Does early maternal responsiveness buffer prenatal tobacco exposure effects on young children's behavioral disinhibition?

Children of trauma survivors: Influences of parental posttraumatic stress and child-perceived parenting

BACKGROUND

Research has established a negative association between parental posttraumatic stress symptoms (PTSS), including subthreshold symptoms, and child physical and behavioral health outcomes. Such intergenerational transmission of risk has multiple possible mechanisms, including lack of positive parenting, increased negative parenting, shared environmental and contextual risks, and potential biological components such as shared genetics or even transmission of epigenetic risk.

METHOD

This study examined 93 parent-child dyads (n = 171 participants total) from a mixed Urban-Suburban US metropolitan area to investigate the relations between parental PTSS and child-perceived parenting and child PTSS. We sought to examine interactions between parental PTSS and parenting on child PTSS.

RESULTS

We found an association between parent and child PTSS, consistent with prior literature showing increased risk for children of trauma survivors. Interestingly, we found effects of positive parenting on diminished child PTSS symptoms only in parents without PTSS, whereas the effect of positive parenting on buffering child symptoms was absent in parents with PTSS.

LIMITATIONS

The present findings are tempered by the use of self-report data to assess parent and child PTSS, which is not as reliable as clinician assessment of symptoms. Further, the use of survey data limits what is known about the extent of trauma exposure in parents and children, and different measures were used to assess PTSS in parents and kids, which limits comparability of these reported symptoms.

DISCUSSION

Limitations notwithstanding, findings suggest joint attention paid to parenting practices and to a parent's recovery, even from subthreshold symptoms of PTSS, as two different but important ways to support trauma survivor parents in their efforts to most optimally parent and protect their children from intergenerational risk.

Bdnf-Nrf-2 crosstalk and emotional behavior are disrupted in a sex-dependent fashion in adolescent mice exposed to maternal stress or maternal obesity

Maternal obesity has been recognized as a stressor affecting the developing fetal brain, leading to long-term negative outcomes comparable to those resulting from maternal psychological stress, although the mechanisms have not been completely elucidated. In this study, we tested the hypothesis that adverse prenatal conditions as diverse as maternal stress and maternal obesity might affect emotional regulation and stress response in the offspring through common pathways, with a main focus on oxidative stress and neuroplasticity. We contrasted and compared adolescent male and female offspring in two mouse models of maternal psychophysical stress (restraint during pregnancy - PNS) and maternal obesity (high-fat diet before and during gestation - mHFD) by combining behavioral assays, evaluation of the hypothalamic-pituitary-adrenal (HPA) axis reactivity, immunohistochemistry and gene expression analysis of selected markers of neuronal function and neuroinflammation in the hippocampus, a key region involved in stress appraisal. Prenatal administration of the antioxidant N-acetyl-cysteine (NAC) was used as a strategy to protect fetal neurodevelopment from the negative effects of PNS and mHFD. Our findings show that these two stressors produce overlapping effects, reducing brain anti-oxidant defenses (Nrf-2) and leading to sex-dependent impairments of hippocampal Bdnf expression and alterations of the emotional behavior and HPA axis functionality. Prenatal NAC administration, by restoring the redox balance, was able to exert long-term protective effects on brain development, suggesting that the modulation of redox pathways might be an effective strategy to target common shared mechanisms between different adverse prenatal conditions.

Exploring the interplay of dopaminergic genotype and parental behavior in relation to executive function in early childhood

Child genotype is an important biologically based individual difference conferring differential sensitivity to the effect of parental behavior. This study explored dopaminergic polygenic composite × parental behavior interactions in relation to young children's executive function. Participants were 135 36-month-old children and their mothers drawn from a prospective cohort followed longitudinally from pregnancy. A polygenic composite was created based on the number of COMT, DAT1, DRD2, and DRD4 alleles associated with increased reward sensitivity children carried. Maternal negative reactivity and responsiveness were coded during a series of structured mother-child interactions. Executive function was operationalized as self-control and working memory/inhibitory control. Path analysis supported a polygenic composite by negative reactivity interaction for self-control. The nature of the interaction was one of diathesis-stress, such that higher negative reactivity was associated with poorer self-control for children with higher polygenic composite scores. This result suggests that children with a higher number of alleles may be more vulnerable to the negative effect of negative reactivity. Negative reactivity may increase the risk for developing behavior problems in this population via an association with poorer self-control. Due to the small sample size, these initial findings should be treated with caution until they are replicated in a larger independent sample.

