Effects of parental depressive symptoms on child adjustment moderated by hypothalamic pituitary adrenal activity: within- and between-family risk

Association of maternal depression and home adversities with infant hypothalamic-pituitary-adrenal (HPA) axis biomarkers in rural Pakistan

BACKGROUND

Each year, almost 35% of children are exposed to maternal depression and more grow up in persistent poverty, increasing the risk for stress-related disease and other socio-developmental deficits later in life. These impacts are likely related to chronic stress via the hypothalamic-pituitary-adrenal (HPA) axis. However, there is little evidence relating early windows of child HPA axis activity to multiple exposures.

METHODS

We investigated chronic measures of hair-derived HPA axis hormones (cortisol and dehydroepiandrosterone (DHEA)) in 104 one-year old infants from rural Pakistan and longitudinal measures of maternal depression, intimate partner violence (IPV), socio-economic status (SES), and the home environment.

RESULTS

Estimates from adjusted linear mixed effects models did not reveal consistent significant associations between infant cortisol and maternal depression or home adversities. By contrast, infants exposed to maternal depression during pregnancy had lower DHEA levels (ß= -0.18 95% confidence interval [CI]: -0.34, -0.02) as did those whose mothers experienced multiple types of IPV (ß=-4.14 95% CI: -7.42, -0.79) within one year postpartum. Higher SES had a significant positive association with infant DHEA levels (ß= 0.77 95% CI: 0.08, 1.47). Depression severity and chronicity at one year postpartum had near significant associations with infant DHEA. Measures of home environment had no observable impacts on infant HPA axis activity.

LIMITATIONS

Limitations include the modest sample size and aggregation of hair samples for analysis.

CONCLUSION

Results point to possible early HPA axis dysregulation driven by changes in DHEA activity, but not cortisol at one year of age. Findings contribute to growing research examining intergenerational transmissions of maternal depression, IPV, and household environment on infant stress-response systems.

The Relation between Specific Parenting Behaviors and Toddlers' Early Anxious Behaviors is Moderated by Toddler Cortisol Reactivity

Differential susceptibility theory posits that neurobiological reactivity (e.g., cortisol levels) should be considered as an individual index of susceptibility to both positive and negative environments. The current investigation separately examines cortisol reactivity and total concentration in toddlerhood as moderators of the longitudinal relation between maternal protection and encouragement of independence and increases or decreases in observed anxious behaviors, respectively. A total of 119 mother-toddler dyads participated in a laboratory visit when toddlers were 12- to 18-months-old. Mothers reported on their parenting behaviors and toddlers participated in a novelty episode from which their anxious behaviors were coded. Toddlers provided three saliva samples, yielding measures of cortisol reactivity and total cortisol concentration. One year later, dyads returned to the laboratory where toddlers participated in another novelty episode to observationally assess anxious behaviors. Results revealed that maternal protection tended to relate to greater increases in anxious behaviors one year later only for toddlers who displayed high cortisol reactivity. Cortisol reactivity also moderated the relation between maternal encouragement of independence and change in toddler anxious behaviors, with this parenting behavior relating to greater decreases in anxious behaviors only for toddlers with high cortisol reactivity. Results examining total cortisol concentration as a moderator were not significant. Results suggest the importance of considering toddler cortisol reactivity a context of susceptibility when examining the longitudinal relation between parenting behaviors and the development of anxious behaviors in toddlerhood.

Hair cortisol in pregnancy interacts with maternal depressive symptoms to predict maternal disrupted interaction with her infant at 4 months

Disrupted maternal interaction in early infancy is associated with maladaptive child outcomes. Thus, identifying early risk factors for disrupted interaction is an important challenge. Research suggests that maternal depressive symptoms and maternal cortisol dysregulation are associated with disrupted maternal interaction, but both factors have rarely been considered together as independent or interactive predictors of disrupted interaction. In a sample of 51 women, hair cortisol concentrations (HCC) and depressive symptoms were assessed during pregnancy, and depressive symptoms were assessed again at 4-month postpartum. Maternal disrupted interaction was assessed during the Still-Face Paradigm at 4 months. Results indicated that HCC and depressive symptoms interacted to predict both maternal withdrawing and inappropriate/intrusive interaction. Withdrawing interaction was associated with high levels of HCC in pregnancy in the context of high depressive symptoms at 4 months; inappropriate/intrusive interaction was associated with high levels of HCC in the context of low depressive symptoms. Thus, high HCC potentiated both forms of disrupted interaction. Results raised questions about the meaning of very low reported depressive symptoms, and underscored the importance of chronic stress physiology and maternal depressed mood as risk factors for distinct forms of maternal disrupted interaction, both of which are deleterious for infant development.

