Department of Psychiatry, UNC Chapel Hill, University of North Carolina, CB 7160, Chapel Hill, NC 27599, USA; Department of Nutrition, University of North Carolina, CB 7400, Chapel Hill, NC 27599, USA; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobels väg 12A, SE-171 77, Stockholm, Sweden. Electronic address: cynthia_bulik@med.unc.edu. Department of Human Genetics, University of Chicago, Cummings Life Science Center, 920 East 58th Street, Chicago, IL 60637, USA. Department of Psychiatry, University of British Columbia, Translational Lab Building Room a3-112 - 3rd Floor, 938 West 28th Avenue, Vancouver, British Columbia V5Z 4H4, Canada; Department of Medical Genetics, University of British Columbia, Translational Lab Building Room a3-112 - 3rd Floor, 938 West 28th Avenue, Vancouver, British Columbia V5Z 4H4, Canada.