI scan. Results showed that, after controlling for concurrent cortisol reactivity, greater total cortisol release in response to a stressor during preschool predicted increased anterior and posterior hippocampal connectivity with the precuneus and cingulate gyrus at school-age. These findings are consistent with literature from adult and non-human investigations and suggest lasting impacts of early stress physiology on the brain.

Cognitive, neural and endocrine functioning during late pregnancy: An Event-Related Potentials study

This study investigated cognitive, neural and endocrine function during late pregnancy. One of the first to examine brain ERPs in pregnant women, the study is unique in its focus on response inhibition function. In the study, cognitive function was evaluated by a digit-symbol coding test, an arithmetic ability test, and a visual stop-signal task which places enhanced demands on impulse control and response inhibition, considered a hallmark of executive function. Brain activity was measured by scalp-recorded Event-Related Potentials (ERPs) during the stop-signal task. HPA axis reactivity was assessed by measuring salivary cortisol levels before and after experimental sessions. Test performance, ERPs and cortisol reactivity were compared across groups of 23 women in their third trimester of pregnancy and 22 non-pregnant controls. Pregnant women scored lower than the control group on the digit-symbol coding test. On the stop-signal task, both groups had similar error rates, but pregnant women had longer response times to Go trials. On the Stop condition of the task in which a response must be inhibited, pregnant women demonstrated significantly better performance. At the electrophysiological level, in response to Go stimuli pregnant women exhibited greater amplitude of P2 than controls. In response to Stop-signals, pregnant women had lesser amplitudes of P1 and N2 and greater amplitude of P3. Cortisol reactivity to the test session was significantly more pronounced in non-pregnant women with significant correlations found between cortisol reactivity and behavioral responses. The results suggest that response patterns of women in late pregnancy are less impulsive and more cautious and controlled.

Extending the toxic stress model into adolescence: Profiles of cortisol reactivity

The toxic stress model posits that extended activation of stress response systems in the absence of a supportive relationship with an adult may over time lead to physiological alterations to these same systems, and ultimately to poorer physical and mental health outcomes. However, empirical tests of model hypotheses in adolescence, a critical period of development, are lacking. This study expands the toxic stress model to include more developmentally-appropriate risk and protective factors for adolescents experiencing overwhelming and uncontrollable stressors. Data were collected for a study of early adolescents from urban low-income households (N = 101; 10-12 years old; 59% female). Participants and a caregiver completed questionnaires; youths completed the modified Trier Social Stress Task alone and provided six saliva samples. Using latent profile analysis, three profiles of cortisol reactivity were identified in early adolescents exposed to chronic environmental stress: Elevated and Reactive (11%), Moderate and Non-Reactive (26%), and Blunted and Non-Reactive (63%). In accordance with the toxic stress model, exposure to more community violence and less family support were associated with blunted cortisol reactivity, and Reactive profile membership was associated with fewer trauma symptoms. Overall, the findings provide empirical support for the extension of the toxic stress model in early adolescence through the application of developmentally-sensitive measures and provide implications for future interventions.

Influence of early adversity on cortisol reactivity, SLC6A4 methylation and externalizing behavior in children of alcoholics

BACKGROUND

Children of parents with alcoholism face considerable stress, and often have externalizing behaviors. Early adversity is known to affect DNA methylation and the functioning of the HPA axis. We investigated the association of early adversity with cortisol reactivity, 5HTTLPR genotype, site specific DNA methylation in the SLC6A4 gene and externalizing behavior in children of alcoholics (COA), and a matched sample of control children.

METHODS

We examined children of alcoholics (N = 50) and age matched control children (N = 50) for exposure to early adversity (both prenatal and postnatal), assessed their salivary cortisol reactivity and evaluated their levels of emotional and behavioral difficulty in terms of externalizing and internalizing behavior. Site-specific DNA methylation at a previously characterized SLC6A4 region was determined in salivary DNA using pyrosequencing. The 5HTTLPR region of the SLC6A4 gene was also genotyped.

