Considering the Genetic and Environmental Overlap Between Bullying Victimization, Delinquency, and Symptoms of Depression/Anxiety

The Chain Mediation Effect of Victimization and Neuroticism on the Association Between Sexual Orientation and Depressive Symptoms: A Prospective Birth Cohort Study

This study tested whether sexual orientation differences in depressive symptoms were partially explained by the chain mediation effect of neuroticism and victimization. Using the Avon Longitudinal Study of Parents and Children from the UK (N = 4647, 36.52% men, 88% White), self-reported neuroticism, sexual orientation, and depressive symptoms were measured at age 13.5, 21, and 22 years, respectively. Childhood abuse between birth and age 11 years and the individuals' experiences of being bullied at age 17.5 years were measured as the components of victimization. Structural equation modeling was used to analyze the data. Non-heterosexual individuals reported higher depressive symptoms than heterosexual individuals, with a total effect (standardized path coefficient) of 0.590 and 0.768 for men and women, respectively. This association was partially explained by childhood abuse (indirect effect = 0.043 and 0.046 for men and women, respectively) and neuroticism directly (indirect effect = 0.036 and 0.056 for men and women, respectively). Sexual orientation differences in depressive symptoms were also partially explained by a path through increased risk of experiencing childhood abuse leading to higher levels of neuroticism (indirect effect = 0.004 and 0.009 for men and women, respectively) and by a path through higher levels of neuroticism leading to increased risk of being bullied (indirect effect = 0.004 and 0.002 for men and women, respectively). The findings suggest that while some of the association between sexual orientation and depression might be explained by neuroticism and experiences of victimization measured prospectively, these factors do not account for most of this relationship.

Gene-Environment Interplay Linking Peer Victimization With Adolescents' Trajectories of Depressive Symptoms

OBJECTIVE

This study examined to what extent genetic and environmental factors explain-either additively or interactively with peer victimization-different trajectories of adolescents' depressive symptoms and whether genetic factors related to distinct trajectories are correlated with peer victimization.

METHOD

Participants included 902 twins (52% girls) who self-reported peer victimization and depressive symptoms in grades 6, 7, 8, 9, and 11.

RESULTS

Growth mixture modeling revealed 3 trajectories of depressive symptoms: low (69.2% of participants), increasing (19.5%), and high-decreasing-increasing (11.3%). Biometric modeling showed that, for both sexes, genetic factors explained roughly half (52.6%, 47.5%) of the probability of following either a low or an increasing trajectory. Genetic influences (41%) were also observed for the high-decreasing-increasing trajectory, albeit only for girls. Nonshared environmental influences explained the remaining variances, along with shared environmental influences (27%) on the high-decreasing-increasing trajectory. Only for the low and the increasing trajectories, nonshared environmental influences increased with more frequent peer victimization (b_low = 0.206, 95% CI [0.094, 0.325]; b_increasing = 0.246, 95% CI [0.143, 0.356]). Moreover, peer victimization was associated with a lower probability of a low trajectory and a higher probability of an increasing or high-decreasing-increasing trajectory, and these associations were mostly explained by common underlying genetic factors.

CONCLUSION

Youth expressing (partly inherited) depressive symptoms may be at risk of peer victimization. However, increasing depressive symptoms in victims may be mitigated by other environmental factors except for those who enter adolescence with already high levels of depressive symptoms.

Longitudinal Associations Between Cybervictimization and Adolescent Sleep Problems: The Role of Anxiety and Depressive Symptoms

Adolescents who have experienced cybervictimization are at risk for sleep problems. However, there is a gap in knowledge about the mechanism that would explain this link. The study used a longitudinal design to test if cybervictimization predicted adolescents' sleep problems 6 and 12 months later, and whether these patterns could be explained in part by emotional distress in response to the victimization. Participants were 1987 Chinese adolescents (56.1% males) ages 10 to 14 (M = 12.32, SD = 0.53) at baseline. Data were collected over the course of 1 year, in three waves 6 months apart. The adolescents completed questionnaires regarding cybervictimization, sleep problems, depressive symptoms, and anxiety symptoms at all three time points. Autoregressive cross-lagged models showed that cybervictimization predicted later sleep problems after controlling for traditional peer victimization, and anxiety and depressive symptoms mediated this link. Multivariate latent growth models showed that the developmental trajectories of cybervictimization, sleep problems, anxiety symptoms, and depressive symptoms were related in complex ways over time. Measures of study variables were self-reported, and generalizability may be limited by a sample of adolescents from school in China. These results are important because of their implications for prevention and treatment of adolescents' sleep problems evoked by cybervictimization.

