 Patients with borderline personality disorder BPD will be provided with an empirically supported form of psychotherapy for BPD patients called transference-focused psychotherapy TFP and medication treatment, if indicated. The primary goal of the current study is to detect changes in psychological, psychosocial and work functioning over the course of 18-months of TFP. Previous research has shown that TFP is an effective treatment for BPD over the course of one year, significantly reducing symptoms. An 18-month treatment period will most likely allow patients to achieve significant and lasting gains in work and psychosocial functioning. Each patient will be assessed prior to baseline, at 3-month intervals throughout, and at the termination of the 18-month treatment period for symptoms, vocational status, and psychosocial functioning. In addition, patients and therapists will complete self-report measures every three months about the therapeutic relationship. 