Abstract
Both environmental (e.g. interpersonal traumatization during childhood and adolescence) and genetic factors may contribute to the development of Borderline Personality Disorder (BPD). Twin studies assessing borderline personality symptoms/features in the general population indicate that genetic factors underlying these symptoms/features are shared in part with the personality traits of the Five Factor Model (FFM) of personality – the “Big Five". In the present study, the genetic overlap of BPD with the Big Five -Openness to Experience, Conscientiousness, Extraversion, Agreeableness and Neuroticism- was assessed. Linkage disequilibrium score regression was used to calculate genetic correlations between a genome-wide association study (GWAS) in central European populations on BPD (N = 2,543) and GWAS on the “Big Five” (N = 76,551–122,886, Neuroticism N = 390,278). Significant positive genetic correlations were found between BPD and the traits Neuroticism (rg=.34, p=6.3*10−5) and Openness (rg=.24, p=.036), but not between BPD and the other personality traits (all |rg|<.14, all p>.30). A cluster and item-level analysis showed positive correlations with the Neuroticism clusters “Depressed Affect” and “Worry”, and with a broad range of Neuroticism items (N = 348,219 – 376,352). The observed associations indicate a partially shared genetic background of BPD and the personality traits Neuroticism and Openness. Larger GWAS of BPD and the “Big Five” are needed to further explore the role of personality traits in the etiology of this disorder.