Psychiatric outcomes of bullying victimization: a study of discordant monozygotic twins

The Role of Disability in the Relationship Between Mental Health and Bullying: A Focused, Systematic Review of Longitudinal Studies

Having both a disability and being bullied increases the risk of later mental health issues. Children with disabilities are at greater risk of being bullied and therefore at greater risk of adverse mental health outcomes. We conducted a limited systematic review of longitudinal studies focusing on the role of disability in relation to bullying and mental health problems. Twelve studies with an initial measure of mental health or disorder, measured no later than 10 years of age, were found. Ten of these twelve studies suggested that having a disability before victimisation increased the impact of mental health problems measured after bullying experiences. The conclusion is that children with a disability, such as behavioural problems, have an increased risk of later mental health problems through bullying victimization. Children with two risk factors had significantly worse mental health outcomes. These additional mental health problems may be alleviated through reduced bullying victimisation.

Peer victimization and social anxiety in adolescence: a comparison between migrant and native students in Italy

The first aim of this study is to investigate the relationship between bullying victimization and social anxiety in native and migrant adolescents in Italy. Specifically, it was hypothesized that migrant adolescents (in comparison with natives) experience more frequent episodes of bullying victimization, which in turn, may be a risk factor for the development of social anxiety symptoms. The second aim of the study is to explore the relationships from reflected minority categorization to perceived ethnic discrimination at school and social anxiety symptoms, in the subgroup of migrant students. Results showed that the migrant (vs. native) status was predictive of higher scores in social anxiety dimensions (Fear of Negative Evaluation, Social Avoidance and Distress in New Situations, and General Social Avoidance Distress), via the mediating effect of increased peer victimization. Moreover, in the subgroup of migrant participants, an indirect effect of reflected minority categorization on social anxiety was observed, mediated by perceived ethnic discrimination at school. These findings may contribute to the understanding of health inequalities among migrant and native people in the Italian context. Limitations and practical implications of the study were discussed.

A cross-lagged twin study of emotional symptoms, social isolation and peer victimisation from early adolescence to emerging adulthood

BACKGROUND

Emotional symptoms, such as anxiety and depressive symptoms, are common during adolescence, often persist over time, and can precede the emergence of severe anxiety and depressive disorders. Studies suggest that a vicious cycle of reciprocal influences between emotional symptoms and interpersonal difficulties may explain why some adolescents suffer from persisting emotional symptoms. However, the role of different types of interpersonal difficulties, such as social isolation and peer victimisation, in these reciprocal associations is still unclear. In addition, the lack of longitudinal twin studies conducted on emotional symptoms during adolescence means that the genetic and environmental contributions to these relationships during adolescence remain unknown.

METHODS

Participants (N = 15,869) from the Twins Early Development Study completed self-reports of emotional symptoms, social isolation and peer victimisation at 12, 16 and 21 years old. A phenotypic cross-lagged model examined reciprocal associations between variables over time, and a genetic extension of this model examined the aetiology of the relationships between variables at each timepoint.

RESULTS

First, emotional symptoms were reciprocally and independently associated with both social isolation and peer victimisation over time, indicating that different forms of interpersonal difficulties uniquely contributed to emotional symptoms during adolescence and vice versa. Second, early peer victimisation predicted later emotional symptoms via social isolation in mid-adolescence, indicating that social isolation may constitute an intermediate pathway through which peer victimisation predicts longer-term emotional symptoms. Finally, individual differences in emotional symptoms were mostly accounted for by non-shared environmental factors at each timepoint, and both gene-environment and individual-specific environmental mechanisms were involved in the relationships between emotional symptoms and interpersonal difficulties.

CONCLUSIONS

Our study highlights the necessity to intervene early in adolescence to prevent the escalation of emotional symptoms over time and to consider social isolation and peer victimisation as important risk factors for the long-term persistence of emotional symptoms.

Stressful life events increase the risk of major depressive episodes: A population-based twin study

BACKGROUND

Previous studies have found that stressful life events (SLEs) are associated with an increased risk of adult depression. However, many studies are observational in nature and limited by methodological issues, such as potential confounding by genetic factors. Genetically informative research, such as the co-twin control design, can strengthen causal inference in observational studies. Discrete-time survival analysis has several benefits and multilevel survival analysis can incorporate frailty terms (random effects) to estimate the components of the biometric model. In the current study, we investigated associations between SLEs and depression risk in a population-based twin sample (N = 2299).

METHODS

A co-twin control design was used to investigate the influence of the occurrence of SLEs on depression risk. The co-twin control design involves comparing patterns of associations in the full sample and within dizygotic (DZ) and monozygotic twins (MZ). Associations were modelled using discrete-time survival analysis with biometric frailty terms. Data from two time points were used in the analyses. Mean age at Wave 1 was 28 years and mean age at Wave 2 was 38 years.

RESULTS

SLE occurrence was associated with increased depression risk. Co-twin control analyses indicated that this association was at least in part due to the causal influence of SLE exposure on depression risk for event occurrence across all SLEs and for violent SLEs. A minor proportion of the total genetic risk of depression reflected genetic effects related to SLEs.

CONCLUSIONS

The results support previous research in implicating SLEs as important risk factors with probable causal influence on depression risk.

The longitudinal course of childhood bullying victimization and associations with self-injurious thoughts and behaviors in children and young people: A systematic review of the literature

INTRODUCTION

Bullying victimization has consistently been highlighted as a risk factor for self-injurious thoughts and behaviors (SITBs) in young people. This systematic review of prospective, community-based studies explored associations between bullying victimization (traditional/face-to-face and cyber) across the full spectrum of self-harm and suicidality, in children and young people aged up to (and including) 25 years. Importantly, associations by sex/gender were explored.

METHODS

MEDLINE, Embase, PsycINFO, CINAHL and Scopus were searched for articles meeting the inclusion criteria. Articles were screened by title, abstract and full text. Quality appraisal was performed using the Newcastle-Ottawa Scale for cohort studies. Data were synthesized narratively. The protocol is registered on PROSPERO (CRD42021261916) and followed PRISMA 2020 guidelines.

RESULTS

A total of 35 papers were included, across 17 countries. Results were presented by bullying type: traditional/face-to-face (n = 25), cyber (n = 7) and/or an aggregate of both types (n = 7). Outcomes included suicidal ideation (n = 17), self-harm (n = 10), suicide attempt (n = 4), NSSI (n = 4), other (n = 7). Studies measured outcomes in under 18s (n = 24), 18-25-year-olds (n = 8) and both under 18s and 18-25-year-olds (n = 3). Studies exploring the role of sex/gender (20%) found some interesting nuances.

