Dialectical Behaviour Therapy (DBT) is a comprehensive cognitive-behavioural treatment for complex, difficult-to-treat mental disorders.  Originally developed to treat chronically suicidal individuals, DBT has since evolved into a treatment for individuals with borderline personality disorder (BPD) with adaptations for a number of other clinical populations including substance use, eating disorders and depressed and suicidal adolescents. It has been delivered in a variety of settings (e.g., inpatient, outpatient, forensic).  DBT is based on the premise that individuals with BPD  lack important interpersonal, self-regulation (including emotional regulation) and distress tolerance skills, and personal and environmental factors often both block and/or inhibit the use of behavioural skills that clients do have, and reinforce dysfunctional behaviours. DBT combines the basic strategies of behaviour therapy with mindfulness practices, residing within an overarching dialectical worldview that emphasizes the synthesis of opposites.