Objective: This double-blind study examined whether olanzapine augments the efficacy of dialectical behavior therapy (DBT) in reducing anger and hostility in borderline personality disorder patients.
Method: Twenty-four women with borderline personality disorder (DSM-IV criteria) and high levels of irritability and anger received 6 months of DBT. Subjects were randomly assigned to receive either low-dose olanzapine or placebo and were assessed with standardized measures in a double-blind manner. The study was conducted from September 2000 to December 2002.
Results: Intent-to-treat analyses indicated that both treatment conditions resulted in significant improvement in irritability, aggression, depression, and self-inflicted injury (p < .01 for each). Irritability and aggression scores tended (p < .10) to decrease more quickly for the olanzapine group than for the placebo group. Self-inflicted injury tended (p < .10) to decrease more for the placebo group than for the olanzapine group.
Conclusions: Olanzapine may promote more rapid reduction of irritability and aggression than placebo for highly irritable women with borderline personality disorder. Effect sizes were moderate to large, with the small sample size likely limiting the ability to detect significant results. Overall, there were large and consistent reductions in irritability, aggression, depression, and self-injury for both groups of subjects receiving DBT.