1. VA Puget Sound Health Care System, Seattle, Washington
2. Division of Gastroenterology, Department of Medicine, University of Washington School of Medicine, Seattle
3. Center of Excellence in Substance Addiction Treatment and Education, VA Puget Sound Health Care System, Seattle, Washington
4. VA Research and Development, VA Puget Sound Health Care System, Seattle, Washington
5. Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle