A double-blind, placebo-controlled study of risperidone addition in serotonin reuptake inhibitor-refractory obsessive-compulsive disorder

Background: To date, only 1 controlled study has found a drug (haloperidol) to be efficacious in augmenting response in patients with obsessive-compulsive disorder (OCD) refractory to serotonin reuptake inhibitor (SRI) monotherapy; patients with comorbid chronic tic disorders showed a preferential response. This report describes the first controlled study of risperidone addition in patients with OCD refractory to treatment with SRI alone. Methods: Seventy adult patients with a primary DSM-IV diagnosis of OCD received 12 weeks of treatment with an SRI. Thirty-six patients were refractory to the SRI and were randomized in a double-blind manner to 6 weeks of risperidone (n = 20) or placebo (n = 16) addition. Behavioral ratings, including the Yale-Brown Obsessive Compulsive Scale, were obtained at baseline and throughout the trial. Placebo-treated patients subsequently received an identical open-label trial of risperidone addition. Results: For study completers, 9 (50%) of 18 risperidonetreated patients were responders (mean daily dose, 2.2+/-0.7 mg/d) compared with 0 of 15 in the placebo addition group (P<.005). Seven (50%) of 14 patients who received open-label risperidone addition responded. Risperidone addition was superior to placebo in reducing OCD (P<.001), depressive (P<.001), and anxiety (P = .003) symptoms. There was no difference in response between OCD patients with and without comorbid diagnoses of chronic tic disorder or schizotypal personalty disorder. Other than mild, transient sedation, risperidone was well tolerated. Conclusion: These results suggest that OCD patients with and without comorbid chronic tie disorders or schizotypal personality disorder may respond to the addition of low-dose risperidone to ongoing SRI therapy.