RESULTS

COA had significantly higher experience of early adversity than control children. Cortisol reactivity was reduced in COA, and negatively correlated with early adversity. Both early adversity and cortisol reactivity correlated with externalizing behavior. SLC6A4 methylation was higher in COA, and correlated with early adversity. SLC6A4 genotype did not show association with any of the variables.

CONCLUSION

Our study provides further evidence that early adversity is associated with blunted cortisol reactivity, increased site-specific CpG DNA methylation at the SLC6A4 gene, and high externalizing behavior.

The Moderating Role of Cortisol Reactivity on the Link Between Maltreatment and Body Mass Index Trajectory Across Adolescence

PURPOSE

Child maltreatment increases risk for obesity, yet differential effects of maltreatment type remain unclear. Cortisol reactivity may help clarify these effects, given links among cortisol reactivity, maltreatment, and obesity. We examined these associations in boys and girls across adolescence.

METHODS

We collected data from 454 adolescents (212 girls) across four waves (aged 8-13 years at Time 1), including 303 maltreated youth. We modeled body mass index (BMI) percentile trajectories arrayed by age separately for boys and girls and tested whether cortisol reactivity at Time 1 moderated the association between maltreatment type and BMI growth.

RESULTS

In girls, cortisol reactivity moderated the association between maltreatment type and quadratic change in BMI. At low levels of cortisol, sexually abused girls had a steeper quadratic increase in BMI compared with comparison (-.65, 95% confidence interval [CI] -1.09 to -.22) and physically abused (-.76, 95% CI -1.29, -.24) girls. At high levels of cortisol, sexually abused girls did not differ from comparison (.15, 95% CI -.40 to .70) or physically abused (.21, 95% CI -.38 to .80) girls in quadratic change in BMI. In boys, cortisol reactivity did not moderate the association between maltreatment type and BMI growth.

CONCLUSIONS

The combination of lower cortisol reactivity and sexual abuse may put girls at risk for BMI increase during later adolescence. Given the negative consequences of high BMI, identifying and intervening with these girls could lead to better health and well-being among this group. Cortisol reactivity may not play the same role among boys.

Repressors exhibit lower cortisol reactivity to group psychosocial stress

Repressors are well-known to monitor potential psychosocial threats to their self-esteem and self-concept. In research, repressors are traditionally categorised as those scoring low on trait anxiety and high on defensiveness (as measured by social desirability scales). Examining repressors' cortisol reactivity to a group socio-evaluative laboratory stressor could be an important way to extend work on the classic 'repressor dissociation', which proposes that this group experience higher levels of physiological stress, but lower levels of subjective affect, during stressful situations. Research however has focused mainly on repressors' higher, more risk-prone levels of autonomic, rather than hypothalamic-pituitary-adrenal (HPA), reactivity to stressful stimuli. We assessed cortisol reactivity using a group-based acute psychosocial stressor, the Trier Social Stress Test for groups (TSST-G), which required participants to individually perform public speaking and mental arithmetic tasks in front of up to six other group members, as well as an evaluative panel of judges. Seventy-seven healthy young females (mean age ± SD: 20.2 ± 3.2 years) took part, of which 64 met the conventional criterion for a response to the TSST-G (<15.5% increase from baseline sample). The Stress-Arousal Checklist was completed pre- and post-TSST-G. Participants also completed the Perceived Stress Scale, the Trait Anxiety Inventory and the Marlow-Crowne Social Desirability Scale. The latter two measures were used to provide a categorisation of repressive coping style. Participants identified as repressive copers exhibited significantly lower cortisol reactivity during the TSST-G. Repressors also self-reported less subjective stress. These findings provide some evidence against the notion of the repressor dissociation and are discussed in terms of how cortisol hyporeactivity may be a pathway through which repressive coping adversely affects health.

