Externalizing Problem Behavior in Adolescence: Dopaminergic Genes in Interaction with Peer Acceptance and Rejection

Maternal disapproval of friends in response to child conduct problems damages the peer status of pre- and early adolescents

BACKGROUND

Herein, we consider the hypothesis that mothers harm peer relations when they respond to child conduct problems by expressing disapproval of friends, which exacerbates the behavior problems they were presumably attempting to deter.

METHODS

A community sample of Lithuanian adolescents (292 boys and 270 girls, aged 9-14 years) completed surveys three times during an academic year. Classmate nominations indexed peer status (acceptance and rejection), self-reports described perceived maternal disapproval of friends, and peer nominations and self-reports separately gauged conduct problems.

RESULTS

Over the course of a school year: (a) conduct problems were associated with subsequent increases in perceived maternal friend disapproval; (b) perceived maternal friend disapproval was associated with subsequent decreases in peer status; and (c) low peer status was associated with subsequent increases in conduct problems. Full longitudinal, random-intercept cross-lagged panel mediation models confirmed that mothers who disapproved of friends were sources of peer difficulties that culminated in conduct problems and intermediaries whose response to child conduct problems damaged peer relations. Findings were stronger for peer rejection than for peer acceptance, suggesting that peers actively dislike those with mothers who intervene in peer relationships.

CONCLUSIONS

Maternal disapproval of friends in response to child conduct problems damages the child's standing among peers, which then exacerbates behavior problems. This consequential cascade underscores the need for parent education about the potential deleterious consequences of well-intentioned interference in peer relations. Practitioners should be prepared to offer constructive, alternative solutions when youth present behavior problems.

Longitudinal Relation between Family Socio-Economic Status and Problem Behaviors in Chinese Children: The Roles of Sense of Coherence and Maternal Warmth

Literature has well-documented the relation of family socio-economic status (SES) to children’s problem behaviors, yet the complex mechanisms underlying the relation are not well understood. Therefore, the primary goal of this one-year longitudinal study was to explore the mediating role of children’s sense of coherence and the moderating role of perceived maternal warmth in the association between family SES and externalizing and internalizing problems in Chinese children. The sample consisted of 913 children (493 boys; Mage = 11.50 years, SD = 1.04) in fourth to sixth grades in an urban area in mainland China. Data were obtained from multiple sources, including child self-reports, parental reports, and teacher ratings. The results indicated that children’s sense of coherence mediated the association between family SES and internalizing problem behaviors, but not externalizing problem behaviors. This mediating role was also moderated by maternal warmth and specifically, family SES was negatively associated with internalizing problem behaviors via the sense of coherence for children who perceived high maternal warmth. Generally, these results highlighted the possible roles of a sense of coherence and maternal warmth in the longitudinal implications of family SES for Chinese children’s internalizing problems.

The association between peer rejection and behavior problems of migrant adolescents in China: A moderated mediation model of delinquent peer affiliation and parenting

Facing a stressful environment of peer rejection and discrimination, Chinese migrant adolescents are at high risk of developing behavior problems while receiving insufficient family support. In this context, the current study aimed to explore the pathway from peer rejection to adolescent behavior problems via the mediating role of delinquent peer affiliation and with the moderating roles of parental company and parental monitoring taken into consideration. A sample of 2041 migrant adolescents (46.2% female, mean age = 13.595) was drawn from the first and second waves of the China Education Panel Survey (CEPS) for running a moderated mediation model. The results demonstrated that peer rejection positively predicted behavior problems through the mediator of delinquent peer affiliation (indirect effect = 0.007, 95% CI = [0.003, 0.014]). This mediating mechanism was moderated by parental company and by parental monitoring. Our study deepened the theoretical understanding and application of the general strain theory by showing how the interaction of peer stressors and parenting elements affected the behavior of migrant adolescents in a Chinese context. Further studies could pay more attention to the dynamic interplay between the family and peer systems, especially for rejected and marginalized adolescent groups. Limitations and implications for future school-based and family-based practices are also discussed.

The association between peer rejection and aggression types: A meta-analysis

BACKGROUND

Although previous studies have assessed the association between peer rejection and aggression, the results are mixed.

OBJECTIVE

This article presents a meta-analysis of the association between peer rejection and aggression types (overt vs. relational) among children and adolescents.

