Personality disorders: model for conceptual approach and classification. Part I: General model

In this article we present data suggesting that one core deficit in personality represents a common dimension extending across most categories of personality disorders (PDs), whereas clinically discrete syndromes classified as PDs in DSM IIIR are categorical maladaptive types related orthogonally to the common borderline dimension. In a sample of 121 subjects with PDs and 67 controls, persons with PDs and without PDs manifested similar profiles on the Millon Clinical Multiaxial Inventory (MCMI) scales for various behavior styles. Conversely, the two groups consistently differed with respect to the MCMI borderline scale: in contrast to non-PD persons, those with PDs were strikingly more borderline and typically scored above 75 points (the latter has been established as the cut off for the diagnosis of Borderline PD). Likewise, persons with PDs scored significantly higher on the Diagnostic Interview for Borderlines than the control group. These results suggest that: i) most symptoms usually considered typical of the borderline personality characterize other PDs as well; ii) borderline features seem to be characteristic of persons with PDs and can be used to distinguish PDs vs. non-PDs. Therefore, symptoms widely regarded as typical of the borderline personality characterize other PDs as well. This shared dimension may explain the overlap in categorical diagnoses of individual PDs. Moreover, this shared dimension may be efficiently used as the classificatory principle for PDs. In Part II of this article, we present a model that classifies deviant behaviors in a systematic way, i.e., combines three levels of functioning (normal, neurotic, and borderline) with a limited number of categories of (mal) adaptive behavior types.