Body mass index and bullying victimization as antecedents for depressive symptoms in a Swedish youth cohort

Aim

The bidirectional association between obesity and depression seen in adults is not clearly established in adolescents. The aim of this study was to investigate the longitudinal association between body mass index (BMI), depressive symptoms and interactions between bullying victimization and BMI, taking gender differences into account.

Subjects and methods

In a Swedish county, self-reported bullying victimization, BMI and depressive symptoms from 1729 adolescents ($$ \overline{y} $$ y ¯ = 14.4, 56% females) were collected in 2012 (wave 1), in 2015 (wave 2) ($$ \overline{y}=17.3 $$ y ¯ = 17.3 ) and in 2018 (wave 3) ($$ \overline{y} $$ y ¯ = 19.9). Longitudinal associations were assessed using binary logistic regression models controlling for confounding factors. Interaction effects between BMI and victimization on depressive symptoms were also assessed.

Results

Wave 1 obese males had approximately six times increased odds ratio compared to normal weight, for wave 2 depressive symptoms. W1 overweight was associated with an odds ratio of 1.5 in all participants for wave 3 depressive symptoms. Victimization was consistently associated with higher odds ratio for future depressive symptoms. We found interaction effects between bullying victimization and BMI for future depressive symptoms with different patterns depending on sex.

Conclusion

Given the present findings, bullying needs to be prevented, and, if it occurs, it needs to be stopped at an early stage to prevent future depressive symptoms.

Substance use confounds associations between peer victimization and aggression in adolescence with mental disorders in adulthood: A prospective birth cohort study

INTRODUCTION

Peer victimization and aggression in adolescence are associated with later mental health morbidity. However, studies examining this association have not controlled for adolescent substance use. We aimed to study the associations between peer victimization, peer aggression, and mental disorders in adulthood, adjusting for substance use in adolescence.

METHODS

Participants were from the prospective Northern Finland Birth Cohort 1986. Data were available for 6682 individuals (70.8% of the original sample). Peer victimization and peer aggression were assessed with items from the Achenbach Youth Self Report at ages 15-16 years. Outcomes were nonorganic psychosis, anxiety disorder, mood disorder, substance use disorder, and any mental disorder (a none-vs-any indicator) at age 33 years collected from nationwide health care, insurance, and pension registers. Family structure, alcohol intoxication frequency, daily smoking, illicit drug use, and baseline psychopathology using Youth Self-Report total score, and parental mental disorders were considered as confounding factors.

RESULTS

In multivariable analyses, the association between peer victimization and psychosis (Hazard ratio [HR]: 2.9, 95% confidence interval [CI]: 1.2-6.9, p = .020) and mood disorder (HR: 1.7, 95% CI: 1.2-2.4, p = .012) in females remained significant after adjusting for confounders. Other associations between female and male peer victimization or aggression and the studied outcomes attenuated after adjustments.

CONCLUSIONS

Some associations between peer victimization and aggression and later mental health morbidity are explained by adolescent substance use. For females, substance use does not account for the increased risk of psychosis and mood disorder in those who experience peer victimization.

