Measuring the core features of personality disorders in substance abusers using the temperament and character inventory(TCI)

Personality disorders (PDs) are still classified through categorical taxonomies that are at odds with current research findings. Dimensional models provide a suitable alternative for measuring individual differences. However, as they have traditionally lacked a clear definition of the disorder construct, the clinical utility of these models has been limited. This study tests whether Cloninger's dimensional model is able to capture two domains: the features that differentiate PD subtypes from each other and the common core features underlying all PDs. Seventy-four drug dependent patients were independently assessed using the SCID-II and Cloninger's TCI. There was a slight relationship between TCI temperament dimensions and the DSM personality disorder subtypes, but the association was not specific enough to allow differential diagnosis. The character dimension Self-Directedness was strongly associated with the presence and severity of all PDs, irrespective of subtype, correctly classifying 77% of subjects. Character dimensions are a reliable, valid and low-cost tool for detecting PDs in drug abusers and may help to provide an operational definition of the common core features underlying all PDs.