Objective: Selective serotonin reuptake inhibitors (SSRIs) are recommended for treatment of affect lability, impulsivity, and aggression in patients with borderline personality disorder. This recommendation is based on positive findings in at least 10 open studies and one small double-blind study of SSRIs for patients with borderline personality disorder and one study of impulsive aggressive patients with different personality disorders. A randomized, placebo-controlled SSRI study with borderline personality disorder patients, however, provided inconclusive results because of a large response to placebo. It was, therefore, decided to conduct a new randomized trial with a larger study group.

Method: A double-blind, placebo-controlled, randomized trial using the SSRI fluvoxamine for 6 weeks followed by a blind half-crossover for 6 weeks and an open follow-up for another 12 weeks was conducted with 38 nonschizophrenic, nonbipolar female patients with borderline personality disorder. The outcome measures were the rapid mood shift, impulsivity, and aggression subscales from the Borderline Personality Disorder Severity Index.

Results: Fluvoxamine but not placebo produced a robust and long-lasting reduction in the scores on the subscale for rapid mood shifts. In contrast, no difference between the fluvoxamine and placebo groups was observed in the effect on the impulsivity and aggression scores.

Conclusions: In this study, fluvoxamine significantly improved rapid mood shifts in female borderline patients, but not impulsivity and aggression. This latter finding may be due to gender-specific differences in impulsivity and aggression.