Intervention within the stages-of-change framework allows the clinician to develop response-specific intervention strategies that are appropriate to the client's behavior pathology. Stages in this treatment model, using alcohol addiction as an example, include: (1) Precontemplation: patients have no interest in quitting drinking and are unaware of any problems caused by their drinking; (2) Contemplation: patients are aware that they have a problem and are considering quitting; (3) Preparation: some reduction in addictive behaviors but no clear criterion for effective action; (4) Action: patients have successfully altered addictive behavior from 1 day to 6 months; and (5) Maintenance: patients have achieved stable abstinence and are working to prevent relapse. The chapter outlines specific intervention strategies for substance abusers with psychopathology and chronically mentally ill substance abusers, both groups in a precontemplative stage of change. Figure, references