Substance abuse by people with schizophrenia is a serious public health problem that is associated with poor treatment compliance, increased rates of relapse, and disruption of role functioning. There is widespread agreement on the need to integrate psychiatric and substance abuse treatment for this pernicious combination, but to date there are no specific treatments with solid empirical support. We are currently completing a Stage 1a project to develop a behavioral treatment for this population: Behavioral Treatment for Substance Abuse in Schizophrenia (BTSAS). We have produced a detailed treatment manual, therapist adherence and competence rating scales, and a variety of process measures. Experience to date demonstrates that the intervention is safe and acceptable to the population, that patients will participate in treatment over a 6-month period, and that therapists can learn to administer the intervention in a reliable and competent manner. Preliminary outcome data are quite promising, and suggest that the treatment may be very effective for patients who are motivated to change. The data also indicate that the insession urinalysis contingency we employ has a significant impact. The purpose of this proposal is to conduct a Stage 1b trial comparing BTSAS to a theoretically driven, manualized control treatment (TAU). 110 patients who have concurrent DSM-IV diagnoses of Schizophrenia or Schizoaffective disorder and Substance Dependence for cocaine, opiates, or cannabis will be randomly assigned to BTSAS or TAU for a 6-month trial. Outcomes will be evaluated with a comprehensive battery of symptom, substance use (self-report and urinalysis), and psychosocial measures administered at Baseline, 3-Months, Post- treatment, and at a 6-month Follow-up. We will also examine a variety of potential predictor and mediator variables (e.g., neuropsychological measures, scales from the Transtheoretical Model of Change), process variables, and therapist performance ratings. These results will provide data on the comparative efficacy of BTSAS and on patient characteristics associated with good outcome, and yield important information about the proves of change in dually diagnosed schizophrenia patients.