1. Department of Psychiatry; Massachusetts General Hospital/Harvard Medical School; Boston Massachusetts (MA) USA
2. Tobacco Research and Treatment Center, Division of General Internal Medicine, Department of Medicine; Massachusetts General Hospital / Harvard Medical School; Boston Massachusetts USA
3. Nuffield Department of Primary Care Health Sciences; University of Oxford; Oxford UK
4. Medicine; Vanderbilt University Medical Center; Nashville TN USA
5. Center for Primary Care and Public Health; University of Lausanne; Lausanne Switzerland
6. School of Experimental Psychology and MRC Integrative Epidemiology Unit; University of Bristol; Bristol UK
7. Department of Psychiatry; Massachusetts General Hospital; Boston Massachusetts USA
8. Department of Health Promotion and Policy; University of Massachusetts; Amherst MA USA