Inclusion, autism spectrum, students' experiences

Objectives: The aim of this study is to examine the gap that exists between the federal mandate to educate children with disabilities or special needs in the least restrictive environment, and the practice of inclusion of students with autism spectrum disorder (ASD) into the general education classroom or interactions with general education students both academically and socially. Practices that are defined as inclusive best practices are often determined and defined by local administrators and educators without the perspective of students on the autism spectrum. Methods: Six American students with a formal diagnosis of differing levels of ASD with mixed exceptionalities, both male and female, participated in this phenomenological study. Personal interviews, documents, and artifacts were used to collect data. Once the data were collected, transcribed, coded, and analyzed, the results of findings were displayed in the study for future discussion on defining inclusion and barriers to inclusion from the perspective of those on the autism spectrum. Results: The students had mixed reviews about their classroom teachers, stating from year to year the teachers' understanding of autism and their treatment in the classroom was different, which was confusing. The students felt distant and experienced a lack of connection with the student body. All six American students felt that both teachers and peers lacked basic awareness and acceptance of autism. Conclusion: The students included in this study give practical suggestions of inclusive practices and describe harmful practices from their experience in the public school system. As researchers discuss best practices and outcomes, it is recommended that future research examine the experience and perspective of those on the autism spectrum. Keywords: ASD, inclusive practices, autism in the classroom, autistic perspective, barriers to inclusion, muted group.

Links between peer victimization, dating violence victimization and depression in adolescence: A genetically-informed study

OBJECTIVE

The current study aimed to test if individuals with inherent dispositions to depression-related cognitions and behaviors are more at risk of experiencing relational difficulties, such as peer victimization and dating violence victimization.

METHOD

This study used a genetically informed design with 806 twins (51.5% girls) to test 1) if at least part of the association between peer victimization in school and dating violence victimization in emerging adulthood can be explained by common underlying heritable factors. Participants provided repeated assessments of their peer victimization in school at ages 13 through 17, their depression symptoms at ages 13 through 19, as well as their victimization in dating relationships at age 19.

RESULTS

A Cholesky decomposition based on structural equation modeling supported the hypotheses. Specifically, the association between peer victimization and dating violence victimization was to a significant extent explained by common underlying genetic vulnerabilities that were associated with depression symptoms. No sex moderation was found.

CONCLUSIONS

The findings highlight the importance of addressing early indicators of vulnerability toward depression symptoms to prevent victimization by peers or dating partners.

Applying Genetic and Genomic Tools to Psychiatric Disorders: A Scoping Review

Introduction

The bioethics literature reflects significant interest in and concern with the use of genetic and genomic information in various settings. Because psychiatric treatment and research raises unique ethical, legal, and social issues, we conducted a scoping review of the biomedical, bioethics, and psychology literature regarding the application of genetic and genomic tools to psychiatric disorders (as listed in the DSM-5) and two associated behaviors or symptoms to provide a more detailed overview of the state of the field.

Objectives

The primary objective was to examine the available bioethics, biomedical, and psychology literature on applying genetic and genomic tools to psychiatric disorders (other than neurodevelopmental disorders) and two behaviors or symptoms sometimes associated with them (aggression or violence and suicidality) to identify the disorders to which these tools have been applied, the contexts in or purposes for which they have been applied, the ethical, legal, or social concerns associated with those uses, and proposed recommendations for mitigating those concerns.

Methods

We used Arksey and O’Malley’s scoping review framework: (1) identify the research question; (2) identify relevant studies; (3) select studies; (4) chart the data; and (5) collate, summarize, and report results (2005). We relied on Levac et al. to inform our application of the framework (2010). The PRISMA extension for scoping reviews checklist informed our reporting (2018). We searched three electronic databases MEDLINE (PubMed), Embase, and PsycInfo (EbscoHost) for peer-reviewed journal articles in English to identify relevant literature. One author screened the initial results and additional screening was done in consultation with other authors. A data extraction form using DSM-5 diagnostic categories (excluding neurodevelopmental disorders) was developed and two authors independently each reviewed approximately half of the articles. Inter-rater reliability was ensured by double-coding approximately 10% of the papers. An additional author independently coded 10% of the articles to audit the data.

Results

In 365 coded publications, we identified 15 DSM-5 diagnostic categories in addition to the two pre-selected behaviors or symptoms (aggression or violence and suicidality) to which genetic or genomic tools have been applied. We identified 11 settings in or purposes for which these tools were applied. Twenty-two types of ethical, legal, or social concerns associated with the application of genetic or genomic tools to these disorders or behaviors/symptoms were identified along with 13 practices or policies that could mitigate these concerns.

