A few studies have tried antipsychotic augmentation in obsessive-compulsive disorder (OCD) patients who are non-responders to selective serotonin reuptake inhibitors. The aim of this study was to investigate the efficacy and tolerability of olanzapine addition to fluvoxamine-refractory OCD patients and to assess if a comorbid chronic tic disorder or a concomitant schizotypal personality disorder was associated with response. Twenty-three OCD non-responders to a 6-month, open-label trial with fluvoxamine (300 mg/day) entered a 3-month open-label trial of augmentation with olanzapine (5 mg/day). OC symptom change was measured with the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the Clinical Global Impression (CGI) scale. Differences between responders and non-responders were assessed with regard to age, sex, duration of illness, baseline Y-BOCS score, and comorbidity with chronic tic disorders or schizotypal personality disorder. A significant decrease of mean Y-BOCS score between pre- and post-treatment (26.8 +/- 3.0 vs. 18.9 +/- 5.9) was found at endpoint. Ten patients (43.5%) were rated as responders. The most common side effects were mild to moderate weight gain and sedation. In our sample, three patients (13.04%) had a chronic motor tie disorder, and four (17.39%) had a codiagnosis of schizotypal personality disorder. Concomitant schizotypal personality disorder was the only factor significantly associated with response. It appears that augmentation of olanzapine in fluvoxamine-refractory OCD may be effective in a large number of patients, including those with comorbid schizotypal personality disorder. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
