Kenneth S. Kendler, MD, is the Banks Distinguished Professor of Psychiatry and Professor of Human Genetics at the Medical College of Virginia, Virginia Commonwealth University. Since 1983, he has been engaged in studies of the genetics of psychiatric and substance use disorders, and he has been the director of the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders since its inception. Dr. Kendler's work has utilized the methods of both large-scale population-based twin studies and molecular genetics. He has published over 430 peer-reviewed articles, has received a number of national and international awards, is a member of the Institute of Medicine of the National Academy of Sciences, serves on several editorial boards, and is Editor of Psychological Medicine. Since 1996, Dr. Kendler has served as Director of the Virginia Institute for Psychiatric and Behavioral Genetics.

Carol A. Prescott, PhD, is Professor of Psychology at the University of Southern California and a practicing clinical psychologist. From 1992 to 2005, she was on the faculty of the Virginia Institute for Psychiatric and Behavioral Genetics of Virginia Commonwealth University, where she served as Co-Director of the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders. Dr. Prescott has published extensively on genetic influences on alcoholism and other forms of psychopathology. She serves as Associate Editor for Behavior Genetics and Alcoholism: Clinical and Experimental Research. Her honors include election to membership in the Society for Multivariate Experimental Psychology and the Theodore Reich Prize from the International Society on Psychiatric Genetics.