The investigators will examine whether MR stimulation enhances prosocial behavior in BPD patients under additional psychosocial stress. Participants will be randomly assigned to receive either fludrocortisone as an MR stimulant or placebo. Afterwards, participants will either undergo the stress or placebo condition of the Trier Social Stress Test ((P-)TSST). Subsequently, cognitive and emotional empathy, as well as sharing and punishment behavior will be measured.
The investigators will examine how a combination of pharmacological mineralocorticoid receptor (MR) stimulation and psychosocial stress will influence prosocial behavior in patients with Borderline Personality Disorder (BPD) compared to healthy controls (HC).