Improving infants' stress-induced cortisol regulation through attachment-based intervention: A randomized controlled trial

Attachment-based parenting interventions have shown positive effects on early cortisol regulation, a key biomarker. Evaluations to date have focused on diurnal cortisol production in high-risk infants. It is important to understand whether attachment-based intervention may also improve stress-induced cortisol production in typically developing infants. This randomized controlled trial tested an enhanced model of U.S. Early Head Start (EHS) services that combined home-based EHS with a brief, attachment-based parenting intervention, Attachment and Biobehavioral Catch-up (ABC). The trial included 153 low-income mothers and their infants (M age 12.4 months [SD = 4.1]). Control participants received home-based EHS plus 10 weekly books. Intent-to-treat analyses using multilevel models revealed a significant indirect intervention effect on infants' rates of cortisol change in response to a series of mild stressors. The intervention increased maternal sensitivity, which in turn improved cortisol regulation, particularly infants' rates of cortisol recovery. The findings illustrate the efficacy of EHS plus ABC for supporting infants' stress-induced cortisol regulation and implicate sensitive maternal behavior as the underlying driver of the intervention effect. Findings are discussed in terms of the preventative value of attachment-based parenting interventions that improve both parenting and infants' physiological regulation.

Basal cortisol, cortisol reactivity, and telomere length: A systematic review and meta-analysis

The objective of the present study is to synthesize the existing empirical literature and perform a meta-analysis of published data on the relationship between cortisol and telomere length. We systematically searched studies that examined the relationship between cortisol and telomere length in humans on electronic databases and screened reference sections of included articles. Fourteen studies were included in the meta-analysis, with effect sizes being extracted for two cortisol measures: basal cortisol levels and cortisol reactivity to acute psychological stress. Results from random effects models showed that basal cortisol levels (13 effect sizes from 12 cross-sectional studies, N = 3675 participants) were not significantly correlated with telomere length (r =-0.05, 95% CI [-0.11, 0.02]). Further, results stratified by the specimen type for cortisol measurement (i.e., saliva, urine, blood) showed that none of the three basal cortisol level measures were correlated with telomere length. However, we found a statistically significant correlation between salivary cortisol reactivity to acute psychosocial stress (6 cross-sectional studies, N = 958 participants) and telomere length (r = -0.13, 95% CI [-0.23, -0.03]). Subgroup analyses revealed that correlations between salivary cortisol reactivity and telomere length were more evident in studies conducted among children (vs. adults) and in studies that included female participants only (vs. both genders). However, the small number of available studies limits the conclusions derived from subgroup analyses, and more studies are needed before moderator effects can be properly established. Overall, findings of this study support the existence of a relationship between cortisol reactivity and telomere shortening.

A meta-analytic review of the association between cortisol reactivity in response to a stressor and attention-deficit hyperactivity disorder

A substantial literature suggests that abnormal cortisol reactivity may be a vulnerability for deleterious mental health outcomes, including ADHD. ADHD has been linked with difficulty in emotion regulation and increased risk of experiencing stressors, both of which may be related to psychobiological abnormalities (e.g., abnormal cortisol reactivity). Research has been mixed regarding the association between cortisol reactivity and ADHD. Therefore, the present meta-analytic review (k = 12) sought to quantify this association and review the relevant methodological issues and theoretical implications of this area of research. Overall, no effect was found between cortisol reactivity and ADHD (r = 0), although significant heterogeneity in the analyses suggested that there might be moderators of this association, if one does exist. Results highlight the importance of addressing limitations of the current literature on cortisol reactivity and ADHD and exploring additional indices of emotion regulation that may be associated with ADHD. Implications for future research efforts are discussed.

