Contingency management is efficacious for treating cocaine abuse, but contingency management interventions have rarely been applied to patients with severe and persistent mental health problems. This pilot project will estimate effect sizes of contingency management for reducing cocaine use in patients receiving psychiatric care at a large community based mental health program. In total, 30 cocaine abusing patients will be randomized to one of two 8-week treatment conditions: standard care or standard care with contingency management. Patients in both conditions will provide breath and urine samples for toxicology testing twice per week. In the contingency management condition, patients will receive the opportunity to win prizes for submitting cocaine negative urine samples. The investigators expect that patients receiving contingency management will evidence reductions in cocaine use and may show improvements in psychiatric symptoms and psychosocial functioning relative to patients in standard care. Effect size estimates obtained from this study will be used to guide larger scale and longer duration evaluations of contingency management for dually diagnosed patients.

Inclusion Criteria:

• age 18 years or older
• meet DSM-IV criteria for cocaine abuse or dependence
• English speaking
• pass a brief quiz regarding study procedures to ensure understanding of the informed consent process.

Exclusion Criteria:

• dementia
• in recovery from pathological gambling