Gene-environment correlation underlying the association between parental negativity and adolescent externalizing problems

Integrating the family stress model within a longitudinal sibling-adoption study of adolescent externalizing behavior

Using a sample of linked adopted children, adoptive and birth parents (N = 561), and biological siblings residing in the birth parent home (N = 191), we examined the role of genetics within family stress processes. We tested parental hostility (7 years) as a mediator of the associations between socioeconomic strain and rearing parent psychopathology (4 years) and adolescent externalizing behaviors (11 years) in adoptive and biological parent homes. Next, we examined parent social support (4 years) as a moderator of paths from socioeconomic strain and parent psychopathology to parental hostility. Parental hostility significantly mediated effects of socioeconomic strain and parent psychopathology on adolescent externalizing behaviors in biological and adoptive parent homes, respectively. Equivalence testing of the paths to adolescent externalizing behaviors across family types indicated a negligible role of passive gene-environment correlation. Parent social support significantly attenuated the effect of parent psychopathology on parental hostility in biological families. Birth parent externalizing behaviors were not significantly associated with adoptee externalizing behaviors nor adoptive parent hostility, suggesting negligible heritable risk or evocative gene-environment processes. Full- and half-sibling correlations indicated that children's unique rearing contexts contributed to the parenting they received and the externalizing behavior they exhibited. Implications for intervention are discussed.

The role of parenting in developmental trajectories of risk for adolescent substance use: a bioecological systems cascade model

Parenting is a key influence and prevention target for adolescent substance use, and changes dramatically in form and function during adolescence. This theoretical synthesis reviews evidence of associations of substance use-specific parenting behaviors, dimensions, and styles with adolescent substance use, and integrates key developmental and family theories (e.g., bioecological, dynamical systems, family systems, developmental cascades) and methodological-conceptual advances to illustrate the complex role that parenting plays for the development of adolescent substance use in combination with child and contextual influences. The resulting bioecological systems cascade model centers the dynamic co-development of parenting and child influences in developmental cascades that lead to more or less risk for adolescent substance use. These trajectories are initiated by intergenerational influences, including genetics, parents' familial environments, and child-parent attachment. Culture and context influences are a holistic backdrop shaping parent-adolescent trajectories. Parenting is influences are conceptualized as a complex process by which specific parenting behaviors are informed by and accumulate into parenting dimensions which together comprise general parenting styles and are informed by the broader family context. The co-development of parenting and child biobehavioral risk is shaped by both parents and children, including by the genetics and environments they do and do not share. This co-development is dynamic, and developmental transitions of individuals and the family lead to periods of increased lability or variability that can change the longer-term trajectories of children's risk for substance use. Methodological avenues for future studies to operationalize the model are discussed.

A genetically informed Registered Report on adverse childhood experiences and mental health

Children who experience adversities have an elevated risk of mental health problems. However, the extent to which adverse childhood experiences (ACEs) cause mental health problems remains unclear, as previous associations may partly reflect genetic confounding. In this Registered Report, we used DNA from 11,407 children from the United Kingdom and the United States to investigate gene-environment correlations and genetic confounding of the associations between ACEs and mental health. Regarding gene-environment correlations, children with higher polygenic scores for mental health problems had a small increase in odds of ACEs. Regarding genetic confounding, elevated risk of mental health problems in children exposed to ACEs was at least partially due to pre-existing genetic risk. However, some ACEs (such as childhood maltreatment and parental mental illness) remained associated with mental health problems independent of genetic confounding. These findings suggest that interventions addressing heritable psychiatric vulnerabilities in children exposed to ACEs may help reduce their risk of mental health problems.

Online parent training platform for complementary treatment of disruptive behavior disorders in attention deficit hyperactivity disorder: A randomized controlled trial protocol

Background

Attention Deficit/Hyperactivity Disorder (ADHD) is associated with a diversity of impairments and Oppositional Defiant Disorder (ODD) is a very frequent comorbidity. Parent Training, as an evidence-based intervention, seems effective in reducing externalizing/disruptive behaviors, possibly leading to a better prognosis. This clinical trial aims to evaluate the effectiveness of an online parent training model as a complementary treatment for ADHD and ODD.

