The Addiction Severity Index (ASI) is probably the most commonly used assessment instrument in the substance abuse treatment field. It is part of most clinical intake assessments in more than 20 states and 50 cities in the United States. The ASI also is included in virtually all clinical trials of patients with substance use disorders. In brief, it is a clinician- or technician-administered, semistructured interview that gathers information on seven functional areas often negatively affected by alcohol and drug abuse: medical status, employment and support, drug use, alcohol use, legal status, family or social status, and psychiatric status. It typically is used upon admission to a treatment program and subsequent follow-up contacts. Clinicians may use the ASI in inpatient and outpatient substance abuse treatment settings ...