Conclusion

Genetic and genomic tools have been applied to a wide range of psychiatric disorders. These raise a range of ethical, legal, and social concerns. Additional research is warranted to better understand the concerns and effective ways to address them. Advancing the literature to identify relevant ethical, legal, or social concerns and solutions to those problems likely requires greater attention to specific applications of genetic or genomic tools to particular psychiatric disorders and associated behaviors/symptoms as well as broad stakeholder engagement.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10730-021-09465-5.

The mediating effects of adolescents’ internalizing and externalizing problems on the relationship between emotion regulation, mindfulness and bullying/victimization at school

The aim of this study was two-fold: to investigate the relationship between emotion regulation, dispositional mindfulness and bullying/victimization experiences at school, and to examine the mediating effects of internalizing and externalizing problems on this relationship. Self-reports measuring the above variables were completed by 444 adolescents (mean age 15.3) who attended high school in Cyprus. Data were collected at three points in time. Specifically, data were collected during the second week of October, 2018 (T1), the third week of January, 2019 (T2) and the first week of June, 2019 (T3). It was found that mindfulness at T1 had a significant negative effect on both internalizing and externalizing symptoms and through these variables, it had an indirect negative effect on both bullying and victimization at T3. Similarly, adaptive emotion regulation at T1 had an indirect effect on victimization, fully mediated by internalizing problems. In contrast, maladaptive emotion regulation had a positive, direct effect on both bullying and victimization.

The Potential of Anti-Bullying Efforts to Prevent Academic Failure and Youth Crime. A Case Using the Olweus Bullying Prevention Program (OBPP)

The effectiveness of bullying prevention programs has led to expectations that these programs could have effects beyond their primary goals. By reducing the number of victims and perpetrators and the harm experienced by those affected, programs may have longer-term effects on individual school performance and prevent crime. In this paper, we use Norwegian register data to study the long-term impact of the Olweus Bullying Prevention Program (OBPP) on academic performance, high school dropout, and youth crime for the average student, which we call population-level effects. The OBPP program is widely acknowledged as one of the most successful programs reducing school-level bullying; yet, using a difference-in-difference design, no statistically significant population-level effects of the OBPP were found on any of the long-term outcomes in this study. When studied at the population level, as in the current project, the base rate prevalence of bullying is a major explanatory factor for these results. Earlier studies have shown that OBPP reduces bullying prevalence by 30-50%. This decrease translates into absolute reductions in bullying victimization and perpetration at the population level of "only" four and two percentage points, respectively. Our results suggest the average causal effects of school bullying involvement are too small to translate this reduction in bullying into a sizeable population-level impact on students' long-term outcomes. However, a limited potential of anti-bullying programs to prevent population-level adversity can very well be compatible with substantial program effects for individual bullies and victims. Further, our results do not speak to the main objective of anti-bullying programs of limiting childhood abuse and safeguarding children's human rights.

Violent Victimization, Stressful Events, and Depression: A Longitudinal Study of Young Adults in the U.S

We surveyed a sample of young adults in the United States to determine (1) whether/how depression is affected by violent victimization during childhood and/or by recent stressful events, as well as (2) whether any observed links between depression and violent victimization and/or stressful events would be uniform across racial/ethnic groups. Using data from the National Longitudinal Survey of Youth 1997 cohort, we measured respondent depression in 5 interview waves dating 2004-2015. Our final sample for analysis numbered 22,549 person-waves. Our study showed that violent victimization in childhood, and recent stressful events, as well, alike exacerbated depression. Moreover, as we analyzed, in turn, the data for each ethnic subsample, we observed differential patterns in depression's associations with victimization. Childhood violent victimization-and also recently encountered stress-has a significant role in the development of depression in adulthood; this role appears to be moderated by race/ethnicity.

