title: Borderline personality disorder co-morbidity: relationship to the internalizing-externalizing structure of common mental disorders.
abstract: BACKGROUND
  Borderline personality disorder (BPD) shows high levels of co-morbidity with an array of psychiatric disorders. The meaning and causes of this co-morbidity are not fully understood. Our objective was to investigate and clarify the complex co-morbidity of BPD by integrating it into the structure of common mental disorders.
  
  
  METHODS
  We conducted exploratory and confirmatory factor analyses on diagnostic interview data from a representative US population-based sample of 34 653 civilian, non-institutionalized individuals aged ≥18 years. We modeled the structure of lifetime DSM-IV diagnoses of BPD and antisocial personality disorder (ASPD), major depressive disorder, dysthymic disorder, panic disorder with agoraphobia, social phobia, specific phobia, generalized anxiety disorder, post-traumatic stress disorder, alcohol dependence, nicotine dependence, marijuana dependence, and any other drug dependence.
  
  
  RESULTS
  In both women and men, the internalizing-externalizing structure of common mental disorders captured the co-morbidity among all disorders including BPD. Although BPD was unidimensional in terms of its symptoms, BPD as a disorder showed associations with both the distress subfactor of the internalizing dimension and the externalizing dimension.
  
  
  CONCLUSIONS
  The complex patterns of co-morbidity observed with BPD represent connections to other disorders at the level of latent internalizing and externalizing dimensions. BPD is meaningfully connected with liabilities shared with common mental disorders, and these liability dimensions provide a beneficial focus for understanding the co-morbidity, etiology and treatment of BPD.
authors.affiliation: Department of Psychology, 75 East River Road, University of Minnesota, Minneapolis, MN 55455-0344, USA. nreaton@gmail.com
authors.forename: N R
authors.initials: NR
authors.lastname: Eaton
authors.forename: R F
authors.initials: RF
authors.lastname: Krueger
authors.forename: K M
authors.initials: KM
authors.lastname: Keyes
authors.forename: A E
authors.initials: AE
authors.lastname: Skodol
authors.forename: K E
authors.initials: KE
authors.lastname: Markon
authors.forename: B F
authors.initials: BF
authors.lastname: Grant
authors.forename: D S
authors.initials: DS
authors.lastname: Hasin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001008:Anxiety Disorders / Q000453:epidemiology; D001883:Borderline Personality Disorder / Q000453:epidemiology* / Q000523:psychology; D015897:Comorbidity; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology*; D008875:Middle Aged; D008960:Models, Psychological; D019964:Mood Disorders / Q000453:epidemiology; D019966:Substance-Related Disorders / Q000453:epidemiology; D014481:United States / Q000453:epidemiology