DSM-5 is scheduled for publication in 2013. The revision process will be the product of over 13 years of work. DSM-5 Work Groups have recently proposed changes in each of the major diagnostic classes of mental disorders and revised their proposals in anticipation of APA-sponsored and APA-conducted Field Trials now underway. This article will review the scientific and philosophical principles guiding the revisions and how they have influenced the development of the proposed changes for the assessment and diagnosis of personality psychopathology for DSM-5. Included are discussions of the definition of mental disorder, dimensional vs. categorical approaches to diagnosis, criteria for change, validity vs. clinical utility, cultural applicability, the relationship of DSM-5 and ICD-11 and diagnosis for specialty vs. primary care settings. Although principles for revising the DSM-5 were articulated some time ago, the revision process thus far has proceeded with some degree of ambiguity, controversy and contradiction. Copyright © 2011 American Psychiatric Association.