Augmentation strategy with olanzapine in resistant obsessive compulsive disorder: an Italian long-term open-label study.

The present study reports the results of an open-label trial on the use of the combination of olanzapine (an atypical antipsychotic) serotonin reuptake inhibitors (SRIs) in 26 resistant outpatients affected by resistant obsessive-compulsive disorder (OCD). All patients had been suffering from OCD, according to DSM IV criteria, for at least 2 years and had different comorbid disorders; they had been treated with an SRI at adequate dosages for at least 6 months, or had tried different augmentation strategies with no or poor response. As a result, olanzapine was added and continued for 1 year. After 12 weeks of this regimen, most of the patients (17) had shown a reduction in OC symptoms, as assessed by a decrease in the Yale-Brown Obsessive Compulsive Scale total score, which continued throughout subsequent months. Only mild side-effects were recorded and no patient halted the treatment. The addition of olanzapine would appear to be a useful short- and long-term strategy for augmenting SRI effectiveness in resistant OCD patients, especially in those presenting comorbidity with bipolar disorders.