Borderline Personality Disorder (BPD) was once thought to be nearly untreatable. However, developments of psychotherapies focused on the symptoms and underlying etiology of BPD have changed that. The Personality Disorders Institute (PDI) at the Weill Medical College of Cornell University hosts an excellent website that provides an overview of BPD and one particular treatment for it, Transference-Focused Psychotherapy. On the site, readers can learn about the labile emotions, stormy relationships, self-defeating behaviors, and troubled identity that define BPD in Overview of Borderline Personality Disorder. The treatment itself, with its focus on exploring and promoting change within these same four areas, is also a great read. The Radio Interviews section is another great resource, featuring several researchers on BPD, Transference-Focused Psychotherapy, and other related topics.