RESUMEN
This study was conducted to compare the efficacy of metacognitive therapy [MCT], fluvoxamine and the combination of MCT with fluvoxamine, in improving thought control strategies and stop signal criteria in patients with obsessive-compulsive disorder [OCD]. Twenty one individuals among outpatients with OCD presenting to clinics in Tehran were selected and randomly divided into three groups: metacognitive therapy, fluvoxamine [50-300 mg/d] and combined therapy. All groups received 10 days of treatment. The Thought Control Questionnaire [TCQ] and Stop Signal Questionnaire [SSQ] were administered pre-treatment and post-treatment to all subjects. Kruskal Wallis test, Mann-Whitney U-test, and ANCOVA were used to analyze data. In comparison with fluvoxamine, MCT and combined treatment led to significant improvements in worry, self-punishment and reappraisal strategies of thought control and stop signal criteria [p<0.01]. There was no significant difference between MCT and combined therapy. MCT and combined treatment are more effective than fluvoxamine [50-300 mg/d] in improving thought control strategies and stop signal criteria in patients with OCD. Adding medication to MCT does not improve the patients' outcome