Early Risk of Tobacco Smoke Exposure and Preschoolers' Hot and Cool Inhibitory Control: Promotive and Protective Roles of Maternal Positivity in Early Mother-child Interaction

Early tobacco smoke exposure (TSE) in utero and/or during the first years after birth poses threats to the development of child executive functioning and self-regulation skills, including inhibitory control. Efforts are still needed to examine under what conditions such effects may occur and thus identify modifiable intervention targets. In addition, a distinction between cool and hot inhibitory control is also important to obtain greater nuance in such links. The cool inhibitory control refers to children's suppression of prepotent automatic responses to a distracting stimulus in solving arbitrary and decontextualized problems, whereas the hot inhibitory control refers to children's control of impulse in motivationally and emotionally high-stake situations. Using data derived from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, we examined the links between early risk of TSE and preschoolers' hot and cool inhibitory control and tested the potential promotive/protective roles of maternal positivity in early mother-child interactions. Results indicate that early risk of TSE was negatively linked to child cool inhibitory control when maternal positivity was low, but this link was nonsignificant when maternal positivity was high (i.e., the protective role of maternal positivity). The link between early risk of TSE and child later hot inhibitory control was not moderated by maternal positivity; instead, early risk of TSE and maternal positivity were negatively and positively associated with child hot inhibitory control above and beyond each other, respectively (i.e., the promotive role of maternal positivity). Accordingly, building a tobacco-free environment during pregnancy and infancy likely yields long-term benefits for child self-regulation development. Improving early mothering may offset the negative link between early TSE and child cool inhibitory control and also facilitate child hot inhibitory control even in the face of early TSE.

Within-person decline in pregnancy smoking is observable prior to pregnancy awareness: Evidence across two independent observational cohorts

Decreased consumption of nicotine and other drugs during pregnancy appears to be a cross-species phenomenon from which mechanism(s) capable of interrupting addictive processes could be elucidated. Whether pregnancy influences smoking behaviour independent of women's knowledge of the pregnancy, however, has not been considered. Using repeated measures analysis of variance (ANOVA), we estimated within-person change in mean cigarettes/day smoked across the estimated date of conception but prior to individually reported dates of pregnancy recognition using longitudinal smoking data from two independent observational cohorts, the Growing Up Healthy (GUH, n = 271) and Midwest Infant Development Studies (MIDS, n = 145). Participants smoked an average of half a pack/day in the month immediately before conception (M (SD) = 12(8.1) and 9.5(6.7) cigarettes/day in GUH and MIDS, respectively). We observed within-person declines in smoking after conception, both before (MGUH  = -0.9; 95% CI -1.6, -0.2; p = 0.01; MMIDS  = -1.1; 95% CI -1.9, -0.3; p = 0.01) and after (MGUH  = -4.8; 95% CI -5.5, -4.1; p < 0.001; MMIDS  = -3.3; 95% CI -4.4, -2.5; p < 0.001) women were aware of having conceived, even when women who had quit and women who were planning to conceive were excluded from analyses. Pregnancy may interrupt smoking-related processes via mechanisms not previously considered. Plausible candidates and directions for future research are discussed.

Differential associations of maternal behavior to preschool boys' and girls' executive function

Boys are more sensitive to environmental factors like parental behavior, an important predictor of executive function. This study examined whether the interaction between child sex and maternal behavior was associated with children's executive function in a manner consistent with the vulnerability or differential susceptibility model. Participants were 146 36-month-old children and their mothers. Maternal responsiveness and negative reactivity were coded during structured mother-child interactions. Executive function was operationalized as latent self-control and working memory/inhibitory control (WMIC). Structural equation modelling supported a sex by responsiveness interaction for self-control but not WMIC. Consistent with a vulnerability model, less responsiveness was associated with poorer self-control for boys relative to girls. Boys' self-control may be more vulnerable to the negative effect of unresponsive maternal behavior helping explain boys increased risk for externalizing behavior problems.

Estimating causal and time-varying effects of maternal smoking on youth smoking

INTRODUCTION

Maternal smoking is a well-known risk factor for youth smoking, yet whether this relationship is causal remains unresolved. This study utilizes propensity score methods for causal inference to robustly account for shared risk factors between maternal and offspring smoking.

