Abstract
BACKGROUND: Borderline personality disorder (BPD) is characterized by instability in interpersonal relationships and fear of abandonment, which intensify during stress. Social stressors seem to activate the hypothalamic-pituitary-gonadal (HPG) axis in healthy controls (HC), but this has not been investigated in patients with BPD. This study aimed to investigate the effects of social stress, i.e., social exclusion on changes of progesterone and estradiol levels in women with BPD compared to HC. METHODS: 82 women with BPD and 82 HC were randomly assigned to either an exclusion or overinclusion condition of the Cyberball paradigm. Saliva samples were collected at baseline (T1), immediately after Cyberball (T2) and 15 min post-Cyberball (T3). Two 3 × 2 × 2 repeated-measures ANOVAs were conducted with time (T1, T2, T3) as the within-subject factor, and group (BPD vs. HC) and condition (exclusion vs. overinclusion) as between-subject factors. RESULTS: On progesterone change, the analysis revealed no significant main effects of group or condition, but a significant group × condition interaction. Post-hoc tests showed that within the BPD group, change of progesterone levels at T3 i.e., after Cyberball, were higher after exclusion than overinclusion. For changes of estradiol levels, no significant main effects for group, condition, or their interaction were found. DISCUSSION: This study provides initial evidence that women with BPD exhibit distinct hormonal dynamics in progesterone after social exclusion versus overinclusion. Further research is needed to better understand this hormonal pattern and its implications for social functioning in BPD.