CONCLUSIONS

Some weak to strong associations between bullying and SITBs were found yet conclusions are tentative due to study heterogeneity (e.g., methods used, conceptualizations and operationalisations of exposures/outcomes). Future research should address methodological issues raised in this review, and further explore gender differences in bullying, including by bullying sub-types (e.g., overt or relational) and victim status (e.g., victim or bully-victim).

Prevalence of bullying victimization and its association with self-perceived health, psychopathology, and suicidality: A nationwide population-based survey in Taiwan

BACKGROUND

The current study aimed to assess the prevalence of bullying victimization (BV) and its association with psychopathology and suicidality in a nationwide general population.

METHODS

The target population were all the people living in Taiwan, the study samples were obtained by the following processes. A computer-assisted telephone interview was performed to identify potential respondents using telephone numbers selected with the stratified proportional randomization method. Self-reported data were evaluated. Moreover, data obtained using the validated Brief Symptom Rating Scale (BSRS-5) and Concise Mental Health Checklist (CMHC) were used to evaluate psychopathological symptoms and overall suicidal risks, respectively. Results were further analyzed using the chi-square tests and logistic regression model.

RESULTS

In total, 1930 respondents from a national general population survey were included in the analysis. The weighted prevalence of lifetime BV in the general population was 13.5%. Based on the chi-square analysis, individuals exposed to BV were at high risk for psychopathology (a BSRS-5 score of ≥6 (x² = 45.5, P ≤ .001) and high BSRS-5 scores for all five items). Bullying exposure was significantly associated with lifetime suicide ideation and suicide attempt (x² = 85.7, P ≤ .001; x² = 17.0, P ≤ .001, respectively). The help-seeking behavior of respondents exposed to bullying did not differ significantly (x² = 4.6, P = .327).

CONCLUSION

Bullying exposure is associated with recent psychopathology and lifetime suicidality. Multifactorial interactive processes contribute to long-term harmful health implications in adulthood. Nevertheless, further research on the relevant mechanisms associated with bullying and potential interventions that can decrease morbidity must be conducted.

Developmental associations between bullying victimization and suicidal ideation and direct self-injurious behavior in adolescence and emerging adulthood

BACKGROUND

Bullying, suicide, and self-injury are significant issues among young people. Extensive research has documented bullying victimization associations with suicidal ideation and self-injury; however, the modeling approaches used have mostly not addressed the relations between these constructs at the within-person level, and it is these links that are critical for testing developmental theories and guiding intervention efforts. This examined the within-person, bidirectional relations between these constructs in adolescence and emerging adulthood.

METHODS

Participants were from the Zurich Project on Social Development from Childhood to Adulthood (z-proso). Random intercept cross-lagged panel models (RI-CLPMs) were fit to general and sexual bullying victimization and suicidal ideation data at ages 15, 17, and 20 (n = 1465), and general and sexual victimization and direct self-injurious behavior data at ages 13, 15, 17, and 20 (n = 1482).

RESULTS

There was a positive within-person effect of age 15 general bullying victimization on age 17 suicidal ideation (β = .10) and age 17 suicidal ideation on age 20 general bullying victimization (β = .14).

CONCLUSIONS

General bullying victimization and suicidal ideation may have detrimental effects on each other over development but at different stages.

Genetically Adjusted Propensity Score Matching: A Comparison to Discordant MZ Twin Models

Discordant monozygotic (MZ) twin methodologies are considered one of the foremost statistical approaches for estimating the influence of environmental factors on phenotypic variance. Limitations associated with the discordant MZ twin approach generates an inability to estimate particular relationships and adjust estimates for the confounding influence of gene-nonshared environment interactions. Recent advancements in molecular genetics, however, can provide the opportunity to address these limitations. The current study reviews an alternative technique, genetically adjusted propensity scores (GAPS) matching, that integrates observed genetic and environmental information to adjust for the confounding of these factors in nonkin individuals. Simulations and a real data example were used to compare the GAPS matching approach to the discordant MZ twin method. Although the results of the simulated comparisons demonstrated that the discordant MZ twin approach remains the more robust statistical technique to adjust for shared environmental and genetic factors, GAPS matching - under certain conditions - could represent a viable alternative when MZ twin samples are unavailable. Overall, the findings suggest that GAPS matching can potentially provide an alternative to the discordant MZ twin approach when limited variation exists between identical twin pairs. Moreover, the ability to adjust for gene-nonshared environment interactions represents a potential advancement associated with the GAPS approach. The limitations of the approach, as well as polygenic risk scores, are also discussed.

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.

Cyber-victimisation and mental health in young people: a co-twin control study

BACKGROUND

The rise of social media use in young people has sparked concern about the impact of cyber-victimisation on mental health. Although cyber-victimisation is associated with mental health problems, it is not known whether such associations reflect genetic and environmental confounding.

METHODS

We used the co-twin control design to test the direct association between cyber-victimisation and multiple domains of mental health in young people. Participants were 7708 twins drawn from the Twins Early Development Study, a UK-based population cohort followed from birth to age 22.

RESULTS

Monozygotic twins exposed to greater levels of cyber-victimisation had more symptoms of internalising, externalising and psychotic disorders than their less victimised co-twins at age 22, even after accounting for face-to-face peer victimisation and prior mental health. However, effect sizes from the most stringent monozygotic co-twin control analyses were decreased by two thirds from associations at the individual level [pooled β across all mental health problems = 0.06 (95% CI 0.03-0.10) v. 0.17 (95% CI 0.15-0.19) in individual-level analyses].

CONCLUSIONS

Cyber-victimisation has a small direct association with multiple mental health problems in young people. However, a large part of the association between cyber-victimisation and mental health is due to pre-existing genetic and environmental vulnerabilities and co-occurring face-to-face victimisation. Therefore, preventative interventions should target cyber-victimisation in conjunction with pre-existing mental health vulnerabilities and other forms of victimisation.

Development and Validation of the Assessment of Bullying Experiences Questionnaire for Neurodivergent Youth

Bullying victimization is a prevalent concern for neurodivergent (e.g., autistic, ADHD) youth. Bullying assessment methods vary widely and there is currently no questionnaire specific to neurodivergent youth. The Assessment of Bullying Experiences (ABE) was created to fill this gap. The ABE questionnaire was completed by 335 parents of school-age youth characterized as autistic, having ADHD, or community comparison. Exploratory and Confirmatory Factor Analysis identified a four-factor solution, aligning with verbal, physical, relational, and cyber victimization. Construct validity analyses indicate the ABE converges with an existing bullying questionnaire and diverges from disruptive behavior or internalizing symptoms. The ABE questionnaire is a valid measure of bullying that furthers understanding of nuance in peer victimization for neurodivergent youth and informs group-specific intervention.