METHODS

An 8-year longitudinal cohort of 900 adolescents in the Chicago area were followed starting from approximately age 15.6. The effects of maternal lifetime smoking (MLS) and prenatal tobacco exposure (PTE) (among participants reporting MLS) on offspring's past 30-day smoking, daily smoking status and smoking frequency were examined using logistic regression and Poisson regression after nearest-neighbor propensity matching. Age dependency of this relationship was then examined across the age range of 15-25 using time-varying effect modeling.

RESULTS

Propensity matching yielded 438 and 132 pairs for MLS and PTE study samples, respectively. MLS demonstrated significant associations with past 30-day smoking (RR 1.09; 95% CI 1.04-1.14), daily smoking (RR 1.08; 95% CI 1.05-1.12), and smoking frequency of offspring (RR 1.32; 95% CI 1.15-1.52), with stable effects across age. Among participants reporting MLS, having PTE showed significant additional effects on daily smoking (RR 1.09; 95% CI 1.02-1.17) and age-dependency that showed significance during young adulthood but not adolescence.

CONCLUSION

The relationship between maternal and offspring smoking was not fully accounted for by shared risk factors, suggesting possible causation with PTE having a delayed effect across age. Targeted prevention efforts should be made on maternal smoking-exposed adolescents to mitigate their risks of developing heavy smoking habits in adulthood.

Dimension- and context-specific expression of preschoolers' disruptive behaviors associated with prenatal tobacco exposure

OBJECTIVE

Precise phenotypic characterization of prenatal tobacco exposure (PTE)-related disruptive behavior (DB) that integrates nuanced measures of both exposures and outcomes is optimal for elucidating underlying mechanisms. Using this approach, our goals were to identify dimensions of DB most sensitive to PTE prior to school entry and assess contextual variation in these dimensions.

METHODS

A community obstetric sample of N = 369 women (79.2% lifetime smokers; 70.2% pregnancy smokers) from two Midwestern cities were assessed for PTE using cotinine-calibrated interview-based reports at 16, 28, and 40 weeks of gestation. A subset of n = 244 who completed observational assessments with their 5-year-old children in a subsequent preschool follow-up study constitute the analytic sample. Using two developmentally-meaningful dimensions previously associated with emergent clinical risk for DB-irritability and noncompliance-we assessed children with 2 parent-report scales: the Multidimensional Assessment Profile of Disruptive Behavior (MAP-DB) and the Early Childhood Inventory (ECI). We also assessed children by direct observation across 3 interactional contexts with the Disruptive Behavior Diagnostic Observation Schedule (DB-DOS). We used generalized linear models to examine between-child variability across behavioral dimensions, and mixed effects models to examine directly observed within-child variability by interactional context.

RESULTS

Increasing PTE predicted increasing impairment in preschoolers' modulation of negative affect (irritability), but not negative behavior (noncompliance) across reported (MAP-DB) and observed (DB-DOS) dimensional measures. Moreover, children's PTE-related irritability was more pronounced when observed with parents than with the examiner. The ECI did not detect PTE-related irritability nor noncompliance.

CONCLUSIONS

Nuanced, dimension- and context-specific characterization of PTE-related DB described can optimize early identification of at-risk children.

Responsive Parenting Buffers the Impact of Maternal PTSD on Young Children

OBJECTIVE

This study investigates maternal responsive parenting behaviors as a theorized buffer to the detrimental impact of maternal PTSD symptoms on young children's depression and anxiety symptoms, disruptive behavior, and stress-related symptoms.

DESIGN

A multi-ethnic sample of 242 trauma-exposed mothers and their preschool-aged children was assessed. Maternal responsive parenting behaviors were observed during standardized parent-child interactions. Maternal and child mental health symptoms were reported by mothers.

RESULTS

Maternal PTSD symptoms were associated with their responsive parenting behaviors and predicted children's mental health symptoms. Responsive parenting was inversely associated with children's depression and stress-related symptoms. Moderation analyses revealed an interactive effect of maternal symptoms and responsive parenting on preschool children's disruptive behavior and stress-related symptoms.

CONCLUSIONS

Responsive parenting behaviors can mitigate the ill effects of maternal PTSD symptoms. Nurturing relationships buffer the impact of maternal PTSD. Helping parents' to sensitively respond to their young children's distress can support positive outcomes in children.