Methods

Patients and their families will be screened upon their entry into the Research Center of Impulsivity and Attention (NITIDA) at UFMG—Brazil. Ninety families whose children are male, between 6–12 years old, and have significant externalizing symptoms and whose primary caregiver have complete high school education will be invited to participate. Families will be randomized (1:1) into 03 groups: 1) standard care; 2) standard care + face-to-face parent training; 3) standard care + online parent training. Interventions are analogous, differing only in delivery format. In the face-to-face format, the intervention will be conducted by a specialized therapist and the online format will be carried out through a platform. There will be six sessions/modules, arranged on a weekly basis. Measures of externalizing symptoms, parental and children quality of life, parental stress and parenting style will be collected at baseline and after the intervention.

Discussion

This clinical trial intends to verify the effects of a new, online, model of an evidence-based intervention, which would allow a wider access in the Brazilian context.

Trial registration

Registered on Brazilian Registry of Clinical Trials (ReBEC). Number: RBR-6cvc85. July 24^th (2020) 05:35 pm.

The role of parental genotype in the intergenerational transmission of externalizing behavior: Evidence for genetic nurturance

The purpose of this study was to examine possible pathways by which genetic risk associated with externalizing is transmitted in families. We used molecular data to disentangle the genetic and environmental pathways contributing to adolescent externalizing behavior in a sample of 1,111 adolescents (50% female; 719 European and 392 African ancestry) and their parents from the Collaborative Study on the Genetics of Alcoholism. We found evidence for genetic nurture such that parental externalizing polygenic scores were associated with adolescent externalizing behavior, over and above the effect of adolescents' own externalizing polygenic scores. Mediation analysis indicated that parental externalizing psychopathology partly explained the effect of parental genotype on children's externalizing behavior. We also found evidence for evocative gene-environment correlation, whereby adolescent externalizing polygenic scores were associated with lower parent-child communication, less parent-child closeness, and lower parental knowledge, controlling for parental genotype. These effects were observed among participants of European ancestry but not African ancestry, likely due to the limited predictive power of polygenic scores across ancestral background. These results demonstrate that in addition to genetic transmission, genes influence offspring behavior through the influence of parental genotypes on their children's environmental experiences, and the role of children's genotypes in shaping parent-child relationships.

Parenting in the Context of the Child: Genetic and Social Processes

The focus on the role of parenting in child development has a long-standing history. When measures of parenting precede changes in child development, researchers typically infer a causal role of parenting practices and attitudes on child development. However, this research is usually conducted with parents raising their own biological offspring. Such research designs cannot account for the effects of genes that are common to parents and children, nor for genetically influenced traits in children that influence how they are parented and how parenting affects them. The aim of this monograph is to provide a clearer view of parenting by synthesizing findings from the Early Growth and Development Study (EGDS). EGDS is a longitudinal study of adopted children, their birth parents, and their rearing parents studied across infancy and childhood. Families (N = 561) were recruited in the United States through adoption agencies between 2000 and 2010. Data collection began when adoptees were 9 months old (males = 57.2%; White 54.5%, Black 13.2%, Hispanic/Latinx 13.4%, Multiracial 17.8%, other 1.1%). The median child age at adoption placement was 2 days (M = 5.58, SD = 11.32). Adoptive parents were predominantly in their 30s, White, and coming from upper-middle- or upper-class backgrounds with high educational attainment (a mode at 4-year college or graduate degree). Most adoptive parents were heterosexual couples, and were married at the beginning of the project. The birth parent sample was more racially and ethnically diverse, but the majority (70%) were White. At the beginning of the study, most birth mothers and fathers were in their 20s, with a mode of educational attainment at high school degree, and few of them were married. We have been following these family members over time, assessing their genetic influences, prenatal environment, rearing environment, and child development. Controlling for effects of genes common to parents and children, we confirmed some previously reported associations between parenting, parent psychopathology, and marital adjustment in relation to child problematic and prosocial behavior. We also observed effects of children's heritable characteristics, characteristics thought to be transmitted from parent to child by genetic means, on their parents and how those effects contributed to subsequent child development. For example, we found that genetically influenced child impulsivity and social withdrawal both elicited harsh parenting, whereas a genetically influenced sunny disposition elicited parental warmth. We found numerous instances of children's genetically influenced characteristics that enhanced positive parental influences on child development or that protected them from harsh parenting. Integrating our findings, we propose a new, genetically informed process model of parenting. We posit that parents implicitly or explicitly detect genetically influenced liabilities and assets in their children. We also suggest future research into factors such as marital adjustment, that favor parents responding with appropriate protection or enhancement. Our findings illustrate a productive use of genetic information in prevention research: helping parents respond effectively to a profile of child strengths and challenges rather than using genetic information simply to identify some children unresponsive to current preventive interventions.