The Early Growth and Development Study: A Dual-Family Adoption Study from Birth Through Adolescence

The Early Growth and Development Study (EGDS) is a prospective adoption study of birth parents, adoptive parents and adopted children (n = 561 adoptees). The original sample has been expanded to include siblings of the EGDS adoptees who were reared by the birth mother and assessed beginning at age 7 years (n = 217 biological children), and additional siblings in both the birth and adoptive family homes, recruited when the adoptees were 8-15 years old (n = 823). The overall study aims are to examine how family, peer and contextual processes affect child and adolescent adjustment, and to examine their interplay (mediation, moderation) with genetic influences. Adoptive and birth parents were originally recruited through adoption agencies located throughout the USA following the birth of a child. Assessments are ongoing and occurred in 9 month's intervals until the adoptees turned 3 years of age, and in 1 to 2 year intervals thereafter through age 15. Data collection includes the following primary constructs: child temperament, behavior problems, mental health, peer relations, executive functioning, school performance and health; birth and adoptive parent personality characteristics, mental health, health, context, substance use, parenting and marital relations; and the prenatal environment. Findings highlight the power of the adoption design to detect environmental influences on child development and provide evidence of complex interactions and correlations between genetic, prenatal environmental and postnatal environmental influences on a range of child outcomes. The study sample, procedures and an overview of findings are summarized and ongoing assessment activities are described.

Parental depression moderates the relationships of cortisol and testosterone with children's symptoms

BACKGROUND

Previous research on the hormone-symptom relationship in children suggests that certain hormone patterns may be associated with symptoms, but only under certain circumstances. Having a parent with a history of depression may be one circumstance under which dysregulated hormone patterns are especially associated with emotional and behavioral symptoms in children. The current study sought to explore these relationships in a community sample of 389 9-year-old children.

METHODS

Children's salivary cortisol and testosterone levels were collected at home over three consecutive days; parental psychiatric histories were assessed using semi-structured diagnostic interviews; and children's internalizing and externalizing symptoms were rated by the child's mother.

RESULTS

Having two parents with a history of depression moderated the associations of reduced total daily cortisol output with higher externalizing scores, as well as the association of reduced testosterone with higher internalizing scores. A maternal history of depression, on the other hand, moderated the relationship between higher cortisol awakening response and higher internalizing scores. Furthermore, lower daily cortisol output was associated with higher internalizing scores among girls, but not boys, with two parents with a history depression.

LIMITATIONS

Limitations include the cross-sectional nature of the current analyses, as well as the limited racial, ethnic, and geographical diversity of the sample.

CONCLUSIONS

Taken together, the current results suggest that the relationship between hormones and internalizing and externalizing symptoms in children may vary as a function of parental depression and child sex, knowledge that may inform intervention efforts aimed at preventing psychopathology in children whose parents have a history of depression.

The interplay of polygenic plasticity and adrenocortical activity as sources of variability in pathways among family adversity, youth emotional reactivity, and psychological problems

This study examined the interplay between a polygenic composite and cortisol activity as moderators of the mediational pathway among family adversity, youth negative emotional reactivity to family conflict, and their psychological problems. The longitudinal design contained three annual measurement occasions with 279 adolescents (Mean age = 13.0 years) and their parents. Latent difference score analyses indicated that observational ratings of adversity in interparental and parent-child interactions at Wave 1 predicted increases in a multimethod, multi-informant assessment of youth negative emotional reactivity to family conflict from Waves 1 to 2. Changes in youth negative emotional reactivity, in turn, predicted increases in a multi-informant (i.e., parents, adolescent, and teacher) assessment of psychological problems from Waves 1 to 3. Consistent with differential susceptibility theory, the association between family adversity and negative emotional reactivity was stronger for adolescents who carried more sensitivity alleles in a polygenic composite consisting of 5-HTTLPR, DRD4 VNTR, and BDNF polymorphisms. Analyses of adolescent cortisol in the period surrounding a family disagreement task at Wave 1 revealed that overall cortisol output, rather than cortisol reactivity, served as an endophenotype of the polygenic composite. Overall cortisol output was specifically associated with polygenic plasticity and moderated the association between family adversity and youth negative emotional reactivity in the same for better or for worse manner as the genetic composite. Finally, moderator-mediated-moderation analyses indicated that the moderating role of the polygenic plasticity composite was mediated by the moderating role of adolescent cortisol output in the association between family adversity and their emotional reactivity.

