Dialectical behavior therapy (DBT) is a cognitive-behavioral psychotherapy developed by Linehan for parasuicidal patients with a diagnosis of borderline personality disorder (BPD). DBT is based on a biosocial theory that views BPD as primarily a dysfunction of the emotion regulation system. The treatment is organized around a hierarchy of behavioral goals that vary in different modes of therapy. In two randomized trials, DBT has shown superiority in reducing parasuicide, medical risk of parasuicides, number of hospital days, dropout from treatment and anger while improving social adjustment. Most gains were maintained through a 1-year follow-up. In one process study testing DBT theory, dialectical techniques balancing acceptance and change were more effective than pure change or acceptance techniques in reducing suicidal behavior.