Understanding trajectories of externalizing problems: Stability and emergence of risk factors from infancy to middle adolescence

Despite considerable efforts to understand the processes that underlie the development of externalizing behavior problems, it is still unclear why externalizing problems remain chronically high for some children, emerge early and cease by late childhood for others, and arise in adolescence in some cases. The purpose of this study was to examine how a wide range of child and family risk factors are linked to trajectories of externalizing behavior and how these relationships vary from infancy to middle adolescence. We used data from the community-based Norwegian Tracking Opportunities and Problems (TOPP) study sample (n = 921). A Cholesky factorization model was specified to separate stable and emerging risk doses across four developmental periods (infancy, early and middle childhood, and middle adolescence). Children in the High Stable class were characterized by substantially elevated risk levels in multiple domains throughout the study period. Children in the High Childhood Limited class had very high levels of temperamental emotionality, internalizing symptoms, and maternal mental distress, suggesting a substantial intrinsic emotional basis for their externalizing problems. Intrinsic factors seemed less salient for the Adolescent Onset class. These findings emphasize the need for a dynamic perspective on risk factors and support the importance of prevention and intervention efforts across multiple domains from early childhood and throughout adolescence.

Child Effects on Parental Negativity: The Role of Heritable and Prenatal Factors

This study examined two possible mechanisms, evocative gene-environment correlation and prenatal factors, in accounting for child effects on parental negativity. Participants included 561 children adopted at birth, and their adoptive parents and birth parents within a prospective longitudinal adoption study. Findings indicated child effects on parental negativity, such that toddlers' negative reactivity at 18 months was positively associated with adoptive parents' over-reactive and hostile parenting at 27 months. Furthermore, we found that child effects on parental negativity were partially due to heritable (e.g., birth mother [BM] internalizing problems and substance use) and prenatal factors (e.g., BM illicit drug use during pregnancy) that influence children's negative reactivity at 18 months. This study provides critical evidence for "child on parent" effects.

Estimating the Heritability of Experiencing Child Maltreatment in an Extended Family Design

Child-driven genetic factors can contribute to negative parenting and may increase the risk of being maltreated. Experiencing childhood maltreatment may be partly heritable, but results of twin studies are mixed. In the current study, we used a cross-sectional extended family design to estimate genetic and environmental effects on experiencing child maltreatment. The sample consisted of 395 individuals (225 women; M_age = 38.85 years, range_age = 7-88 years) from 63 families with two or three participating generations. Participants were oversampled for experienced maltreatment. Self-reported experienced child maltreatment was measured using a questionnaire assessing physical and emotional abuse, and physical and emotional neglect. All maltreatment phenotypes were partly heritable with percentages for h² ranging from 30% (SE = 13%) for neglect to 62% (SE = 19%) for severe physical abuse. Common environmental effects (c²) explained a statistically significant proportion of variance for all phenotypes except for the experience of severe physical abuse (c² = 9%, SE = 13%, p = .26). The genetic correlation between abuse and neglect was ρ_g = .73 (p = .02). Common environmental variance increased as socioeconomic status (SES) decreased (p = .05), but additive genetic and unique environmental variances were constant across different levels of SES.

Neural Dynamic Responses of Monetary and Social Reward Processes in Adolescents

Adolescence is an essential developmental period characterized by reward-related processes. The current study investigated the development of monetary and social reward processes in adolescents compared with that in children and adults; furthermore, it assessed whether adolescents had different levels of sensitivity to various types of rewards. Two adapted incentive delay tasks were employed for each participant, and event-related potentials (ERPs) were recorded. The behavioral results showed that both monetary and social rewards could motivate response speed, and participants were more accurate under the monetary reward condition than under the social reward condition. The behavioral performances of individuals increased with age. For the ERP data, the cue-P3, target-P2, target-P3 and feedback-related negativity (FRN) components were investigated to identify reward motivation, emotional arousal, attention allocation and feedback processing. Children and adolescents showed higher motivation (larger cue-P3) to rewards than adults. Adolescents showed larger emotional responses to rewards; that is, they had larger target-P2 amplitudes than adults and shorter target-P2 latencies than children. Children showed stronger emotional reactivity for monetary rewards than for social rewards. All age groups had stronger attentional control (larger target-P3) under the monetary reward condition than under the social reward condition. The present study sheds light on the neurodevelopment of reward processes in children, adolescents and adults and shows that various reward process stages demonstrate different age-related and reward-type-related characteristics.

