 The efficacy of screening and brief intervention SBI for drug use among primary care patients is unknown. National organizations do not recommend universal screening. But policy is at odds with the evidence: federal efforts to disseminate SBI are underway, and reimbursement codes to compensate clinicians have been developed. Thus there is a need to study SBI for drug use. The objective of this study is to determine the efficacy of two models of brief intervention BI for decreasing drug use and consequences in primary care patients. In collaboration with a state project implementing SBI as part of a federal program, we will screen patients in a large hospital-based primary care practice for drug use. We will then enroll screen-positive subjects, randomly assign them to 1 of 3 groups, and follow them for 6 months. Subjects in 1 intervention group will be assigned to a standard BI model, conducted by trained health advocates implementing a Federal program locally. In another group, subjects will be assigned to an enhanced BI model that includes an optional booster contact and is conducted by masters-level counselors trained and monitored intensively. The control group will receive information i.e., a written list of local resources to help people using drugs and, at the end of six months, standard BI if they are still using drugs. 