1. From the Departments of Psychiatry and Behavioral Sciences (D.C.S., K.R.R.K.), Duke University Medical Center, Durham, NC; the Departments of Biostatistics (H.C.), Neurology (W.T.L.), and Epidemiology (W.T.L.), University of Washington, Seattle; the School of Public Health (M.C.), Johns Hopkins University, Baltimore, MD; and the Department of Public Health Sciences (G.L.B.), Wake Forest University School of Medicine, Winston-Salem, NC.