Bullying and psychotic symptoms in youth with bipolar disorder

BACKGROUND

Childhood trauma is associated with psychosis in adults with bipolar disorder (BD). Although bullying represents a widespread form of childhood trauma, no studies thus far have investigated the association of bullying and psychosis in pediatric bipolar disorder (PBD). We aim to examine the association between psychosis in PBD with bullying victimization.

METHODS

We included 64 children and adolescents (age± mean= 12±3.43) outpatients with BD spectrum disorders. Psychiatric diagnoses were assessed with the semi- structured interview Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime (KSADS-PL) version with additional depression and manic symptom items derived from the Washington University in St. Louis Kiddie Schedule for Affective Disorders (WASH-U-KSADS). Bullying, demographic, and clinical variables were assessed during the clinical interview.

RESULTS

A lifetime history of psychotic symptoms was associated with bullying (p = 0.002), suicidal behavior (p = 0.006), low socioeconomic status (p = 0.04), and severity of PBD (p = 0.02). Only bullying (OR = 7.3; 95%CI = 2-32) and suicidal behavior (OR = 7.6; 95%CI = 1.5-47.8) remained significant after adjustment for confounders. In a supplementary analysis, we developed a model using supervised machine learning to identify the most relevant variables that differentiated participants with psychotic symptoms, which included bullying, Clinical Global Impression-Severity scale (CGI-S), and suicidal behavior (accuracy = 75%, [p = 0.03]; sensitivity = 77.91%; specificity = 69.05%; area under the curve [AUC] = 0.86).

LIMITATIONS

Small sample, cross-sectional design, and generalizability of findings beyond the outpatient clinical sample.

CONCLUSIONS

Findings underscore the importance of assessing bullying in PBD participants. Future longitudinal studies with larger samples are needed to replicate our findings and determine causality.

Parenting and prenatal risk as moderators of genetic influences on conduct problems during middle childhood

This study examines interactions of heritable influences, prenatal substance use, and postnatal parental warmth and hostility on the development of conduct problems in middle childhood for boys and girls. Participants are 561 linked families, collected in 2 cohorts, including birth parents, adoptive parents, and adopted children. Heritable influences on internalizing and externalizing (including substance use) problems were derived from birth mothers' and fathers' symptoms, diagnoses, and age of onset from diagnostic interviews, and the proportion of first-degree relatives with the same type of problems. Smoking during pregnancy (SDP) and alcohol use during pregnancy were assessed retrospectively from birth mothers at 5 months postpartum. Earlier externalizing problems and parental warmth and hostility and were assessed at 1 assessment prior to the outcome (Cohort II: 4.5 years; Cohort I: 7 years). Conduct problems were symptoms from a diagnostic interview assessed at age 6 (Cohort II) or 8 (Cohort I). Findings from regression analyses suggest that (a) SDP plays an important role for the development of conduct problems, (b) some relatively well-accepted effects (e.g., parental hostility) were less important when simultaneously considering multiple factors influencing the development of conduct problems, and (c) main effects of genetic risk and SDP, and interactions among genetic risk and postnatal warmth, SDP and postnatal warmth, and genetic risk, SDP, and postnatal hostility for conduct problems were important for boys' but not girls' conduct problems. Replication is needed, but the current results provide preliminary but empirically grounded hypotheses for future research testing complex developmental models of conduct problems. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Did I Inherit My Moral Compass? Examining Socialization and Evocative Mechanisms for Virtuous Character Development

Virtuous character development in children is correlated with parenting behavior, but the role of genetic influences in this association has not been examined. Using a longitudinal twin/sibling study (N = 720; Time 1 (T1) Mage = 12-14 years, Time 3 (T3) Mage = 25-27 years), the current report examines associations among parental negativity/positivity and offspring responsibility during adolescence, and subsequent young adult conscientiousness. Findings indicate that associations among parental negativity and offspring virtuous character during adolescence and young adulthood are due primarily to heritable influences. In contrast, the association between concurrent parental positivity and adolescent responsibility was due primarily to heritable and shared environmental influences. These findings underscore the contributions of heritable influences to the associations between parenting and virtuous character that have previously been assumed to be only environmentally influenced, emphasizing the complexity of mechanisms involved in the development of virtuous character.

