Dimensional Models of Personality Disorders

Dimensional models of personality disorders, also called the dimensional approach to personality disorders or dimensional classification, treat personality disorders as quantitatively rather than qualitatively distinct from normal personality, viewing a disorder as an extreme position on a continuous trait dimension that the general population shares, made up of extreme, maladaptive levels of characteristics commonly described as facets within broader personality traits. This stands in contrast to the categorical approach used in the standard DSM-5 classification, under which a person either does or does not possess a given characteristic, with no account taken of degree. How these diagnostic dimensions should be built was debated heavily ahead of the DSM-5's publication, and several dimensional models have been produced, differing in construction and intended interpretation, falling into four broad types: a dimensional recasting of the DSM's original disorder categories, a dimensional model based on latent traits identified within those DSM disorders, a dimensional model based on traits drawn from normal-personality research, and a model integrating multiple dimensional approaches, for instance through network analysis. The dimensional approach appears in the DSM-5 itself, in its Section III on emerging measures and models, under the title Alternative DSM-5 Model for Personality Disorders, though the decision to keep the older DSM-IV categorical model as the manual's primary system was controversial, and efforts continue toward replacing it with the dimensional model in a future DSM 5.1.