PARTICIPANTS AND SETTING

A total of 61 eligible studies with 70 independent effect sizes were included in the analysis (45,966 participants, M_age = 10.34, SD = 3.13).

METHODS

First, random-effects meta-analyses were conducted to explore the association between peer rejection and aggression types (overt vs. relational). Next, moderation analyses were conducted based on the Q statistics for categorical variables (culture, reporting method of peer rejection, reporting method of aggression) and the meta-regression analyses for continuous variable (age).

RESULTS

Peer rejection was positively correlated with overall aggression (r = 0.42, 95 % CI [0.38, 0.47], p < 0.001), overt aggression (r = 0.46, 95 % CI [0.38, 0.54], p < 0.001) and relational aggression (r = 0.43, 95 % CI [0.35, 0.51], p < 0.001). This correlation was positive for each type when controlling for other form of aggression. Moderation analyses suggested that reporting method of aggression (self-report vs. peer-nomination vs. adult-report vs. observation), reporting method of peer rejection (self-report vs. peer-nomination vs. adult-report) and culture (collectivist vs. individualist) were moderators of the association between peer rejection and overall aggression. Culture moderated the association between peer rejection and overt aggression, while age moderated the association between peer rejection and relational aggression.

CONCLUSIONS

The findings showed a strong positive association between peer rejection and aggression, although this association varied by aggression type and other moderating variables.

Integrative Brain Dynamics in Childhood Bullying Victimization: Cognitive and Emotional Convergence Associated With Stress Psychopathology

Bullying victimization is a form of psychological stress that is associated with poor outcomes in the areas of mental health and learning. Although the emotional maladjustment and memory impairment following interpersonal stress are well documented, the mechanisms of complex cerebral dysfunctions have neither been outlined nor studied in depth in the context of childhood bullying victimization. As a contribution to the cross-disciplinary field of developmental psychology and neuroscience, we review the neuropathophysiology of early life stress, as well as general psychological stress to synthesize the data and clarify the versatile dynamics within neuronal networks linked to bullying victimization. The stress-induced neuropsychological cascade and associated cerebral networks with a focus on cognitive and emotional convergence are described. The main findings are that stress-evoked neuroendocrine reactivity relates to neuromodulation and limbic dysregulation that hinder emotion processing and executive functioning such as semantic cognition, cognitive flexibility, and learning. Developmental aspects and interacting neural mechanisms linked to distressed cognitive and emotional processing are pinpointed and potential theory-of-mind nuances in targets of bullying are presented. The results show that childhood stress psychopathology is associated with a complex interplay where the major role belongs to, but is not limited to, the amygdala, fusiform gyrus, insula, striatum, and prefrontal cortex. This interplay contributes to the sensitivity toward facial expressions, poor cognitive reasoning, and distress that affect behavioral modulation and emotion regulation. We integrate the data on major brain dynamics in stress neuroactivity that can be associated with childhood psychopathology to help inform future studies that are focused on the treatment and prevention of psychiatric disorders and learning problems in bullied children and adolescents.

Sensitivity, but to which environment? Individual differences in sensitivity to parents and peers show domain-specific patterns and a negative genetic correlation

The idea that individuals differ in their sensitivity to the environment's effects is a cornerstone of developmental science. It has been demonstrated repeatedly, for different kinds of stressors, outcomes, and sensitivity markers. However, almost no empirical work was done to examine whether environmental sensitivity is domain-general (i.e., the same individuals are sensitive to different environmental contexts) or domain-specific (i.e., different individuals are sensitive to different environmental contexts), despite its importance to understanding human development, learning, and behavior. To address this question, phenotypic sensitivity to parents and to peers were compared in 1313 11-year-old Israeli adolescent twins. We found that, (1) our phenotypic markers indeed moderate environmental influences, with a discriminant predictive utility, (2) adolescents who are sensitive to their parents are not necessarily sensitive to their peers, and (3) sensitivity to parents and sensitivity to peers have different etiologies and show a negative genetic correlation, indicating that adolescents carrying genetic markers for sensitivity to parents are less likely to carry genetic markers for sensitivity to peers. These findings suggest that environmental sensitivity shows domain-specific patterns, as different individuals can be sensitive to different environments. We discuss the theoretical, empirical, and practical implications of domain-specificity of environmental sensitivity.

