Efficacy and tolerability of olanzapine in the treatment of schizotypal personality disorder

Background: Few treatment studies of schizotypal personality disorder (SPD) have investigated the new, atypical antipsychotic drugs. This study examined the efficacy and tolerability of olanzapine, an atypical antipsychotic drug, in a series of patients with DSM-IV diagnosed schizotypal personality disorder. Method: This was a 26-week, open-label study with flexible dose design in 11 subjects with a diagnosis of schizotypal personality disorder based on Structured Clinical Interview for DSM-IV (SCID) and Personality Disorder Examination (PDE Journal of Psychiatric Disorders 1 (1987) 1). Subjects were treated with a low dose (average 9.32 mg/day) of olanzapine. Psychopathology was assessed at baseline and at the end of the study and analyzed with last observation carried forward analysis. Results: Patients showed significant improvements in psychosis and depression ratings, as well as in overall functioning. Olanzapine was well tolerated, though significant weight gain was observed. Conclusion: This study provides preliminary data regarding olanzapine efficacy and tolerability in schizotypal personality disorder subjects. These data need to be confirmed in larger controlled clinical trials.