Contributions of mothers' and fathers' parenting to children's self-regulation: Evidence from an adoption study

The origins of top-down self-regulation are attributed to genetic and socialization factors as evidenced by high heritability estimates from twin studies and the influential role of parenting. However, recent evidence suggests that parenting behavior itself is affected by parents' own top-down self-regulation. Because children's top-down self-regulation is influenced by genetic factors and parenting is influenced by top-down self-regulation, the effects of parenting on children's top-down self-regulation identified in prior studies may partially reflect passive gene-environment correlation. The goal of this study was to examine parenting influences on children's top-down self-regulation using a longitudinal, adoption-at-birth design, a method of identifying parenting influences that are independent of the role of shared genetic influences on children's characteristics because adoptive parents are genetically unrelated to their adopted child. Participants (N = 361) included adoptive families and biological mothers of adopted children. Adoptive mothers' and fathers' harsh/negative parenting were assessed when children were 27 months of age and biological mothers' top-down self-regulation was assessed when children were 54 months of age. Adopted children's top-down self-regulation was assessed when they were 54 and 72 months of age. Results, accounting for child gender, biological mother top-down self-regulation, and the potential evocative effects of adopted child anger, provide evidence that inherited influences and socialization processes uniquely contribute to children's top-down self-regulation. Furthermore, findings demonstrate the importance of both mother's and father's parenting behavior as an influence on young children's top-down self-regulation. The implications of these findings for understanding the complex mechanisms that influence children's top-down self-regulation are discussed.

A Review of the Historical, Criminological, and Theoretical Understandings of the Cambodian American Population: A Call for More Comprehensive Research

The collective view of Asian Americans as model minorities is evident with the extensive amount of statistical data showing support for the academic and socioeconomic success of Asian Americans in the United States. This perception, however, often presents an inaccurate portrayal of Asian Americans, in general, as it overlooks many of the difficulties and hardships experienced by Asian American ethnic groups such as Southeast Asians. Within this group, Cambodian Americans are at the highest risk for experiencing socioeconomic hardships, behavioral health problems, substance use disorders, and contact with the criminal justice system, with deportation also being a prevailing issue. Unfortunately, research in this area is scant and contemporary research on Cambodian Americans has several limitations. To begin to address this issue, the present article merges information from existing research on this population from a sociohistorical, criminological, and theoretical standpoint to call for more comprehensive research on Cambodian Americans.

Shared genetic influences do not explain the association between parent-offspring relationship quality and offspring internalizing problems: results from a Children-of-Twins study

BACKGROUND

Associations between parenting and child outcomes are often interpreted as reflecting causal, social influences. However, such associations may be confounded by genes common to children and their biological parents. To the extent that these shared genes influence behaviours in both generations, a passive genetic mechanism may explain links between them. Here we aim to quantify the relative importance of passive genetic v. social mechanisms in the intergenerational association between parent-offspring relationship quality and offspring internalizing problems in adolescence.

METHODS

We used a Children-of-Twins (CoT) design with data from the parent-based Twin and Offspring Study of Sweden (TOSS) sample [909 adult twin pairs and their offspring; offspring mean age 15.75 (2.42) years], and the child-based Swedish Twin Study of CHild and Adolescent Development (TCHAD) sample [1120 adolescent twin pairs; mean age 13.67 (0.47) years]. A composite of parent-report measures (closeness, conflict, disagreements, expressions of affection) indexed parent-offspring relationship quality in TOSS, and offspring self-reported internalizing symptoms were assessed using the Child Behavior Checklist (CBCL) in both samples.

RESULTS

A social transmission mechanism explained the intergenerational association [r = 0.21 (0.16-0.25)] in our best-fitting model. A passive genetic transmission pathway was not found to be significant, indicating that parental genetic influences on parent-offspring relationship quality and offspring genetic influences on their internalizing problems were non-overlapping.