Bullying victimization and its associated factors among adolescents in Kozhikode district, Kerala, India: a mixed-methods study [version 1; peer review: 1 approved]

Background

Bullying victimization among adolescents is a serious concern as it leads to poor psycho-social adjustments in the future. Literature on bullying at schools in Kerala is limited. This study aimed to investigate the magnitude of bullying and the factors associated with it among adolescents.

Methods

A sequential explanatory study design was used. A cross-sectional study among 764 adolescents (mean age 13.3 years, males 58.5%) selected through multistage cluster sampling was done. We used the Olweus Bully-Victim Questionnaire, Global School Health Survey, and Patient Health Questionnaire 9 for data collection. Binary logistic regression was performed to identify predictors of bullying victimization. After this, in-depth interviews were carried out among key stakeholders.

Results

About 117 (15.3%) respondents reported being bullied at least twice a month. Verbal bullying was reported by 30% (n=229), physical bullying by 23.3% (n=178), sexual bullying by 11% (n=89) and cyber-bullying by 3.3% (n=25). Adolescents aged 14 years and above (OR 2.09, 95% CI: 1.34-3.26), being male (OR 3.50, 95% CI: 1.97-5.87), the parent's response to bullying (OR 5.27, 95% CI: 2.44-11.36), the victim's reaction to being bullied (OR 8.101, CI: 4.53-14.36) and the teacher's action against the bully (OR 3.59, CI: 1.91-6.73) were major predictors of bullying. Qualitative exploration of pathways of bullying phenomena revealed the influence of parenting on a child being a victim or a bully, and a lack of competence and training among teachers to address bullying at school.

Conclusions

Bullying is highly prevalent among adolescents in schools and has short- and long-term implications. Targeted interventions for bullying prevention should focus on older adolescent boys and those who report being bullied. Anti-bullying policies at school are vital to sensitize teachers, parents, and students to bullying.

A Co-Twin Control Study of the Association Between Bullying Victimization and Self-Harm and Suicide Attempt in Adolescence

PURPOSE

The aim of the study was to investigate the magnitude of an independent association between bullying victimization and self-harm and suicide attempt in adolescence after adjusting for unmeasured and measured confounding factors.

METHODS

Using the Child and Adolescent Twin Study in Sweden, we examined twins born between 1994 and 1999 (n = 13,852). Twins self-reported bullying victimization at age 15 years and self-harm and suicide attempt at age 18 years. We created a factor score of 13 bullying items, on which self-harm and suicide attempt items were regressed in three models: (1) among unrelated individuals; (2) among co-twins, in which a twin exposed to more bullying was compared with his/her co-twin who was exposed to less; and (3) among co-twins while adjusting for indicators of childhood psychopathology.

RESULTS

Among unrelated individuals, a one standard deviation increase in bullying victimization was associated with increased odds for self-harm (odds ratio [OR], 1.29 [95% confidence interval, 1.23-1.36]) and suicide attempt (OR, 1.68 [1.53-1.85]). Among co-twins, the odds attenuated for self-harm (OR, 1.19 [1.09-1.30]) and suicide attempt (OR, 1.39 [1.17-1.66]). Finally, when accounting for childhood psychopathology, there was a 14% (1.04-1.25) and 25% (1.03-1.52) relative increase in odds of self-harm and suicide attempt, respectively.

CONCLUSIONS

The results suggest that bullying victimization was uniquely associated with self-harm and suicide attempt over and above the confounding because of unmeasured and measured factors (i.e., familial vulnerability and pre-existing psychopathy). However, magnitudes were small, suggesting that additional interventions and screenings are needed to address suicidality apart from bullying interventions.

Unravelling the contribution of complex trauma to psychopathology and cognitive deficits: a cohort study

BACKGROUND

Complex traumas are traumatic experiences that involve multiple interpersonal threats during childhood or adolescence, such as repeated abuse. Complex traumas are hypothesized to lead to more severe psychopathology and poorer cognitive function than other non-complex traumas. However, empirical testing of this hypothesis has been limited to clinical/convenience samples and cross-sectional designs.

AIMS

To investigate psychopathology and cognitive function in young people exposed to complex, non-complex, or no trauma from a population-representative longitudinal cohort, and to consider the role of pre-existing vulnerabilities.

METHOD

Participants were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a population-representative birth-cohort of 2,232 British children. At age 18 years (93% participation), we assessed lifetime exposure to complex and non-complex trauma, past-year psychopathology, and current cognitive function. We also prospectively assessed early childhood vulnerabilities: internalizing and externalizing symptoms at age 5, IQ at age 5, family history of mental illness, family socioeconomic status, and sex.

RESULTS

Participants exposed to complex trauma had more severe psychopathology and poorer cognitive function at age 18 compared to both trauma-unexposed participants and those exposed to non-complex trauma. Early childhood vulnerabilities predicted risk of later complex trauma exposure, and largely explained associations of complex trauma with cognitive deficits, but not with psychopathology.

CONCLUSIONS

By conflating complex and non-complex traumas, current research and clinical practice under-estimate the severity of psychopathology, cognitive deficits, and pre-existing vulnerabilities linked with complex trauma. A better understanding of the mental health needs of people exposed to complex trauma could inform the development of new effective interventions.

Twins and Causal Inference: Leveraging Nature's Experiment

In this review, we discuss how samples comprising monozygotic and dizygotic twin pairs can be used for the purpose of strengthening causal inference by controlling for shared influences on exposure and outcome. We begin by briefly introducing how twin data can be used to inform the biometric decomposition of population variance into genetic, shared environmental, and nonshared environmental influences. We then discuss how extensions to this model can be used to explore whether associations between exposure and outcome survive correction for shared etiology (common causes). We review several analytical approaches that can be applied to twin data for this purpose. These include multivariate structural equation models, cotwin control methods, direction of causation models (cross-sectional and longitudinal), and extended family designs used to assess intergenerational associations. We conclude by highlighting some of the limitations and considerations that researchers should be aware of when using twin data for the purposes of interrogating causal hypotheses.

