Comorbid personality disorders and their impact on severe dissociative experiences in Mexican patients with borderline personality disorder.

To identify personality disorders comorbid with borderline personality disorder (BPD) that may confer greater risk for the presence of severe dissociative experiences. Three hundred and one outpatients with a primary diagnosis of BPD were evaluated using the Structured Clinical Interview for DSM-IV Axis II personality disorders, the Borderline Evaluation of Severity Over Time (BEST) and the Dissociative Experiences Scale (DES). The most frequent personality disorders comorbid to BPD were paranoid (83.2%,  = 263) and depressive (81.3%,  = 257). The mean BEST and DES total score were 43.3 ( = 11.4, range 15-69) and 28.6 ( = 19.8, range 0-98), respectively. We categorized the sample into patients with and without severe dissociative experiences (41% were positive). A logistic regression model revealed that Schizotypal, Obsessive-compulsive and Antisocial personality disorders conferred greater risk for the presence of severe dissociative experiences. Our results suggest that a large proportion of patients with BPD present a high rate of severe dissociative experiences and that some clinical factors such as personality comorbidity confer greater risk for severe dissociation, which is related to greater dysfunction and suffering, as well as a worse progression of the BPD.