Background: Fluoxetine, a selective serotonin reuptake blocker, is an antidepressant medication that has also been shown in open clinical trials and one controlled trial to be effective in the treatment of obsessive compulsive disorder (OCD). OCD is often complicated by depression, and depressive symptoms may interfere with response to both pharmacologic and behavioral treatments. Method: We describe pilot data from 10 outpatients who met DSM-III-R criteria for OCD in whom the possibility of a depressive reaction or lack of antidepressant response occurred during an open trial of fluoxetine. Results: Rapid increase in fluoxetine dose to high doses was associated with depressive symptoms in 6 patients. In 8 patients, improvement in depression was associated with addition of a tricyclic antidepressant to fluoxetine treatment. In 5 patients, both OCD and depressive symptoms improved when the patient was switched to the partially selective serotonin reuptake blocker clomipramine. Conclusion: This paper serves to alert clinicians to the possibility of a depressive reaction, or lack of antidepressant response, to fluoxetine in OCD patients. This possibility can only be resolved scientifically by adequately controlled experimental trials. If depression occurs, combined fluoxetine and tricyclic treatment, or a switch to a partially selective serotonin reuptake inhibitor, may be helpful. Special considerations and side effects of combined fluoxetine-tricyclic treatment are described.
