Developing the diagnostic and statistical manual V: what will "statistical" mean in DSM-V?

In February of 2004, the American Psychiatric Institute for Research and Education (APIRE) hosted a Launch and Methodology Conference to discuss the role statistics might play in the eventual revision of the Fourth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the Ninth Edition of the International Classification of Diseases (ICD9). The conference consisted of talks on specific topics by statisticians and epidemiologists from North America and Great Britain, followed by group discussion by experts in nosology and psychopathology. We report here on the development of specific themes related to the future interaction between statisticians and nosologists in DSM-V development that arose as a result of that meeting. The themes are related to (1) the nature of the statistician/nosologist interaction; (2) specific areas of concern in that interaction, and (3) the use of novel and complex statistical methods to challenge and inspire new avenues of thinking among nosologists.