Epigenetic regulation of DAT gene promoter modulates the risk of externalizing and internalizing behaviors on a normative population: An explorative study

Accumulating research addressed epigenetic modifications and their role on behavioral phenotypes. We recently proposed to study methylation dynamics of two CpG motifs within the 5'-UTR of dopamine transporter (DAT) gene. Starting from a normative population sample of young adults, we selected three sub-groups based on their prevalent symptoms: subjects were assigned to Internalizing, Externalizing and Low-risk sub-groups according to elevated scores in specific phenotypic scales. Using a new approach, we calculated three independent matrixes of cross-correlation between CpG methylation levels, one within each phenotypic sub-group, to determine in which dynamics did the sub-groups differ. We found specific cross-correlation patterns in Externalizing (CpG1, 2 and 3, opposite to the methylation at CpG6) and Internalizing individuals (CpG1 methylation opposite to CpG2, 3 and 6), while Low-risk individuals could follow both trends. The aim of our study was to look for a specific DAT methylation pattern, providing a biomarker that allows early identification of the risk for psycho-pathological deviance.

Longitudinal Links between Adolescent and Peer Conduct Problems and Moderation by a Sensitivity Genetic Index

The most extensively studied influence on adolescent conduct problem behaviors is peers, and the literature points to genetics as one source of individual differences in peer influence. The purpose of this study was to test the hypothesis that an environmental sensitivity genetic index comprised of DRD4, 5-HTTLPR, and GABRA2 variation would moderate the association between peer and adolescent conduct problems. Latent growth modeling was applied to PROSPER project longitudinal data from adolescents and their peers. Results showed the hypothesis was supported; adolescents with more copies of putative sensitivity alleles were more strongly influenced by their peers. The interaction form was consistent with differential susceptibility in follow-up analyses. Strengths and weaknesses of genetic aggregates for sensitivity research are discussed.

Effect of Methylphenidate on Resting-State Connectivity in Adolescents With a Disruptive Behavior Disorder: A Double-Blind Randomized Placebo-Controlled fMRI Study

Some studies suggest that methylphenidate (MPH) might be an effective treatment for antisocial and aggressive behavior in adolescence. However, little is known about the mechanism of action of MPH in adolescents with this kind of psychopathology. MPH is a dopamine and norepinephrine reuptake inhibitor and thus it is likely to affect dopaminergic mesocorticolimbic pathways. This is the first study to investigate the effect of MPH on resting-state connectivity of three mesolimbic seed regions with the rest of the brain in clinical referred male adolescents with a disruptive behavior disorder (DBD). Thirty-six male DBD adolescents and 31 male healthy controls (HCs) were included. DBD subjects were randomly allocated to a single dose of MPH (DBD-MPH, n = 20) or placebo (DBD-PCB, n = 16). Seed-based resting-state functional connectivity of the nucleus accumbens (NAcc), amygdala, and ventral tegmental area (VTA) with the rest of the brain was compared between groups. The NAcc seed showed increased connectivity in DBD-PCB compared to HC with the occipital cortex, posterior cingulate cortex (PCC), precuneus, and inferior parietal lobule (IPL) and increased connectivity in DBD-PCB compared to DBD-MPH with occipital cortex, IPL, and medial frontal gyrus. The amygdala seed showed increased connectivity in DBD-PCB compared to HC with the precuneus and PCC. The VTA seed showed increased connectivity in the DBD-MPH compared to the DBD-PCB group with a cluster in the postcentral gyrus and a cluster in the supplementary motor cortex/superior frontal gyrus. Both NAcc and amygdala seeds showed no connectivity differences in the DBD-MPH compared to the HC group, indicating that MPH normalizes the increased functional connectivity of mesolimbic seed regions with areas involved in moral decision making, visual processing, and attention.

Internalizing Problems in Adolescence: Linking Loneliness, Social Anxiety Symptoms, and Depressive Symptoms Over Time