The role of stress response in the association between autonomy and adjustment in adolescents

Developing autonomy is an important developmental task that has implications for adolescent adjustment and may be impacted by adolescents' response to stress. This study examined whether stress reactivity (i.e., cortisol and heart rate reactivity) to a parent-adolescent conflict interaction moderates the effect of autonomy on adjustment assessed one year later in 100 adolescents (M age = 15.09; 68% girls). Multiple group models suggested that youth who evidenced higher stress reactivity when compared to those with lower stress reactivity were more likely to report decreased externalizing problems and internalizing problems when their parents granted more autonomy. In contrast, youth who evidenced higher stress reactivity who experienced undermining of autonomy were more likely to report increased externalizing and internalizing problems than youth who evidenced lower stress reactivity. Results support biological sensitivity to context theory and highlight the importance of considering individual differences in the effect of developmental milestones on adolescents' adjustment.

Early Life Stress and Childhood Aggression: Mediating and Moderating Effects of Child Callousness and Stress Reactivity

Early life stress (ELS) has been implicated in the development of aggression, though the exact mechanisms remain unknown. This study tested associations between ELS, callousness, and stress reactivity in the prediction of school-age and persistent early childhood aggression. A longitudinal sample of 185 mother-child dyads completed a lab visit and mothers completed an online follow-up when children were preschool-aged and school-aged, respectively. Physiological and behavioral measures of stress reactivity were collected during the preschool period. Ratings of child aggressive behavior, ELS, and callousness were collected as well. The results suggested that ELS was related to measures of both school-age and persistent early childhood aggression, and that callousness had a mediating role in this process. Cortisol reactivity also moderated the association between ELS and persistent childhood aggression, such that the ELS-aggression relationship was stronger among children who had higher levels of cortisol reactivity during the preschool period. Clinical implications are discussed.

The Interactive Effects of Stressful Family Life Events and Cortisol Reactivity on Adolescent Externalizing and Internalizing Behaviors

This study investigated the associations between stressful family life events and adolescent externalizing and internalizing behaviors, and the interactive effects of family life events and cortisol reactivity on problem behaviors. In a sample of 100 mothers and their adolescents (M age = 15.09; SD age = .98; 68 % girls), adolescent cortisol reactivity was measured in response to a mother-adolescent conflict interaction task designed to elicit a stress response. Mothers reported on measures of family life events and adolescent problem behaviors. Results indicated that a heightened adolescent cortisol response moderated the relations between stressful family life events and both externalizing and internalizing behaviors. Results support context-dependent theoretical models, suggesting that for adolescents with higher cortisol reactivity (compared to those with lower cortisol reactivity), higher levels of stressful family life events were associated with greater problem behaviors, whereas lower levels of stressful family life events were related to fewer problem behaviors.

Cortisol reactivity and suicidal behavior: Investigating the role of hypothalamic-pituitary-adrenal axis responses to stress in suicide attempters and ideators

Every 40s a person dies by suicide somewhere in the world. The causes of suicidal behavior are not fully understood. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, is one potential risk factor. The current study aimed to investigate whether cortisol reactivity to a laboratory stress task differentiated individuals who had previously made a suicide attempt from those who had thought about suicide (suicide ideators) and control participants. One hundred and sixty participants were recruited to a previous attempt, a suicidal ideation or a control group. Participants completed background questionnaires before completing the Maastricht Acute Stress Test (MAST). Cortisol levels were assessed throughout the stress task. Measures of suicide behavior were measured at baseline, 1 month and 6 month follow-up. Participants who had made a previous suicide attempt exhibited significantly lower aggregate cortisol levels during the MAST compared to participants in the control group; suicide ideators were intermediate to both groups. This effect, however, was driven by participants who made an attempt within the past year, and to some degree by those with a family history of attempt. Participants who made a suicide attempt and had a family history of suicide exhibited the lowest levels of cortisol in response to stress. Finally, lower levels of cortisol in response to the MAST were associated with higher levels of suicidal ideation at 1-month follow-up in the suicide attempter group. These results are consistent with other findings indicating that blunted HPA axis activity is associated with some forms of suicidal behavior. The challenge for researchers is to elucidate the precise causal mechanisms linking stress, cortisol and suicide risk.

