Effortful control and context interact in shaping neuroendocrine stress responses during childhood

Longitudinal links between early adolescent temperament and inflammation among young black adults

A large body of research demonstrates that inflammation is involved in physical health problems that cause substantial morbidity and early mortality. Given inflammation's role in the etiology of chronic diseases, pediatric scientists have begun to study childhood factors that presage elevation of inflammatory biomarkers later in life. The purpose of this study was to test hypotheses designed to determine whether early adolescent emotionally intense and low attention temperaments forecast (a) inflammation at ages 25 and 29 years and (b) worsening levels of inflammation between these two data points. Toward this end, 307 Black children from the rural southeastern United States participated in an 18-year longitudinal study (mean age at baseline, 11.2 years) to determine whether and how early adolescent's behavioral styles or emotionally intense and low attention temperaments may be associated with absolute and worsening levels of inflammation in young adulthood. When children were 11-13 years of age, different teachers at each age provided assessments of emotionally intense and low attention temperaments. Thus, multiple measures of the same temperament constructs were obtained across 3 years for each participant. At age 25, participants provided data on their self-regulation abilities. Peripheral blood was collected at ages 25 and 29 years from which inflammation was quantified, using soluble urokinase plasminogen activator (suPAR), the proinflammatory cytokines interleukin (IL) IL-6, IL-10, and tumor necrosis factor-alpha (TNF-α). Covariates associated with inflammation in prior studies were also assessed; these included socioeconomic risk, gender, cigarette smoking, body mass index (BMI), adverse childhood experiences (ACEs), depressive symptoms, and medication use. An early adolescent emotionally intense temperament was associated directly with higher suPAR and cytokine levels at age 29, and with worsening cytokine levels between ages 25 and 29. A low attention temperament was associated with suPAR levels at age 29. Collectively, these observations highlight pathways that could underlie health risks associated with early adolescent temperaments. The findings suggest that emotionally intense and low-attention early adolescent temperaments forecast higher and worsening inflammation levels across young adulthood.

Early temperament and physical health in school-age children: Applying a short temperament measure in a population-based cohort

Temperament has drawn considerable attention in the understanding of behavioural problems and psychopathology across developmental stages. However, less of a focus has been placed on the role of temperament in physical aspects of health. We aimed to examine the relations between early temperament traits and physical health in school-age children. This study used longitudinal data of 18,994 children (52.4% boys) born in 2005 from the Taiwan Birth Cohort Study, in which follow-up surveys were conducted via face-to-face interviews with the child's caregiver. Temperament at 5.5 years of age was assessed using a nine-item measure, and two higher-order temperament traits, surgency and regulation, were derived through confirmatory factor analysis. Physical health outcomes at age 8 included caregiver-rated general health status and medically attended injuries. Multiple logistic regression analysis was applied, with the child's birth outcome, early health status or injury history, health behaviours and family socioeconomic status as control variables. The results indicated that higher levels of surgency and regulation, as early temperament traits, significantly predicted lower odds of caregiver-rated poor health in later years. Higher level of regulation was also associated with lower odds of injury risk. Our findings suggest that assessing early temperament traits could be useful for the promotion and management of physical health in young school-age children.

Children's diurnal cortisol output and temperament in two different childcare settings at 2 and 3.5 years of age

Prior research suggests that child temperament may play an important role in early childhood stress regulation. We compared children's diurnal cortisol and the association between cortisol and temperament in two different childcare settings. Cortisol was measured from saliva samples over 2 days in children (N = 84) attending out-of-home childcare and in children (N = 27), who were cared for at home at the age of 3.5 years. There was no difference between the childcare groups in total diurnal cortisol. However, of the individual measurements, afternoon cortisol levels were higher in the out-of-home childcare group during their childcare day when compared with their home day. Child temperament was not associated with total diurnal cortisol. Comparison with our prior measurements showed that the association between temperamental surgency/extroversion and total diurnal cortisol diminished along with the child age from 2 to 3.5 years in both childcare settings. This may indicate that more extroverted children are physiologically more reactive to environmental stimuli when they are younger, but this association does not appear as the children develop. Our results further suggest that the afternoon hours in the out-of-home childcare may be demanding and accelerate the hypothalamus-pituitary-adrenal axis activation in young children independent of their age.

Associations between Effortful Control, Cortisol Awakening Response, and Depressive Problems in Latino Preadolescents

The present study examined associations between effortful control, a trait marker of self-regulation, adaptive HPA system functioning (as reflected by the CAR), and concurrent and longitudinal depressive problems, in a sample of preadolescent Latino youth (N = 119, mean age = 11.53 years, 59% female). We hypothesized that trait readiness for self-regulation (e.g., effortful control) could be related to physiological state readiness for self-regulation (e.g., CAR), and that both may counter depressive problems. We found that youth's CAR was positively associated with effortful control, and negatively with youth depressive problems. Effortful control and youth depressive problems were also negatively associated. Longitudinal relations of CAR and effortful control on depressive problems at T2 were not significant in the structural equation model after controlling for T1 depressive problems, although these variables were significant in the bivariate correlations. Results suggest that both trait-regulation and physiological regulation may counter depressive problems in Latino youth.