Adolescents are particularly vulnerable to experiencing loneliness, social anxiety symptoms, and depressive symptoms. These internalizing problems often co-occur but, until now, it remains unclear how they are associated over time. Insight in these temporal sequences is important to enhance our understanding of how internalizing problems arise and may reinforce each other over time. To examine these temporal sequences, three samples of adolescents were used: Sample 1 consisted of 1,116 adolescents (48.97% girls, M_age = 13.59), Sample 2 of 1,423 adolescents (52.42% girls, M_age = 13.79), and Sample 3 of 549 adolescents (62.66% girls, M_age = 14.82). Adolescents filled out well-established self-report measures of loneliness, social anxiety symptoms, and depressive symptoms during regular school hours at three measurement occasions with a 1-year interval. Meta-analytic techniques were used to estimate the average true effects across three-variable autoregressive cross-lagged models in the three samples. In addition, indirect effects and gender differences in the temporal associations were explored in all three samples. The results suggest that social anxiety symptoms play a crucial role as potential antecedent of emerging feelings of loneliness and depression in adolescence. In addition, in line with theoretical expectations, our results suggest the presence of a vicious cycle between adolescents' feelings of loneliness and social anxiety symptoms. The indirect effects were inconsistent across samples and no gender differences were found. These findings shed more light on the unique temporal relationships among different internalizing problems. Clinical interventions should target social anxiety symptoms to prevent feelings of loneliness and vice versa.

Loneliness, Social Anxiety Symptoms, and Depressive Symptoms in Adolescence: Longitudinal Distinctiveness and Correlated Change

Loneliness, social anxiety symptoms, and depressive symptoms are internalizing problems that are highly intertwined and often co-occur during adolescence. This overlap and co-occurrence raises the question whether three different labels are used for the same underlying phenomenon. The present study adopts a comprehensive approach to this issue by investigating the development of the three phenomena simultaneously. Specifically, this study aimed to investigate (1) the developmental trend for all three internalizing problems separately, (2) whether they are best described by a single developmental trend, (3) how they co-develop across adolescence, and (4) gender differences in this co-development. The analyses were run in three three-wave longitudinal samples of adolescents with one-year intervals in order to verify the robustness of the findings. Sample 1 (roughly ages 15, 16, and 17) comprised 549 adolescents (63% girls), and Samples 2 and 3 (roughly ages 13, 14, and 15) comprised 811 adolescents (46% girls) and 1101 adolescents (52% girls), respectively. Latent growth curve modeling for the three phenomena separately showed either small increases or stable patterns. A comparison of a Multiple Indicator Latent Growth Model (MILGM) with a Parallel Process Latent Growth Curve Modeling (PPLGCM) showed that the three internalizing problems followed unique, but related, developmental trends across adolescence. The intercepts of the three phenomena were positively correlated with one another in all samples and increases in loneliness were associated consistently with increases in social anxiety symptoms. Only in Sample 3 evidence was found for a similar association between loneliness and depressive symptoms and between social anxiety symptoms and depressive symptoms. Except for differences in initial levels, gender differences in the development of the three problems were limited. Overall, the results of the present study clearly indicate that the three internalizing problems are longitudinally distinct from one another, but co-develop across adolescence.

Three phases of Gene × Environment interaction research: Theoretical assumptions underlying gene selection

Some Gene × Environment interaction (G×E) research has focused upon single candidate genes, whereas other related work has targeted multiple genes (e.g., polygenic scores). Each approach has informed efforts to identify individuals who are either especially vulnerable to the negative effects of contextual adversity (diathesis stress) or especially susceptible to both positive and negative contextual conditions (differential susceptibility). A critical step in all such molecular G×E research is the selection of genetic variants thought to moderate environmental influences, a subject that has not received a great deal of attention in critiques of G×E research (beyond the observation of small effects of individual genes). Here we conceptually distinguish three phases of G×E work based on the selection of genes presumed to moderate environmental effects and the theoretical basis of such decisions: (a) single candidate genes, (b) composited (multiple) candidate genes, and (c) GWAS-derived polygenic scores. This illustrative, not exhaustive, review makes it clear that implicit or explicit theoretical assumptions inform gene selection in ways that have not been clearly articulated or fully appreciated.

Cyberbullying: relationship with developmental variables and cyber victimization

BACKGROUND AND OBJECTIVE

Cyberbullying is increasingly turning into a significant problem for children and adolescents due to its adverse psychological and academic outcomes. In the present study, the protective and risk factors for cyberbullying has been investigated. One of the aims of the study was to examine the relationship between peer relations, negative emotion regulation strategies, and cyberbullying. The successful identity development process is thought to influence both cyberbullying behaviors as well as adolescents' peer relations and emotion regulation. Also, cyber victimization is seen as a risk factor for cyberbullying. The second aim of the study is to investigate the causal relationship between cyber victimization and cyberbullying.

METHOD

The study is a descriptive research in which both cross-sectional and longitudinal data were used. In the cross-sectional part of the study, 1,151 adolescents have participated, and the data of the second wave was obtained from 322 of them four months later. Data were analyzed through structural equation modeling (SEM) and hierarchical regression analyses.