The Relevance of Victimization Experiences for Predicting the Development of Threat Symptoms During Adolescence and Early Adulthood

The "threat" portion of the threat/control override symptom constellation is characterized by the belief by an individual that others seek to do them harm. There has yet to be an examination of the link between perceived threat symptomatology and the experience of victimization, despite the fact that both constructs are linked to the perpetration of violent behavior. Furthermore, there has yet to be research which examines the heterogeneity in developmental patterns of threat symptomatology. The present research utilized the Pathways to Desistance data to model the developmental heterogeneity in perceived threat symptomatology across adolescence and early adulthood using group-based trajectory modeling. A series of multinomial logistic regression models were then estimated to examine the relevance of victimization experiences for predicting trajectory group assignment. A five-group model of development during adolescence and early adulthood best fit the threat symptom data. Victimization experienced prior to age 16 predicted assignment to all groups in the model characterized by presentation of threat symptoms at some point during the study. Victimization experienced between ages 16 and 23 predicted assignment to the High Chronic group and marginally predicted assignment to the Accelerating group. These results indicate that victimization does indeed predict the presentation of perceived threat symptomatology. This indicates that presentation of threat symptoms may be indicative of a history of victimization. Proper screening of those presenting threat symptoms may help to better orient treatment plans for modalities centered on victimization experiences. Future research should investigate the possibility that threat symptoms mediate the relationship between victimization and violent behavior.

Assessment of School Anti-Bullying Interventions: A Meta-analysis of Randomized Clinical Trials

IMPORTANCE

Bullying is a prevalent and modifiable risk factor for mental health disorders. Although previous studies have supported the effectiveness of anti-bullying programs; their population impact and the association of specific moderators with outcomes are still unclear.

OBJECTIVE

To assess the effectiveness of school anti-bullying interventions, their population impact, and the association between moderator variables and outcomes.

DATA SOURCES

A search of Ovid MEDLINE, ERIC, and PsycInfo databases was conducted using 3 sets of search terms to identify randomized clinical trials (RCTs) assessing anti-bullying interventions published from database inception through February 2020. A manual search of reference lists of articles included in previous systematic reviews and meta-analyses was also performed.

STUDY SELECTION

The initial literature search yielded 34 798 studies. Included in the study were articles that (1) assessed bullying at school; (2) assessed the effectiveness of an anti-bullying program; (3) had an RCT design; (4) reported results; and (5) were published in English. Of 16 707 studies identified, 371 met the criteria for review of full-text articles; 77 RCTs were identified that reported data allowing calculation of effect sizes (ESs). Of these, 69 independent trials were included in the final meta-analysis database.

DATA EXTRACTION AND SYNTHESIS

Random-effects and meta-regression models were used to derive Cohen d values with pooled 95% CIs as estimates of ES and to test associations between moderator variables and ES estimates. Population impact number (PIN), defined as the number of children in the total population for whom 1 event may be prevented by an intervention, was used as an estimate of the population impact of universal interventions targeting all students, regardless of individual risk.

MAIN OUTCOMES AND MEASURES

The main outcomes are the effectiveness (measured by ES) and the population impact (measured by the PIN) of anti-bullying interventions on the following 8 variable categories: overall bullying, bullying perpetration, bullying exposure, cyberbullying, attitudes that discourage bullying, attitudes that encourage bullying, mental health problems (eg, anxiety and depression), and school climate as well as the assessment of potential assocations between trial or intervention characteristics and outcomes.

RESULTS

This study included 77 samples from 69 RCTs (111 659 participants [56 511 in the intervention group and 55 148 in the control group]). The weighted mean (range) age of participants in the intervention group was 11.1 (4-17) years and 10.8 (4-17) years in the control group. The weighted mean (range) proportion of female participants in the intervention group was 49.9% (0%-100%) and 50.5% (0%-100%) in the control group. Anti-bullying interventions were efficacious in reducing bullying (ES, -0.150; 95% CI, -0.191 to -0.109) and improving mental health problems (ES, -0.205; 95% CI, -0.277 to -0.133) at study end point, with PINs for universal interventions that target the total student population of 147 (95% CI, 113-213) and 107 (95% CI, 73-173), respectively. Duration of intervention was not statistically significantly associated with intervention effectiveness (mean [range] duration of interventions, 29.4 [1 to 144] weeks). The effectiveness of anti-bullying programs did not diminish over time during follow-up (mean [range] follow-up, 30.9 [2-104] weeks).

CONCLUSIONS AND RELEVANCE

Despite the small ESs and some regional differences in effectiveness, the population impact of school anti-bullying interventions appeared to be substantial. Better designed trials that assess optimal intervention timing and duration are warranted.

Cyberbullying and post-traumatic stress symptoms in UK adolescents

OBJECTIVE

Cyberbullying involvement carries mental health risks for adolescents, although post-traumatic stress (PTS) symptoms have not received strong attention in the UK. This study aimed to assess the overlap between cyber and traditional (ie, face-to-face) bullying, and the relationship to PTS symptoms in UK adolescents.

DESIGN

A cross-sectional survey.

SETTING

Four secondary schools in London,UK.

PARTICIPANTS

2218 secondary school students (11-19 years).

MAIN OUTCOME MEASURES

The Olweus Bully/Victim Questionnaire and the Children Revised Impact of Events Scale.

RESULTS

There was a significant overlap between traditional bullying and cyberbullying. However, cyberperpetrators were less frequently involved in concurrent traditional bullying. Of 2218 pupils, 46% reported a history of any kind of bullying (34% were involved in traditional bullying and 25% in cyberbullying), 17% as victims, 12% as perpetrators, and 4% as both victims and perpetrators. A significant proportion of those who were cybervictims (n=280; 35%), cyberbullies (n=178; 29.2%) or cyberbully-victims (n=77; 28.6%) presented clinically significant PTS symptoms. Cybervictims (both cyber-only and cyberbully-victims) suffered more intrusion (p=0.003; p<0.001) and avoidance (p=0.005; p<0.001) than cyberbullies. However, cyberbullies still suffered more PTS symptoms than the non-involved (intrusion: z=-3.67, p=0.001; avoidance: z=-3.57, p=0.002). Post-traumatic stress symptoms were significantly predicted (R²=13.6) by cyber and traditional victimisation.

CONCLUSIONS

Cyberbullying, as victim only or as a victim-perpetrator, seems to be associated with multiple types of PTS symptoms. Cyber and traditional victimisation significantly predicted intrusion and avoidance. Paediatricians, general practitioners and mental health professionals need to be aware of possible PTS symptoms in young people involved in cyberbullying. Screening and early cost-effective treatments could be implemented.

A Novel Approach to Tackling Bullying in Schools: Personality-Targeted Intervention for Adolescent Victims and Bullies in Australia

OBJECTIVE

To examine the secondary effects of a personality-targeted intervention on bullying and harms among adolescent victims and bullies.

