No evidence for altered prenatal exposure to testosterone in young females diagnosed with Borderline Personality Disorder

Abstract

Introduction. Borderline Personality Disorder (BPD) is characterised, among other features, by increased impulsivity and aggression, both directed toward the self and others. These clinical signs most likely arise from complex gene-environment interactions. In our study, we sought to elucidate the role of prenatal testosterone exposure in female patients with BPD. Materials and Methods. In a sample of 42 patients and 50 controls matched for age and biological sex, we measured the ratio of the second to the fourth digit of both hands (2D:4D ratio), which is established as a reliable correlate of prenatal testosterone levels in the foetus. In addition, we used several self-rating scales to determine personality dimensions, impulsivity, aggressiveness and risk-taking behaviour. Results. No differences between the groups emerged with regard to 2D:4D ratio of both hands. In ad-dition, there were almost no correlations between psychological measures and the 2D:4D ratio in the entire sample. Conclusions. Contrary to predictions, female patients with BPD did not differ from controls in 2D:4D ratio bimanually, suggesting no abnormal intrauterine (prenatal) exposure to testosterone in this clinical group. As expected, differences between patients and controls in personality traits, impulsivity, aggressiveness and risk-taking were highly significant and in concordance with the existing body of knowledge. Since BPD features are highly heterogeneous, it could be interesting to study subgroups of BPD patients, rather than the broader phenotype according to DSM-5 criteria.