RESULTS AND CONCLUSION

According to the results of SEM, good peer relations predicted less cyberbullying. The expressive repression explained the cyberbullying through peer relationships. For identity development, contrary to expectations, commitment dimension of identity seemed to be positively related to more cyberbullying and so did higher reconsideration of commitment. Cross-lagged panel analyses revealed that Time 1 cyber victimization predicted Time 2 cyberbullying. Given the pattern of cross-lagged relationships, it was tentatively inferred that cyber victimization was the temporal precursor to cyberbullying. The results of the study have implications for the prevention of cyberbullying.

Childhood maltreatment affects adolescent sensitivity to parenting and close friendships in predicting growth in externalizing behavior

Childhood maltreatment robustly predicts adolescent externalizing behaviors (EB; e.g., violence, delinquency, substance use) and may crystalize patterns of EB by influencing sensitivity to the social environment (e.g., parenting, friendships). In a nationally representative sample of 9,421 adolescents, we modeled latent growth curves of EB from age 13 to 32 years. Next, we explored whether maltreated youth differed from nonmaltreated youth in their sensitivity to parental closeness, friendship involvement, and polymorphisms from dopamine genes linked to EB (dopamine receptors D2 and D4, dopamine transporter). Overall, maltreated youth had significantly higher levels of EB across adolescence and adulthood; however, maltreated and nonmaltreated youth showed similar patterns of EB change over time: violent behavior decreased in adolescence before stabilizing in adulthood, whereas nonviolent delinquency and substance use increased in adolescence before decreasing in the transition to adulthood. Maltreatment reduced sensitivity to parental closeness and friendship involvement, although patterns varied based on type of EB outcome. Finally, none of the environmental effects on EB were significantly moderated by the dopamine polygenic risk score after accounting for multiple testing. These findings underline the enduring effects of early maltreatment and implicate that maltreatment may contribute to long-term risk for EB by influencing children's sensitivity to social relationship factors in adolescence.

Using biological factors to individualize interventions for youth with conduct problems: Current state and ethical issues

A growing body of evidence suggests that biological factors such as genes, hormone levels, brain structure, and brain functioning influence the development and trajectory of conduct problems in youth. In addition, biological factors affect how individuals respond to the environment, including how individuals respond to programs designed to prevent or treat conduct problems. Programs designed to reduce behavior problems in youth would have the greatest impact if they were targeted toward youth who need it the most (e.g., who are mostly likely to demonstrate persistent behavior problems) as well as youth who may benefit the most from the program. Biological information may improve our ability to make decisions about which type or level of intervention is best for a particular child, thus maximizing overall effectiveness, but it also raises a number of ethical concerns. These include the idea that we may be providing fewer services to some youth based on biological factors, and that information about biological risk could potentially lead to discrimination or labeling. In this article, I discuss the risks and benefits of using biological information to individualize interventions for youth with conduct problems.

Emotional insecurity as a mediator of the moderating role of dopamine genes in the association between interparental conflict and youth externalizing problems

This study tested whether the association between interparental conflict and adolescent externalizing symptoms was moderated by a polygenic composite indexing low dopamine activity (i.e., 7-repeat allele of DRD4; Val alleles of COMT; 10-repeat variants of DAT1) in a sample of seventh-grade adolescents (Mean age = 13.0 years) and their parents. Using a longitudinal, autoregressive design, observational assessments of interparental conflict at Wave 1 predicted increases in a multi-informant measurement of youth externalizing symptoms 2 years later at Wave 3 only for children who were high on the hypodopaminergic composite. Moderation was expressed in a “for better” or “for worse” form hypothesized by differential susceptibility theory. Thus, children high on the dopaminergic composite experienced more externalizing problems than their peers when faced with more destructive conflicts but also fewer externalizing problems when exposed to more constructive interparental conflicts. Mediated moderation findings indicated that adolescent reports of their emotional insecurity in the interparental relationship partially explained the greater genetic susceptibility experienced by these children. More specifically, the dopamine composite moderated the association between Wave 1 interparental conflict and emotional insecurity 1 year later at Wave 2 in the same “for better” or “for worse” pattern as externalizing symptoms. Adolescent insecurity at Wave 2, in turn, predicted their greater externalizing symptoms 1 year later at Wave 3. Post hoc analyses further revealed that the 7-repeat allele of the dopamine receptor D4 (DRD4) gene was the primary source of plasticity in the polygenic composite. Results are discussed as to how they advance process-oriented Gene x Environment models of emotion regulation.