CONCLUSION

These results indicate that this intergenerational association is a product of social interactions between children and parents, within which bidirectional effects are highly plausible. Results from genetically informative studies of parenting-related effects should be used to help refine early parenting interventions aimed at reducing risk for psychopathology.

Parental involvement as an etiological moderator of middle childhood oppositional defiant disorder

The goal of this study was to investigate parental involvement as an etiologic moderator of oppositional defiant disorder (ODD) during middle childhood. Previous studies examining the influence of genetic and environmental factors on ODD have not considered whether and how these factors might vary by parental involvement. We thus conducted a series of "latent genetic by measured environmental" interaction analyses, in which measured parental involvement was allowed to moderate genetic, shared, and nonshared environmental influences on child ODD. Participants include 1,027 twin pairs (age ranged from 6 to 11 years old) from the Michigan State University Twin Registry. Results did indeed suggest that the etiology of ODD varies with maternal involvement, such that genetic influence on ODD became more prominent as maternal involvement decreased. However, these results were specific to children's perceptions of maternal involvement and did not extend to maternal perceptions of her involvement. There was no evidence that paternal involvement moderated the etiology of ODD, regardless of informant. The different results found in twins' and parents' data are consistent with those in previous research showing that children may have different perceptions from parents' about their family relationships and that this discrepancy needs to be taken into account in future research. (PsycINFO Database Record

Roles of Response Inhibition and Gene-Environment Interplay in Pathways to Adolescents' Externalizing Problems

This study used two waves of data to investigate pathways through which adolescents' response inhibition related to later externalizing problems. A polygenic risk score indexed genetic risk for poor response inhibition. Adolescents' performance on a response inhibition task mediated the relation between adolescents' polygenic risk scores and mother's inconsistent parenting (i.e., evocative rGE), even after controlling for mothers' genetic risk (i.e., passive rGE). Mothers' inconsistent parenting subsequently prospectively predicted adolescents' externalizing problems. Adolescents' response inhibition also prospectively predicted later externalizing behaviors. These findings were subgroup-specific, with greater risk for non-Hispanic Caucasian boys with substance-disordered parents. Results suggest that poor response inhibition may increase risk for adolescents' externalizing problems both directly and by evoking certain environmental conditions.

Etiological Influences on Perceptions of Parenting: A Longitudinal, Multi-Informant Twin Study

Children and their parents often differ in their perception of the relationship they share. As this relationship changes developmentally, the nature of these differences may also change. Longitudinal genetic designs can be used to investigate the developmental etiologies of shared and distinct perceptions. In this study, we used longitudinal psychometric models to analyze child and parent reports of negative parenting for 6417 twin pairs from the Twins Early Development Study at ages 9, 12 and 14 years. Within-time cross-reporter correlations, indicating the degree to which children and parents perceived negative parenting behaviors similarly at each age, were moderate (r = .44 - .46). Longitudinal genetic analyses revealed these shared perceptions to be relatively stable during the transition into adolescence, with this stability driven by a combination of children's genetic factors and family-wide environmental factors. In contrast, child- and parent-specific perceptions of parenting were predominantly age-specific, a developmental pattern underpinned by child genetic factors and a combination of family-wide and unique environmental influences. These results and their implications are discussed in the context of interplay between reciprocal interactions, subjective insight and developmental behavioral change in the parent-child relationship.

Birth and Adoptive Parent Antisocial Behavior and Parenting: A Study of Evocative Gene-Environment Correlation

Negative parenting is shaped by the genetically influenced characteristics of children (via evocative rGE) and by parental antisocial behavior; however, it is unclear how these factors jointly impact parenting. This study examined the effects of birth parent and adoptive parent antisocial behavior on negative parenting. Participants included 546 families within a prospective adoption study. Adoptive parent antisocial behavior emerged as a small but significant predictor of negative parenting at 18 months and of change in parenting from 18 to 27 months. Birth parent antisocial behavior predicted change in adoptive father's (but not mother's) parenting over time. These findings highlight the role of parent characteristics and suggest that evocative rGE effects on parenting may be small in magnitude in early childhood.

