The purpose of this study is to determine the effectiveness of a behavioral treatment, contingency management, in reducing stimulant use in persons with serious mental illness.

This study will evaluate the efficacy of a twelve week contingency management (CM) intervention for treating psycho-stimulant substance abuse when delivered in the context of a community mental health center (CMHC) setting for adults suffering from serious mental illness (SMI). The CM paradigm to be used is one which has been shown effective in several recent large clinical trials, using the variable magnitude of reinforcement procedure. The reinforcers will be vouchers or actual items useful for day to day living in this population. Two hundred SMI participants with co-occurring stimulant disorders will be recruited from a large urban CMHC and randomized to receive either the active CM paradigm plus treatment as usual (TAU), or TAU which will include the delivery of reinforcement for study involvement (reinforcement that is not contingent on drug abstinence). The primary outcome is change in psycho-stimulant use (methamphetamine, amphetamine and/or cocaine). Secondary outcomes include: changes in use of other illegal drugs or alcohol; changes in CMHC treatment adherence and follow-through; changes in psychiatric symptoms, quality of life, and community outcomes (homelessness, incarcerations, etc.). Additional outcomes to be measured include changes in drug craving, stage of change, nicotine use, and HIV risk status. The study involves two phases, the 12 week treatment phase, where CM and control treatments are delivered, as well as a 3 month follow up phase.

Inclusion Criteria:

• Enrolled patient at Community Psychiatric Clinic (CPC), a large mental health center in urban Seattle, Washington;
• Between 18 and 65 years of age;
• Diagnosis of of methamphetamine, amphetamine(illegal), or cocaine dependence or abuse;
• CPC medical record diagnosis of schizophrenia, schizoaffective disorder, bipolar I or II, or recurrent major depressive disorder
• Stimulant drug use one month before enrollment;
• Ability to understand written and spoken English;
• CPC clinical case manager must affirm the potential participant's ability to provide informed consent and clinical appropriateness (i.e., safety/severity of mental/substance/ physical health) to participate in the study.

Exclusion Criteria:

• Any medical/psychiatric condition, or severity of that condition, that, in the opinion of Dr. Ries, the PI, would compromise safe study participation
• Chart defined organic brain disorder or dementia;
• Current participation in a methadone maintenance program;
• Any other circumstances that in the PI's opinion precludes safe study participation.