The beneficial effects of a positive attention bias amongst children with a history of psychosocial deprivation

Children raised in institutions experience psychosocial deprivation that has detrimental influences on attention and mental health. The current study examined patterns of attention biases in children from institutions who were randomized at approximately 21.6 months to receive either a high-quality foster care intervention or care-as-usual. At age 12, children performed a dot-probe task and indices of attention bias were calculated. Additionally, children completed a social stress paradigm and cortisol reactivity was computed. Children randomized into foster care (N=40) exhibited an attention bias toward positive stimuli but not threat, whereas children who received care-as-usual (N=40) and a never-institutionalized comparison group (N=47) showed no bias. Stability of foster care placement was related to positive bias, while instability of foster care placement was related to threat bias. The magnitude of the positive bias was associated with fewer internalizing problems and better coping mechanisms. Within the foster care group, positive attention bias was related to less blunted cortisol reactivity.

Psychological and cortisol reactivity to experimentally induced stress in adults with ADHD

Individuals with ADHD suffer from increased vulnerability to environmental and mental stressors and may be at increased risk for chronic stress in everyday life. The Hypothalamic-Pituitary-Adrenal (HPA) axis is a critical physiological system that mediates responses to stress. The present study seeks to examine test performance, test anxiety, self-reported psychological stress and cortisol reactivity to mental-cognitive stress in adults with ADHD when compared with healthy controls. Stress was induced by an arithmetic ability test. Psychological stress was assessed repeatedly throughout the experimental session. Salivary cortisol, an indicator of the HPA axis function, was evaluated immediately upon arrival, as well as 1 min and 20 min post-test completion. Results revealed higher levels of test anxiety and poorer performance on the test in the ADHD group. The ADHD and control groups showed no difference in base-line levels of subjective stress and in subjective stress levels 20 min after the test. In contrast, individuals with ADHD reported significantly higher levels of stress at the test anticipation phase and 1 min post-test completion. Cortisol response to stress differed according to group: in the ADHD group, 20 min post-test cortisol levels were significantly higher than base-line cortisol levels. This was not evident in the control group. These results suggest greater activation of the HPA axis in response to stress in adults with ADHD when compared with healthy controls. Adults with ADHD do not differ from controls in basal levels of subjective stress and cortisol, but do have stronger psychophysiological reactions in response to stressful challenges. The present findings are among the first to demonstrate significant alterations in cortisol reactivity to stress in adults with ADHD.

Prenatal maternal stress predicts stress reactivity at 2½ years of age: the Iowa Flood Study

Prenatal maternal stress (PNMS) predicts psychosocial development in offspring. It has been hypothesized that during PNMS, glucocorticoids pass the placenta, reaching the foetus, leading to a long-term reprogramming and dysregulation of the foetal hypothalamic-pituitary-adrenal (HPA) axis. However, results are inconsistent across PNMS studies. One problem may be the confounding of objective degrees of hardship due to the stressor and subjective degrees of distress in the mother. The present study investigated the association between objective and subjective PNMS due to a natural disaster, the June 2008 Iowa floods, and stress reactivity in the offspring at 2½ years of age. Women who were pregnant during the floods were recruited, on average, within three months of the floods and their stress levels assessed. Mothers and their toddlers (n = 94 dyads) participated in a brief mother-toddler separation to induce physiological stress responses in the offspring. Salivary cortisol samples were collected four times during the procedure. We computed absolute change in cortisol (baseline to 20-minute post-stressor; baseline to 45-minute post-stressor) and Area Under the Curve with respect to increase and ground (AUCi; AUCg). Objective and subjective PNMS were positively correlated with AUCi, as was timing in gestation: the later in pregnancy the exposure occurred, the greater the cortisol increase. Controlling for objective hardship and other covariates, sex-by-subjective PNMS interactions showed a significant and positive association between subjective PNMS and Absolute Increase (45 min) and AUCi in females only, with little effect in males. These results suggest that PNMS leads to long-term alterations in the functioning of the HPA axis, evident as early as 30-months of age.