METHOD

Outcomes were examined for victims and bullies in the Climate and Preventure study, Australia. Participants completed self-report measures at baseline and four follow-up assessments (6, 12, 24, and 36 months). Thirteen intervention schools (n = 1,087) received Preventure, a brief personality-targeted cognitive-behavioral therapy intervention for adolescents with high-risk personality types (hopelessness, anxiety sensitivity, impulsivity, sensation seeking). Thirteen control schools (n = 1,103) received health education as usual. Bullying was examined for high-risk victims (n = 143 in Preventure schools versus n = 153 in control schools) and bullies (n = 63 in Preventure schools versus n = 67 in control schools) in the total sample. Harms were examined for high-risk victims (n = 110 in Preventure schools versus n = 87 in control schools) and bullies (n = 50 in Preventure schools versus n = 30 in control schools) in independent schools.

RESULTS

There was no significant intervention effect for bullying victimization or perpetration in the total sample. In the subsample, mixed models showed greater reductions in victimization (b = -0.208, 95% CI -0.4104 to -0.002, p < .05), suicidal ideation (b = -0.130, 95% CI -0.225 to -0.034, p < .01), and emotional symptoms (b = -0.263, 95% CI -0.466 to -0.061, p < .05) among high-risk victims in Preventure versus control schools. Conduct problems (b = -0.292, 95% CI -0.554 to -0.030, p < .05) showed greater reductions among high-risk bullies in Preventure versus control schools, and suicidal ideation showed greater reductions among high-risk female bullies in Preventure versus control schools (b = -0.820, 95% CI -1.198 to -0.442, p < .001).

CONCLUSION

The findings support targeting personality in bullying prevention.

CLINICAL TRIAL REGISTRATION INFORMATION

The CAP Study: Evaluating a Comprehensive Universal and Targeted Intervention Designed to Prevent Substance Use and Related Harms in Australian Adolescents; http://www.anzctr.org.au/; ACTRN12612000026820.

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.

Twin study designs as a tool to identify new candidate genes for depression: A systematic review of DNA methylation studies

Monozygotic (MZ) twin studies constitute a key resource for the dissection of environmental and biological risk factors for human complex disorders. Given that epigenetic differences accumulate throughout the lifespan, the assessment of MZ twin pairs discordant for depression offers a genetically informative design to explore DNA methylation while accounting for the typical confounders of the field, shared by co-twins of a pair. In this review, we systematically evaluate all twin studies published to date assessing DNA methylation in association with depressive phenotypes. However, difficulty to recruit large numbers of MZ twin pairs fails to provide enough sample size to develop genome-wide approaches. Alternatively, region and pathway analysis revealed an enrichment for nervous system related functions; likewise, evidence supports an accumulation of methylation variability in affected subjects when compared to their co-twins. Nevertheless, longitudinal studies incorporating known risk factors for depression such as childhood trauma are required for understanding the role that DNA methylation plays in the etiology of depression.

The Mid-Atlantic Twin Registry of Virginia Commonwealth University

The Mid-Atlantic Twin Registry (MATR) is a population-based registry of more than 60,000 twins primarily born or living in Virginia, North Carolina and South Carolina. Researchers may utilize the MATR for administration of research services, including study recruitment, data or sample (e.g., DNA) collection, archival dataset creation, as well as data collection through mailed, phone or online surveys. In addition, the MATR houses the MATR Repository, with over 1700 DNA samples primarily from whole blood available for researchers interested in DNA genotyping. For over 40 years MATR twins have participated in research studies with investigators from a range of scientific disciplines and institutions. These studies, which have resulted in numerous publications, explored diverse topics, including substance use, smoking behaviors, developmental psychopathology, bullying, children's health, cardiovascular disease, cancer, the human microbiome, epigenetics of aging, children of twins and sleep homeostasis. Researchers interested in utilizing twins are encouraged to contact the MATR to discuss potential research opportunities.

The contribution of bullying victimisation to the burden of anxiety and depressive disorders in Australia

AIM

There is now a strong body of literature showing that bullying victimisation during childhood and adolescence precedes the later development of anxiety and depressive disorders. This study aimed to quantify the burden of anxiety and depressive disorders attributable to experiences of bullying victimisation for the Australian population.

METHODS

This study updated a previous systematic review summarising the longitudinal association between bullying victimisation and anxiety and depressive disorders. Estimates from eligible studies published from inception until 18 August 2018 were included and meta-analyses were based on quality-effects models. Pooled relative risks were combined with a contemporary prevalence estimate for bullying victimisation for Australia in order to calculate population attributable fractions (PAFs) for the two mental disorder outcomes. PAFs were then applied to estimates of the burden of anxiety and depressive disorders in Australia expressed as disability-adjusted life years (DALYs).

RESULTS

The findings from this study suggest 7.8% of the burden of anxiety disorders and 10.8% of the burden of depressive disorders are attributable to bullying victimisation in Australia. An estimated 30 656 DALYs or 0.52% (95% uncertainty interval 0.33-0.72%) of all DALYs in both sexes and all ages in Australia were attributable to experiences of bullying victimisation in childhood or adolescence.

CONCLUSION

There is convincing evidence to demonstrate a causal relationship between bullying victimisation and mental disorders. This study showed that bullying victimisation contributes a significant proportion of the burden of anxiety and depressive disorders. The investment and implementation of evidence-based intervention programmes that reduce bullying victimisation in schools could reduce the burden of disease arising from common mental disorders and improve the health of Australians.

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.

Individual and Classroom Social-Cognitive Processes in Bullying: A Short-Term Longitudinal Multilevel Study

The aim of this study was to examine whether individual and classroom collective social-cognitive processes (moral disengagement and self-efficacy) were associated with bullying perpetration among schoolchildren. An additional aim was to examine whether changes in these processes from grade 4 (Time 1) to grade 5 (Time 2) were associated with a change in bullying perpetration. Self-reported survey data were collected from 1,250 Swedish students from 98 classrooms. Results of multilevel analysis indicated that individual and classroom collective moral disengagement (CMD) were positively associated with bullying, and defender self-efficacy (DSE) was negatively associated with bullying. The effect of changes in individual moral disengagement on changes in bullying was positive, and the effects of changes in DSE and classroom collective efficacy on changes in bullying were negative. Thus, the findings demonstrate the changeability of moral disengagement, DSE and collective efficacy over time, and how these changes are linked to changes in bullying perpetration.

Peer Victimization and Selective Attention in Adolescence: Evidence from a Monozygotic Twin Difference Design

Peer victimization impacts 13% of adolescents worldwide (Currie et al. 2012). Despite its prevalence and associated adverse outcomes, global cognitive processes that could be affected by peer victimization have not been thoroughly investigated. Using a monozygotic (MZ) twin difference design that rigorously controls for the influence of genetic and familial level confounders, we examined the relation between peer victimization exposure and selective attention processes during an affective go/no go task. Twins who experienced more severe peer victimization were biased towards detecting goal relevant stimuli during the task. Our findings suggest an environmentally salient relation between peer victimization and goal oriented selective attention. Future work should investigate how this process might serve to enhance or buffer risk of peer victimization exposure for developing later adverse outcomes.