Prenatal programming of postnatal plasticity for externalizing behavior: Testing an integrated developmental model of genetic and temperamental sensitivity to the environment

Although both gene- and temperament-environment interactions contribute to the development of youth externalizing problems, it is unclear how these factors jointly affect environmental sensitivity over time. In a 7-year longitudinal study of 232 children (aged 5-10) with and without ADHD, we employed moderated mediation to test a developmentally sensitive mechanistic model of genetic and temperamental sensitivity to prenatal and postnatal environmental factors. Birth weight, a global measure of the prenatal environment, moderated predictions of child negative emotionality from a composite of dopaminergic polymorphisms (i.e., DRD4 and DAT1), such that birth weight inversely predicted negative emotionality only for children with genetic plasticity. Negative emotionality, in turn, predicted externalizing behavior 4-5 years later, beyond genetic and postnatal parenting effects. Finally, birth weight moderated the indirect effect of dopaminergic genotypes on externalizing problems through negative emotionality, partially supporting a prenatal programming model. We discuss theoretical and empirical implications for models of environmental sensitivity.

Polymorphisms in dopaminergic system genes; association with criminal behavior and self-reported aggression in violent prison inmates from Pakistan

Genetic factors contribute to antisocial and criminal behavior. Dopamine transporter DAT-1 (SLC6A3) and DRD2 gene for the dopamine-2 receptor are dopaminergic system genes that regulate dopamine reuptake and signaling, and may be part of the pathogenesis of psychiatric disorders including antisocial behaviors and traits. No previous studies have analyzed DAT-1 and DRD2 polymorphisms in convicted murderers, particularly from Indian subcontinent. In this study we investigated the association of 40 bp VNTR polymorphism of DAT-1 and Taq1 variant of DRD2 gene (rs1800479) with criminal behavior and self-reported aggression in 729 subjects, including 370 men in Pakistani prisons convicted of first degree murder(s) and 359 control men without any history of violence or criminal tendency. The 9R allele of DAT-1 VNTR polymorphism was more prevalent in convicted murderers compared with control samples, for either one or two risk alleles (OR = 1.49 and 3.99 respectively, P = 0.003). This potential association of DAT-1 9R allele polymorphism with murderer phenotype was confirmed assuming different genetic models of inheritance. However, no genetic association was found for DRD2 Taq1 polymorphism. In addition, a combined haplotype (9R-A2) of DAT-1 and DRD2 genes was associated with this murderer phenotype. Further, 9R allele of DAT-1 was also associated with response to verbal abuse and parental marital complications, but not with other measures pertinent to self-reported aggression. These results suggest that 9R allele, which may influence levels of intra-synaptic dopamine in the brain, may contribute to criminal tendency in this sample of violent murderers of Pakistani origin. Future studies are needed to replicate this finding in other populations of murderers and see if this finding extends to other forms of violence and lesser degrees of aggression.

Externalizing Problem Behavior in Adolescence: Parenting Interacting With DAT1 and DRD4 Genes

This study extends previous gene-by-environment (G × E) research through design and methodological advances and examines alternative hypotheses of diathesis stress, vantage sensitivity, and differential susceptibility. In a sample of 984 adolescents and their parents, we examined whether effects of parental support, proactive, punitive, harsh punitive, and psychological control on externalizing problem behavior are moderated by adolescents' genotype for the dopamine transporter (DAT1) or receptor D4 (DRD4) gene. Results provided evidence for main effects of parenting behavior and DRD4, and multiple interaction effects of which one survived Bonferroni correction. Adolescents carrying a long DRD4 variant were more susceptible to the effects of parental proactive control on aggression, for better and for worse. Critical considerations were made regarding the complexity of G × E research.