Heritability of Bullying and Victimization in Children and Adolescents: Moderation by the KiVa Antibullying Program

Objective: Bullying affects approximately a quarter of schoolchildren and is associated with numerous adverse outcomes. Although distinct risk factors for bullying and victimization have been identified, few studies have investigated the genetic and environmental underpinnings of bullying and victimization. The aims of this study were twofold: first, to examine the contributions of genetic and environmental factors to bullying and victimization, and second, to analyze whether the KiVa antibullying program moderated the magnitude of these contributions by comparing estimates derived from the KiVa versus control groups.Method: The sample comprised students from schools that participated in the evaluation of the KiVa antibullying program in Finland during 2007-2009. Bullying and victimization were measured using peer nominations by classmates. The sample for the twin analyses comprised of 447 twins (107 monozygotic and 340 dizygotic twins) aged 7-15.Results: Genetic contributions accounted for 62% and 77% of the variance in bullying and in victimization at pre-intervention, respectively. There was a post-intervention difference in the overall role of genetic and environmental contributions between the intervention and the control group for bullying and victimization, with non-shared environmental effects playing a lesser role (and genes a larger role) in the intervention than in the control group context.Conclusions: This study replicates previous findings on the genetic underpinnings of both bullying and victimization, and indicates that a school-based antibullying program reduces the role of non-shared environmental factors in bullying and victimization. The results indicate that prevention and intervention efforts need to target both environmental and (heritable) individual level factors to maximize effectiveness.

Evidence that Different Types of Peer Victimization have Equivalent Associations with Transdiagnostic Psychopathology in Adolescence

Experiences of peer victimization are common in adolescence and have been associated with a broad variety of psychopathology in adolescence. The present study aimed to test whether some types of victimization are more harmful than others; whether the harms associated with different types of peer victimization are specific to particular domains of psychopathology; and whether these relationships vary by gender. Participants included adolescents aged 14-15 from a nationally representative cohort study (n= 3335; mean age 14.4 years; 49.1% female; 90.1% spoke English as the main language at home). Participants provided self-report information on their experiences of peer victimization, as well as symptoms of depression, anxiety, conduct problems, hyperactivity and inattention, and substance use. These data were analyzed in a dimensional and hierarchical framework using latent variable indirect effects modeling. The associations between peer victimization and psychopathology were not unique to specific symptom domains, but rather showed broadband associations with all symptom domains via a transdiagnostic association with general psychopathology. For example, an average of only 9% of the total relationship with each symptom domain was unique to the symptom-domain level, with the remaining proportion accounted for by higher-order factors (i.e., internalizing, externalizing, and general psychopathology). Further, the strength of the relationships did not vary as a function of the type of peer victimization experience (i.e., physical, verbal, or relational), and showed evidence of strict measurement invariance by gender. These findings suggest that peer victimization might present a useful target for the prevention of general psychopathology.

Genetic and Environmental Influences on Different Forms of Bullying Perpetration, Bullying Victimization, and Their Co-occurrence

Bullying comes in different forms, yet most previous genetically-sensitive studies have not distinguished between them. Given the serious consequences and the high prevalence of bullying, it is remarkable that the aetiology of bullying and its different forms has been under-researched. We present the first study to investigate the genetic architecture of bullying perpetration, bullying victimization, and their co-occurrence for verbal, physical and relational bullying. Primary-school teachers rated 8215 twin children on bullying perpetration and bullying victimization. For each form of bullying, we investigated, through genetic structural equation modelling, the genetic and environmental influences on being a bully, a victim or both. 34% of the children were involved as bully, victim, or both. The correlation between being a bully and being a victim varied from 0.59 (relational) to 0.85 (physical). Heritability was ~ 70% for perpetration and ~ 65% for victimization, similar in girls and boys, yet both were somewhat lower for the relational form. Shared environmental influences were modest and more pronounced among girls. The correlation between being a bully and being a victim was explained mostly by genetic factors for verbal (~ 71%) and especially physical (~ 77%) and mostly by environmental factors for relational perpetration and victimization (~ 60%). Genes play a large role in explaining which children are at high risk of being a victim, bully, or both. For victimization this suggests an evocative gene-environment correlation: some children are at risk of being exposed to bullying, partly due to genetically influenced traits. So, genetic influences make some children more vulnerable to become a bully, victim or both.

Tracing the delinquency acquisition sequence from older siblings, to friends, to self: A mediation analysis

INTRODUCTION

This study tested the hypothesis that sibling and peer delinquency are connected and that this connection is relevant to future criminal offending.

