title: Genetic variation in personality traits explains genetic overlap between borderline personality features and substance use disorders.
abstract: OBJECTIVE
  To examine the genetic overlap between borderline personality features (BPF) and substance use disorders (SUDs) and the extent to which variation in personality traits contributes to this covariance.
  
  
  METHODS
  Genetic structural equation modelling was used to partition the variance in and covariance between personality traits, BPF and SUDs into additive genetic, shared and individual-specific environmental factors.
  
  
  METHODS
  All participants were registered with the Australian Twin Registry.
  
  
  METHODS
  A total of 3127 Australian adult twins participated in the study.
  
  
  METHODS
  Diagnoses of DSM-IV alcohol and cannabis abuse/dependence (AAD; CAD) and nicotine dependence (ND) were derived via computer-assisted telephone interview. BPF and five-factor model personality traits were derived via self-report questionnaires.
  
  
  RESULTS
  Personality traits, BPF and substance use disorders were partially influenced by genetic factors with heritability estimates ranging from 0.38 (neuroticism; 95% confidence interval: 0.30-0.45) to 0.78 (CAD; 95% confidence interval: 0.67-0.86). Genetic and individual-specific environmental correlations between BPF and SUDs ranged from 0.33 to 0.56 (95% CI = 0.19-0.74) and 0.19-0.32 (95% CI = 0.06-0.43), respectively. Overall, there was substantial support for genetic influences that were specific to AAD, ND and CAD (30.76-68.60%). Finally, genetic variation in personality traits was responsible for 11.46% (extraversion for CAD) to 59.30% (neuroticism for AAD) of the correlation between BPF and SUDs.
  
  
  CONCLUSIONS
  Both genetic and individual-specific environmental factors contribute to comorbidity between borderline personality features and substance use disorders. A substantial proportion of this comorbidity can be attributed to variation in normal personality traits, particularly neuroticism.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: Lauren R
authors.initials: LR
authors.lastname: Few
authors.forename: Julia D
authors.initials: JD
authors.lastname: Grant
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Trull
authors.forename: Dixie J
authors.initials: DJ
authors.lastname: Statham
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Martin
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lynskey
authors.forename: Arpana
authors.initials: A
authors.lastname: Agrawal
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000235:genetics / Q000523:psychology; D000704:Analysis of Variance; D001315:Australia; D001883:Borderline Personality Disorder / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology; D002605:Character; D004200:Diseases in Twins / Q000235:genetics*; D005260:Female; D059647:Gene-Environment Interaction; D014644:Genetic Variation / Q000235:genetics*; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000235:genetics / Q000523:psychology; D008957:Models, Genetic; D010641:Phenotype; D013223:Statistics as Topic; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology; D014029:Tobacco Use Disorder / Q000235:genetics / Q000523:psychology; D055815:Young Adult
keywords: Alcohol use disorders; borderline personality disorder; cannabis use disorders; comorbidity; five-factor model; genetics; nicotine dependence; personality traits; substance use disorders