Genetic and Environmental Overlap Between Childhood Maltreatment and Adult Physical Health

Past research demonstrates a phenotypic relationship between childhood maltreatment and adult health problems. Explanations of this association usually point to either: (a) a direct causal link, whereby exposure to early stress disrupts biological functioning during sensitive periods of development; or (b) an indirect effect operating through socioeconomic attainment, poor health behaviors, or some other pathway leading from childhood to adulthood. The current study examined whether the association between childhood maltreatment and adult health reflects genetic or environmental mediation. Using a large sample of adult American twins, we separately estimated univariate biometric models of child maltreatment and adult physical health, followed by a bivariate biometric model to estimate genetic and environmental correlations between the two variables. We found that a summary count of chronic health conditions shared non-trivial genetic overlap with childhood maltreatment. Our results have implications for understanding the relationship between maltreatment and health as one of active interplay rather than a simple cause and effect model that views maltreatment as an exogenous shock.

Antisocial peer affiliation and externalizing disorders: Evidence for Gene × Environment × Development interaction

Gene × Environment interaction contributes to externalizing disorders in childhood and adolescence, but little is known about whether such effects are long lasting or present in adulthood. We examined gene-environment interplay in the concurrent and prospective associations between antisocial peer affiliation and externalizing disorders (antisocial behavior and substance use disorders) at ages 17, 20, 24, and 29. The sample included 1,382 same-sex twin pairs participating in the Minnesota Twin Family Study. We detected a Gene × Environment interaction at age 17, such that additive genetic influences on antisocial behavior and substance use disorders were greater in the context of greater antisocial peer affiliation. This Gene × Environment interaction was not present for antisocial behavior symptoms after age 17, but it was for substance use disorder symptoms through age 29 (though effect sizes were largest at age 17). The results suggest adolescence is a critical period for the development of externalizing disorders wherein exposure to greater environmental adversity is associated with a greater expression of genetic risk. This form of Gene × Environment interaction may persist through young adulthood for substance use disorders, but it appears to be limited to adolescence for antisocial behavior.

The etiology of the association between child antisocial behavior and maternal negativity varies across aggressive and non-aggressive rule-breaking forms of antisocial behavior

There is a robust association between negative parenting and child antisocial behavior problems. However, the etiology of this association remains unclear. Extant literature has reported strikingly different conclusions across studies, with some highlighting genetic mediation and others highlighting environmental mediation. One possible reason for these discrepancies across studies may be the failure to differentiate between aggressive and non-aggressive (rule-breaking) dimensions of childhood antisocial behavior, given their notably different etiologies and developmental trajectories (Burt 2012). The current study sought to examine the phenotypic and etiologic associations of maternal negativity with aggressive and rule-breaking antisocial behavior, respectively. Participants included 824 mothers and their twin children between the ages of 6 and 10. Our results highlighted clear etiologic distinctions in the associations of aggression and rule-breaking with maternal negativity. Aggression was associated with maternal negativity via both genetic and environmental factors, whereas the association between non-aggressive rule-breaking and maternal negativity was entirely environmental in origin. These findings provide additional support for the presence of meaningful distinctions between aggressive and non-aggressive forms of antisocial behavior, and highlight the complex relationship between parenting and child outcome.

Genetic Influences on Peer and Family Relationships Across Adolescent Development: Introduction to the Special Issue

Nearly all aspects of human development are influenced by genetic and environmental factors, which conjointly shape development through several gene-environment interplay mechanisms. More recently, researchers have begun to examine the influence of genetic factors on peer and family relationships across the pre-adolescent and adolescent time periods. This article introduces the special issue by providing a critical overview of behavior genetic methodology and existing research demonstrating gene-environment processes operating on the link between peer and family relationships and adolescent adjustment. The overview is followed by a summary of new research studies, which use genetically informed samples to examine how peer and family environment work together with genetic factors to influence behavioral outcomes across adolescence. The studies in this special issue provide further evidence of gene-environment interplay through innovative behavior genetic methodological approaches across international samples. Results from the quantitative models indicate environmental moderation of genetic risk for coercive adolescent-parent relationships and deviant peer affiliation. The molecular genetics studies provide support for a gene-environment interaction differential susceptibility model for dopamine regulation genes across positive and negative peer and family environments. Overall, the findings from the studies in this special issue demonstrate the importance of considering how genes and environments work in concert to shape developmental outcomes during adolescence.