Co-Twin Control Studies: Natural Events, Experimental Interventions and Rare Happenings/Twin Research: Cancer Risk in Overweight Twins; Prognosis After Fetal Loss of One Twin; Twin Concordance for Parkinson's Disease; Neuroanatomy of Musically Discordant MZ Twins/News Articles: Twin Birth with Two Wombs; Twins' Prenatal Interactions; Switched-at-Birth Twins; Fetus-in-Fetu; Unsolved Paternity

Co-twin control is a well-known methodological twin research design, but its variations and complexities are less well known. Various issues and illustrations are presented with reference to studies involving natural events, experimental interventions and rare happenings that underlie monozygotic (MZ) twins' environmental differences. This discussion is followed by summaries of recent twin research pertaining to cancer risk in overweight twins, the physical risk to surviving twins after fetal loss of a co-twin, a 20-year update of twin concordance for Parkinson's disease, and neuroanatomical differences in musically discordant MZ twin pairs. Several twin-related items that have attracted attention in the news are also summarized.

Peer Victimization and Onset of Social Anxiety Disorder in Children and Adolescents

Background: In the literature, several studies have proposed that children and adolescents with social anxiety had experienced previously victimization from peers and siblings. The aim of this review was to contribute to the updating of recent findings about the relationship between peer victimization and onset of social anxiety in children and adolescents. Methods: A selective review of literature published between 2011 and 2018 on Social Anxiety Disorder in children and adolescents that experienced peer victimization during childhood and adolescence. Results: Seventeen studies are included. All studies showed that peer victimization is positively correlated to the presence of social anxiety. Moreover, the perpetration of peer victimization may contribute to the maintenance and the exacerbation of social anxiety symptoms. Conclusions: In children and adolescents with Social Anxiety Disorder, it is necessary to evaluate firstly the presence of peer victimization experiences. Subsequently, therapeutics programs targeted to elaborate these experiences and to reduce the anticipatory anxiety and the avoidance that characterized these children and adolescents can be proposed.

Do natural experiments have an important future in the study of mental disorders?

There is an enormous interest in identifying the causes of psychiatric disorders but there are considerable challenges in identifying which risks are genuinely causal. Traditionally risk factors have been inferred from observational designs. However, association with psychiatric outcome does not equate to causation. There are a number of threats that clinicians and researchers face in making causal inferences from traditional observational designs because adversities or exposures are not randomly allocated to individuals. Natural experiments provide an alternative strategy to randomized controlled trials as they take advantage of situations whereby links between exposure and other variables are separated by naturally occurring events or situations. In this review, we describe a growing range of different types of natural experiment and highlight that there is a greater confidence about findings where there is a convergence of findings across different designs. For example, exposure to hostile parenting is consistently found to be associated with conduct problems using different natural experiment designs providing support for this being a causal risk factor. Different genetically informative designs have repeatedly found that exposure to negative life events and being bullied are linked to later depression. However, for exposure to prenatal cigarette smoking, while findings from natural experiment designs are consistent with a causal effect on offspring lower birth weight, they do not support the hypothesis that intra-uterine cigarette smoking has a causal effect on attention-deficit/hyperactivity disorder and conduct problems and emerging findings highlight caution about inferring causal effects on bipolar disorder and schizophrenia.

The cost incurred by victims of bullying from a societal perspective: estimates based on a German online survey of adolescents

Being a victim of bullying is linked to various social, emotional and behavioral problems potentially leading to a reduced quality of life. Furthermore, victims of bullying may cause extensive costs for society, for example by an above-average need for healthcare services. The present study was designed to quantify the costs and the loss of quality of life attributable to bullying by comparing victims with a control group of non-bullied students. A cross-sectional sample of 1293 adolescents (mean age 14.07, SD = 1.36) and their parents reported on bullying victimization, quality of life (adolescents' self-report), and annual direct (medical and non-medical) as well as indirect costs (parents' self-report) from a societal perspective (all expressed in €, year 2014 and 2015). For frequent (20.6% of our sample; costs: €8461.80 p.a.) but not occasional (13.3%; costs: €2850.06) bullying, victimization was associated with significantly higher costs compared to non-bullied adolescents (costs: €3138.00; annual difference between frequently bullied students and controls: €5323.01 p.a.; p = 0.008). Cost drivers included increased direct medical costs, but mostly indirect costs caused by productivity losses of the parents. Self-reported quality of life of frequent victims was considerably reduced (T = - 10.96; p < 0.001); also occasional bullying showed significantly reduced values in global quality of life (T = - 5.73; p < 0.001). The present findings demonstrate that frequent bullying is associated with substantial cost to society and reduced quality of life of victims. This observation underscores the need for effective school-based bullying prevention and suggests a high potential of effective programs to be cost effective as well.

Developmental Contributions of Schizophrenia Risk Alleles and Childhood Peer Victimization to Early-Onset Mental Health Trajectories

OBJECTIVE

Twin studies suggest that genetic factors contribute to continuity in mental health problems and that environmental factors are the major contributor to developmental change. The authors investigated the influence of psychiatric risk alleles on early-onset mental health trajectories and whether the trajectories were subsequently modified by exposure to childhood victimization.

METHODS

The sample was a prospective U.K. population-based cohort, the Avon Longitudinal Study of Parents and Children. The developmental trajectories of emotional problems were estimated in childhood (approximately ages 4-8 years) and adolescence (approximately ages 12-17 years). Psychiatric risk alleles were indexed by polygenic risk scores (PRS) for schizophrenia using genome-wide association study results from the Psychiatric Genomics Consortium. Chronic peer victimization in late childhood (ages 8.5 and 10.5 years) was assessed as an index of environmental exposure. Individuals with sufficient data on emotional problems, the PRS, and victimization were included in the main analyses (N=3,988).

RESULTS

Higher schizophrenia PRSs were associated with a trajectory of early-onset increasing emotional problems (odds ratio=1.18, 95% CI=1.02-1.36) compared with a trajectory of low-stable emotional problems. Subsequent exposure to victimization increased the likelihood of transitioning from a trajectory of low-stable emotional problems during childhood (before exposure) to an increasing trajectory in adolescence (after exposure) (odds ratio=2.59, 95% CI=1.48-4.53).