Interactive effects of early and recent exposure to stressful contexts on cortisol reactivity in middle childhood

BACKGROUND

Given mixed findings as to whether stressful experiences and relationships are associated with increases or decreases in children's cortisol reactivity, we tested whether a child's developmental history of risk exposure explained variation in cortisol reactivity to an experimentally induced task. We also tested whether the relationship between cortisol reactivity and children's internalizing and externalizing problems varied as a function of their developmental history of stressful experiences and relationships.

METHOD

Participants included 400 children (M = 9.99 years, SD = 0.74 years) from the Children's Experiences and Development Study. Early risk exposure was measured by children's experiences of harsh, nonresponsive parenting at 3 years. Recent risk exposure was measured by children's exposure to traumatic events in the past year. Children's cortisol reactivity was measured in response to a social provocation task and parents and teachers described children's internalizing and externalizing problems.

RESULTS

The effect of recent exposure to traumatic events was partially dependent upon a child's early experiences of harsh, nonresponsive parenting: the more traumatic events children had recently experienced, the greater their cortisol reactivity if they had experienced lower (but not higher) levels of harsh, nonresponsive parenting at age 3. The lowest levels of cortisol reactivity were observed among children who had experienced the most traumatic events in the past year and higher (vs. lower) levels of harsh, nonresponsive parenting in early childhood. Among youth who experienced harsh, nonresponsive parent-child relationships in early childhood and later traumatic events, lower levels of cortisol reactivity were associated with higher levels of internalizing and externalizing problems.

CONCLUSIONS

Hypothalamic-pituitary-adrenal (HPA) axis reactivity to psychological stressors and the relationship between HPA axis reactivity and children's internalizing and externalizing problems vary as a function of a child's developmental history of exposure to stressful relationships and experiences.

The relation between gaze aversion and cortisol reactivity in middle childhood

The present study sought to investigate the relation between ethological observations of children's gaze aversion during a psychosocial stress task and their cortisol reactivity to the task, and how this relation might be moderated by how stressful the children perceived the stress task to be. Videos of 140 children (74 girls; Mage=10.60years) performing a psychosocial stress task in front of a jury were coded for displays of the children's gaze aversion from the jury, and saliva samples were taken to determine their cortisol reactivity. A questionnaire assessed the children's level of perceived stress. Results showed higher cortisol reactivity in children who perceived the task as more stressful. Furthermore, a quadratic relation between gaze aversion and cortisol was found which depended on the level of perceived stress: for children with low levels of perceived stress, cortisol reactivity was lowest with intermediate levels of gaze aversion, whereas for children with high levels of perceived stress cortisol reactivity was highest at intermediate levels of gaze aversion. The results suggest a modest association between subjective and physiological stress responses in 9- to 11-year-olds, and indicate that gaze aversion may play only a minor role as a behavioural coping strategy at this age.

Speaking under pressure: low linguistic complexity is linked to high physiological and emotional stress reactivity

What can a speech reveal about someone's state? We tested the idea that greater stress reactivity would relate to lower linguistic cognitive complexity while speaking. In Study 1, we tested whether heart rate and emotional stress reactivity to a stressful discussion would relate to lower linguistic complexity. In Studies 2 and 3, we tested whether a greater cortisol response to a standardized stressful task including a speech (Trier Social Stress Test) would be linked to speaking with less linguistic complexity during the task. We found evidence that measures of stress responsivity (emotional and physiological) and chronic stress are tied to variability in the cognitive complexity of speech. Taken together, these results provide evidence that our individual experiences of stress or "stress signatures"-how our body and mind react to stress both in the moment and over the longer term-are linked to how complex our speech under stress.