Examining Morning HPA Axis Activity as a Moderator of Hostile, Over-reactive Parenting on Children's Skills for Success in School

This study examined children's morning HPA axis activation as a moderator of links between hostile, over-reactive parenting at age 4.5 years and children's skills for success in school (higher executive function and literacy, and less externalizing behavior) at age 6. Participants included 361 adoptive families. Parenting was self-reported. HPA axis activation was measured by basal levels in morning cortisol. Executive function and literacy were assessed via standardized tasks. Externalizing behavior was reported by teachers. Results indicated that hostile, over-reactive parenting predicted more externalizing behavior and lower executive functioning regardless of children's morning HPA axis activation. HPA axis activation moderated the effects of hostile, over-reactive parenting on literacy. Among children with moderate to high morning HPA axis activation (approximately 60% of the sample), harsh parenting was linked with lower literacy; children with low morning HPA axis activation exhibited better literacy in the context of more hostile, over-reactive parenting. Yet, across the sample, hostile, over-reactive parenting remained in the low to moderate range, not in the high range. Findings are discussed in the context of considering not only whether children's stress system activation moderates responses to their environments, but also how these processes operate for different developmental outcomes.

Child cortisol moderates the association between family routines and emotion regulation in low-income children

Biological and social influences both shape emotion regulation. In 380 low-income children, we tested whether biological stress profile (cortisol) moderated the association among positive and negative home environment factors (routines; chaos) and emotion regulation (negative lability; positive regulation). Children (M age = 50.6, SD = 6.4 months) provided saliva samples to assess diurnal cortisol parameters across 3 days. Parents reported on home environment and child emotion regulation. Structural equation modeling was used to test whether cortisol parameters moderated associations between home environment and child emotion regulation. Results showed that home chaos was negatively associated with emotion regulation outcomes; cortisol did not moderate the association. Child cortisol level moderated the routines-emotion regulation association such that lack of routine was most strongly associated with poor emotion regulation among children with lower cortisol output. Findings suggest that underlying child stress biology may shape response to environmental influences.

Infant hair cortisol: associations with salivary cortisol and environmental context

Early chronic stress has enduring implications for physical and mental health outcomes. Hair cortisol concentration (HCC) has emerged as a marker of cumulative cortisol exposure, yet HCC in infants is not well understood. We examined how infant HCC relates to widely used basal salivary cortisol measures, maternal HCC, and environmental context in 111 infants assessed at 6 and 12 months of age. Maternal HCC at 6 and 12 months was correlated with infant HCC at 12 months. At 12 months, infant HCC was positively associated with waking salivary cortisol concentration (SCC), evening SCC, and area under the curve (AUC), but was independent of diurnal slope. Breastfeeding was associated with lower HCC, whereas increased sleep disruption was related to flatter slope. Reduced nighttime sleep duration was related both to higher HCC and to flatter slope. A person-focused analysis indicated that the combination of high HCC and flattened slope was associated with more environmental risks, highlighting the importance of investigating the interplay between HCC and diurnal cortisol slope. Results support the validity of HCC as a marker of cumulative cortisol exposure in infancy, while emphasizing the value of including multiple cortisol measures assessing distinct aspects of hypothalamic-pituitary-adrenal (HPA) function.