METHODS

Drawing on research showing that both sibling and peer delinquency predict future participant offending, a causal mediation analysis was performed on 411 boys from the Cambridge Study in Delinquent Development. In this study, older sibling delinquency served as the independent variable, school problem behavior and friend delinquency served as mediator variables, and participant's reports of their own offending served as the dependent variable.

RESULTS

The indirect effect running from older sibling delinquency at age 10-11, to school problem behavior at age 12-13, to friend delinquency at age 14-15, to participant delinquency at age 16-17 proved significant. The effect remained significant when the number of officially recorded criminal convictions between the ages of 16 and 19 replaced self-reported delinquency as the dependent variable. By contrast, the direct effect from sibling delinquency at age 10-11 to participant delinquency at age 16-17 and several shorter paths (older sibling delinquency → school problem behavior → participant delinquency; older sibling delinquency → friend delinquency → participant delinquency) were non-significant.

CONCLUSIONS

These results imply that older sibling delinquency may lead to future delinquency and crime by encouraging early school problems, which, in turn, may precipitate future offending by encouraging the child to select and associate with a delinquent peer group.

Delinquent Behavior: Systematic Review of Genetic and Environmental Risk Factors

Delinquency refers to a juveniles' behavior pattern characterized by repeated offending, and is regarded mainly in its social, but also criminal aspects. Delinquent and non-delinquent individuals may be a product of the same society or even the same family. Young individuals who are unable to find affection and protection within the family may become more susceptible to delinquency as a form of empowerment. More than socioeconomic conditions, the lack of interaction between parents and children, the existence of psychopathological problems in either parent, and academic problems, together with a biological vulnerability, may be deciding factors for the involvement of young individuals in delinquent behavior. This review aims to analyze the influence of environmental and genetic factors in the development of delinquent behavior. Studies related to the influence of the environment and genes on the development of delinquent behavior were obtained from multiple databases, through rigorous exclusion and inclusion criteria. Of the 152 documents retrieved, 87 were retained for further analysis, and 36 final studies were considered eligible for inclusion. In addition to these, ten studies were added trough manual search, with the final sample thus comprising 46 articles, published between 1983 and 2016. Objectives, methodological aspects (samples and instruments), and main conclusions were extracted from each study. Overall, the interaction between genetic and environmental factors appears to best explain the variation of delinquent behavior. Environmental risk factors may have differential effects on the behavior of individuals, particularly according to their genetic propensity for delinquency.

Multi-Polygenic Score Approach to Identifying Individual Vulnerabilities Associated With the Risk of Exposure to Bullying

Importance

Exposure to bullying is a prevalent experience with adverse consequences throughout the life span. Individual vulnerabilities and traits, such as preexisting mental health problems, may be associated with increased likelihood of experiencing bullying. Identifying such individual vulnerabilities and traits is essential for a better understanding of the etiology of exposure to bullying and for tailoring effective prevention.

Objective

To identify individual vulnerabilities and traits associated with exposure to bullying in childhood and adolescence.

Design, Setting, and Participants

For this study, data were drawn from the Avon Longitudinal Study of Parents and Children (ALSPAC), a population-based birth cohort study. The initial ALSPAC sample consisted of 14 062 children born to women residing in Avon, United Kingdom, with an expected date of delivery between April 1, 1991, and December 31, 1992. Collection of the ALSPAC data began in September 6, 1990, and the last follow-up assessment of exposure to bullying was conducted when participants were 13 years of age. Data analysis was conducted from November 1, 2017, to January 1, 2019.

Exposures

The polygenic score approach was used to derive genetic proxies that indexed vulnerabilities and traits. A total of 35 polygenic scores were computed for a range of mental health vulnerabilities (eg, depression) and traits related to cognition (eg, intelligence), personality (eg, neuroticism), and physical measures (eg, body mass index), as well as negative controls (eg, osteoporosis).

Main Outcomes and Measures

Single and multi-polygenic score regression models were fitted to test the association between indexed traits and exposure to bullying. Children completed the Bullying and Friendship Interview Schedule at the ages of 8, 10, and 13 years. A mean score of exposure to bullying across ages was used as the main outcome.

