BPD adolescents will be compared to typically developing controls in two complementary experimental designs: (1) Monitoring of neurovegetative, hormonal and body motion responses to an acute stress, with the hypothesis that stress reactivity might account for the physiopathology of the disorder; (2) Structural and functional imaging (fMRI BOLD) in the context of a reward processing task to delineate the neural/functional basis of BPD risk taking behavior.