Maternal depression across the first years of life compromises child psychosocial adjustment; relations to child HPA-axis functioning

Maternal depression across the first years of life negatively impacts children's development. One pathway of vulnerability may involve functioning of the hypothalamic-pituitary-adrenal (HPA) axis. We utilize a community cohort of 1983 women with no comorbid risk repeatedly assessed for depression from birth to six years to form two groups; chronically depressed (N=40) and non-depressed (N=91) women. At six years, mother and child underwent psychiatric diagnosis, child salivary cortisol (CT) was assessed three times during a home-visit, mother-child interaction was videotaped, and child empathy was coded from behavioral paradigms. Latent Growth curve Model using Structural Equation Modeling (SEM) estimated the links between maternal depression and mother's negative parenting and three child outcomes; psychopathology, social withdrawal, and empathy as related to child CT baseline and variability. Depressed mothers displayed more negative parenting and their children showed more Axis-I psychopathology and social withdrawal. SEM analysis revealed that maternal depression was associated with reduced CT variability, which predicted higher child psychopathology and social withdrawal. Whereas all children exhibited similar initial levels of CT, children of controls reduced CT levels over time while children of depressed mothers maintained high, non-flexible levels. Mother negativity was related to lower initial CT levels, which predicted decreased empathy. Findings suggest that chronic maternal depression may compromise children's social-emotional adjustment by diminishing HPA-system flexibility as well as limiting the mother's capacity to provide attuned and predictable caregiving.

Biological Sensitivity to Family Income: Differential Effects on Early Executive Functioning

The study examined how the interplay between children's cortisol response and family income is related to executive function (EF) skills. The sample included one hundred and two 5- to 6-year-olds (64% minority). EF skills were measured using laboratory tasks and observer ratings. Physiological reactivity was assessed via cortisol response during a laboratory visit. A consistent, positive association between family income and EF skills emerged only for children who showed high cortisol response, a marker of biological sensitivity to context. In contrast, family income was not related to EF skills in children who displayed low cortisol response. Follow-up analyses revealed a disordinal interaction, suggesting that differential susceptibility can be detected at the level of basic cognitive and self-regulatory skills that support adaptive functioning.

Raised by depressed parents: is it an environmental risk?

The mechanisms explaining how parental depression compromises healthy child development are complex and multifaceted, with genetic and environmental pathways intertwined. Reexamination of whether and how maternal and paternal depression serve as environmental risk factors is important because such an investigation can be helpful to identify modifiable mechanisms that are accessible to interventions. We review studies that have employed designs that isolate the effects of the environment from genetic influences, including adoption studies and children of twins studies. Findings indicate that maternal depression is an environmental risk factor for the emotional, behavioral, and neurobiological development of children. Although more studies are needed, preliminary findings suggest that paternal depression appears to be a weaker environmental risk as compared to maternal depression, at least during infancy and toddlerhood. Implications for theory and future research are discussed.

Parental depression and child cognitive vulnerability predict children's cortisol reactivity

Risk for depression is expressed across multiple levels of analysis. For example, parental depression and cognitive vulnerability are known markers of depression risk, but no study has examined their interactive effects on children's cortisol reactivity, a likely mediator of early depression risk. We examined relations across these different levels of vulnerability using cross-sectional and longitudinal methods in two community samples of children. Children were assessed for cognitive vulnerability using self-reports (Study 1; n = 244) and tasks tapping memory and attentional bias (Study 2; n = 205), and their parents were assessed for depression history using structured clinical interviews. In both samples, children participated in standardized stress tasks and cortisol reactivity was assessed. Cross-sectionally and longitudinally, parental depression history and child cognitive vulnerability interacted to predict children's cortisol reactivity; associations between parent depression and elevated child cortisol activity were found when children also showed elevated depressotypic attributions as well as attentional and memory biases. Findings indicate that models of children's emerging depression risk may benefit from the examination of the interactive effects of multiple sources of vulnerability across levels of analysis.

The relationship between parental depressive symptoms and offspring psychopathology: evidence from a children-of-twins study and an adoption study

BACKGROUND

Parental depressive symptoms are associated with emotional and behavioural problems in offspring. However, genetically informative studies are needed to distinguish potential causal effects from genetic confounds, and longitudinal studies are required to distinguish parent-to-child effects from child-to-parent effects.

METHOD

We conducted cross-sectional analyses on a sample of Swedish twins and their adolescent offspring (n = 876 twin families), and longitudinal analyses on a US sample of children adopted at birth, their adoptive parents, and their birth mothers (n = 361 adoptive families). Depressive symptoms were measured in parents, and externalizing and internalizing problems measured in offspring. Structural equation models were fitted to the data.

