Treating depression in patients with bipolar disorder. It is also used to treat depression in patients who have not responded to 2 other medicines. It may also be used for other conditions as determined by your doctor. Olanzapine/fluoxetine is a combination of an atypical antipsychotic and a selective serotonin reuptake inhibitor (SSRI). It works by affecting certain substances in the brain, including serotonin. This helps to improve certain mood problems.