Special feature: personality and personality disorders. A facet theoretical analysis of the similarity relationships.

Categorical and dimensional models of personality, and personality disorders and their interrelationships, are discussed. A facet theoretical analysis of the structural relationships between personality factors and disorders is described. It is hypothesized that higher-order personality traits organize the personality of both the psychically healthy and the psychically ill, and that personality disorders represent maladaptive variants of traits that are evident in all persons to varying degrees. Data were collected from a clinical (n = 165) and a nonclinical sample (n = 100). Results show that the two classes of variables (personality factors and disorders) have similar relationships to each other, and can be structured in the form of a radex in both samples. Finally, the compatibility of the radex structure with other models is examined, comparing facet theory with factor analytical techniques. The results of the facet theoretical analysis further support the hypothesis of a universal personality model, and a continuous transition from normal personalities to personality disorders.