RESULTS

Results of model fitting suggest that associations between parental depressive symptoms and offspring internalizing and externalizing problems remain after accounting for genes shared between parent and child. Genetic transmission was not evident in the twin study but was evident in the adoption study. In the longitudinal adoption study child-to-parent effects were evident.

CONCLUSIONS

We interpret the results as demonstrating that associations between parental depressive symptoms and offspring emotional and behavioural problems are not solely attributable to shared genes, and that bidirectional effects may be present in intergenerational associations.

Combined Influences of Genes, Prenatal Environment, Cortisol, and Parenting on the Development of Children's Internalizing Versus Externalizing Problems

Research suggests that genetic, prenatal, endocrine, and parenting influences across development individually contribute to internalizing and externalizing problems in children. The present study tests the combined contributions of genetic risk for psychopathology, prenatal environments (maternal drug use and internalizing symptoms), child cortisol at age 4.5 years, and overreactive parenting influences across childhood on 6-year-old children's internalizing and externalizing problems. We used data from an adoption design that included 361 domestically adopted children and their biological and adopted parents prospectively followed from birth. Only parenting influences contributed (independently) to externalizing problems. However, genetic influences were indirectly associated with internalizing problems (through increased prenatal risk and subsequent morning cortisol), and parenting factors were both directly and indirectly associated with internalizing problems (through morning cortisol). Results suggest that prenatal maternal drug use/symptoms and children's morning cortisol levels are mechanisms of genetic and environmental influences on internalizing problems, but not externalizing problems, in childhood.

Disentangling the effects of genetic, prenatal and parenting influences on children's cortisol variability

Developmental plasticity models hypothesize the role of genetic and prenatal environmental influences on the development of the hypothalamic-pituitary-adrenal (HPA) axis and highlight that genes and the prenatal environment may moderate early postnatal environmental influences on HPA functioning. This article examines the interplay of genetic, prenatal and parenting influences across the first 4.5 years of life on a novel index of children's cortisol variability. Repeated measures data were obtained from 134 adoption-linked families, adopted children and both their adoptive parents and birth mothers, who participated in a longitudinal, prospective US domestic adoption study. Genetic and prenatal influences moderated associations between inconsistency in overreactive parenting from child age 9 months to 4.5 years and children's cortisol variability at 4.5 years differently for mothers and fathers. Among children whose birth mothers had high morning cortisol, adoptive fathers' inconsistent overreactive parenting predicted higher cortisol variability, whereas among children with low birth mother morning cortisol adoptive fathers' inconsistent overreactive parenting predicted lower cortisol variability. Among children who experienced high levels of prenatal risk, adoptive mothers' inconsistent overreactive parenting predicted lower cortisol variability and adoptive fathers' inconsistent overreactive parenting predicted higher cortisol variability, whereas among children who experienced low levels of prenatal risk there were no associations between inconsistent overreactive parenting and children's cortisol variability. Findings supported developmental plasticity models and uncovered novel developmental, gene × environment and prenatal × environment influences on children's cortisol functioning.

The Early Growth and Development Study: a prospective adoption study from birth through middle childhood

The Early Growth and Development Study is a prospective adoption study of birth parents, adoptive parents, and adopted children recruited in two cohorts (N = 561 triads). The primary study aims are to examine how family, peer, and contextual processes affect children's adjustment, and to examine their interplay (mediation, moderation) with genetic influences. Participants were recruited through adoption agencies located throughout the United States following the birth of a child. Assessments are ongoing, in 9-month intervals until the child reaches 3 years of age and in 1-year intervals thereafter through age 9. Data collection includes the following primary constructs: child temperament, social behavior, school performance, mental health, and health; birth and adoptive parent personality characteristics, mental health, competence, stress, health, context, substance use, parenting, and marital relations; and pregnancy use of drugs and maternal stress during pregnancy. DNA and salivary cortisol samples have also been collected. Analyses have indicated evidence for genotype-environment interactions during early childhood. Study procedures, sample representativeness (including tests of potential confounds in the adoption design), and an overview of findings to date are summarized, and future plans are described.