Risperidone augmentation of SRI treatment for refractory obsessive-compulsive disorder

Background: Although serotonin reuptake inhibitors (SRIs) are the mainstay of pharmacologic treatment for obsessive-compulsive disorder (OCD), many patients do not have an adequate response to these medications. One approach to treating SRI-refractory OCD patients has been to add other classes of medications to the SRI. We. predicted that augmentation with risperidone would alleviate symptoms in SRI-refractory OCD patients. Method: 21 patients were treated openly with the combination of an SRI and adjunctive risperidone (mean dose = 2.75 mg/day). All met DSM-IV criteria for obsessive-compulsive disorder and had a variety of comorbid disorders. Prior to addition of risperidone, all patients had failed to respond to at least one adequate trial of an SRI. Response was determined by clinical judgment and standardized rating scales. Results: 5 (24%) of the 21 patients experienced side effects (most commonly, akathisia), which forced discontinuation of risperidone. Of the 16 patients who tolerated combined treatment, 14 (87%) had substantial reductions in obsessive-compulsive symptoms within 3 weeks. Patients with horrific mental imagery had the strongest and fastest response, often within a few days. Patients with comorbid psychotic disorders improved gradually over 2 to 3 weeks, Patients with comorbid tic disorders had the poorest rate of response and highest rate of akathisia. Conclusion: These results suggest that risperidone augmentation is effective and well tolerated in patients with SRI-refractory obsessive-compulsive disorder. Response to risperidone augmentation appears to be influenced by symptom subtypes and comorbid conditions. Controlled trials are required to confirm the efficacy of risperidone augmentation for refractory OCD.