Chronic Stressors and Adolescents' Externalizing Problems: Genetic Moderation by Dopamine Receptor D4. The TRAILS Study

The existing literature does not provide consistent evidence that carriers of the Dopamine D4 Receptor 7-repeat allele are more sensitive to adverse environmental influences, resulting in enhanced externalizing problems, compared to noncarriers. One explanation is that the adverse influences examined in prior studies were not severe, chronic, or distressing enough to reveal individual differences in sensitivity reflected by DRD4–7R. This study examined whether the 7-repeat allele moderated the association between chronic stressors capturing multiple stressful aspects of individuals’ lives and externalizing problems in adolescence. We expected that chronic stressor levels would be associated with externalizing levels only in 7-repeat carriers. Using Linear Mixed Models, we analyzed data from 1621 Dutch adolescents (52.2% boys), obtained in three measurement waves (mean age approximately 11, 13.5, and 16 years) from the TRacking Adolescents’ Individual Lives Survey (TRAILS) population-based birth cohort and the parallel clinic-referred cohort. Across informants, we found that higher levels of chronic stressors were related to higher externalizing levels in 7-repeat carriers but not in noncarriers, as hypothesized. Although previous studies on the 7-repeat allele as a moderator of environmental influences on adolescents’ externalizing problems have not convincingly demonstrated individual differences in sensitivity to adverse environmental influences, our findings suggest that adolescent carriers of the Dopamine D4 Receptor 7-repeat allele are more sensitive to chronic, multi-context stressors than noncarriers.

Adolescent externalizing behaviour, psychological control, and peer rejection: Transactional links and dopaminergic moderation

This study investigated (1) reciprocal links among parental psychological control, peer rejection, and adolescent externalizing (aggressive and rule-breaking behaviour), and (2) the moderating effect of an adolescent genetic factor (biologically informed polygenic score for dopamine signalling). Three-year longitudinal data from 1,116 adolescents (51% boys; M age = 13.79) and their parents included psychological measures (adolescent-reported psychological control, peer-reported rejection, and parent-reported aggressive and rule-breaking behaviour). Cross-lagged analyses showed bidirectional effects between psychological control and both aggressive and rule-breaking behaviour and a unidirectional effect of peer rejection on both forms of problem behaviour over time. Multigroup structural equation modelling revealed genetic moderation only for rule-breaking behaviour: for adolescents with intermediate levels of dopamine signalling significant environmental effects were present, whereas adolescent effects of rule-breaking behaviour on psychological control were significant for adolescents with both intermediate and high profiles and effects on peer rejection only for adolescents with high dopamine profiles. Statement of contribution What is already known on this subject? Parental psychological control is related to adolescent externalizing problems. Experiencing peer rejection reinforces aggressive and rule-breaking behaviour. Single-gene studies show that dopaminergic genes influence externalizing problems directly or in interaction with the environment. What does this study add? Parental psychological control and adolescent aggressive and rule-breaking behaviour exacerbate one another longitudinally. Longitudinal associations between peer rejection and both subtypes of externalizing behaviour are unidirectional. With a polygenic approach, dopaminergic moderation is present for rule-breaking behaviour only.

Transactional Links Between Teacher-Student Relationships and Adolescent Rule-Breaking Behavior and Behavioral School Engagement: Moderating Role of a Dopaminergic Genetic Profile Score

Throughout adolescence, there is an increase in rule-breaking behavior and a decrease in behavioral school engagement. The role of teacher-student relationship quality in the development of these adjustment problems remains understudied. This study examined how adolescent-reported teacher-student affiliation and dissatisfaction and parent-reported rule-breaking behavior and behavioral engagement impact one another throughout adolescence. In addition, we examined the moderating effect of genes by means of a Biologically Informed Multilocus genetic Profile Score (BIMPS), a composite score reflecting the cumulative effect of multiple dopaminergic genes, with a higher score indicating higher dopamine signaling in the adolescent brain. We used three-year longitudinal data from 1111 adolescents (51 % boys; M age = 13.79), and their parents. Cross-lagged analyses revealed a transactional process in which adolescents who display more rule-breaking behavior and less behavioral engagement experienced increased subsequent dissatisfaction with their teachers, which in turn further increased their adjustment problems. Also, adolescents with more adjustment problems experienced decreased subsequent affiliation with their teachers. The other way around, adolescents' behavioral engagement also benefitted from positive relationships with teachers. Multi-group analyses revealed genetic moderation for behavioral engagement, but not for rule-breaking. Specifically, adolescents who had a BIMPS score coding for moderate levels of dopamine signaling (instead of high or low signaling) were most affected in their behavioral engagement when they experienced dissatisfaction with their teachers. Our study findings may guide schools in implementing interventions to create a supportive class and school environment including positive, supportive teacher-student relationships and indicate that providing a such a supportive school environment is important for all adolescents.

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.