CONCLUSIONS

While the early development of emotional problems was associated with genetic risk (schizophrenia risk alleles), the subsequent course of emotional problems for those who might otherwise have remained on a more favorable trajectory was altered by exposure to peer victimization, which is a potentially modifiable environmental exposure.

Confirmatory factor structure and psychometric properties of the Multidimensional Peer Victimization Scale

The Multidimensional Peer Victimization Scale (MPVS; Mynard & Joseph, 2000) is a 16-item self-report scale that captures peer victimization across four dimensions: physical victimization, verbal victimization, social manipulation, and attacks on property. Performance of the scale has not been evaluated among older adolescents. We examined the factor structure, internal consistency reliability, and performance of the scale in two separate epidemiological U.S. samples representing different age groups: 9-14 year olds (N=610) and 15-17 year olds (N=524). The four-factor structure of the scale was affirmed in both samples, however; there was not metric invariance by gender in the younger age group. The scale and its subscales were found to have good internal consistency. Expected relationships between the MPVS and measures of irritability, anxiety, and depression were affirmed. Results support continued use of the MPVS among child and adolescent samples.

Authoritative classroom climate and its relations to bullying victimization and bystander behaviors

Authoritative school climates have been associated with less school bullying and other antisocial behaviors. However, studies focusing on the classroom level, as well as on bystander behaviors, are lacking. The aim of the current study was to examine whether authoritative classroom climates were associated with bullying victimization and various bystander behaviors (reinforcer, outsider, and defender behaviors) in school bullying. We included gender as a covariate at the individual and classroom levels. Participants were 1540 5th-grade students (824 girls) from 104 classrooms in Sweden who completed a questionnaire. The findings revealed that girls and students in classes with greater authoritative classroom climates were more inclined to defend. Boys reinforced more as did students in classes with more boys and more authoritative classroom climates. Boys showed more outsider behaviors as did students in classes with less authoritative classroom climates. Students in classrooms with less authoritative climates were victimized to a higher degree. Thus, the current findings suggest that a warm, caring, supportive, controlled, demanding, and cohesive classroom climate should be considered a vital protective factor against bullying victimization and negative bystander responses, and a facilitator of defending and supporting victims.

Why do children and adolescents bully their peers? A critical review of key theoretical frameworks

Bullying is a significant public health problem for children and adolescents worldwide. Evidence suggests that both being bullied (bullying victimisation) and bullying others (bullying perpetration) are associated with concurrent and future mental health problems. The onset and course of bullying perpetration are influenced by individual as well as systemic factors. Identifying effective solutions to address bullying requires a fundamental understanding of why it occurs. Drawing from multi-disciplinary domains, this review provides a summary and synthesis of the key theoretical frameworks applied to understanding and intervening on the issue of bullying. A number of explanatory models have been used to elucidate the dynamics of bullying, and broadly these correspond with either system (e.g., social-ecological, family systems, peer-group socialisation) or individual-level (e.g., developmental psychopathology, genetic, resource control, social-cognitive) frameworks. Each theory adds a unique perspective; however, no single framework comprehensively explains why bullying occurs. This review demonstrates that the integration of theoretical perspectives achieves a more nuanced understanding of bullying which is necessary for strengthening evidence-based interventions. Future progress requires researchers to integrate both the systems and individual-level theoretical frameworks to further improve current interventions. More effective intervention across different systems as well as tailoring interventions to the specific needs of the individuals directly involved in bullying will reduce exposure to a key risk factor for mental health problems.

Annual Research Review: The persistent and pervasive impact of being bullied in childhood and adolescence: implications for policy and practice

BACKGROUND

We have known for some time that being bullied was associated with children's and adolescents' adjustment difficulties and well-being. In recent years, we have come to recognise that the impact of childhood bullying victimisation on the development of mental health problems is more complex. This paper aims to review the evidence for an independent contribution of childhood bullying victimisation to the development of poor outcomes throughout the life span, including mental, physical and socioeconomic outcomes, and discuss the implications for policy and practice.

FINDINGS

Existing research indicates that (a) being bullied in childhood is associated with distress and symptoms of mental health problems. This large body of evidence supports actions aimed at reducing the occurrence of bullying behaviours; (b) the consequences of childhood bullying victimisation can persist up to midlife and, in addition to mental health, can impact physical and socioeconomic outcomes. These new findings indicate that interventions should also focus on supporting victims of bullying and helping them build resilience; (c) research has identified some factors that predispose children to be targeted by bullying behaviours. These studies suggest that public health interventions could aim at preventing children from becoming the target of bullying behaviours from an early age.

CONCLUSIONS

It is a truism to emphasise that further work is needed to understand why and how young people's aspirations are often cut short by this all too common adverse social experience. In parallel, we must develop effective strategies to tackle this form of abuse and its consequences for the victims. Addressing bullying in childhood could not only reduce children's and adolescents' mental health symptoms but also prevent psychiatric and socioeconomic difficulties up to adulthood and reduce considerable costs for society.

Adolescent Victimization and Early-Adult Psychopathology: Approaching Causal Inference Using a Longitudinal Twin Study to Rule Out Noncausal Explanations

Adolescence is the peak age for both victimization and mental disorder onset. Previous research has reported associations between victimization exposure and many psychiatric conditions. However, causality remains controversial. Within the Environmental Risk Longitudinal Twin Study, we tested whether seven types of adolescent victimization increased risk of multiple psychiatric conditions and approached causal inference by systematically ruling out noncausal explanations. Longitudinal within-individual analyses showed that victimization was followed by increased mental health problems over a childhood baseline of emotional/behavioral problems. Discordant-twin analyses showed that victimization increased risk of mental health problems independent of family background and genetic risk. Both childhood and adolescent victimization made unique contributions to risk. Victimization predicted heightened generalized liability (the “p factor”) to multiple psychiatric spectra, including internalizing, externalizing, and thought disorders. Results recommend violence reduction and identification and treatment of adolescent victims to reduce psychiatric burden.

Concurrent and Longitudinal Contribution of Exposure to Bullying in Childhood to Mental Health: The Role of Vulnerability and Resilience

IMPORTANCE

Exposure to bullying is associated with poor mental health. However, the degree to which observed associations reflect direct detrimental contributions of exposure to bullying to mental health remains uncertain, as noncausal relationships may arise from genetic and environmental confounding (eg, preexisting vulnerabilities). Determining to what extent exposure to bullying contributes to mental health is an important concern, with implications for primary and secondary interventions.

OBJECTIVE

To characterize the concurrent and longitudinal contribution of exposure to bullying to mental health in childhood and adolescence using a twin differences design to strengthen causal inference.

