title: Psychiatric outcomes of bullying victimization: a study of discordant monozygotic twins.
abstract: Bullying victimization in childhood is associated with a broad array of serious mental health disturbances, including anxiety, depression, and suicidal ideation and behavior. The key goal of this study was to evaluate whether bullying victimization is a true environmental risk factor for psychiatric disturbance using data from 145 bully-discordant monozygotic (MZ) juvenile twin pairs from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) and their follow-up into young adulthood.
  
  
  
  Since MZ twins share an identical genotype and familial environment, a higher rate of psychiatric disturbance in a bullied MZ twin compared to their non-bullied MZ co-twin would be evidence of an environmental impact of bullying victimization. Environmental correlations between being bullied and the different psychiatric traits were estimated by fitting structural equation models to the full sample of MZ and DZ twins (N = 2824). Environmental associations were further explored using the longitudinal data on the bullying-discordant MZ twins.
  
  
  
  Being bullied was associated with a wide range of psychiatric disorders in both children and young adults. The analysis of data on the MZ-discordant twins supports a genuine environmental impact of bullying victimization on childhood social anxiety [odds ratio (OR) 1.7], separation anxiety (OR 1.9), and young adult suicidal ideation (OR 1.3). There was a shared genetic influence on social anxiety and bullying victimization, consistent with social anxiety being both an antecedent and consequence of being bullied.
  
  
  
  Bullying victimization in childhood is a significant environmental trauma and should be included in any mental health assessment of children and young adults.
authors.affiliation: Department of Human and Molecular Genetics,Virginia Commonwealth University School of Medicine,Richmond,Virginia,USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Silberg
authors.affiliation: Department of Psychiatry and Behavioral Sciences,Duke University Medical Center,Durham,North Carolina,USA.
authors.forename: W
authors.initials: W
authors.lastname: Copeland
authors.affiliation: Department of Psychiatry,Virginia Commonwealth University School of Medicine,Richmond,Virginia,USA.
authors.forename: J
authors.initials: J
authors.lastname: Linker
authors.affiliation: Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University,Richmond,Virginia.
authors.forename: A A
authors.initials: AA
authors.lastname: Moore
authors.affiliation: Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University,Richmond,Virginia.
authors.forename: R
authors.initials: R
authors.lastname: Roberson-Nay
authors.affiliation: Department of Human and Molecular Genetics,Virginia Commonwealth University School of Medicine,Richmond,Virginia,USA.
authors.forename: T P
authors.initials: TP
authors.lastname: York
mesh_terms: D000293:Adolescent; D000328:Adult; D001010:Anxiety, Separation / Q000453:epidemiology* / Q000209:etiology; D058445:Bullying / Q000706:statistics & numerical data*; D002648:Child; D019548:Crime Victims / Q000706:statistics & numerical data*; D004200:Diseases in Twins / Q000453:epidemiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D000072861:Phobia, Social / Q000453:epidemiology* / Q000209:etiology; D059020:Suicidal Ideation; D014430:Twins, Monozygotic; D055815:Young Adult
keywords: Discordant MZ twins; bullying victimization