The five-factor model of personality and borderline personality disorder: a genetic analysis of comorbidity.
BACKGROUND
Recently, the nature of personality disorders and their relationship with normal personality traits has received extensive attention. The five-factor model (FFM) of personality, consisting of the personality traits neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness, is one of the proposed models to conceptualize personality disorders as maladaptive variants of continuously distributed personality traits.


METHODS
The present study examined the phenotypic and genetic association between borderline personality and FFM personality traits. Data were available for 4403 monozygotic twins, 4425 dizygotic twins, and 1661 siblings from 6140 Dutch, Belgian, and Australian families.


RESULTS
Broad-sense heritability estimates for neuroticism, agreeableness, conscientiousness, extraversion, openness to experience, and borderline personality were 43%, 36%, 43%, 47%, 54%, and 45%, respectively. Phenotypic correlations between borderline personality and the FFM personality traits ranged from .06 for openness to experience to .68 for neuroticism. Multiple regression analyses showed that a combination of high neuroticism and low agreeableness best predicted borderline personality. Multivariate genetic analyses showed the genetic factors that influence individual differences in neuroticism, agreeableness, conscientiousness, and extraversion account for all genetic liability to borderline personality. Unique environmental effects on borderline personality, however, were not completely shared with those for the FFM traits (33% is unique to borderline personality).


CONCLUSIONS
Borderline personality shares all genetic variation with neuroticism, agreeableness, conscientiousness, and extraversion. The unique environmental influences specific to borderline personality may cause individuals with a specific pattern of personality traits to cross a threshold and develop borderline personality.
Distel
Marijn A
MA
Department of Biological Psychology, VU University Amsterdam, 1081 BT Amsterdam, the Netherlands. ma.distel@psy.vu.nl
Trull
Timothy J
TJ
Willemsen
Gonneke
G
Vink
Jacqueline M
JM
Derom
Catherine A
CA
Lynskey
Michael
M
Martin
Nicholas G
NG
Boomsma
Dorret I
DI
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001883:Borderline Personality Disorder / Q000235:genetics*; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D007391:International Cooperation; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D010551:Personality / Q000235:genetics*; D010555:Personality Inventory; D010641:Phenotype; D012043:Regression, Psychology; D035781:Siblings; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D055815:Young Adult