1. University of Texas School of Public Health; Dallas; Texas
2. School of Community Health; Portland State University; Portland; Oregon
3. Center for Public Health Studies; Portland State University; Portland; Oregon
4. Department of Psychiatry; Oregon Health and Science University; Portland; Oregon
5. Social and Epidemiological Research Department; Centre for Addiction and Mental Health; Toronto; Ontario; Canada
6. Office of the Medical Investigator; University of New Mexico School of Medicine; Albuquerque; New Mexico