The concurrent and longitudinal associations of temperament and nutritional risk factors in early childhood

BACKGROUND

Early childhood temperament is increasingly recognized as an important attribute that may impact screen time use, outdoor play and childhood obesity. The relationship between temperament and nutrition in preschool children is less clear.

OBJECTIVE

The objective of the study is to investigate if temperament dimensions (negative affectivity, effortful control and surgency) in early childhood are associated with nutritional risk factors.

METHODS

Six hundred seventy-eight children were followed (mean age at baseline visit 3.1 years; mean time to follow-up 16.5 months). Parents reported on child temperament and nutritional risk factors during regularly scheduled well-child clinic visits.

RESULTS

A mixed effect model demonstrated a significant association between higher negative affectivity (1.03; 95% CI 0.69 to 1.37) and higher effortful control (-0.88; 95% CI -1.27 to -0.49) on concurrent nutritional risk, independent of covariates. Multivariate linear regression analysis identified that higher effortful control, and not negative affectivity, was significantly associated with a decrease in nutritional risk (-0.67; 95% CI -1.10 to -0.24) over time, independent of covariates. There was no relationship identified between surgency and nutritional risk.

CONCLUSION

Three-year-old children with higher effortful control had reduced nutritional risk at 5 years of age. Future nutritional risk prevention strategies may benefit from interventions to increase effortful control in early childhood.

The psychology of HPA axis activation: Examining subjective emotional distress and control in a phobic fear exposure model

The HPA axis plays a key role in mediating the effects of "stress" on health, but clarifying mechanisms requires an understanding of psycho-biological linkages. There has long been an implicit assumption that subjective emotional distress (e.g., fear) should activate the HPA axis. Although this assumption was challenged 25 years ago (Curtis, 1976), laboratory studies in humans are limited. In this study we sought to replicate Curtis' findings and extend it by investigating if presence or absence of stressor control shapes HPA axis reactivity in a phobic fear exposure model. We recruited 19-45-year-old specific phobia participants (n=32 spider/snake phobia; n=14 claustrophobia) and gradually exposed them to their feared object or situation while measuring hormonal (ACTH and cortisol) and subjective (emotional distress, perceived control) responses. Utilizing a dyadic yoked design, we compared HPA reactivity when the pace of exposure was controlled by participants to identical exposure given to matched participants in the absence of control. Results showed that phobic fear exposure generated intense emotional distress without a corresponding increase in HPA axis activity. Although our actual manipulation of control failed to impact HPA responses, perceived control during exposure was associated with lower cortisol, an effect that was moderated by actual availability of stressor control. Our findings replicate Curtis' findings and challenge the still common but unsupported assumption that HPA axis activity reflects subjective distress. These results also highlight the importance of both perceived and actual aspects of stressor control in understanding what is truly "stressful" to the HPA axis system.

Trait and state rumination interact to prolong cortisol activation to psychosocial stress in females

There is a growing realization that cognitive processes associated with stress coping, such as rumination and distraction, can impact the hypothalamic-pituitary-adrenal-axis (HPA-axis). Yet, little is known about what aspects of the HPA-axis stress response (rate of activation, duration of activation, rate of recovery) is impacted by such cognitive processes. This study examines the impact of both ruminative trait tendencies and experimentally induced rumination on salivary cortisol responses to a social evaluative stress task. Participants (n=71) were exposed to the Trier Social Stress Test (TSST) and were then randomized to complete either a rumination or distraction task. Trait rumination was also assessed at baseline. Results showed no main effects of either trait rumination or experimental condition, but they interacted to predict the cortisol response. Specifically, participants high in trait rumination had prolonged duration of cortisol activation in the rumination condition, compared to those in the distraction condition. In contrast, cortisol responses of participants with low trait rumination did not differ by condition. Notably, our interaction effect was only significant in females. Our findings highlight the complex relationship between rumination and HPA-axis activity, suggesting an interaction of trait and state rumination in shaping HPA-axis responses to stress, and call attention to sex differences in this relationship.

Measuring the development of inhibitory control: The challenge of heterotypic continuity

Inhibitory control is thought to demonstrate heterotypic continuity, in other words, continuity in its purpose or function but changes in its behavioral manifestation over time. This creates major methodological challenges for studying the development of inhibitory control in childhood including construct validity, developmental appropriateness and sensitivity of measures, and longitudinal factorial invariance. We meta-analyzed 198 studies using measures of inhibitory control, a key aspect of self-regulation, to estimate age ranges of usefulness for each measure. The inhibitory control measures showed limited age ranges of usefulness owing to ceiling/floor effects. Tasks were useful, on average, for a developmental span of less than 3 years. This suggests that measuring inhibitory control over longer spans of development may require use of different measures at different time points, seeking to measure heterotypic continuity. We suggest ways to study the development of inhibitory control, with overlapping measurement in a structural equation modeling framework and tests of longitudinal factorial or measurement invariance. However, as valuable as this would be for the area, we also point out that establishing longitudinal factorial invariance is neither sufficient nor necessary for examining developmental change. Any study of developmental change should be guided by theory and construct validity, aiming toward a better empirical and theoretical approach to the selection and combination of measures.