Dialectical behavior therapy (DBT) was developed as a treatment for parasuicidal women with borderline personality disorder and has been adapted for several other populations. This article describes standard DBT and several adaptations of it and reviews outcome studies with borderline patients in outpatient, inpatient, and crisis intervention settings, borderline patients with substance use disorders, suicidal adolescents, patients with eating disorders, inmates in correctional settings, depressed elders, and adults with attention-deficit/hyperactivity disorder. This treatment outcome review is followed by discussion of predictors of change in DBT, possible mechanisms of change, and current developments in theory, practice, and research.