Taxometric analysis of borderline and antisocial personality disorders in a drug and alcohol dependent population
The current study assessed the validity of the DSM-IV categorical model of antisocial and borderline personality disorders (PD) in a substance abusing population. High comorbidity rates suggest that this conceptualization of personality pathology is inadequate and that a dimensional model may be better. This study compares these alternative models empirically. To do this 460 poly-substance abusing subjects from a VA hospital and an outpatient methadone program were given the Personality Diagnostic Questionnaire-Revised (PDQ-R) along with other interview and self report measures. We conducted multiple taxometric analyses (MaxCov, MAMBAC, and Consistency Tests; Meehl, 1995) on the Antisocial and Borderline PDQ-R scales to evaluate whether the data were best modeled according to discrete categories or dimensions. Analyses produced evidence for the discreteness of antisocial personality, supporting the categorical DSM model. The indicators used by the PDQ-R to detect this discreteness provided valid but low discrimination ability. Antisocial items that were more important in determining discreteness were those which described character traits of traditional notions of psychopathy. Contrarily, no evidence supporting a categorical/DSM model for Borderline PD was found.
Exploratory analysis of the found taxon reveal that measures of childhood and adult trauma, dissociation, depression, perceptual aberration and hostility distinguished taxon and complement groups. Further analysis revealed three overall traits that predicted taxon membership: sadism, schizotypy and childhood physical abuse. These results support the current categorical model of antisocial PD. Simultaneously, these findings call into question the current categorical diagnosis of borderline personality disorder in a substance abusing population. Overall, these results point to the complexity of diagnosis and treatment of personality pathology, particularly in substance abusers.
0632: Psychological tests