Abstract
This study examines psychopathology and clinical characteristics of patients with borderline personality disorder (BPD) and comorbid narcissistic personality disorder (NPD) from two international randomized controlled trials. From a combined sample of 188 patients with BPD, 25 also fulfilled criteria for a comorbid diagnosis of NPD according to DSM-IV. The BPD patients with comorbid NPD, compared to the BPD patients without comorbid NPD, showed significantly more BPD criteria (M = 7.44 vs. M = 6.55, p < ,001), fulfilled more criteria of comorbid histrionic (M = 3.84 vs. M = 1.98, p < .001), paranoid (M = 3.12 vs. M = 2.27, p = .014), and schizotypal (M = 1.64 vs. M = 1.02, p = .018) personality disorders, and were more likely to meet criteria for full histrionic PD diagnosis (44.0% vs. 14.2%, p < .001). The BPD-NPD group also reported significantly fewer psychiatric hospitalizations in the previous year (M = 0.40 vs. M = 0.82, p = .019) and fewer axis I disorders (M = 2.68 vs. M = 3.75, p = .033). No differences could be found in general functioning, self-harming behavior, and suicide attempts.