1. Center for the Clinical Trials Network, National Institute on Drug Abuse, 6001 Executive Blvd., Bethesda, MD 20892 USA,
2. Columbia University School of Social Work, Social Intervention Group, 1255 Amsterdam Avenue, New York, NY, 10027 USA
3. Division of Scientific Investigations, Office of Compliance, CDER, FDA, Federal Research Center, 10903 New Hampshire Ave., Silver Spring, MD 20993 USA
4. Department of Psychiatry, Medical University of South Carolina, 67 President Street, Charleston, SC 29425 USA