DESIGN, SETTING, AND PARTICIPANTS

Participants were drawn from the Twins Early Development Study, a population-based cohort recruited from population records of births in England and Wales between January 1, 1994, and December 31, 1996. Data collection took place when the participants were between 11 and 16 years of age from December 1, 2005, to January 31, 2013. Data analysis was conducted from January 1, 2016, to June 20, 2017.

EXPOSURES

Participants completed the Multidimensional Peer-Victimization Scale at 11 and 14 years of age.

MAIN OUTCOMES AND MEASURES

Mental health assessments at 11 and 16 years of age included anxiety, depression, hyperactivity and impulsivity, inattention, conduct problems, and psychotic-like experiences (eg, paranoid thoughts or cognitive disorganization).

RESULTS

The 11 108 twins included in the final sample (5894 girls and 5214 boys) were a mean age of 11.3 years at the first assessment and 16.3 years at the last assessment. The most stringent twin differences estimates (monozygotic) were consistent with causal contribution of exposure to bullying at 11 years to concurrent anxiety, depression, hyperactivity and impulsivity, inattention, and conduct problems. Effects decreased over time; that is, substantial concurrent contributions to anxiety (β = 0.27; 95% CI, 0.22-0.33) persisted for 2 years (β = 0.12; 95% CI, 0.04-0.20) but not 5 years. Direct contributions to paranoid thoughts and cognitive disorganization persisted for 5 years.

CONCLUSIONS AND RELEVANCE

This study is the largest to date to characterize the contribution of exposure to bullying in childhood to mental health using a twin differences design and multi-informant, multiscale data. Stringent evidence of the direct detrimental contribution of exposure to bullying in childhood to mental health is provided. Findings also suggest that childhood exposure to bullying may partly be viewed as a symptom of preexisting vulnerabilities. Finally, the dissipation of effects over time for many outcomes highlights the potential for resilience in children who were bullied. In addition to programs that aim to reduce exposure to bullying, interventions may benefit from addressing preexisting vulnerabilities and focus on resilience.

Adolescent Desire for Cosmetic Surgery: Associations with Bullying and Psychological Functioning

BACKGROUND

Adolescent bullying may be a key driver of interest in cosmetic surgery. This study examined the extent of such interest and whether any effect was sex-specific, and examined psychological functioning as a potential mechanism through which bullying involvement may lead to a wish for cosmetic surgery.

METHODS

A two-stage design was used. In the first stage, 2782 adolescents (aged 11 to 16 years) were screened for bullying involvement using self-reports and peer nominations. In the second stage, 752 adolescents who were bullies, victims, bully-victims, or uninvolved in bullying reported their desire for cosmetic surgery. Psychological functioning was constructed as a composite of self-esteem and emotional problems (assessed at stage 1) and body-esteem scores (assessed at stage 2).

RESULTS

Adolescents involved in bullying in any role were significantly more interested in cosmetic surgery than uninvolved adolescents. Desire for cosmetic surgery was greatest in adolescents who were bullied (victims and bully-victims) and girls. Desire for cosmetic surgery was highest in girls, but sex did not interact with bullying role. Being victimized by peers resulted in poor psychological functioning, which increased desire for cosmetic surgery. In contrast, desire for cosmetic surgery in bullies was not related to psychological functioning, which was in the normal range.

CONCLUSIONS

Bullying victimization is related to poor psychological functioning, and both are related to a greater desire for cosmetic surgery in adolescents. Cosmetic surgeons should screen candidates for psychological vulnerability and may want to include a short screening questionnaire for a history of peer victimization.

Do MZ twins have discordant experiences of friendship? A qualitative hypothesis-generating MZ twin differences study

Using a qualitative monozygotic (MZ) twin differences design we explored whether adolescent MZ twins report discordant peer relationships and, if so, whether they perceive them as causes, consequences or correlates of discordant behaviour. We gathered free-response questionnaire data from 497 families and conducted in-depth telephone interviews with 97 of them. Within this dataset n = 112 families (23% of the sample) described discordant peer relationships. Six categories of discordance were identified (peer victimisation, peer rejection, fewer friends, different friends, different attitudes to friendship and dependence on co-twin). Participants described peer relationship discordance arising as a result of chance occurrences, enhanced vulnerability in one twin or discordant behaviour. Consequences of discordant peer relationships were seen as discordance in self-confidence, future plans, social isolation, mental health and interests. In all cases the twin with worse peer experiences was seen as having a worse outcome. Specific hypotheses are presented.

Does psychological functioning mediate the relationship between bullying involvement and weight loss preoccupation in adolescents? A two-stage cross-sectional study

Background

Adolescent bullying is associated with a range of adversities for those who are bullied i.e., victims and bully-victims (e.g., those who bully others and get victimised), including reduced psychological functioning and eating disorder symptoms. Bullies are generally well-adjusted psychologically, but previous research suggests that bullies may also engage in problematic diet behaviours. This study investigates a) whether adolescents involved in bullying (bullies, victims, bully-victims) are at increased risk of weight loss preoccupation, b) whether psychological functioning mediates this relationship and c) whether sex is a key moderator.

Method

A two-stage design was used. In stage 1, adolescents (n = 2782) from five UK secondary schools were screened for bullying involvement using self and peer reports. In stage 2, a sample of bullies, victims, bully-victims and uninvolved adolescents (n = 767) completed a battery of assessments. The measures included the eating behaviours component of the Child and Adolescent Psychiatric Assessment, which was reduced to one factor (weight loss preoccupation) and used as the outcome variable. Measures of self-esteem, body-esteem and emotional problems were reduced to a latent (mediator) variable of psychological functioning. Multi-group analysis examined the effects of sex and all models were adjusted for covariates (BMI, pubertal stage, age, parental education and ethnicity).

Results

Bullies, victims and bully-victims were at increased risk of weight loss preoccupation compared to adolescents uninvolved in bullying. The mechanism by which bullying involvement related to increased weight loss preoccupation varied by bullying role: in bullies the effect was direct, in victims the effect was indirect (via reduced psychological functioning) and in bully-victims the effect was both direct and indirect. Sex significantly moderated the relationship in bullies: weight loss preoccupation was only statistically significant in bullies who were boys.

Conclusion

Bullying involvement during adolescence is associated with weight loss preoccupation. Bullies are likely driven by a desire to increase attractiveness and social status; whereas weight loss preoccupation in bullied adolescents may have maladaptive influences on diet and exercise behaviours due to its association with reduced psychological functioning. Future research should consider peer victimisation as a potential modifiable risk factor for reduced psychological functioning and weight loss preoccupation, which if targeted, may help to prevent maladaptive diet and exercise behaviours.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-017-0491-1) contains supplementary material, which is available to authorized users.