1. Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
2. Department of Psychology, Illinois Institute of Technology, Chicago, Illinois
3. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
4. School of Medical Science, Örebro University, Örebro, Sweden
5. Department of Genetics, Virginia Commonwealth University, Richmond, Virginia
6. Department of Psychiatry, Virginia Commonwealth University, Richmond, Virginia