This is a request for a continuation of the Mental health Statistics (MHS) Training Program offered by the Division of Biostatistics at Columbia university's Sch of Public Health. The MHS program trains statisticians completing the requirements of doctoral degrees in biostatistics (predoctoral fellows) and mental health researchers already holding a doctoral degree (postdoctoral fellows). Through these complementary programs, we aim to facilitate collaboration between statisticians and mental health researchers and to train statisticians who will specialize in psychiatric research as an area of application. Predoctoral fellows study advanced statistics in order to earn the Ph.D. or Dr. P.H. in Biostatistics, and also receive training in psychiatric nosology, psychiatric epidemiology, and psychometrics. They are expected to engage in collaborative research on mental health related projects. Postdoctoral fellows receive training in biostatistics by earning a Master's degree in Biostatistics. This component of the program is designed for psychologist, psychiatrists, sociologists or epidemiologists who have conducted research on mental health problems and who want an unusually thorough background in quantitative methods. Postdoctoral applicants with strong quantitative background (e.g., a doctorate in applied mathematics or mathematical statistics) and interest in statistical genetics are also invited to apply. These applicants may not need to work toward a biostatistics degree; instead they engage in statistical research with psychiatric applications. They learn about mental health research by taking courses in psychiatric nosology and structured assessment, by attending the weekly seminars, and by participating in mental health related research projects. Postdoctoral and predoctoral fellows interact with each other, with fellows of Columbia University's Psychiatric Epidemiology training Program, and with researchers in Columbia's Psychiatry Department and at the New York State Psychiatric Institute. The quality and breadth of the research conducted at these institutions provides a unique opportunity for MHS fellows to obtain interdisciplinary training in mental health and statistics, as well as statistical genetics. In each of years 17 through 21, we request funding for one predoctoral fellow and three postdoctoral fellows.