Results

A total of 5028 genotyped individuals (2481 boys and 2547 girls) with data on exposure to bullying were included. Among the 35 initially included polygenic scores, 11 were independently associated with exposure to bullying; no significant association was detected for the 24 remaining scores. In multivariable analyses, 5 polygenic scores were associated with exposure to bullying; the largest associations were present for genetic risk relating to mental health vulnerabilities, including diagnosis of depression (standardized b = 0.065; 95% CI, 0.035-0.095) and attention-deficit/hyperactivity disorder (standardized b = 0.063; 95% CI, 0.035-0.091), followed by risk taking (standardized b = 0.041; 95% CI, 0.013-0.069), body mass index (standardized b = 0.036; 95% CI, 0.008-0.064), and intelligence (standardized b = -0.031; 95% CI, -0.059 to 0.003).

Conclusion and Relevance

Using the multi-polygenic score approach, the findings implicate preexisting mental health vulnerabilities as risk factors for exposure to bullying. A mechanistic understanding of how these vulnerabilities link to exposure of bullying is important to inform prevention strategies.

The Causal Relationship between Childhood Adversity and Developmental Trajectories of Delinquency: A Consideration of Genetic and Environmental Confounds

An extensive line of research has found that children exposed to multiple forms of early life adversity are more likely to engage in high levels of delinquent behavior during adolescence. Several studies examining this association have used a range of multivariate statistical techniques capable of controlling for observable covariates. Fewer studies have used family-based research designs to additionally control for unobservable confounds, such as genetic and shared environmental influences, that may be associated with exposure to childhood adversity and delinquency. The current study analyzes self-report data on 2534 full-siblings (50% female) from the National Longitudinal Survey of Youth 1997 to conduct a sibling-comparison analysis to provide a rigorous test of the causal hypothesis that exposure to childhood adversity causes differences in developmental patterns of delinquent behavior. Results from multivariate latent growth curve models revealed that childhood adversity was associated with higher starting levels of delinquency during adolescence and slower rates of decline from adolescence to emerging adulthood. Results from multivariate sibling-comparison models, however, revealed that siblings exposed to higher levels of childhood adversity reported higher starting levels of delinquent behavior, but not slower declines over time, suggesting that childhood adversity may not be directly associated with long-term patterns of delinquent behavior after genetic and shared environmental factors are taken into account. Implications of these results for future research are discussed.

Causality and Pleiotropy in the Association Between Bullying Victimization in Adolescence and Depressive Episodes in Adulthood

Children and adolescents who are victims or perpetrators of bullying victimization are at elevated risk for maladjustment problems, concurrently and in the long run. Previous studies suggest that this correlation is partly explained by genetic influence. However, whether the genetic correlation is independent of a causal effect of victimization on maladjustment remains unclear. Using data from 2,510 females from the TwinsUK registry, we applied an innovative extension of the Cholesky decomposition to investigate to what extent the association between victimization in adolescence and self-reported depressive episodes in adulthood is caused by shared genetic effects (pleiotropy), and to what extent it is due to a phenotypic causal relationship. We find that around 60% of the association between victimization and self-reported depressive episodes is due to a causal effect of victimization on depressive episodes, and 40% is due to pleiotropic effects. These findings underline the importance of integrating genetic information into social science research and demonstrate a neat strategy to elucidate causal mechanisms in the absence of experimental designs.

Sex Differences in Childhood Bullying Victimization and Trajectories of Substance Use From Adolescence to Adulthood

Recent research has found that repeated bullying victimization increases the risk of developing several unhealthy habits later in life including periodic substance use. Comparatively less research, however, has examined whether the association between bullying victimization and developmental growth in substance use is different for males and females. The present study addressed this gap in the literature by analyzing data from the National Longitudinal Survey of Youth 1997. Results from a series of sex-specific latent growth curve models reveal that bullied males experience faster increases in cigarette and marijuana use from adolescence to young adulthood compared to non-bullied males, while bullied females experience faster increases in cigarette use compared to non-bullied females. Bullied males also experience slower declines in cigarette and marijuana use from adolescence to middle adulthood, while bullied females experience slower declines in alcohol and cigarette use. Implications of these findings for research on sex differences in bullying victimization and developmental patterns of substance use are discussed.