Parental criticism is an environmental influence on adolescent somatic symptoms

Previous studies have suggested that parental criticism leads to more somatic symptoms in adolescent children. However, this research has not assessed the direction of causation or whether genetic and/or environmental influences explain the association between parental criticism and adolescent somatic symptoms. As such, it is impossible to understand the mechanisms that underlie this association. The current study uses the Extended Children of Twins design to examine whether parents' genes, adolescents' genes, and/or environmental factors explain the relationship between parental criticism and adolescent somatic symptoms. Participants came from 2 twin samples, including the Twin and Offspring Study in Sweden (N = 868 pairs of adult twins and each twin's adolescent child) and from the Twin Study of Child and Adolescent Development (N = 690 pairs of twin children and their parents). Findings showed that environmental influences account for the association between parental criticism and adolescent somatic symptoms. This suggests that parents' critical behaviors exert a direct environmental effect on somatic symptoms in adolescent children. Results support the use of intervention programs focused on parental criticism to help reduce adolescents' somatic symptoms.

Understanding Associations among Family Support, Friend Support, and Psychological Distress

Emotional support from family and friends is associated with lower psychological distress. This study examined whether genetic and environmental influences explain associations among family support, friend support, and psychological distress. Data were drawn from the Midlife Development in the United States (MIDUS) study and included 947 pairs of MZ, same-sex DZ, and opposite-sex DZ twins. Results showed that a genetic factor explains the relationship between friend support and psychological distress, independent of family support. Alternatively, a nonshared environmental factor accounts for an association among family support, friend support, and psychological distress. Thus, heritable factors shape a distinct relationship between friend support and psychological distress, but unique experiences contribute to a link among family support, friend support, and psychological distress.

A constructive replication of the association between the oxytocin receptor genotype and parenting

Behavioral genetic studies have robustly indicated that parenting behaviors are heritable-that is, individual differences in parenting are at least partially a function of genetic differences between persons. Few studies, however, have sought to identify the specific genetic variants that are associated with individual differences in parenting. Genes that influence the oxytocin system are of particular interest, given the growing body of evidence that points to the role of oxytocin for social behaviors, including parenting. The current study conducted examinations of associations between a variant in the oxytocin receptor gene (OXTR rs53576) and parental warmth, control, and negativity in a sample of 1,000 twin children and their parents (N = 500 families) from the Michigan State University Twin Registry to constructively replicate and extend prior work (Bakermans-Kranenburg & van IJzendoorn, 2008; Michalska et al., 2014). Analyses were conducted both at the level of the child and the level of the parent, allowing us to examine both child-driven (via evocative gene-environment correlation) and parent-driven genetic effects on parenting. Mothers' OXTR genotype predicted her warmth toward her children, even after controlling for child genotype. This association was not found for fathers. These findings add to the growing body of evidence linking oxytocin functioning to parental behavior and also highlight potential etiological differences in parenting across mothers and fathers.

Parental knowledge is an environmental influence on adolescent externalizing

BACKGROUND

There is evidence both that parental monitoring is an environmental influence serving to diminish adolescent externalizing problems and that this association may be driven by adolescents' characteristics via genetic and/or environmental mechanisms, such that adolescents with fewer problems tell their parents more, and therefore appear to be better monitored. Without information on how parents' and children's genes and environments influence correlated parent and child behaviors, it is impossible to clarify the mechanisms underlying this association.

METHOD

The present study used the Extended Children of Twins model to distinguish types of gene-environment correlation and direct environmental effects underlying associations between parental knowledge and adolescent (age 11-22 years) externalizing behavior with a Swedish sample of 909 twin parents and their adolescent offspring and a US-based sample of 405 White adolescent siblings and their parents.

RESULTS

Results suggest that more parental knowledge is associated with less adolescent externalizing via a direct environmental influence independent of any genetic influences. There was no evidence of a child-driven explanation of the association between parental knowledge and adolescent externalizing problems.

CONCLUSIONS

In this sample of adolescents, parental knowledge exerted an environmental influence on adolescent externalizing after accounting for genetic influences of parents and adolescents. Because the association between parenting and child development originates in the parent, treatment for adolescent externalizing must not only include parents but should also focus on altering their parental style. Thus, findings suggest that teaching parents better knowledge-related monitoring strategies is likely to help reduce externalizing problems in adolescents.