Young has proposed a schema mode model of borderline personality disorder (BPD), hypothesizing that BPD patients tend to flip from 1 of 4 maladaptive schema modes to another. The present study is the first empirical test of this model, investigating whether these 4 modes are specific for BPD patients and whether BPD-relevant stress specifically increases one of the modes, the detached protector mode. Eighteen BPD patients, 18 cluster-C personality disorder (PD) patients and 18 non-patient controls (all women) filled out trait and state versions of a newly developed schema mode questionnaire, assessing cognitions, feelings and behaviors characteristic of 7 schema modes. Using a cross over design, subjects subsequently watched a neutral and a BPD-specific emotional movie fragment (order balanced). After watching each movie, subjects again filled out the schema mode questionnaire, state version. Trait as well as state versions indicated that BPD patients were indeed characterized by the hypothesized four maladaptive modes (Detached Protector, Punitive Parent, Abused/Abandoned Child, Angry/Impulsive Child). BPD patients were lowest on the Healthy Adult mode. The stress induction induced negative emotions in all groups, but the BPD group was unique in that the Detached Protector mode increased significantly more than in both control groups.